# Cirrus V8 rotary valve engine build 2x scale up



## bazmak (Nov 27, 2015)

After i finished the 3 cyl rotary engine i wanted something bigger and more taxing.I downloaded the drws ,many thanks to Chuck Fellows
Again i wanted to make changes
1 I scaled up the drgs /dims x 2 and nudged a few things to suit
2 I plan to fit ball brgs to the 2 outer posns  And a split brass bearing to the middle
Everything else will be sorted when i get there,this build is just starting so any comments/input will be welcome.Any thoughts on replacing the timing gears
with a small commercial timing belt
INSTEAD OF JUST ADDING PHOTOS AT THE END OF THIS THREAD I THOUGHT I WOULD TRY SOMETHING DIFFERENT
AND EDIT EACH POST BY DELETING THE OLD PHOTOBUCKET BLANKS AND ADDING NEW PHOTOS


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## Herbiev (Nov 28, 2015)

I'm going to enjoy this build. Is that a wood router bit in the mill Baz.?


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## bazmak (Nov 29, 2015)

Yes Herbie,i have mentioned it on many posts.I have a couple of cheap sets
of carbide router bits and they work well on aluminium and brass
OGee,int and ext rad,g chamfering and dovetail. Mine are only 6mm shank,the bigger ones would be better.Try it they really remove the metal.I have 2 boxed sets the only cost me $10 each


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## Herbiev (Nov 29, 2015)

Thanks Baz. I got a heap of 1/2" shaft router bits so will try them out.


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## barnesrickw (Nov 29, 2015)

they are loud though


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## bazmak (Nov 30, 2015)

High speed,light cuts and then run back.Climb milling gives a super finish
Use them all the time for detailing the corners of stands/plinths etc


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## bazmak (Dec 4, 2015)

Progress with the sump and crankcase.Bought 5kg of alum and threw
1/2 of it as chips in the bin
BLANK PHOTOS REMOVED AND ADDED AT END OF THREAD


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## bazmak (Dec 4, 2015)

3 days ago i decided to make the crankshaft.I realized that it would be easier to make from solid rather than fabricate.So with a lump of mild steel 40mm dia x 240mm lg heres how.I had to spend some time making a turning fixture but it was well worth it.I rough turned one eccentric ,spun 90o and repeated 3 times
removed some more x 4 and again reducing cuts and stress until i was almost there.The ability to remove from the lathe and reset with accurate repeatabiliy
worked really well.I took my time and my fears were not realized.Everything came out to size and concentric within 2 thou
BLANK PHOTOS DELETED AND NEW ONES REINSERTED AT THE END OF THE THREADS


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## bazmak (Dec 4, 2015)

Forgot to mention that i used the collar to drill thru at the headstock end
and drill and tap 4 no M4 holes in the web.I then used a 
n M4 capscrew to bolt the fixture to the crank.It can then be positioned at 90o
for each eccentric.The tailstock collar was set in position at the tailstock end
and clamped in position until the whole job was complete


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## Herbiev (Dec 4, 2015)

Really enjoying this post Baz. Don't waste those aluminium chips. Put them in a cake tin and leave them outside. With 40 degree temps for this weekend you'll get another solid blank


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## dsage (Dec 5, 2015)

Hey Baz:
Help me out with the scale of this engine. Maybe the base dimensions of the block or something. Bore and stroke too if you don't mind. As usual it's tough to tell from the photos alone.

Sage


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## bazmak (Dec 5, 2015)

Hi, sump is 6" lg 31/2 w and 1/12 deep.Crankcase is 6x3.3x 2"
Bore will be 3/4" dia and stroke 1".Plans are on the download section
Most things are just doubled.End brgs will be 12mm or 10mm 
Centre brass brh is 12mm.* cylinders have been cut to size 32x48x63mm
I think the original size would be too small now for my eyesite regards barry


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## bazmak (Dec 6, 2015)

Just spent a few hours in the shed.40oc outside and 50oc inside
Chips didnt melt herbie but started to go soft like me in the head
Next job was to finish shaping the top of the crankcase and bore 
out 8 holes for the cylinders.Made good use of the indipendant jaw vice and 
homemade boring tool.Everything went well. PHOTOBUCKET DELETED


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## mu38&Bg# (Dec 7, 2015)

I have to ask, what type of rotary valve arrangement will you use in this engine?


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## bazmak (Dec 7, 2015)

as per drgs,a shaft goes thru the top on Cl with 2 gears from crankshaft
The drgs are in the download section.I have sortedm out the problems in my head but concentrating on the details as i come to them.Too much input all at once causes headaches.The plans are in the download section


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## toolznthings (Dec 7, 2015)

Lot of nice work you have done ! Following along as you go.

Brian


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## cfellows (Dec 9, 2015)

Very nice build.  Craftsmanship looks top shelf.  The only comment I have is that you'll need a pretty large air compressor to keep it running for any length of time... .  If you have any questions on exhaust springs, port sizes, etc., I'm happy to share what I know.

Chuck


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## bazmak (Dec 9, 2015)

Thanks chuck,please keep an eye on me.I am doing the easier mech. parts first
When i get to the tricker bits,pipework ,timming etc i will need advice but hopefullyi will be more into it.I dont have a compressor yet so have not run any models under air,but hopefully will eventually. Regards barry


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## bazmak (Dec 11, 2015)

Next was the conn rods.Drg says alum but i dont like ally as a bearing media
Trying to bush out was too fiddly so i decided to make from solid brass
blank photos deleted and a couple of new ones added with more at the end of the thread


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## cfellows (Dec 11, 2015)

Nice work.  Finish on the con rods looks really good.

Chuck


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## mattty (Dec 12, 2015)

Love the engine. can't wait to hear it running.


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## bazmak (Dec 12, 2015)

When i first started i checked stock of alum.I bought 2 pieces for the sump and crankcase but had had enough matl for 8 cylinders.So first job was to saw and mill to size 8 pieces nom 32x38x63.I made shimmed packs to give me 38x38
so i could hold central in 4 jaw SC chuck and centred all 8
Now i could perform small ops on each and remove / refit and keep concentric
as accurate as chuck.Then setting stops and using dials i was able to perform
a no of ops to all parts.PHOTO REPLACED DOWN THE LINE


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## bazmak (Dec 14, 2015)

Next job was to drill the cylinder fixing
I made a drilling template from 3mm plt located on the cyl spigot
and drilled all holes 3mm.Made a location spigot and drilled all
holes 3mm in crankcase.Crankcase was then tapped M4 an the cylinders opened out to 4.1mm.Cleaned everything up and trial fitted together
Next job will be to make the pistons and bore out the cylinders


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## johnmcc69 (Dec 15, 2015)

That's looking real good Baz!

 John


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## bazmak (Dec 21, 2015)

Next stage was to bore cylinders and make pistons


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## bazmak (Dec 22, 2015)

Next is the first stage of assy of the above.Just a note .I first ftted all cyls as individuals so each cyl can be checked.If you try all 8 together it is difficult to isolate any binding on any particular cylinder.In this instance i was able to isolate bad interference on cyls 3 and 6 and remedy easily.The next stage is to assemble all 8 and turn over


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## 10K Pete (Dec 22, 2015)

Those are some really beautiful parts! Just itching to see it together.

Pete


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## bazmak (Dec 23, 2015)

Its looking nice and the right size.The original would have been too small
One problem is that i drilled the cylinder head for the inlet and exhaust valve
the wrong way round but i have a simple solution.I dont like or trying to make
the 90o elbow in the 3/16 supply pipe and always intended to make a combination manifold to make manufacture easier.The brass manifold i intend to let into the head and also form a new ball valve seat in brass,after i have drilled the spring hole thru.Still in my head but resolve itself when i get there
Merry Xmas


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## Herbiev (Dec 23, 2015)

I love the lapping tool. Great idea. Im always having trouble with those brake cylinder honing stones


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## bazmak (Dec 23, 2015)

Its an oldie and cheapy Herbie but its always worked well for me.
Last few ops this morning before Xmas
Assembled all 8 cylinders and it turned over well.Set up in the lathe and run in for a few minutes with plenty of WD40 before stripping down.All freedup nicely no high spots to take off.Bored out the crankcase and turned the crankshaft
and fitted outer ball bearings


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## bazmak (Jan 2, 2016)

Happy new year all.Further progress not made easy by our inclement weather
We have had a week over 100c peaking at 110c but 130c in my shed
Cant really complain as we have not had,floods,blizzards tornadoes etc
my sympathies go to all UK and USA residents affected
I did not envisage all the difficulties produced by scalling up x 2
First job was to drill the CC 11.5mm 3"" deep from each end and hope they line up.Careful setup in the mill and looking good.I could not get suitable tube for the bush so made from 1/2" dia x 7" lg brass.Few problems but final success
I made and fitted 8 no brass nipples and drilled thru into the bush.Photos show all,i am very pleased so far,limits and fits were to me perfect
One point of note.When i turned and finished the o/d of the brass the first skim in the lathe gave a 6 thou taper.Fortunately Sieg had delivered the goods
on the SC4 and there were 2 easily adjustable grub screws to adjust the tailstock.A few minutes was all it took to adjust the tailstock to turn to 1/2 thou over 7" length.Turned to +1thou and then nudged/fitted to light push fit in crankcase


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## dsage (Jan 3, 2016)

Bazmak:

>> We have had a week over 100c peaking at 110c but 130c in my shed

I think you mean degrees F right?

Water would be boiling sitting on the table at 100c.

Nice job on the engine. Looking forward to seeing it run.

Sage


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## bazmak (Jan 3, 2016)

Yes degrees F for our american friends.Poms are still both but for ozzies etc
40/43 or 55oc inside


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## bazmak (Jan 3, 2016)

Next job was to fit the valve stem.I polished a few tenths off the high spots
then set up in the lathe to run in for a few minutes with plenty of WD40
in the nipples.Cant believe what a good fit it is after drilling and reaming from both ends over 7" long


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## bazmak (Jan 3, 2016)

Next job was to pipe all the cylinders,but with design changes and upscaling etc
i did not want to produce 8 each of all parts then find problems so decided to just complete i individual cylinder and finalize details and dims.
I did not want to make the tight pipe bend and intended to make a simplified manifold.As i mentioned previousley i had drilled the valve holes in the head the wrong way round.Many solutions involving a lot of work but the best one was not the most obvious.Leave the drillings as is and let the manifold into the head anf form the ball seat.The spring and ball could be fitted from the pipe end the the other side adapted for the exhaust.I made a new manifold and flare nut.Made a fixture to flare the 3/16" pipe then nudged everything to fit.Minor problems were sorted and the final dims noted.Now for the next 7


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## bazmak (Jan 6, 2016)

While i am finishing pipeping the cylinders i am starting to give thought to the pair of gears.13t and 26t.I have never cut gears and know very little.Not worth buying a set of 8 invalute cutters and reading about the nonclenture is making my head spin.Here are my thoughts,hopefully someone out there will be able to advise/comment.The centres are fixed,double the scale i assume means i need
a 26t and 52t ?? The 2/1 ratio drive i think is critical Pressure angle is given at 141/2o and dias need to be doubled
I plan to make a single point cutter and cut on the mill with a deviding head I have change gears from the lathe.If i grind a tool to that form and make a pair in alum,will that work.Any input before i start will be most appreciated


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## Cogsy (Jan 6, 2016)

Doubling the tooth count on both gears will double the centre distance of the shafts so that works out nicely for you, and of course you need to maintain the 2:1 ratio. However, the outside diameter of the gears does not exactly double, it is the PCD of the gears (the point where they mesh) that doubles.

You will need to do the math using your DP, pressure angle and tooth count to calculate the OD required for the gear blanks. I've never made a single point cutter (looked too tricky to get it right in the size I needed) but I have used this site LINK to make a straight hob that does the job well.

Alternatively, you may be able to use gears with a different mod/DP and tooth count to achieve the centre distances you need, or even the original gears specified with idlers between them to form an interesting gear train.


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## bazmak (Jan 7, 2016)

Thanks Cogsey,i think i am missing the DP from the drawing,all i have is pressure angle,centres and diameters.I have ordered the book by Ivan Law but i need more info on the tooth form before attempting to make a single point cutter.Question,does the Dp change with no of teeth?. When i made  the tumbler reverse for for the Advance lathe i used Myford gears which were 20dp
and 14.5 Pa. Dp i found out was the no of teeth on a 1" dia gear. I really need to work backwards as the fixed ctres and dias given with the no of teeth must
determine i assume the Dp. Tooth form is unimportant as these 2 gears only mesh together so could be any form that fits my fixed criteria.Will try and sent a private message to Chuck Fellows.Keep on with the input Regards barry


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## Cogsy (Jan 7, 2016)

bazmak said:


> does the Dp change with no of teeth?


 
Not really. DP is how many teeth in 1 inch, so 25 teeth in one inch would be 25DP. Module (Mod) is metric and is the distance in mm between the teeth, so a Mod 0.8 is 1 tooth per 0.8mm. To change Mod to DP simply take the mod number and times it by 25.4 to give DP. This works out teeth per inch. eg Mod 0.8 x 25.4 = 20.32 DP. To go from DP to Mod just divide DP by 25.4 to give the Mod eg 25DP / 25.4 = 0.984 Mod - close enough to use Mod 1 probably.

If you increase the DP the tooth count for a given diameter gear gets bigger as you can fit more teeth in per inch. For a Mod, if you increase the Mod you are making the teeth larger and tooth count goes down for a given diameter.

As far as your application goes, the tooth form has to be reasonably accurate so they will mesh, plus your blank diameters have to be spot-on so you get the correct number of teeth, with the correct spacing all the way round.

Edit to add - I don't know if you will be able to make these two gears with a single point cutter as they have such different tooth counts. I suspect you'll have to make a cutter for each gear. As the tooth count goes down, the relative curve of the gear increases and a different tooth profile is cut so it will mesh with other gears of the same DP or Mod. This is why a full set of 8 cutters is needed for all tooth ranges per Mod or DP. The straight hob I linked to uses a different method and you only need to make one of them per Mod or DP.


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## Herbiev (Jan 7, 2016)

Thanks for the link Cogsy. That saves making different single point cutters for different gears


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## bazmak (Jan 7, 2016)

Thank you cogsy things are starting to look more clear.A couple of questions for an old thicko.The tool is cut with a straight sided tool form? The tool is passed scross the blank at centre height without moving the blank therefore cutting one tooth and a couple of partial ones.The blank does not revolve as in hobbing?How is the invalute profile achieved? Or does the blank revolve as in hobbing.Please excuse my ignorance


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## Cogsy (Jan 7, 2016)

No worries Baz. The blank doesn't revolve when the cut is being made and the centre V of the cutter is right on the centre line of the blank. So you have 1 'V' cut straight into the blank, then 2 progressively smaller 'V's each side of that, which are not pointing straight at the centre. You then index the blank 1 tooth and cut again, which recuts some of the 'V's at a slightly different angle and depth. The differing cut angles produce the involute shape. It does mean that you have to index the blank the number of teeth + 3 to ensure the last few teeth are cut completely on both sides.

Hopefully that explain it clearer than I think it does. On the link I gave there is a menu on the right with all the info about how it works and how to do the calculations, etc.


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## bazmak (Jan 7, 2016)

Many thanks Cogsy,things are becoming clearer.Please follow my thread
regards barry
ALL THE ABOVE IGNORANCE ON MY PART IS NOW A THING OF THE PAST AS YOU ALL KNOW
I LATER SPENT A LOT OF TIME AND EFFORT TO OVERCOME MY GEARCUTTING INADEQUACY
and i am know confident enough to cut gears


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## bazmak (Jan 7, 2016)

Next i made a total of all items.Manifolds,flared pipes compression nuts
I also reworked some commercial springs to 30mm lg from 9/32" dia x 35lg x 0.25wire.Received some 8mm balls from china and assembled everything
Next will be those pesky gears


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## bazmak (Jan 7, 2016)

Next i made a total of all items.Manifolds,flared pipes compression nuts
I also reworked some commercial springs to 30mm lg from 9/32" dia x 35lg x 0.25wire.Received some 8mm balls from china and assembled everything
Next will be those pesky gears


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## bazmak (Jan 7, 2016)

I recieved confirmation that the gear DP should be 24.This means that a 2" gear
would have 48 teeth.???. I measured a 50 tooth gear from my lathe and it was just over 2" so somewhere close.I then measured 3 gears from the set and found that the OD was the no of teeth + 1.9mm the depth of the teeth was 
2mm. THEREFORE I DEDUCED THAT THE OD WAS THE NO OF TEETH + THE TOOTH DEPTH. iS THAT COINCIDENCE OR IS IT A RECOGNISED FORMULA??
Using this info i i caculated the dia of a 26t and a 52t gear and made 2 blanks from alum.When fitted on the shafts at the fixed centres they overlapped x 2mm,the tooth depth.So therefore we must be in the ballpark.I decided to try to
grind a single point tool to match a 40t gear from the lathe.Hopefully this is the mean of the 26 and 52t gears.Question,should i try to grind a single point tool from HSS or should i turn from drill rod then harden.Depending how successful i am the next step might be to make a cutter as advised by Cogsy and even a new pair of gears from brass.I have ordered Ivan Laws book for some light reading.Watch this space regards Barry


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## swarfrat (Jan 8, 2016)

The recognized formula for determining the outside diameter of a spur gear with full-depth teeth is to add 2 to the number of teeth and divide the sum by the diametral pitch. For your 24-tooth gear, that would be (24+2)/24=1.083" outside diameter. Applying the same formula to the 48-tooth gear derives an outside diameter of 2.083".  The whole depth of the cut, measured from the outside diameter, is 2.250/DP: 2.250/24=0.09375"
I have been following your project with great interest. Very nice!
Craig


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## bazmak (Jan 8, 2016)

Thank you Craig,any input is welcome.My problem is that the gears should be
i now know to be DP24 with given od s and fixed centres 14.5 pa
I am trying to determine the mod of existing gears to use as tooth form to grind a tool and also check the dias for a 26 and 52t,which are double the original.How can i accurately measure the mod of the lathe gears to compare to the specified ones of 24dp??.I think that the lathe gears are somewhere near to the specified ones and am hoping to cut the lathe gear form and fit in place of the specified ones


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## 10K Pete (Jan 8, 2016)

bazmak said:


> I recieved confirmation that the gear DP should be 24.This means that a 2" gear
> would have 48 teeth.???. I measured a 50 tooth gear from my lathe and it was just over 2" so somewhere close.I then measured 3 gears from the set and found that the OD was the no of teeth + 1.9mm the depth of the teeth was
> 2mm. THEREFORE I DEDUCED THAT THE OD WAS THE NO OF TEETH + THE TOOTH DEPTH. iS THAT COINCIDENCE OR IS IT A RECOGNISED FORMULA??
> Using this info i i caculated the dia of a 26t and a 52t gear and made 2 blanks from alum.When fitted on the shafts at the fixed centres they overlapped x 2mm,the tooth depth.So therefore we must be in the ballpark.I decided to try to
> grind a single point tool to match a 40t gear from the lathe.Hopefully this is the mean of the 26 and 52t gears.Question,should i try to grind a single point tool from HSS or should i turn from drill rod then harden.Depending how successful i am the next step might be to make a cutter as advised by Cogsy and even a new pair of gears from brass.I have ordered Ivan Laws book for some light reading.Watch this space regards Barry



HSS will be fine. Probably better than drill rod hardened!

I'm learning a lot from the exchange between you and cogsey!

Pete


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## cfellows (Jan 8, 2016)

Barry, I made 24DP gears for my engine.  The pitch diameter of a gear is to about the radial center of the gear tooth and is calculated by multiplying DP times the number of teeth.  So a 26 tooth gear of 24DP is 26/24 = 1.083" pitch diameter.  The overall diameter of the gear blank is calculated by adding 2 to the number of teeth and divide by the DP.  The minor diameter is calculated by subtraction 2 from the number of teeth and dividing by the DP, then subtract another .006" to .010" for clearance.

To calculate the size of gears you need, take the distance between the shaft centers, divide by 3 and multiply the result by 2 to get the pitch diameter of the smaller gear.  The larger gear is simply double the pitch diameter of the smaller gear.

Based on my gear sizes, my center distance, without consulting the drawings, is probably close to 0.8125" which means yours is around 1.625".  If this is correct, you'll need a small gear with a pitch diameter of 1.083" and a large gear with a pitch diameter of 2.167".

I think the easiest solution for you would be to use 12dp gears, double the pitch of mine.  That would keep the scale of everything the same and provide you the most accurate spacing.  I've run the numbers on everything from 12dp to 23dp and no other pitch will give the correct spacing.  

I'll  post a spreadsheet showing the various pitches and the distances they provide.  By the way, the most common diametral pitches for gears are 12, 16, 20, 24, 32, etc.  Finding involute cutters for odd pitches might be difficult.

You might also find a metric gear pitch that suits your needs, but that is another whole area of study that I've never gotten into.

Chuck


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## cfellows (Jan 8, 2016)

Attached is an Excel spreadsheet showing gear sizes and spacing for diametral pitches ranging from 12DP to 24DP.  As you can see, 12DP is the only one that will get you the exact spacing you need.

Chuck 

View attachment Gear Spacing.xlsx


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## bazmak (Jan 8, 2016)

Thanks for your info Chuck,i dont have office so i cant see your charts.
I was told the Dp was 24,however the drawing dims seem incorrect
My actual centres are 1.557" and i need a ratio of 2/1 drive.Working on everything else then becomes a problem,especially as i have never cut gears
and have limited knowledge,
Working back thru with Dp and no of teeth to arrive at a centre distance
would be easier and the way to go,unfortuneately i am stuck with what i have
I have 2 sets of metric gears with the lathe and measuring various i have arrived at the dims for a 26 and 52 t gear.I have made 2 blanks and when fitted appear to somewhere near to a few thou.I plan to form a tool to suit the largest gear 127t with 3 cutting teeth as per Gogsy and see how we go
Prior to cutting the teeth in this thread i will open another thread as i have other items to make before starting.Please if you have the time follow my threads to keep an eye on me.I am very interested in how this will turn out
and how close ,if at all the gears will mesh.Another learning curve Barry


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## cfellows (Jan 8, 2016)

Here's a JPG of the excel spread sheet.  Hope you can read it...






''

By the way, .010" to .020" variation on the gear spacing won't make much difference as long as you don't get them too tight.  The looser they are, the more noise they will make, but looser is better than too tight.

Chuck


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## johnmcc69 (Jan 8, 2016)

Based on Chuck's chart, 23DP gears with 24 & 48 teeth seem to work out ok. This is with the gear center distance at 1.564. (The original drawing shows .782, so, at 2X scale 1.564) 

John 

View attachment gear-layout.pdf


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## bazmak (Jan 8, 2016)

Thanks John ,your dims seem ok but i needed a tooth profile to shape a cutter to
Just opened a thread to proceed with a 26 and a 52 t gear to the mod gears with the lathe .Will have see how it pans out.By the time i have finished i should know a lot more about cutting gears


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## bazmak (Jan 11, 2016)

I have just cut the 26 & 52t gears in alum with moderate success.Very pleased but with a few problems to sort out.I have taken 4 videos but they were taking 1.5 hrs each to upload so have just spent a couple of hrs downloading software to compress the files.Now they are taking 5min each to upload to photobucket.First problem was mounted the camera next to the mill on the bench so there is some camera shake.Wont happen again.After cleaning off the burrs the gears do mesh with a few problems
I cut the 52t first in 3 passes.!mm deep then 1.5 then full depth of cut at 2mm deep.During this op the RT locked up so i had to disturb the setup and on a couple of occations i didnt fully clear the cutter before moving a tooth,so slight damage to a couple of teeth. When i had completed 3 passes i carried on on found i was still taking light cuts at the same setting so carried on again all round.I thought i had taken off too much but when finished the OD was within 2 thou
I cut the 26t next and decided to to make one pass at full 2mm depth,when finished the tooth profile did not look quite right and the full dia was was about 30 thou down.When i checked the cutter there was alum build up and that had spoilt the tooth profile somewhat.I cleaned up both gears and they did fit the engine and did mesh quite well.After measuring i found the teeth had not been cut to full depth/profile.I need to add back and side clearance to the teeth on the cutter
use some WD 40 when cutting,make a no of passes rather than one big heavy cut and check were i went wrong with the tooth depth.(bloody chinese dials)Any way very happy so far,will make these adjustments then make another pair in brass,in the next few days.Looking good


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## bazmak (Jan 11, 2016)

I made a new blank in brass for the 26t gear.Nudged a few dims and honed the cutter adding a little side and bottom clearance to the teeth with a diamond file
Same setup but cut the gear in 4 cuts starting with 20 thou and finishing with 10 thou.Then went round again at the same setting passing the cutter across the gear 2 or 3 times to polish the teeth and take out any spring same as with a boring bar.Very pleased it looks more like a proper gear.Next will be to the alum 52t gear back thru the setup to get correct tooth depth before deciding if i will make a new one also in brass.The cutter needs sharpening and has a small chip i will probably make another with more clearance


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## bazmak (Jan 12, 2016)

I ran the 52 t gear back thru the mill.It meshes well and is acceptable for now
Same problem.The alum welds to the tool and produces a bad cut.Brass cuts much better.However i found the tool easy to make so will make another and play about weith increased rake and clearances.Anything of interest i will post
I made the timing dial from a bit of 4mm alum plate and screwed on the scrap alum 26t gear.(waste not want not) as my old pappy used to say
Final job is to strip down and drill the timing valve.BEFORE I DO CAN ANYONE ADVISE THE PISTON POSITION WHEN THE CYLINDER FIRES.I assume tdc or just past


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## cfellows (Jan 13, 2016)

Timing is not critical, but I like to set it so the valve just starts opening at TDC.  The holes in the valve tube should be small enough that they are completely closed before bottom dead center.

Chuck


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## Toolguy (Jan 16, 2016)

May I suggest TapMagic for Aluminum. It will make all aluminum machining operations a breeze with no buildup on the tools and super surface finish. Also works good for any nonferrous metal, including copper, which is notoriously hard to deal with.

This is a very nicely done build! There is a lot of fine craftsmanship in this one.
Thanks for sharing!


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## 10K Pete (Jan 16, 2016)

+1 on the Tap Magic for Aluminum.

Pete


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## bazmak (Jan 29, 2016)

I borrowed a compressor,made some inlet nipples and tried to run my models
0 out 0f 5 so far.The V8 wont even think about it.Too stiff and lots of leaks.Main problem is i think that the 8mm balls are too large and the springs too strong
as chuck mentioned.Will sleeve the heads and fit smaller balls and lighter springs.Will also fit gaskets to leaks,but more probably some gasket compound
as heat is not a problem,will also have to ease off some tight spots.Timing is set so its right or wrong.Bear with me.The Sturt 10 almost runs.If or when i have success i will post videos


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## davidyat (Aug 17, 2017)

Baz, I moved to Indiana recently. When my shop is up and running, my next build would be your 2X build of the Cirrus V8. Is it possible to get rid of the Photo Bucket stuff covering up your pictures? I would like to see your pictures as I'm sure they will help me with my build.
Thanks,
Dave


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## bazmak (Aug 17, 2017)

Hi Dave ,i will post a few at a time,and try to keep them in order
Will also try to add additional text if needed. Good luck and start a post
regards barry


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## bazmak (Aug 17, 2017)

Hope i dont clog up the system


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## davidyat (Aug 18, 2017)

Baz, thanks. Now with the pictures, I'm excited to get my shop running and start building.

Dave


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## bazmak (Aug 18, 2017)




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## bazmak (Aug 18, 2017)

If posting all these photos causes a problem please let me know
And i can arrange to email direct


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## bazmak (Aug 20, 2017)

Well Dave i have added a no of photos to the thread and then went back to the beggining of the post and deleted blank photos and added new ones
Concequently the thread text posts are in the correct sequence but not necessarily the photos.Its the best i can do.Will add the last relevant photos now,hope it all helps.Please post when you start and i will help further where i can. Tried uploading some video showing the running in etc but no go
So will take some more and upload to Utube.I can also take additional specific 
photos at your request if and when required All the best Barry


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## davidyat (Sep 21, 2017)

Baz,

   When hogging out the crankcase, I notice you don't have a half circle drilled into the crankcase (where the bearings will go) to allow your home made boring bar to move half way into the crankcase to make a true 1.250 inch radius. Do you have to make a true 1.250 inch radius? If not what is the diameter of the vertical bar that you've drilled out for the boring bit? I've made my crankcase from a square block of aluminum that I just sawed in half diagonally length wise so I'm already at the crankcase 45 degree mark. I've learned don't start taking off metal until you're sure of what you're doing. I await your reply. Let's see if I can upload a couple of pictures of my setup.

Dave


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## bazmak (Sep 21, 2017)

Hi Dave the first photos the start of hogging out the crankcase
the second photos show the finish hogging with the half holes and centre bearing recess machined for when i realized i had to get the tool all the way in
Dims are not important as the case has clearance for the moving parts
Regards barry


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## bazmak (Sep 21, 2017)

I got the sump finished and then fitted to the crankcase with the required fixings then rough out the CC,bolt together and bore the end holes and machine
the centre bearing section This then allows you to finish machining the crankcase


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## davidyat (Sep 23, 2017)

Thanks, Barry. Now to make some aluminum chips!

Dave


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## bazmak (Sep 23, 2017)

Yes a foundrys worth


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## davidyat (Sep 28, 2017)

Barry,

   During the machining of your crankshaft, I noticed that the ends weren't turned to the final diameter. Just what was the chronology (in decreasing diameters) did you use during the machining of the crank. On the plans, if you double everything, the final end looks like it should be 0.376 in. Did you go that small? What was the final OD and ID of the ball bearing you used on the ends? It looks like you didn't go to final diameter until the end. I'm assuming you did this to keep some beef at the ends for stability during the machining of the eccentrics and the middle bearing surface. I almost botched the end of my slug for my crank. I also forgot some machining teachings of a Master Machiist. I got piggy in trying to hog out too much material in the block. Now I'm waiting for some new 3/8 inch boring bars after breaking off a brazed end. And everything I do wrong never goes into the trash. I save all my learning experiences (botched work) in a drawer. And from time to time when I'm looking for something, when I find that stuff, I take the time to look at them and remind myself, "Don't do that again!!"
Dave


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## bazmak (Sep 28, 2017)

Hi David,i did not double up everything exactly.The cheap skate bearings
are 21x12x5. The shaft ends i finished at 10mm rather than .375. where possible i went slightly larger than size in some areas.The crankcase was was \bored out to 16mm dia The centre brass bearing can be anything but i kept it
to 16mm for strength.Everything was kept oversize while the main turning was done and final turning to size kept light.I will repost all my photos here with
additional text.Hope it all makes sense.My memory has faded


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## bazmak (Sep 28, 2017)

And the rest


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## davidyat (Sep 29, 2017)

Thanks Barry,
   In the future, you don't have to show pictures to me. I have all the pictures you've posted on a flash drive. So anytime I need to see what you've done, I can always refer to my flash drive. Now with your reply, a lot of things are making sense to me now. Not only you, but I have a best friend who's a retired master machinist who's guiding this "grasshopper" on what to do. Let's see if I have the smarts to actually LISTEN and not go off on my own!!!

Dave


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## bazmak (Sep 29, 2017)

Keep going grasshopper.Dont forget it was daunting for me and i learned
as i went.Everything worked out well for well for me so dont deviate too much
Keep us posted.Allthough Chuck Fellows did the design and supplied all the drawings,the changes i made made it the biggest and most complex job to date for me.But looking back doing it in stages made it easier


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## Sansspaceship (Sep 30, 2017)

Hi Barry,

Just a quite note to say thanks for the build thread, and taking the time to update the photos after photo bucket did the dirty on everyone; greatly appreciated!

Cheers,
.adrian


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## davidyat (Feb 2, 2018)

Barry,

   Finished my Oak Bookcase and can get back to the shop. Not only am I making chips, I'm also botching up the crankcase. Blew the first one. And almost finished the second one when this happened. On the C journal, even at 28 rpm on my LeBlond (1947) Lathe and turning in the cross slide by hand a few thousandths at a time, on one revolution, it grabbed the crank and you can see the end result. :wall: My retired master machinist who is guiding me, said I could have been to slow a speed on the lathe. I also did what he suggested which was to hog out a lot of material in the journal areas on the mill before going to the lathe. You can see some of the hogout in one of the pictures. The first 2 journals were no problem at all which I hope you can see in the picture. Now with all that said, is it possible to make a crankshaft out aluminum? Possibly 7075 T6 aluminum? Also, when I tried on the first crankshaft without hogging out material in the journal area, the square nose tool would really grab the crank and would scare me half to death. Can you give me any advice on how to attack crankshaft #3 (and hopefully the last). I also posted a picture of my LeBlond.
Thanks,
The Learning Grasshopper


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## davidyat (Feb 2, 2018)

Barry,

   I forgot to mention that I was using a 0.500 square nose cutting tool on the lathe. Then I noticed you were using a square nose much smaller and taking more cuts. Is this where I possibly made my mistake?

Thanks,
The Grasshopper


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## petertha (Feb 2, 2018)

Sorry to hear about your crankshaft machining problem. 
- can you describe (or show) your cutting tool?
- I'm curious about the offset fixture on headstock side, how is the crank retained in that (wondering out loud if it loosened within the fixture)
- did the outer journals cut or sound worse as you progressed away from the successful ones closer to the headstock? On one hand one would think more flex in the crank as it cantilevers, but now you seem to be getting proportionately closer to tailstock support, no?

I've seen pics where people insert temporary webs in the machines sections. I always assumed it was for minimizing distortion, but maybe part is to bulk up the rigidity as more material is progressively removed.


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## bazmak (Feb 2, 2018)

Hi Grasshopper,i never had any problems.Although i show a 4mm wide
carbide tool i did use a variety of tools including a parting off tool
The eccentris bearing journals were for 12mm dia bearings and i left
the eccentric parts oversize at 14/15mm dia for strength.I roughted out everything carefully by nibbling with light cuts and taking everything down in size in stages to keep strength
The width of the webs i cut down with a LH and RH tool..Speed was between 100 and 200 rpm.Looks like you might have tried to machine one area too far
and weakend it. I took my time in stages keeping as much meat as could 
Final fish very light cuts with sharp tools .5 wide tool no good try starting with a 2.5mm wide parting tool  and work mainly with the edges to get almost to full witdth.If you take everything down to nom 1mm oversize then treat it as a casting to finish all dims.The 12mm eccentric dias should be done last then the shaft ends finished to size.Have attached all my photos.Hope this helps.As i said 
i did not have any problems but if i remember did spend a couple of days
With collet and tailstock ctre and the 2 fixtures it ok to move the job about until the final finish. Good luck


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## bazmak (Feb 2, 2018)

more photos


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## davidyat (Feb 3, 2018)

Here are some pics of the tooling. The offset jigs are aluminum with the set screws for holding the crankshaft. I used a 1/2 inch square nose tool bit for my cutting the journals. I ground a little clearance behind the cutting head so to make sure I wouldn't get any interference with the shank as it went deeper into the rod journal. I hope you can also see that I went to the mill and ground out a lot of material in the rod journal areas before I plunged the square nose in. This left me with about a 5/8 inch square where the journal is. This minimized the amount of material to be ground off for the journal. When I get another blank to start, I'm going to really look at your pictures. I can understand now about flexing as I get away from the head stock and toward the tail stock. My next approach will be to make the journals first, then grind the concentrics. Also I'm going to  make another set of offset jigs. On my first two learning experiences (I never have failures, only learning experiences. Learning how NOT to do it), I first ground the ends to 1/2 inch, ground out the concentrics, made the jigs to fit the 1/2 inch ends. This time I'll leave the ends more beefier, 5/8 or 3/4 inch to hopefully get less flexing. 
The Grasshopper


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## bazmak (Feb 3, 2018)

There are too main points to consider when machining.Is the lathe robust enough and is the finished item robust enough to withstand the cutting forces
Looking at your lathe pictures the answer to your first question is yes.However you need a sustancial workpiece to withstand the cutting forces from a .5" wide 
carbide tool with very little rake.Although the lathe will take the load THE JOB WONT.I show a 4mm wide carbide tool for roughing,however you can see in the photos that i instantly started with chatter.I quickly switched to HSS with top rake and gently nibbled out the majority of the material
I did NOT machine down fully the eccentrics or concentrics but roughed out all of them one at time to nom 10mm depth of cut.Working nearest the chuck where possible and reversing the job to repeat.I then repeated to stage 2 and 
a depth of cut overall of nom 15mm deep,and again repeated again to stage 3 etc reducing depth of cut all the time.The aim being to keep a max strength as long as i could to all journals. Once i had the main turning done to within 1mm i finished off very slowly and carefull with 3 parting tools
1 grd LH,1 x RH and 1 sq,just to finish the sides of the webs and dia of the journals etc
Your main mistake is the use of the wide carbide tool and milling out the meat.Use a ground HSS tool say a parting tool,good for the final depth and dont overmachine 1 web as this gives a weak point when you start another web.Break it down gradually in stages to keep max strength as long as you can.Finishing cuts should be no more than a couple of thou.As i said i took my time and spent a couple of days making sure i did not overstress the workpiece. Good luck and post photos as you go will be happy to help further
Regards Barry


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## bazmak (Feb 3, 2018)

Also  i should point out when machined the crankcase i bored the ends and centre to 16mm dia so could check the alignment with a 16mm dia shaft
Then i machined the centre of the shaft to 12mm dia and made and fitted the brass centre bearing.when i made the crankshaft i machined the ends to 16mm dia to turn all the journals then machined down the the end dias last.Again to keep max strength in the workpiece throuout the hogging process


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## davidyat (Feb 4, 2018)

Barry,
   A thousand thanks for your advice. I can now see the logic in your words. I've often been described as "A Bull In A China Shop" and my work is showing it. Taking the time with smaller cutting tools and finesse is the way to go. As I've said before, I just learned another way of how NOT to machine a crankshaft. Let's see if "Third Time Is The Charm". Again, thank you.

Dave


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## bazmak (Feb 4, 2018)

take some photos and do it in 3 stages to + 1mm all round.The concentrics
finish at say 14mm dia from 40mm dia thats 13mm depth of cut.Stage 1 go to 5mm deep then stage 2 to 10mm deep then down to =1mm. do the same for 
the eccentrics journals but note deeper overall.Start with the one near the chuck then the middle,reverse in chuck and repeat.Total of 7 in all. Take them all to stage 1 then repeat etc.Dont forget the centre one will be finished to 12 dia for brass bearing.The other 2 concentric can finish at 14/15mm not important.I then finished the sides of all the webs to size and width wit both LH and RH parting tools and some side clearance.I finishe the journels to size with
the square end parting tool and u cut slightly the corners  with the lh and rh tools,although it was not necessary as i countersunk the big end bores in the
brass conn rods.Take your time its worth the effort and much easier on the mind than cocking one up.Guess i was just timid and lucky. Last job is to turn the shaft ends to suit bearings etc.Cant remember if i taped packs between the webs but dont over tighten the tailstock centre


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## davidyat (Feb 16, 2018)

Barry,

   I see you made the monthly newsletter. Your build was the one that got me started on my build. I'm taking a sabatical on the crank until I get another blank and working on other things for the build. I've managed to mate the cylinders with the block and am now working on the brass manifolds that will mate with the top of the cylinders. I've also made the decision to go with a toothed belt for the crank and the rotary valve. I've seen one work on youtube. I found this company that sells the items I believe will work for my build:
https://www.ondrivesus.com/
And I'm sure I can make an adjustable tensioning device for the toothed belt to keep it in proper tension.
The Grasshopper


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## bazmak (Feb 16, 2018)

Looking great,hows it going with the crankshaft ?


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## johnmcc69 (Feb 16, 2018)

Looking good so far. Nice work.

John


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## davidyat (Feb 17, 2018)

From my previous post, I'm taking some time off on the crank. I'm going to work on some better, stronger offset jigs for the crankshaft. Then psych myself up to tackle another crank. Then go back and read and absorb the wisdom of Barry and take a lot of time on the next crank. I've been using my time to make the jig for the rods and finishing up the intake manifolds.

Grasshopper


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## bazmak (Feb 17, 2018)

Good work grasshopper.I too thought of a small toothed belt drive
but finished up using gears.I am very interested in how yours goes
should look much improved  with a nice tensioner/idler pulley


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## davidyat (Feb 18, 2018)

Barry,

   I looked at your Locomotive blog. And NO, this will not get me started on one myself like I was inspired by your Cirrus V-8 2X build! But at the end, I see you're going for a tool post grinder. Have you started this project yet and have posted anything on it? With my problems with my crankshaft, I'm thinking maybe a tool post grinder for making the crankshaft might be a safer way to grind the journals. Your thoughts?
Grasshopper


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## bazmak (Feb 18, 2018)

I had no problems whatsever turning the crankshaft so nor should you
Grinder finished but i think turning the crank is the best way
Just take it slowly in stages


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## davidyat (Apr 17, 2018)

Grasshopper here. I've been busy with other projects and a trip to California for income taxes. Moved out of CA and am now living in Indiana just 8 miles from Turn One at the Indianapolis Motor Speedway. Yes, I have my tickets for this year's 500. Hope my pictures come through. First off, this Saturday, I'm going up near Detroit, Michigan for the NAMES (North American Model Engineering Society) Model Show. Here is their website:

http://www.namesexposition.com/

I'm hoping to get a lot of information. They say the show has 30,000 square feet of exhibits. At this stage of my machining learning process, I will need all the information I can get. I'm hoping to meet a lot of macinists with more knowledge for me to absorb.
I've managed to make the intake manifolds. I'm going to use brass compression fittings for the manifold and the block. That way the air tube doesn't have to be exact in its' length. 
8 Pistons
8 Rods ready for finishing
The 4 inch rotary table with the jig for the rods
The new offset jigs for the crankshaft with 0.750 inch holes for the ends of the crankshaft. I'll turn the ends down to the 0.500 inch I need for the sealed roller bearings when the crank is done.
The crank with one end turned down to 0.750 inch. Working on the other end.


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## davidyat (May 2, 2018)

Well I'm getting ready to turn my THIRD crankshaft. But first, I did go to the NAMES Model Engineering Show near Detroit, Michigan. OH, MY GOD!!! I was in heaven. Some of these more experienced machinists were to be admired. And they were so polite and wanted to hear of anything you're working on and didn't talk down to you no mattrer what your experience. I did spend 1/2 of my time going through the vendors and found a good amount of tooling I could use. Let's see how many photos I can get in one reply. I highly recommend this show to any machinist. And also if anyone is near San Diego, California, I also recommed The Joe Martin Craftsmanship Museum. Here's the URL: https://www.craftsmanshipmuseum.com/

Grasshopper


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## petertha (May 2, 2018)

Nice pics. Did you happen to catch what radial is in pic-2 & builder?

ps - good luck with the crankshaft.


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## davidyat (May 3, 2018)

Unfortunately, no. I was like a kid in a candy store. Go here, go there and just snapping pictures at random. Will do better next time.


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## davidyat (May 18, 2018)

Grasshopper update. Well, I'm taking advice from my mentor, Ray. If you don't feel comfortable, don't machine it. I started to turn the crankshaft using a 0.125 parting tool. I didn't feel comfortable. No matter what I did, I didn't like the feel. So I bit the bullet and got a used Dumore Model 14-001 tool post grinder. Got a 0.250 grinding wheel. I needed to make a better holder for my purposes. The first bit of grinding did feel a whole lot better. It's going to be time consuming and tedious, but I don't think I'll mess up this one. I'm sure it will make a world of difference when I get to the rod journals.


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## Cogsy (May 19, 2018)

1/8" is still a fairly large parting blade, though it likely would be ok if ground properly. I use a 0.093" (I think) blade with the end 'bifurcated' which means split in two with a small v ground in the centre. So it has small contact area and handles cutting side to side. I'm sure grinding will work out though, I just couldn't handle the noise for that long.


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## davidyat (Jun 21, 2018)

SUCCESS!!!

Grasshopper here. I never thought this day would come. I now have a crankshaft! I started on a blank steel shaft. One of my 2 best friends was here visiting me from California. He owns a grinding shop where he uses Blanchard machines and double disc grinding. He was seeing my frustration with the steel. Since he has so much experience with grinding all kinds of metal, even Inconel, he suggested using 416 Stainless Steel. He said since the motor wasn't going to power anything, just run on compressed air for a few minutes, 416 SS would be so much easier to machine and would hold up to what I wanted it to do. So I got a blank. The pictures show I started by machining the ends down to 3/4 inch and the interior center areas also to 3/4 inch. I wanted to keep as much beef as I could during the machining process. Barry (Bazmak) gave me a lot of advice for machining. After the centers, I loaded the blank into the offset jigs. I started by using a 1/8 inch cut off tool to go in about 0.125 inch, move over about 0.200, go in again at 0.125. Then put in a 0.375 flat nose tool and went in 0.125. I wanted any surface I was grinding to be no more than 0.125. Two cuts with 0.125 (0.250) would result in the 0.375 only cutting 0.125 of surface area. AND TALK ABOUT SLOW. 60 rpm on the lathe, moving the cross slide in 1 to 1 1/2 thousandths per revolution. It's taken me 1 month to finish this crank. With it installed in the block, I can see that if my old eyeballs are correct, I'm going to have to adjust 10 thou here and 20 thou there to get everything to line up correctly width wise. One bank looks pretty good and the other side might have to be adjusted. I just want to thank all you experienced machinists and your advice to this novice. I'm learning a lot. I can't thank my mentor, Ray Clyde (a master machinist who also helped build the B-2 Stealth Bomber), Bill Birch(the Grinder) and Barry from down under. 






















P.S. After cleaning up the machining area, went and sat down on my front porch swing, and opened the most awesome tasting COLD beer I've had in a long time!!!


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## davidyat (Jun 21, 2018)

Again thanks Barry for the advice on putting support between the rod journals for support.


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## natalefr (Jun 21, 2018)

YEAH !


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## bazmak (Jun 21, 2018)

Congrats,i think one of your problems was the initial cutter.It looks far too wide and would creat too much pressure
I initially started with a parting tool ground to a point and simply nibbled out the meat,gradually facing the sides
When i was almost there i used a lh and rh tool to finish the webs to size and the parting tool to finish the diameters
Took quite a while but the beauty of the turning fixture is you can remove /reset and nibble the eccentrics.Isnt it a good feeling
when you get there.Now dont drop it


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## davidyat (Jun 22, 2018)

Barry,
   Thanks again. You were so right on the cutter. It was way too big. I look back on the crank machining and even with all my mistakes on the first 3 and botching them up, I consider it a learning experience. I learned how NOT to machine a crankshaft. The lessons I learned on the 4th crank I think will stay with me a long time. I've built plastic and balsa models for over 65 years and thought I had the patience part down. NO, the crank taught me MORE patience. Now I'll be working on the cylinders. I still have to bore out the 3/4 inch hole for the pistons. I know there will be some adjustments needed to get everything into alignment. I think I'm going to take some time from the V-8 and mess around with the 1/4 Scale Myers/Rider-Ericsson that's almost completed. When I was at the NAMES show last April, I was told that making the displacer piston out of BBQ grate cleaner (a stone like material that's a lot lighter) would be a better approach. Will keep you updated.

Grasshopper


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## davidyat (Jul 27, 2018)

*Barry,

   Grasshopper here. A question on the crankshaft. I've enclosed a picture of my progress so far. My question is, do I have to turn the middle 3 concentric's to 0.500 inch? I left them at 0.750 inch for beefing up the crank during the machining of the rod journals to 0.500 inch. I have sealed ball bearings with a 0.500 inch hole for the ends, which will be turned to 0.500 in to fit the ball bearings. I'm hesitant to machine the middle 3 to 0.500 inch.  I haven't made the hole for the inner concentric brass bearing yet. I can bore the brass inner bearing to 0.750 inch and leave well enough alone. Or am I leaving too much mass for the air to turn the engine?
Thanks,
Grasshopper*


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## bazmak (Jul 27, 2018)

I cant remember the exact size but i did turn the 3 inside concentrics to a larger dia as they are not doing anything
and i thought it better to leave them heavier for strength.No fixed rules just do what looks/feels right
From memory 3/4" seems a bit large.If the big end eccs are 1/2" or so then i think i made the concentrics 5/8"


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## davidyat (Jul 28, 2018)

*Thanks, now to make some chips.

Grasshopper*


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## davidyat (Sep 12, 2018)

Barry, 
   I have installed the cylinders with the pistons and everything moves with no obvious problems. What would you suggest for max diameter of the bore of the cylinder. I have 6 to 7 with very good fit. Pull the rod and piston out of the cylinder and you get a good pop. On the 8th, the piston is 0.750 and the cylinder is 0.764. One question, I can make another piston if needed out of 7/8 brass rod and turn it down to 0.764. Think I need one? Next what is your suggestion for the springs that hold the ball bearings in the head? Length and compression load? My hole for that is 5/16. What did you use on yours and where did you get them. Today, I'm going over to a supply house and get toothed pulleys and belts. I want to get the pulleys before I bore the air rotary valve and a few belts of various lengths in case I would need an idler pulley.
Grasshopper


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## bazmak (Sep 12, 2018)

Yes I would say there is no reason why you cannot make an oversize piston to suit cylinder 8 as long as they are clearly marked
I was very limited with commercial available springs and used the lightest I could get,however I think they are still too strong
If you read back thru the post Chuck Fellows also pointed this out.I think it is a case of suck it and see. I did not get mine running
with borrowed compressor so put it to one side for when I have my own compressor and more time to play.I got distracted with other projects
Keep up the good work


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## davidyat (Sep 13, 2018)

Thanks Barry. I will go to McMaster Carr and I believe I can specify the wire diameter of the spring. Will look for a light one. I've just ordered my 2 to 1 toothed pulleys for the crank and sleeve valve. I will probably use an idler pulley to keep tension.  I need to get the pulleys before I drill the 6 inch hole for the intake sleeve valve.  I am also going to use a compression fitting into the block for the air intake tube. 3/16 fitting with a 1/8 pipe thread. This way I don't have to be EXACT in my length of the intake tube. I have a large brass block at the top of the head where I will silver solder the tube into.


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## davidyat (Sep 28, 2018)

*An update. I received the cogged belts and pulleys. I was able to bore the hole for the rotary valve in the engine block and pressed the brass bearing in by putting the block in the oven at 500 degrees and the brass bearing in the freezer. 














 Having a small nagging problem with the brass bearing and the rotary valve. When the steel valve is rotating about 500 rpm in the lathe, the engine block with the brass bearing pressed in, will pass freely. But when I stop the lathe, the steel valve will have a slight resistance when installed about half way. I've been lapping for 2 days and can't seem to solve this problem. I don't know if the brass or steel is slightly bent by a few thousandths causing this problem. Will try to put the steel valve in the lathe and see if it's out of round and by how much. Anyway, I have been able to put both cogged pulleys on the crank and valve and have no clearance problems. The cogged pulleys are 15 teeth on the crank and 30 teeth on the valve. You can see by the photos that a standard belt has too much slack. I did order a few over sized belts and you can see that I will figure out an idler pulley system to keep everything snug.*


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## davidyat (Oct 3, 2018)

Baz, Grasshopper here. I'm almost ready to bore for the rotary valve. I must be very tired. I'm trying to figure which end is which. In this picture of your turning of the crank, which journal is closest to the live center in the tail stock, A or D? If you stand the crank upright and look at the dimension page to get the orientation of B and C journal, is A at the top or bottom. Pretty much it doesn't make any difference to me, if one way is wrong, just turn the crank around. Thanks in advance.
Grasshopper


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## davidyat (Oct 22, 2018)

Well, Grasshopper finished the Cirrus Compressed Air V-8. It's either an engine or a very expensive paper weight. When I hooked up the air, I got two apparent exhaust pops and nothing since. Won't run. I've listed some pictures of the finished engine and how I drilled the timing ports. I used an extra cylinder to make sure number #1 piston was at TDC. Installed timing wheel and went to work. Some of my thoughts as to why it won't run. Springs too strong in the head, air leaks, possible air ports not lining up (I did back off the timing holes to just be opening at TDC but 





 maybe not enough?), the cogged belt too tight (if loosened up too much, cogged belt will jump some teeth?) or other problems I haven't thought of. I will take time off to contemplate my next moves. Anyway, some pictures.


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## stevehuckss396 (Oct 22, 2018)

It is very common to have problems getting a fresh build to run. Stay with it and double check valve timing. Look for things that didn't get tightened. Make sure parts didn't move due to set screws slipping etc. Its probably something simple.


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## davidyat (Oct 22, 2018)

Thanks, the first thing I'll do is double check the valve timing. Then the springs holding the ball bearings that keep air from backing up into the valve. I am concerned with the rather snugness of things when the cogged belt is snugged up with the idler gear. I can turn everything by hand but I do notice it's not as easy as when the belt is off and I turn the crank, then the rotary valve. Like I said, it's been almost a year and a half and I'm going to take  some time to REALLY think about what I've done and look at things from a different perspective. 
Grasshopper


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## stevehuckss396 (Oct 22, 2018)

If it seems a little snug and think it might be the crankshaft or camshaft, try putting it in the lathe and use the lathe to motor the assembly for a half hour making sure it is well lubricated. If that seems to loosen things up, give it another half hour. Getting it rotating freely will give you a huge advantage when trying to get it to run on it's own power.

To motor it put the crankshaft in the chuck and lightly tighten it. Move the toolpost over so the engine block cannot rotate. If possible support the other end of the crankshaft with a live center in the tailstock. Put the lathe in neutral and spin the chuck by hand and see if everything turns without hitting something it shouldn't. If good put the lathe in a slow speed like 150 RPM and turn it on. Just let the lathe spin it around for a while.


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## bazmak (Oct 22, 2018)

Well grasshopper congrats on your progress.A nice job you are at the stage I was and encountering the same problems
I too ran it for quite a while in the lathe and had a sticking valve.I think because its a long thin wall tube it not perfectly
concentric and straight.Dont know if honing will completely cure it.Also mu initial springs I also thought wer too strong
and I had plenty of leaks.So put it on the backburner/shelf and gave up for now .May try and resurrect it in the near future
Its a nice looking engine and looks great turning over by hand with the sump off.I have now goy into restoring Myfords
Please keep trying and posted.I like the belt drive.I too thought of it  but did not think I had the room.CONGRATULATIONS


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## davidyat (Oct 22, 2018)

Thanks for all the input. I never thought of the lathe. I secured the whole motor and put a cordless drill on the crank, filled the sump with enough oil so the crank would dip into it. Then zip tied the trigger closed and kept replacing the batteries when they died out. I'll next try the lathe and let it run a while. Great suggestion.
Grasshopper


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## bazmak (Oct 22, 2018)

Found a couple of videos of running in in the lathe.I think it preferable not to fit the sump its easier to keep whttps://youtu.be/fxUKdic9https://www.youtube.com/watch?v=fxUKdic9WCQWCQatch and lubed


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## bazmak (Oct 22, 2018)

/www.youtube.com/watch?v=LNFVb2GdPA8
Can you let me have some details and photos of the timing belt drive
I might get back into this.If you run it in the lathe with plenty of wd 40
its a mild abrasive and does mild lapping


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## davidyat (Oct 23, 2018)

Barry,

   Just got up. Later today, I'll get some pictures for you. Last night as I was getting to sleep, I may have had an Eureka moment. Something I may have overlooked. Will get back to you later today.
Grasshopper


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## davidyat (Oct 23, 2018)

Barry,
   Here are the pictures of the timing belt. Some background on what I did. I ordered a 0.500 inch brass tube and 3/8 inch steel tube from McMaster Carr for the rotary valve setup. The inner hole on the brass was 0.370 inch, which made reaming for the 3/8 rotary valve easy. After making the rotary valve, I lapped it in and silver soldered the end to close it up. The cogged pulleys were from Megadyne, 221 South Westgate Dr., Carol Stream, IL 60188 (630)752-0600 USA. Megadyne doesn't sell to the public, so I used Motion Industries, 4410 Sam Jones Expressway, Indianapolis, IN 46241 (317)248-2100 as the supplier who got the cogged pulleys and belts for me. I live near Indianapolis Indiana. The bore on the rotary valve pulley is 3/8 inch, 30 teeth, the crank pulley bore is 1/2 inch, 15 teeth and the idler pulley is 1/8 inch bore, 10 teeth. To get you started, here is the site for one of the pulleys I used. https://products.beltcorp.com/item/...ys-1-5-pitch-xl-pulleys-aluminum/15xl037-6fa6
You can see what this company has to offer. For the idler gear, I made the fixture, bored a 1/8 inch hole and tapped for a set screw to hold it. I had so many 1/8 drill bits, that I just snapped off the base on one and used it to mount the idler pulley. I would suggest if you do this, you can see that I have a very long set screw (one laying around) and found out it is very useful to put your thumb on it to take up the slack on the belt before tightening the assembly on the block. Also, Chuck Fellows pointed out to me to remember with this set up, the rotary valve is rotating the opposite direction of his. So when I was boring for the air inlets, I made sure of where cylinder #1 was at TDC, mounted the degree wheel with a pointer at 0 degrees and rotated clockwise every 90 degrees. I could look into the cylinder holes and made sure which cylinder was at TDC and drilled the air inlet at that cylinder with a jig I made to make sure the 1/8 drill was centered. I also had a spare cylinder 
that I chopped off the top to find TDC of piston #1 with a dial indicator.


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## davidyat (Oct 23, 2018)

Oh and yes I did have to put the 30 and 15 tooth pulleys in the lathe and remove some of the outer ridges to make clearance after mounting. I have about 20 or 30 thou of clearance between the two pulleys after installation.


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## davidyat (Oct 29, 2018)

Well I tried a test run of the engine. A couple of exhaust pops and then the engine wouldn't turn and air was pouring out of #4 & 8 exhaust tubes. No matter how hard I tried to turn the crank, no go under pressure. OK, what did I do wrong? Started checking everything and got down to the rotary valve. Then I saw what I did wrong. After drilling 5 ports, somehow I got distracted and instead of following my prints and was using my eyes to see what rod journal was at TDC. BAD IDEA. The last 3 ports were totally out of whack. Lucky for me, I ordered way more steel tube for the inner rotary tube than I needed. Now it's back to the lathe to make another steel rotary tube. Thank God, I don't have to remove the brass bushing for the rotary valve and the SECOND ONE should be no problem. I do keep forgetting sometimes, one of my mottos, "Do you want to do it RIGHT the first time or RIGHT the SECOND time!!"
Grasshopper


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## davidyat (Oct 31, 2018)

Wouldn't you know it, it happened on Halloween!!! As Dr. Frankenstein said when he shot the juice to the monster, "IT'S ALIVE, IT'S ALIVE!!!" The V-8 engine lives. When I made the CORRECT rotary valve, it works. Now my next problem. I have video of it running. One is about 1 minute, another about 22 seconds, taken with a Samsung camera capable of video. Then another about 20 seconds taken with an iPhone 7. Every time I try to upload, this site keeps saying the file is too big. They are MP4 files. I could really use someone like a 12 year old to take me by the hand and show me how to upload. HELP!!!
Grasshopper


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## johnmcc69 (Oct 31, 2018)

Congratulations Grassshopper!
 Sorry I can't help with the video upload, by am looking forward to seeing it run.

 John


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## bazmak (Oct 31, 2018)

You have to upload videos to Utube and then put the link into your post.Cant wait to see it running


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## davidyat (Oct 31, 2018)

OK, now to see if they will upload to youtube.
Grasshopper


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## davidyat (Oct 31, 2018)

OK, let's see if this works. The video shows the engine running and not very fast. Later after I clean up the shop, I'll try some adjusting of the timing and see if that makes any difference.
Grasshopper


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## bazmak (Nov 1, 2018)

That's great grasshopper.I will seak your advice when I get back to finishing mine


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## ShopShoe (Nov 1, 2018)

That is nice to see running. I look forward to seeing it after your adjustments.

Thank You for posting,

--ShopShoe


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## bazmak (Nov 1, 2018)

Don't forget it wont run fast unless you have  a big air supply.* cylinders goes thru a lot of juice
Slow is good.how about a video with the sump removed,lets see the crankshaft you struggled with


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## davidyat (Nov 1, 2018)

Barry,
   You are so right about the volume of air the cylinders use. I have a small upright compressor tank and the engine (with a full tank of air) will activate the compressor to fill after about 9 or 10 seconds of quiet running. Unfortunately I can't show the crank running on air. In some of the previous pictures, you can see the idler pulley assembly is attached to the sump. No sump, no pulley. So what I did was turn the crank by hand for you.



Grasshopper


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## davidyat (Nov 2, 2018)

Barry, I've put together an album of my build of the V-8. This is the title page you see first. I'd love to put your real name on it. I will understand if you still want Bazmak used. Thanks to all who helped me.
Grasshopper


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## neil_1821 (Nov 2, 2018)

Congratulations on getting it running! It always feels like a huge weight is lifted off your shoulders when they fire up. 
Best thing for videos is to upload them to a YouTube account. If you’re struggling you could e-mail the videos to me in a zipped format and I can upload them to my channel and post the links for others to see. Just send me a message and I’ll try to help you.


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## davidyat (Nov 2, 2018)

Thanks, Neil, I've made myself a youtube account and learned how to upload videos to them, then putting the URL in my replies. It works fine. You can see a couple of videos up above.
Grasshopper


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## bazmak (Nov 2, 2018)

Thanks for the invite,my name is Barry Midgley,dont forget Chuck Fellows was the original designer,i used his concept and just doubled everything


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## davidyat (Nov 3, 2018)

Thank you, Barry. If you go back to the title page you will see that I put in, Designed by Chuck Fellows


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