# Big Earls Farmboy #758



## bigearl91 (Jun 2, 2019)

Going to give this project thread a little go. If no one takes anything from it, at least it will give me a nice run through of everything I did and the order/process I went through. My last project (Webster) was very much a first go, with a lot of learning and admittedly some impatience. This time I will be taking it much steadier, I also have a much broader set of tools and larger machine tools sat my disposal, and learned a lot since I started this hobby.





Some of the main stock materials laid out. Flywheels not yet purchased, some brass still to buy and crankshaft materials depending on which route I take to construct/machine it.





Whilst I wait for my 6" vice to arrive I decided to start work on the connecting rod. Laziness pushed me down the path of hogging away an pretty oversized piece of 2014A down to the correct size. Maybe I should make a power hacksaw first...





I will be making all critical cuts using the DRO but I still like the reassurance marking out gives. Some of the critical sizes marked, along with the lines to cut the angle between the little and big end. Difficult to see granted due to the Dykem not adhering too well to the machined surface (maybe some contaminants)





Never got any photos, but setup the piece in the vice, shaved a few thou off the big end flat and then wound up the 3.9" to the little end. Drilled, then reamed for 8mm. 

Setup using angle blocks in the vice.





12mm end mill with 2mm radius.





One side finished - a little bit of meat left on unintentionally. The depth of cut was determined using the marked line, with the setup and DRO allowing me to just flip it and cut the opposite side identically. I will keep the flats on the little end cutting the radius as the last operation to allow a reference baseline that spans the work piece.




At this point my battery powered garage decided to give up, which where I leave this until next time.

Thanks for reading - my format will probably change as I progress, maybe less words maybe not.
Earl


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## bigearl91 (Jun 3, 2019)

Ok so I have never had to think about workholding outside of using a vice, 3/4 jaw and collet chuck so a lot of tonight was spent working out the best way to hold the conrod on the rotary table - which I have also yet had chance to use.

Started out by cutting the other side of the con-rod:




Pretty happy with how it turned out:




I did manage to mess up a dimension but I can adjust if needs be at a later date (also I am aware of the 2 (degree angle on this from cutting with angle blocks):




Little bit more marking out




As I say never had to do this before so did some different trials on the bench first before setting it up in the mill - this setup would never have worked! Which I "soon" realised when thinking through how it would be machined.




Whilst the vice was being removed, a wee touch up with way oil




Another looks at the setup that would have been a disaster:




Centring the rotary table on on the mill - again a first time, took a good bit of time just getting the bleeding dial indicator in a useful position. Hopefully I can leave this up the left hand side of the table and still get my vice back on meaning I won't need to recenter this for a while.




Final setting of the workpiece - used the centre finder and 2 degree angle block again, with the marked centreline as a check, both agreed. Delighted.












Tomorrow I will cut out the web/flange of the conrod and ideally get the little end bearing machined, and see about finishing off the big end, although I think it would be sensible to wait until I finish the crank.




Cheers
Earl


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## Brian Rupnow (Jun 3, 2019)

Okay Earl--I'm watching. When I make a con rod, I generally cut the big end off on what would be the centerline and tap the two holes which will hold the cap bolts. I make the bolt on cap separate, then do the outer profile only. I drill and tap the rod, put clearance holes in the cap, and bolt it on. Then I pick up on the small end diameter, wind the DRO until I've moved the exact center distance, then drill and ream the big end hole into both pieces at the same time.---Brian


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## bigearl91 (Jun 4, 2019)

Thanks for your comment Brian, 

Much appreciated. 

I should add, any tips or suggestions are welcome here. This is only my second project, as much as I learned on the Webster, I am already into unchartered waters so any advice is well recieved. After all something second nature to you guys might take me an hour to work out

Cheers
Earl


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## bigearl91 (Jun 4, 2019)

Just another quick hit, nothing major other than finishing off the detail on the con-rod, and now the new vice has arrived squaring up one of the aluminium pieces to begin the frame front. Already filled a rubble sack with aluminium chips. Spending half the time cleaning 

First central cut




Rotary table used to match 2 degree taper on external faces. Making sure I was always approaching the rotation from the same direction to eliminate any error from slop in the backlash.




 Final cut back to origin - no ovals 









Trimmed the webs to design thickness.







Rinse and repeat c'est voila








New toys arrived so I spent a good hour disassembling, cleaning and reassembling. You can see it dwarfing the mill and the 4" Abwood below - although still pretty adequate Z axis remaining. Managed to get it on with the rotary table too. Not able to use X axis all the way to the end of the jaws but it works for the biggest pieces on this build so hopefully can stay as it now.











Now for the frame to begin. I think will pick up the con-rod again once I get onto some lathe work









Quick squareness check showed around 0.03mm variation over the 3.5" squared face which I am more than satisfied with.




Some final checks showed average deviation to be around 0.02mm across the faces. To be honest the surface plate will probably play more a part in this.







I have dug out the big old Enco 3" boring head as I am contemplating fly cutting the finishing cuts. The face mill has given pretty good results so face though.


I will need to research and grind a tool for a good finish on 6082 (6061). I am thinking a very large radius with a high rake? Any advice would be appreciated as again, this will be uncharted territory for me.

Thanks again for reading.
Earl


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## Rudy (Jun 5, 2019)

Hi Earl,
You will have a good time building this engine. I have just finished my #651. It has been a pleasure to build it. Lots of machining. This was also my second project. I have a thread on my build.
The biggest challenge I encountered was getting the main bearings in line. A reamer did't make it. I used my boring head and went through the bearings WERY slowly. 10 minutes each bearing block. This way I got it straight. My goal was to have the bearings on the crank with no play before clamping it in the block, and still spinning freely when I tightened the bearing blocks. Of cause the crank had to be true in the first place.
I started with a PICTIM ignition, but it died on me (the PIC controller). Probably because of the big car coil I used, don't know. I ended up with building my own ignition driver (have a thread on this too).
I run on propane. I have started to make a propane demand valve after the drawings from Howel. However, I'm modifying the design a bit. Propane seems to be a well suited fuel for this engine. Almost no exhaust and no soot.
I actually run it now on just connecting a hose to the mixer and directly to a butane torch with removed burner. Mot of the gas escapes out in the free, so there is a bit of smell from that. The first run was even simpler, as shown in the video.

An issue I have to go back on is the piston ring. I use some "ordinary" black rubber ring I found laying around, but it lasts only for a short time. I did go back and polished the cylinder to a near mirror finish and it helped. So pay attention to that. I have ordered some Viton silicone rings now.

In the video the noise from the gears is somewhat pronounced. Not that bad in real life. I made the gears with a hand made gear cutter, so there is room for improvements. I have bought proper gear cutters and will make new gears.

I stil wonder how to make some text and graphic on it. Free hand pin striping is not my game. Ordering a CNC carved brass plate at the local lock smith is cheating.

So Earl, I will follow your build and hope you will keep us updated on the progress. So good fun to see such builds brought to life.
For inspiration I put up a picture of mine in a nearly finished state and a link to a video of it's first run.

Rudy


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## Brian Rupnow (Jun 5, 2019)

Earl--I see that you are in the U.K.--do you work in metric or Imperial inches, or does it matter.---Brian


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## bigearl91 (Jun 5, 2019)

Rudy said:


> Hi Earl,
> You will have a good time building this engine. I have just finished my #651. It has been a pleasure to build it. Lots of machining. This was also my second project. I have a thread on my build...



Hey Rudy, thanks for sharing this very nice job - I am a fan of the green, and the finish of the base!. I will probably be using the Mini Magneto ignition system - which I used on the Webster very reliably. I actually looked into the PICTIM and its newer/alternate siblings but think in the end I will just stick with the Minimag as for me it is the same thing - I am no electronic engineer - it makes a spark when a switch closes/opens.

As for the rings, I ordered some nitrile "Quad" seal o-rings that I am hoping I will have fortune with. If I wear through them all quickly, I have a heap of Viton rings, and then failing that I will machine some cast iron rings. Fingers crossed the quad seals work - I will be spending some time polishing the cylinder up to minimise wear here.

https://maydayseals.co.uk/quad-rings-/2853-q-020-nitrile-quad-ring.html

Be good to know how you get on with the Viton though!



Brian Rupnow said:


> Earl--I see that you are in the U.K.--do you work in metric or Imperial inches, or does it matter.---Brian



Hmh...
My preference is metric, because I grew up using it and all my tools, drills, taps, dies, reamers (bar a few essentials) etc. are metric. and when I think of a fractional or decimal inch my head converts it to equivalent mm to 'picture the size'

That said, as imperial is so prevalent with this hobby I am starting to get my head round the sizes. Still a [financial] pain with all my tools though.

Something I believe you are familiar with having read your builds is that, it is a given, every different project needs new tools no matter how hard you try to not use any more of those precious beer tokens.

And then of course my lathe's screw cutting gearbox is imperial...

In short Brian - it doesn't matter 

Cheers
Earl


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## bigearl91 (Jun 5, 2019)

Going to reduce the size of the images as they were a bit overbearing. Nothing too much progress wise as I has some stuff to get sorted and only ended up with a few hours on the tools - a LOT of sweeping and hoovering though.

Stock size compared to finished size - never did go with the fly cutter as these will be coating in a fetching British Racing Green enamel.




No 3rd dimension here but trust me its a big pile - gonna have another 2 like this with the frame read and hopper...




Everything cleaned down again, removed the RT too as for what its worth it was just in the way. Touching off the edges, offsetting 1" and centre drilling for setting up on the lathe.










Then I had a panic as the face mill pattern made it look like I had messed an offset up.... fortunately it was a false alarm - always mark out for sanity's sake!





Ordered the wrong size chuck key for the 4 jaw (not sure where mine has gone) so after some half-arsed grinding, bob's your firkin.







Found some chocolate import aluminium to used for protection against the chuck jaws:




Started setting up the piece as my final task for the day but unfortunately it was lights out before I could finish.







I might end up removing the 4 jaw and sticking the ER40 chuck on to making a test bar to position between a dead centre in the tail stock and the spot drilled point on the workpiece, then using the DTI against that to get the workpiece positioned perfectly (something I believe I read in "The Amatuers Lathe - L.H. Sparey")

It feels a bit like cheating just sticking the DC straight into the centre drilled hole - maybe not? if anyone wants to convince me this is kosher that would be great 

Thanks again for reading guys.

Take it easy
Earl


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## Mago (Jun 6, 2019)

It seems this is the month for Farm Boy manufacture and this is another one.
It follows the Jerry Howell design with a few mods.
Couldn't face the machining of the flywheels from CI so made some patterns and had them cast in bronze.
All went well but machining them in a small lathe is a challenge. Spokes need some finishing but this will be done when I have some time and nothing to do.
I decided to fabricate the crankshaft using silver steel for shafts and big end. All the joints were pinned and glued with Loctite.
My engineering experience was before "O" rings and Loctite so decided to forget the fabrication experience and go back to cutting it out of the solid.
I changed the ignition pick up design to provide some advance and retard adjustment.
The oil delivery system to the cylinder is home design and not used when only short runs are made.
In its initial start ups the engine is too stiff to start by hand so a starter is used. Unfortunately it actuates the governor control so that it prevents the motor stating unless it is set for fast running.
This negates the H & M function. More work needed here.


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## bigearl91 (Jun 6, 2019)

Thanks for showing interest Mago, I am quite keen to see a wee close-up of your ignition timing setup if that's possible? I like the idea of it however I am keen to use the spark saver option and off the top of my head am thinking it may just require some fundamental changes in the design to achieve both of these features. Have you found it makes much difference in the running of this? being it only hits every so often?

Would love bronze flywheels but £££££££. I found someone on ebay that sells 6" cast iron castings at a reasonable price - I also don't quite fancy machining away that much EN3B/Cast Iron.

I have priced up the 01 flat bar but purposely haven't pulled the trigger on it yet as I haven't made either a proper built up or turned crankshaft yet and will probably go for the built up option as it seems less upsetting (mentally and financially) to bugger up.

Cheers
Earl


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## bigearl91 (Jun 6, 2019)

Disaster strikes.

Everything was going incredibly well...lets starts at the beginning.

I decided that I needed a test bar to make certain I had my piece offset correctly. I found some mystery metal with yellow paint on the end. It was vaguely magnetic, the chips were small flakes and it was pretty well formed. Anyway, off with the 4 jaw. On with the ER40 collet chuck. After turning an adequate length down I put a 60 degree taper on the piece. Then reversed and used a centre drill to put the required hole. Any error in concentricity at between each end of the bar these points along this baseline doesn't trouble me.
























And the bar in use. between a centre and centre point.








The first cut! no turning back. Had the lathe in back gear at around 300RPM as the balance was an issue - this meant the machining took a lot longer than normal.







Cut the 1.202" thru hole after checking a few times with the T bore gauges I got it cock on




Continued below...


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## bigearl91 (Jun 6, 2019)

This puppy has been waiting for its moment!




Measuring up the required depth of cut and setting the DTI













The final cut, again managed to get the diameter cock on and the depth of cut just shy of perfect at 1.803"...... This is where I made a right howler!

Happy with the finish of the bore though.








1.5006" diameter.




Heres the howler:




I was only meant to bore to a depth of 1.355" at dia. 1.5" I have effectively deleted the 1.202 hole (once everything else is machined away)

Really disappointed to be honest. I could make up a ring and press it in, but I don't now if it will have the required strength - I could pin it and loctite it.

Still - shouldn't be making these mistakes, annoyingly I had worked that size out when I started boring but I think I was focussing so much on the diameter being correct, I read the 1.8" and just went for it.

Thanks for reading, any suggestions on what to do to fix this are welcome, I might start again which is a bit of  shame.


Cheers
Earl


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## Rudy (Jun 6, 2019)

I'm a big fan of this Farm Boy engine. I always recommend it. Very well designed. So good fun to make and it works so well. Love sit watching it puff away.
Another tip that came to my mind, the collets for the flywheels. I didn't want visible runnout on the flywheels. Did the flywheels very accurate, but still got wobble. It was the collets. Had to machine both inside and outside before I took it out of the lathe. 

Some clever setups Earl. I did my block parts in the mill. Also like your large wise. I have a 6" my selves, and a 4" on the shelf, alone, all day, every day in fact. A big wise is never too big (for the work), but always more rigid.

I will let you know about the Viton ring. Also let us know how your Quad-ring project works.

Mago, I would like some details on how you did the timing adjustment. I plan to make new gears and make the engine rotate the other way. Why? I'm afraid this thing will chop the nose of me. Or an arm. That crank with those two heavy flywheels won't stop rotating if you put something in between it and the frame. Something will give. I also like the strange look of an engine turning the "wrong" way.

I did mine in metric since me and my tools are metric, but I just calculated all the measurements to mm. Lot o extra work and a lot of odd numbers to keep track on. All the bolts in closest metric, easy.
Strangely enough, as a metric guy from birth, I see the logic in the imperial system. Always so easy to splitt or multiply. Metric 10 splitt in half just once and you ar in odd numbers (trouble) already. 

Rudy


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## bouch (Jun 6, 2019)

bigearl91 said:


> Heres the howler:
> 
> 
> 
> ...



My gut instinct is to scrap bin the part and start over.  Starting over will make sure you have it right.  If you have a questionable fix, you might do a bunch more work just to find out that the piece is junk.

You're really not that far into the work on this part, its not like it was the final hole you drilled in the wrong place.  If that was the case, I would try to save it, but you have a lot more work to do on this part.  

Sometimes, at the end of the day all you've made is a pile of chips and a piece of scrap.  For example, I'm slowly working on a PM Research #5 "Coke Bottle" engine.  I made 3 crankshafts before I got one that was right...

Mike


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## bigearl91 (Jun 6, 2019)

Thanks for speaking sense Mike!

Oddly, she never has much interest in my hobby but her immediate reaction was exactly what you just said. Why potentially waste more time and then its still a write off!

Now I have done it all once it should be quicker the second time round. Lessons learned! It is only basic machining processes too, some fac milling drilling and boring. Just need to be a bit more vigilant next time!

Cheers
Earl


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## bigearl91 (Jun 6, 2019)

Rudy said:


> I did mine in metric since me and my tools are metric, but I just calculated all the measurements to mm. Lot o extra work and a lot of odd numbers to keep track on. All the bolts in closest metric, easy.
> Strangely enough, as a metric guy from birth, I see the logic in the imperial system. Always so easy to splitt or multiply. Metric 10 splitt in half just once and you ar in odd numbers (trouble) already.
> 
> Rudy



Yeah im mostly keeping it imperial but it is definitely going to end up a hybrid


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## Brian Rupnow (Jun 6, 2019)

Sorry Earl--I don't know that engine well enough to see what it is that you have done wrong. I have made some amazing "saves" over the years on engines I have been working on. Something you will learn as you build more engines.--Never back up. Once part way into a project and you screw something up---Fix it and carry on.


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## bigearl91 (Jun 6, 2019)

I will sleep on it and see how I feel tomorrow. Early start for a big day. Cut today short after realising this error in order to get everything recharged for a big shift. Generating that 440v 3 phase (for the mill) really takes its toll on the setup...

Lets see what tomorrow brings...

Cheers again
Earl


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## Rudy (Jun 7, 2019)

Making this, and other bar stock engines has that benefit that you can make parts over and over again. My first project, a Stuart 10V built from castings, there where no way back and I was a bit intimidated by that. Did some of the parts on my Farm Boy 3 times... (BTW, the valves and fly wheel collets).
Rudy


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## bigearl91 (Jun 7, 2019)

Well my  gut said to just start again so that's what happened - I am not where I would like to be but I did more than I expected today. Apologies if some of this feels like Top Gear on Dave.

Whilst I was starting again squaring off the stock, I decided to square off 3 sides of the remaining chunks which will later become the frame rear and water hopper.




In the interest of saving money by buying the stock at one size, it shows just how much needs to be removed!




Placed next to the scrap piece you can get a sense of what about needs to be taken off




After my first cut, measured and the DRO set so it's simply a case of working toward the 3.0000" mark - double checked on final cut and it came in perfectly. Rotated 90 degrees on the Y axis and did the same. Then rotated 90 degrees along X axis and worked to 2". Came in a hair under at 1.998" I am very surprised at the finish this facemill is giving, and the linear patterns to bother me and most of this will end up in a rubble sack as chips...







This time marking out the centre point before drilling:







Indicating it in on the 4 jaw - using my "premade" test bar.




Halleluyah the dimensions are spot on this time. The scrap in the background there...




I have to say I am very pleased with this marking out. I just recently got the height gauge for a very reasonable £39 and it looks brand new! Few important lines marked up. And then on wards with more chip making!




Auld ripper.








And unfortunately, on that last photograph is exactly where it got left. I had given the battery some abuse almost continually today for around 6 hours. At one point I was drawing around 250A when face milling - the terminals on the cells themselves were cooking! I think we are looking at a good 21hr recharge on it but hopefully be ready for a go on Sunday! And with much less of a tough day I might get more than 6 hours out of them - I couldn't even finish hoovering today!

Thanks again for reading

Earl


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## bigearl91 (Jun 7, 2019)

bigearl91 said:


>



Just having a look over this post and it goes to show that taking a break and looking over your progress can help reevaluate the method you have planned.

Change of plan with this first cut... 

Earl


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## Mago (Jun 7, 2019)

I cheated.
I made the conrod complete with cap and bored big end.
Then had a friend with a wire cutter remove the cap, finished.
The wire cut is only a few thous, just enough to nip up the big end bearing.

Mago


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## bigearl91 (Jun 15, 2019)

Mago said:


> I cheated.
> I made the conrod complete with cap and bored big end.
> Then had a friend with a wire cutter remove the cap, finished.
> The wire cut is only a few thous, just enough to nip up the big end bearing.
> ...



Part of me thought about doing something like this too. I kind of wish I had but I don't really have anythign thinner than a 18 thou slitting saw (could have shimmed it though). I have found that any time I try to execute a "better" idea of my own, I find out there is a reason it was designed a certain way! 

Cheers
Earl


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## bigearl91 (Jun 15, 2019)

Ok so, back home after a quick week away with work. Got pretty much straight back into it.

Spoiler - I had another challenge with the frame front. However I think I have adequately worked around the issue...

After some thought, and a change of plan, as mentioned earlier. I wanted to remove the next lot of material with the frame laid on its side. This way I could also drill the holes to hold the hit and miss mechanism at the same time.

As far as I know, the quicker way to remove material is saw, then drill. Then the rest.
First thing after setting on the work piece and indicating in - some drilling.








Then some roughing - it really does remove the material fast but gives a whore eh finish. Look closely and you can still see the marked out sizes on the work piece.








Never took any photos of the milling but I replaced the ripper for a normal end mill, I had considerable stick out to give clearance from the tool holder. Unfortunately this resulted in chatter and a very poor surface finish. not to worry, this piece is to look cast and not machined. It actually looks like its just another ripper end mill! I later found that the tool had also bit into to work a bit more than I had hoped. again - not to worry.








I finally got to use the Enco boring head I got as a bargain! I have to say. The flat on the weldon shank felt backwards relative to the boring head! but I made it work and can grind something in if needs be, It is worth noting this was the first time since owning this mill I have used a boring head. Previously I had an import mill with an MT2 taper and it was really a completely different experience. The thing felt dangerous! whereas this was rock solid! Similar thing between an import lathe and the Chipmaster but not to the same degree.





First cut.







The difference in the surface finish was mega apparent! single pointed cutting tools to work well!





Bang on with the marked out sizes! delighted.




Again the finish was really good. At this point I realised I was a bit too conservative with my end milling up to the tangent of the radius. Just nipped back over it quickly.











Once I was happy with this, it was time to move onto the small M2 (2-54?) holes for holding the hit and miss mechanism and push rod. Starting with centre drilling to avoid any wander with the tiny 1.6mm drill bits....

4th hole - disaster strikes! (again). Although this time only indirectly my fault. I wanted to use the smallest possible centre drill for the 1.6mm hole so it was finished to size from the surface down. I have a feeling this came as a freebie set with some Asian machine I bought - annoying as I have a heap of British made bits, but this just happened to be the one I grabbed. the tip snapped into my nice sticky aluminium. After some thought (and swearing) I decided to try picking it out. No good. So then I thought maybe I could break the tip by giving it full welly with a centre dab allowing me to drill out the fragments with the aluminium. This merely drove it deeper. So I thought I would just try drilling it out with a 1.6mm HSS bit - we all know this didn't work.

Finally, I had to bite the bullet. It was being removed one way or another and all I had small enough and hard enough was milling cutters. I have a few decent carbide end mills and slot drills -  I did toy with the idea of just having 3 bolts and a fake one - probably would have been fine but then the centre drill wins! And that's not good news. A small 4mm piece of silver steel .225" (actually .220) was turned with an M2 hole tapped through. This was loctited (a real verb?) into the frame. I never looked further down the line as to whether this could cause issues but that's many bridges away.


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## bigearl91 (Jun 15, 2019)

A little counter sinking to aid tapping it in with the toffee hammer.
















.220 dialed in.







Decided to colour the piece in purple as it would have been impossible to find even with all the swarf if it fell.











Overall pretty happy with the bodge. It will be filled in sanded and painted anyway so shouldn't be visible.

You can see those left over cutting marks, my final work on the piece was just cleaning it up for the next set of cuts.











Final task, setup the rotary table for tomorrow.




Thanks for reading.
Earl


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## bigearl91 (Jun 17, 2019)

Little bit more progression this time - chipping away, would like to get this piece laid to rest tomorrow! 

Onwards!

Setting up for cutting the radius:







Award for the most tragic photo:




You can see by the shavings I was being incredibly conservative with the depth of cut, moving the table 0.5mm between cuts, as the setup was asking to grab the workpiece! The way the piece was held in also, JUST didn't let me take that last edge off the left hand side. Nothing a bit of wet and dry can't solve.





And the holes drilled to take the M3.5 bolts - the eagle eyed would notice I took the work off the table, to realise straight away it was exactly the thing I didn't want to do! Reset the piece and drilled away.





Next, flip the work piece and start carving out the cutaway. You can see this endmill is pretty nasty, so I switched out and cut only the final radius'd edges with this. Even with a brand new carbide slot drill I was still getting a fair bit of chatter, with the surface finish clearly showing it. This I believe is pushing the depth a short end mill can cut to (or stick out) as the collet wasn't fully gripping along its entire length.














Then onto the flanges (?) for joining together the frame pieces.











Setting up the workpiece for the final set of cuts other than a hold at TDC on the radius cut. You can see here were I just couldn't finish the cut on the rotary table earlier.





I just took some material away first with a ripper, then back with the boring head.







Cheers
Earl


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## bigearl91 (Jun 18, 2019)

Quick hit,

Just to finish off the most of this frame front, I do have the base mounting holes to drill, along with the holes for the lubricator but I will get those done later on once I have some other pieces made up and a base decided on.

I have to say, my plan is to paint these British racing green, but I could be tempted to polish up and leave as is. Or maybe just paint the hopper or some other combo.

Finished up the boring, was apparent pretty quickly I had milled out the top radius no where near deep enough, but not to worry. Nothing a bit of elbow grease can't solve. I was pretty happy with the finished.

















After a bit of filing and wet and dry paper




And some finishing to remove the blemishes.

















Next, the frame rear...

Cheers
Earl


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## Rudy (Jun 19, 2019)

Grate job Earl! I also considered leave it unpainted. Pity to cover up a good finish. However, when I had the green glossy finish, I was happy with that too. I also considered shrink paint to simulate a rough casting.
Rudy


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## bigearl91 (Jun 19, 2019)

Thanks Rudy, did you need to acid etch primer it first? And can you provide more information on the type of paint you used?

Cheers
Earl


Rudy said:


> Grate job Earl! I also considered leave it unpainted. Pity to cover up a good finish. However, when I had the green glossy finish, I was happy with that too. I also considered shrink paint to simulate a rough casting.
> Rudy


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## Rudy (Jun 20, 2019)

Earl, on aluminium you will always need a good etch primer, and the surface must be sanded down and cleaned thoroughly of cause. I have tried the regular non etch types with bad result. I bought a rattle can with primer, so it's not two component as normally used in car paint shops. Guess there are several vendors for this. Not cheap though.. The paint is "ordinary" car paint on rattle can. Don't think the brand is important. The important part is the primer sticking to the aluminium. Any paint will easily stick to any primer, mostly.
Rudy


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## bigearl91 (Jun 20, 2019)

Rudy said:


> Earl, on aluminium you will always need a good etch primer, and the surface must be sanded down and cleaned thoroughly of cause. I have tried the regular non etch types with bad result. I bought a rattle can with primer, so it's not two component as normally used in car paint shops. Guess there are several vendors for this. Not cheap though.. The paint is "ordinary" car paint on rattle can. Don't think the brand is important. The important part is the primer sticking to the aluminium. Any paint will easily stick to any primer, mostly.
> Rudy



Tremendous Rudy, thanks for the input!

Cheers again
Earl


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## bigearl91 (Aug 25, 2019)

Well after having a couple of months off enjoying the sun I got the itch and decided to continue with the build. I broke myself in gently enough. Not going to go into too much detail as not a great deal has been done but probably put another 6-8 hours in and the frame rear is starting to take shape.

Hogged out the majority of the material:









Rotated to workpiece to continue the material removal. At first I had planned to use and end mill, but decided the facemill was going to be much faster:













And taking down the overall width to 2" up to the con rod bearing cap area. The facemill wasn't really the right tool but I left a couple of thou on to clean up the surface with wet and dry, and this size isn't critical:








You can see the quality of the first cutout (the area held in the vise) but this is cut well undersize with a finish cut to be taken on the 8 degree design slope.




I initially set up the work piece on the angle blocks to cut both sides of the 8 degree slope at the same time to keep things equal. But changed my mind in the end and went with the facemill. I should be able to quite easily rotate the work piece to cut the internal angle, setting it up on the angle blocks again and indicating the surface I have cut during this setup.




You can see the setup isn't perfect but that imperfection can't be felt and will wet and dry out quite easily:




Using the same setup to start boring out the 1.5" dia cutout, that from what I can see also follows the 8 degree angle.








That's it for now,

Thanks for reading.
Earl


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## Rudy (Aug 25, 2019)

Grate work Earl! I'm enjoying the progress. Nice posts.
Rudy


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## bigearl91 (Oct 14, 2019)

Been on holiday between my rotation so only spent 3 days at home in the last 6 weeks prior to Thursday there.

Just a wee update to stop the thread stagnating, no huge progression. Got around 3 hours on it today as I was busy tidying up and improving the lighting around the garage. There's always wee jobs to do in between the wee jobs in between the wee projects of course.

Continued just where I left off, finishing off boring to size. It become very apparent just how much breathing room I had given myself when first hogging out the large cavity/void are (or whatever it could be called)









Work piece turned and again supported on the angle blocks for finishing off cutting out the opened area.





As this was now sat at 8 degrees, and not having 3 arms to be able to ramp this properly down I just cut it close enough. The original material removal was done with the piece sat parallel to the table, where as now tilted up I ran the risk of cutting into that level plane at the bottom of the cut out - knowing there would be a better way to display this rather than describe I called on a friend of mine for some artistic assistance.





I just did what I could knowing that this area was not critical, and probably wouldn't be seen in great detail either - turned out good enough.





Tidied it up with the Dremel and some wet and dry. The piece isn't finished yet so I didn't put a heap of time into it knowing it will be getting put back to the mill for more machining.









Back to the mill for the next cutting operation, which is where I finished up for the day.













Not the best finish to look at but it feels smooth and this will be wet and dried back either for painting or polishing.

Thanks for reading, hopefully get a bit more worked through next up date but I have some projects for work I want to get done - which was actually the reason I carried on with this, to get it bored and out the vice.

Earl


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## bigearl91 (Oct 14, 2019)

Not sure how but I have left a [\URL] in somewhere, cant see where but never mind.


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## Brian Rupnow (Oct 14, 2019)

Earl--I see that you are polishing the aluminum parts. That is a good thing if you plan on not painting the parts. The wax used while polishing will keep those parts from oxidizing almost forever.  Not so good though if you plan on painting the parts. Anything polished will definitely need to be washed thoroughly with paint thinner to get rid of the wax, then scuff sanded with 1000 grit paper to make the paint stay on. I have thirty some model engines setting around my office, and only one of them is painted.--and it is painted with a rattle can of blue automotive paint with no primer.---Brian


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## bigearl91 (Oct 14, 2019)

Thanks for the advice Brian,

If I am so paint these, I will be heavily priming them with acid etch. I will take your advice on board when considering the surface preparation. I am guessing painting  aluminium can be so much hassle that leaving the parts as bare metal is easier but still looks good.

Cheers again,

Earl


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## Brian Rupnow (Oct 14, 2019)

Earl--I was always taught that to properly adhere to aluminum, paint needed a good zinc chromate primer laid down first.  That being said, I've never had a problem with spray on enamel from my local hardware store. A lot of the reason that I don't paint my engines is tied into the way I build them. I assemble my engines piece by piece as I build the pieces. By the time the last piece is finished and assembled, I never have the urge to take everything apart to paint it properly.


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## Steven Tarr (Nov 21, 2020)

It has been a year since the last posting. I am curious to know what the status of the project is as I am in the middle of my own effort. One thing I will mention is Mr. Howell talks about using acetone as a fuel. If you want to do that, don't paint the frame.


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## Engine maker (Nov 21, 2020)

Nice work, Just keep plugging away and one day you'll realize you have no more parts to build. 

One thing about FarmBoys:  If one is good, then two are better. And bigger is always better. I finished this one the end of Sept. I have to get busy on the skid! But with Covid around there's no rush to show engines.


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