# TB2 - Modifications to the build



## Brass_Machine (Jun 30, 2008)

Base - Will be made thicker and larger footprint to allow for use of cap head screws and some detail work.

Bearings - a threaded 6-32 hole to allow the use of oil cups

Cylinder - 1/2 " longer shaft to allow mounting of the flywheel on the outside.

Extra spacer - Machined to the width of the flywheel to allow flywheel to be moved to the outside of small bearing.

Cam Ring - Machined to allow lettering at the top. Color still undecided

Forks - Wes's idea of a set screw


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## bretk (Jun 30, 2008)

I would Like to offer to donate oil cups if anyone would like them Oil cups have 6-32 thread.







-Bret


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## Brass_Machine (Jun 30, 2008)

I really like those oil cups. I wonder if we can work them in?


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## Powder keg (Jun 30, 2008)

They could go on top of the bearings fine i think? I'll have to look at my print)


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## zeusrekning (Jun 30, 2008)

Oil cups would look good.


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## joe d (Jun 30, 2008)

Yes please oil cups. 

Joe


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## Brass_Machine (Jun 30, 2008)

Changes have been added

 ;D

Eric

I love this job!


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## Powder keg (Jul 3, 2008)

It would be nice for provisions to disassemble the rod forks and the piston from the piston rod. The way it is, they are soldered together at assembly  There is no way to disassemble them. They could probably be drilled for a wire or maybe drilled and tapped to 0-80 or something? What does everyone think?

Wes


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## kvom (Jul 4, 2008)

As for the forks, why not thread the ends of the rod and use two small jam nuts on each end to hold them in place? Adjustment would be easy and once in place the nuts could be secured with blue loctite.


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## bretk (Jul 4, 2008)

Drill and pin won't work as it needs to be fitted at time of assembly to the cam ring for a spacing of .005. as for threading the fork that wouldnt work as you wouldnt be able to spin the fork to adjust it as the retaining ears would get in the way, threading the rod end could be done, although it would induce some wobble in the fork as you would not be able to stabilize the fork on the little stub of threaded rod. There isnt much room for a set of jam nuts either as the piston end moves pretty darn close to the fork at full travel. :-\

-Bret


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## GailInNM (Jul 4, 2008)

What I had thought of doing on my existing engine was to change the fork to widen the slot for the rollers and insert a PTFE keyed washer on each side of the roller to act as flanges. Cut down the fork length so it is the same as the roller on the end nearest the cam. Then the pins could be removed and the washers and rollers removed to remove the cylinder assy from the cam ring. This still does not let you disassemble the piston from the cylinder.

Since this is a new build, it would be possible to change the internal dimensions on the cam ring to allow the piston rod to be lengthened by about 0.160 overall so the ends could be threaded and a THIN jam nut used against the ends of the fork. But to do the job right, one end of the rod should be right hand threads and the other left hand threads, and the forks and jam juts would also have to be left and right hand pairs. Otherwise you would be limited to adjustments of half the pitch of the thread. All the other parts, bearing blocks, base, etc could remain the same. I have not started the cam rings yet, so this change is still possible up until then. I think that making left handed nuts and threaded forks and piston rods is probably more work than it is worth.

I have attached a drawing of what I would do as far as modifying the fork and the guide washers. I have not tried this, but I think that it should work OK.


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## joe d (Jul 4, 2008)

I was thinking that maybe we could turn the bottom of the fork (the part with the hole to be soldered on the shaft) thread it, slit it vertically with a really thin-kerf slitting saw, and then use a thin-profile nut on it as a compression type fitting? If we do enlarge the ID of the cam ring this would allow a little bit bigger nut as well. (We do have a whole 1/8th of an inch to play with, after all....)

Joe


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## Powder keg (Jul 4, 2008)

I don't think it would be good threading the piston rod. The only adjustment you would have is a half turn at a time. Could the forks be made a touch thicker on one side and be drilled and tapped for a setscrew? This would let you adjust the legnth. 

Wes


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## kvom (Jul 4, 2008)

My suggestion on threading the rod did not include threading the fork. If the hole in the fork is equals the diameter of the rod, then there is unlimited adjust, not half a pitch.

I had another wacky idea in thinking about this, so here goes (ignore if ridiculous):

The fork has to be held in place for two reason: keep the wheel tracking the cam ring, and to maintain the correct length. If the wheel were to be notched to fit the ring, it would track itself and prevent the fork from rotating around the rod. Therefore the only adjustment to the fork is proper distance. So thread the end of the rod and use a jam nut to press the wheel against the cam.

To do this might require widening the fork and wheel to fit the cam, or rounding off the inside of the cam surface.


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## GailInNM (Jul 4, 2008)

I like Wes's idea about a setscrew. There would only be a minor change to the fork and nothing else would change. Use a flat tip set screw so the shaft does not get a a dimple in it that the set screw would try to go into during adjustment. 

Gail in NM,USA


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## Powder keg (Jul 4, 2008)

There could also be a small flat on the piston rod to keep things from turning. I like the idea of the flat bottomed setscrews. If the piston is not removable, I don't see that as a problem. I mainly wanted to be able to take it apart for cleaning. 

Wes


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## bretk (Jul 4, 2008)

You know, not meaning to sound like a bunch of sour grapes, but as the person who brought this item up specifically as a reason to upsize the engine, this would have been all alot easier if we upsized the engine......... :big: :big: :big:

If you twist my arm : I can order a 3-C 5/16" square collet too. 

I like the setscrew Idea too. I think starting with 5/16 Square stock instead of 1/4" square stock will give me plenty of meat for the setscrew hole. I may even plan to use a SS hex head bolt for the setscrew. Nice look. 

The roller axles will need to be longer though..


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## Dick L. (Jul 5, 2008)

I shipped the brass pieces to Kirk and Eric last Wednesday..... I don't have any larger dia. in that amount.They could be dedicated flywheel builders and use it for a future build. ;D
 Being my first one..... are we waiting for a close to critical dimensions mods before we start machining? I don't want to make wrong size parts. 
       Dick


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## kvom (Jul 5, 2008)

Given that Gail's engine runs with no flywheel, the flywheel dimensions see pretty non-critical. Even if the engine is scaled up some we could keep the flywheel dimensions the same, or just thicker.


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## Dick L. (Jul 5, 2008)

Not much thicker Kirk, I cut to length to be sure I had enough to get all the pieces. There is an extra .100" for facing and squaring. ;D
 I was thinking of proportional appearance really not functional. Good point that it really isn't even needed.
            Dick


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## kvom (Jul 5, 2008)

Dick,

Since I'm such a newb I think I can plan on messing up at least one :-[ If I run out I'll buy some extra stock locally.


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## Dick L. (Jul 5, 2008)

Can we do a sectioning job on the cam ring so that we could use the threaded piston rod and fork idea? Adjustment could be done in the gap ,then loctite with a light grade (242 blue) if no room for a jam nut.I've attached some pdf to show what I mean. Dick 

View attachment Cam ring insert.PDF


View attachment Cam Ring Assembly.PDF


View attachment cam ring.PDF


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## Powder keg (Jul 5, 2008)

I like that idea Dick, But for that to work the we would need left and right handed threads on the ends of the piston rod and the forks. With out that, the adjustment would be a half turn at a time and on this little guy, too much or too little, I think. I think a setscrew will be easier. Plus if we use a hex head bolt, it wont look bad)

Wes


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## Dick L. (Jul 5, 2008)

Hi Wes, yes it would take a bit of hassle to achieve. I've just been playing with the models of it as I go based on some things we discussed. The set screws will be fine on a small model this size with no real load. I'm hoping to build one complete as well as the team build which is why I'm modeling it. I'm sure I will try a few different things along the way.I'll be very interested in everyones setups and fixturing for their different pieces. 
             Dick


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## Powder keg (Jul 5, 2008)

Forgot to add. Those drawings are awesome Dick!!! I like the removable insert at the bottom. I drew the cam ring up with Master cam. I scaled it up to 3X its original dimensions. I talked to my boss and he said I could mill a couple of them out after work one of these days) 

Wes


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## te_gui (Jul 8, 2008)

Was someone going to redraw this with our proposed mods in place or are we ready to start building? I thought I had seen someone volunteer...

Brian


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## Dick L. (Jul 8, 2008)

I think what we need is a list of modifications that we are all aware of. So far the base is thicker, we are using oil cups, possibly an angled hole to fasten the flywheel,and set screws on the forks I think .
 I was playing with the cam ring to see what else might work easily. I have drawn a lot of this engine but with no regard to changes (what I've mentioned is cosmetic) because as time allows I want to build another one complete.
I had also planned on using a small oilite bushing on the small bearing end I'm making and allowing it to be slightly above the surface on on side to act as a thrust bearing , keeping the valve body in arrangement.
                           Dick


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## kvom (Jul 8, 2008)

> possibly an angled hole to fasten the flywheel


First I've heard of this ???

In any case my instructor seems agreeable to me making the flywheels as an in-class class project.


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## GailInNM (Jul 8, 2008)

I am ready to make the cams when I am sure that all the dust from modifications has settled. I don't want to lock anybody into anything that they are not comfortable with. 

I drew up a modified cam ring with just a cosmetic modification to it. It would not affect any other part. I drew in two different forms. One is aluminum with CNC engraved lettering and filled with black lacquer stick and the other black anodized with the lettering laser engraved into the anodized surface. The anodized one depends on if I get my anodizing tank set back up. I have everything on hand for the anodizing, just need to set it up. I used to do, but quite a while ago.

Let me know what you would like. I would like to make them all the same. 
1. Standard to Elmer's Drawing
2. Aluminium with engraved and filled letters
3. Black anodized with laser engraving

Gail in NM,USA


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## Dick L. (Jul 8, 2008)

I think what happened was a lot of discussion happened here in the original thread...
                          Dick
http://www.homemodelenginemachinist.com/index.php?topic=2335.15


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## kvom (Jul 8, 2008)

I for one like the black annodized version.


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## bretk (Jul 8, 2008)

That aluminum one sure looks nice with the black filled letters ;D


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## Powder keg (Jul 8, 2008)

I vote for the aluminum one with the black letters also)

Wes


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## Brass_Machine (Jul 8, 2008)

I am up for either of the cam rings!

Eric


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## Brass_Machine (Jul 8, 2008)

Dick,

Could you please explain a little about the oilite bearing for the small end? What did you have in mind so we can add it to the list of modifications?

Eric


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## Dick L. (Jul 8, 2008)

Instead of just using the aluminum as the bearing surface I propose inserting a 3/16 id 5/16 od oil lite bushing in the small end bearing. If you look on page 219 of the plans on the top view the flywheel sets the sideplay of the valve body in the big end bearing. By using a bushing in the small end and leaving it above the surface slightly it will provide a thrust surface for the flywheel hub to contact keeping the drag off of the flywheel rim and the forks and cam ring. Hope this helps. I can do a drawing if it's still not clear. But I can't do it right now.          
             Dick


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## Brass_Machine (Jul 8, 2008)

Dick L.  said:
			
		

> Instead of just using the aluminum as the bearing surface I propose inserting a 3/16 id 5/16 od oil lite bushing in the small end bearing. If you look on page 219 of the plans on the top view the flywheel sets the sideplay of the valve body in the big end bearing. By using a bushing in the small end and leaving it above the surface slightly it will provide a thrust surface for the flywheel hub to contact keeping the drag off of the flywheel rim and the forks and cam ring. Hope this helps. I can do a drawing if it's still not clear. But I can't do it right now.
> Dick



No need for the drawing just yet. Though we may need them for the people doing the bearings when it comes time for them to build. I understand what you are saying. How would it interfere with the oil cups? would the just become ornamental then or do we drill a small hole in the bearing to allow for oil flow? 

Also, would we want a bearing on the big end too?

Eric


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## Dick L. (Jul 8, 2008)

Eric , On the small end it won't interfere with the oil cups at all. On the big end the strap of aluminum above the bore is only 1/8" . That is why I asked about making them a little taller when the oil cups were agreed on. No need to increase the height just for the cups but if you want a bearing on the big end too we would have to make them taller. I would want a matched set myself so I would change both (taller) or none.
              Dick


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## joe d (Jul 8, 2008)

Dick L.  said:
			
		

> I would want a matched set myself so I would change both (taller) or none.
> Dick



That's my outlook too, it would look a little odd to me with them asymmetrical. Putting the oilite bushings in seems like a good idea to me too. Presumably just a question of drilling through the bushing for feed from the oil cups? Regarding Gail's cam rings, I like the anodized one best, but will bow to the group decision what ever it turns out to be!

Joe


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## Dick L. (Jul 8, 2008)

Almost forgot, I like the aluminum with filled letters. 
            Thanks,
            Dick


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## GailInNM (Jul 8, 2008)

The oilite bushings are porous and impregnated with oil. There is no need to drill through them for oil. If you drill up to them, light oil will be absorbed by them if necessary, but generally they have a service life of several years of continuous service with out requiring any additional oil. 
Gail in NM,USA


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## BobWarfield (Jul 8, 2008)

Personally, I'd pass on the oilite bushings. If the group wants 'em, I'll build 'em, but they don't do much for me. It's an extra complication is all.

Cheers,

BW


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## Powder keg (Jul 8, 2008)

I think Bob is right. This thing is so small it will probably never get wore out. Especially with the oil cups)

Wes


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## ksouers (Jul 9, 2008)

For the cam ring, I like them both! Can I get anodized on one side and polished on the other?? Just kidding. My vote goes for the black lettering.

Early on lengthening the small bearing shaft was mentioned as a possible mod, so the flywheel could be moved outside the bearing. Is that still a go?


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## Brass_Machine (Jul 9, 2008)

ksouers  said:
			
		

> For the cam ring, I like them both! Can I get anodized on one side and polished on the other?? Just kidding. My vote goes for the black lettering.
> 
> Early on lengthening the small bearing shaft was mentioned as a possible mod, so the flywheel could be moved outside the bearing. Is that still a go?



Yup


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## Dick L. (Jul 9, 2008)

Lets not forget that is we choose to move the flywheel outside we need to have a spacer inside the bearing blocks to keep the valve body located.
                              Dick


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## te_gui (Jul 9, 2008)

Or the base could change to accommodate that. This is why I was thinking we should pull all the ideas together and have someone cadualate (my term) them up for review.

Brian


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## zeusrekning (Jul 9, 2008)

te_gui  said:
			
		

> Or the base could change to accommodate that. This is why I was thinking we should pull all the ideas together and have someone cadualate (my term) them up for review.
> 
> Brian


Hit the nail on the head there. I highly recommend going this route.
Tim


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## Brass_Machine (Jul 9, 2008)

Dick L.  said:
			
		

> Lets not forget that is we choose to move the flywheel outside we need to have a spacer inside the bearing blocks to keep the valve body located.
> Dick



One step ahead Dick. I added that to the list of mods in my first post yesterday 

Eric


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## Brass_Machine (Jul 9, 2008)

zeusrekning  said:
			
		

> Hit the nail on the head there. I highly recommend going this route.
> Tim



You up for that Tim?

Eric


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## zeusrekning (Jul 9, 2008)

UHH, Well. Sure. As long as no one needs to start this weekend  I am slammed with work in the home shop and at work. If you or someone could compile me a nice list of modifications and PM them to me I should be able to get new drawings made up no problem. You could post the list and let everyone else verify what we are shooting for before I start.
Tim


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## Dick L. (Jul 10, 2008)

I have it modeled up with the flywheel outside the bearings, and the oil-ite bushing in the small end . Also the sleeve to take the place of the flywheel for retaining valve body position. This should give an idea of how it will appear.
         Dick 

View attachment TB2 assembly.PDF


View attachment TB2 assembly2.PDF


View attachment TB2 assembly-section.PDF


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## Dick L. (Jul 12, 2008)

Just saw this link Wes posted in another thread .

http://cedesign.net/steam/coomber.htm

 What do the rest of you think of re styling the bearings a bit so they aren't so plain and square. I was thinking something like on this link. Especially if the flywheel is moved outside. Your thoughts? 
    Dick


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## rake60 (Jul 12, 2008)

Dick L.  said:
			
		

> Just saw this link Wes posted in another thread .
> 
> http://cedesign.net/steam/coomber.htm
> 
> ...



Dick the guy that owns that web site is a senile old buzzard!
We call him Steve. 

I'm not a participant in the build, but I like the idea!

Rick


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## Cedge (Jul 12, 2008)

rake60  said:
			
		

> Dick the guy that owns that web site is a senile old buzzard!
> We call him Steve.



I gotta take this from a guy who proudly lives in a town that annually celebrates over sized rodents?.... Sheeeeesh!!!. uh.... forgot what else I was gonna say. :

Steve


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## Bogstandard (Jul 12, 2008)

Steve,

That's the senility setting in.

Bogs


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## Brass_Machine (Jul 12, 2008)

Cedge  said:
			
		

> ...
> uh.... forgot what else I was gonna say. :
> 
> Steve



Steve,

They have medicines for that now! :big: :big:

Eric


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## Dick L. (Jul 12, 2008)

Hi Steve, What a great engine you have there! I really like the brass inlays and contouring, right down to the wood lagged cylinder. Thanks for sharing that! I know we're just starting out with the Team Builds and not everyone can't participate all the time, but it would be great if at some point we can get to that level of BLING ;D.
      Dick


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## Cedge (Jul 12, 2008)

Thanks Dick, but I'm not the one to credit on that one. It was an engine I got in trade from a recently joined member of the board. He bout it on Ebay from the guy who did the CNC work that made all those e curves and inlays possible. I just managed to get a good deal. 

Steve


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## rake60 (Jul 12, 2008)

Cedge  said:
			
		

> I gotta take this from a guy who proudly lives in a town that annually celebrates over sized rodents?.... Sheeeeesh!!!. uh.... forgot what else I was gonna say. :
> 
> Steve



LOL
Sorry Steve, I couldn't resist!
Perhaps it the senility of living so close to a groundhog showing. ???

Rick


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## Brass_Machine (Jul 13, 2008)

Brass_Machine  said:
			
		

> Base - Will be made thicker and larger footprint to allow for use of cap head screws and some detail work.
> 
> Bearings - a threaded 6-32 hole to allow the use of oil cups
> 
> ...



So these are the modifications to date. I have left out the oillite bearing on the small end. Look them over. I want to firm these up and get started on our build.

Eric


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## BobWarfield (Jul 13, 2008)

Looks good to me. What is the thinking on a target due date? 3 months like the last one?

This is really a unique looking engine. I'm looking forward to it.

Cheers,

BW


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## te_gui (Jul 13, 2008)

Can anyone confirm if the hole pattern in the base is gonna change as a result of moving the flywheel? I see talk of a spacer, but if it simplifies things I can move holes. I haven't studied the plans to completely understand what the other changes might entail. I am OK with a 3 month build time, I am hoping to avoid my normal procrastinative tendencies and knock them out earlier so I have time to do the bling polish.

Brian


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## joe d (Jul 13, 2008)

Looks good to me. I'm up for a three month build as well. Te_gui/Brian: Once you've finalized the size/layout of the bases, would you post or PM me the details so I can plan the wooden sub-bases?

Joe


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## Brass_Machine (Jul 14, 2008)

te_gui  said:
			
		

> Can anyone confirm if the hole pattern in the base is gonna change as a result of moving the flywheel? I see talk of a spacer, but if it simplifies things I can move holes. I haven't studied the plans to completely understand what the other changes might entail. I am OK with a 3 month build time, I am hoping to avoid my normal procrastinative tendencies and knock them out earlier so I have time to do the bling polish.
> 
> Brian



Hole pattern stays the same.

Eric


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## Dick L. (Jul 16, 2008)

Is it safe to do the bearings now? From what I see they will be as drawn with the addition of the 6-32 threaded hole for oil cups. 
           Dick


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## Brass_Machine (Jul 16, 2008)

Dick L.  said:
			
		

> Is it safe to do the bearings now? From what I see they will be as drawn with the addition of the 6-32 threaded hole for oil cups.
> Dick



Yes sir


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## ksouers (Jul 16, 2008)

Do we have dimensions for the shaft mod yet? The plans call for a 3/8 inch flywheel. I'm thinking just add that.

Someone also mentioned putting a hub on the flywheel to avoid cross-drilling the circumference.

Materials arrived last week so I'm itching to at least build a prototype.


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## Brass_Machine (Jul 17, 2008)

ksouers  said:
			
		

> Do we have dimensions for the shaft mod yet? The plans call for a 3/8 inch flywheel. I'm thinking just add that.
> 
> Someone also mentioned putting a hub on the flywheel to avoid cross-drilling the circumference.
> 
> Materials arrived last week so I'm itching to at least build a prototype.



I think 1/2" extension would be better. The material that was donated for the flywheels really wont allow the hub.


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## Brass_Machine (Jul 17, 2008)

To give us about 3 months of build time, we should be shipping these parts in the last half of October.

I need everyone to PM their address so I can set up a distribution schedule. For our members who are out of the US, they will only have to ship to 1 address and in return, they will receive all their parts in one box.

Eric


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## ksouers (Jul 17, 2008)

Thanks Eric.

Shaft will be made +.500 longer for an overall length of 2.531


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## Dick L. (Jul 17, 2008)

Dick L.  said:
			
		

> we are using oil cups, possibly an angled hole to fasten the flywheel,                          Dick


 
  I had mentioned drilling the existing hub on an angle to avoid the hole in the periphery .
               Dick


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## Dick L. (Jul 17, 2008)

Forgot to mention the recess is only 1/32" on the plans. If we increase that recess it will be easier to put in on an angle and break out on center. 
      just a thought,
           Dick
I think deeper recess would look better too.


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## kvom (Jul 17, 2008)

I showed the flywheel blanks to my shop instructor for advice on the best ways to machine them. He too suggested an angled hole for a set screw.


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## kvom (Jul 21, 2008)

I faced all of the flywheel blanks yesterday. The thickness of the 8 blanks runs from .450 to .521". If the shaft extends .5" beyond the bearing, does it make sense to narrow all of the flywheels to .375, or can we leave them wider? On my other thread Powder Keg stated that some might want the flywheel inside, in which case they would need to be .375.

Personally I would prefer a heavier flywheel and a slower running engine. I think I will keep mine wider and outside, but can do whatever everyone else wants. With a wider wheel the indentations can be deeper than 1/32", which I think might look better.


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## ksouers (Jul 21, 2008)

Kirk,
If you don't mind, I'll take a wider flywheel. Not that I know you'll be making _my_ flywheel.

One possibility is make them all wide and let the final owner thin it down if they want it inside.

Hmm, just a thought... if someone wants the flywheel inside will there be any interference with an angled grub screw?


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## kvom (Jul 21, 2008)

Eric is doing the other 8, so until he knows the thickness of his blanks we won't know how thick all can be. In the meantime I won't cut any more off, and will just drill/ream the center holes when I get machine time at school.


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