Team Build 8

[Path]

Chuck,
Glad you are with us and having fun.

If I understand you correctly ... you threaded the keeper 2-56 but not the rod.
So the fit is not a threaded. That's probably okay, the fit needs tight enough so it doesn't move during heating. You want a .002 -.004" clearance for the melted solder to flow around the threads. In this application a little will go a long way doesn't even have to be all around the thread ... low forces. Let gravity do the work by placing a small piece of solder on the flat surface (not at at rod junction), with the keeper up in the air and the torch at the junction of the rod/keeper. (maybe a picture would help this description )

The important part of the soldering is cleaning. I would not use acetylene ... just too hot especially with these small parts ... burns the flux off before the pieces are at the proper melting temperature. I use Mapp gas.
Try some sample like parts before using the good ones, so you can get some practice.

If needed I can solder mine or the groups.

Hope this helps ... can go into more detail in needed.

Dale,

I will look into the o-ring and get back to you later today.
I would use the #38 drill at a depth of .375" then tap 5-40 at a depth of about .12 or so. The builder can decide what style exhaust they want.

Pat H.

 

[Path]

... . Pat what are we going to use ,a packing or an o-ring ,and what persent squeeze will their be on the o-ring.... Please advise as to what we will use. Thanks Dale

Dale,

Okay ...

Changes are based on using the AS568-007 O-ring, which is for the .187" rod. <<< TYPO S/B .157"

The current squeeze is over 30%, the recommended squeeze is 5 -10%. If we aim for the 10% then the hole for the o-ring (Top Cylinder head) would need to be change from .250 to .282". That requires the mounting holes for the Packing Glad be changed the same amount (from .187" to .203"). This is where an issue becomes apparent. The mounting hex screws heads and washers for the Top Cylinder Head may not have a enough room to rotate. However, the Hex screws and washers could be trimmed a little to provide additional room. Or use a Socket Head Cap Screw that would also provide additional room. With these changes corresponding changes would be needed for the Packing glad, plus the insert length changed from .250" to .205".
Other little wiggles here and there could be done so that the O-ring could be used.

There is nothing wrong with using packing material for air sealing .. they do leak a little and may require more maintenance. But for this application it probably would work just fine.

Since you are making all these parts I think the final decision should be yours, if that is okay.

If you do decide to go with the O-ring I would be glad to make drawings and send you the pdf file. Also you may want to make a Packing Glad and Cylinder Head (or part of one) to see how the screw holes actually line up etc. before making 10 of each.

Comments and discussion welcomed

.

Pat H.

 

[chucketn]

Here's what I have so far.

http://i571.photobucket.com/albums/ss157/chucketn/DSCF1344.jpg

The top is as the rod will be assembled, with the flat piece soldered (just pressed on at the moment), the clevis threaded on. The small holes in the flat piece are tapped 2-56.

I have used a very fine file to debur all the parts. I don't have a clue on how to polish them any better. Wire wheel?

Chuck

 

[dalem9]

Chuch they look good to me ,nice work . What size is the rod. If you want to polish them more get some buffing conpond from an auto parts store , and a peice of leather an buff it . Pat I do not need a drawing i have it prety much figured out for the o-ring Thank to all. Dale

 

[chucketn]

Dale, the rod is plain jane 3/16" crs from Fastenal. Thanks for the "looks good". I plan to go over the ends with a seel and a brass wire wheel, and maybe buff them. Not sure yet. Still got to get the stuff for silver soldering. Have you guys seen my posts about silver solder technique? My last post to that thread wxplains what I have, and what I need.

Chuck

 

[Path]

Chuck,

Great looking work!

See post 201.

Pat H.

 

[dreeves]

Looks great chuck. The brown truck it dropping off the material I need to get the rest of my parts complete.

 

[dalem9]

Pat I am confuesed , Has there been a change in the plans that I am not awere of . The plans that I have show the piston rod at .157 . The 007 o-ring will not work with a .187 rod . The 007 o-ring has an .070 cross section . We will have to go to an oo8 o-ring and make changest acordingly . Please let me know and I will redesign the head too . Thanks Dale

 

[chrispare]

Well I hope the piston rod is not suppose to be .187 as I have got them done to .157

Just looking at the plans, is Pat looking at the steam chest or the cylinder head and piston rod.


Chris

 

[Path]

Dale and Chris

My bad typo error ... rod is .157" not .187" :wall:
See changes in the thread #202

Take a look at the rest of the paragraph for suggested changes.
Sounds like you want to use the O-ring.
As with any changes there is a risk that something won't work the same without some testing first.


In passing it looks like the Steam Chest and Valve Packing Gland could be changed to an o-ring. That would make it easier because it would eliminate the threads.

Joe any thoughts?

Pat H.

 

[dalem9]

Pat Chuck has the rod at .187 I will redesgne the head to use the rod that he has already made .This should be no problem seeing that I am making the head and gland . Please let me know if this is o.k. Thanks Dale

 

[Path]

Well I hope the piston rod is not suppose to be .187 as I have got them done to .157

Just looking at the plans, is Pat looking at the steam chest or the cylinder head and piston rod.


Chris

Dale


What ??? ... I read that he has made them at .157"

Pat H.

 

[dalem9]

Pat Check post 205 . Thanks Dale

 

[dalem9]

Mow I see 209

 

[dalem9]

Pat Chris is making the rods not Chuck Dale

 

[dalem9]

O.K. So .157 An 007 O-ring it shall be . Dale

 

[chucketn]

Hey folks, I went out today and bought fire brick, solder, flux and a hose for my Presto Torch set I inherited from my Dad. I'll be trying my hand at silver soldering tomorrow! Wish me luck!

Chuck

 

[chucketn]

Soldering still on hold! Went to open the flux that came in the kit and the bottle (plastic) shattered in my hand! After a panicky call to the manufacturer for MDS info, we worked out a replacement. What a mess! Guess I didn't get poisoned though, and my hands haven't fallen off yet!
In the mean time, planning for the next part, the connecting rod bearing.
I plan to buy a piece of brass for this part as the brass I have would take a lot of cutting and milling to get to size.
I do not have any reamers. Can anyone sugest a beginners set of reamers and sizes? Do I by just the one required or a set? 1/4" seems to be used a lot in model engine building. I know I could bore the part but looking for the easiest way. What size hole/reamer?

Chuck

 

[maverick]

Chuck,
To bad about the flux bottle, glad your hands haven't fallen off.
The crankshaft stock I'm using is .2502 but will have to be polished a bit.
I'd say use a 1/4" reamer and see how a 1/4" end mill shank fits. If too tight,
we polish the crank a little bit. If too loose, file a bit off of the bearing halves.
As far as buying a reamer set, I just buy the size for the project. You'll end up
with more sizes that get used that way.

Regards,
Mike

 

[chucketn]

Woohooo! Sucess! I got the new replacement kit from Harris(Lincoln Electric) today. Took it to the shop and soldered up the connecting rods. My military electronics soldering experience served me well. Got all the rods soldered and cleaned up. I am sooo pleased with the results!
Next is the brass bearing and the keeper plates and Bob's yer uncle!
Celebrating with an adult beverage! Even wearing my lucky "How do you like your Dickel" t-shirt!

Chuck