Team Build 8

[Path]

Looks like we are missing a part drawing.
I couldn't find anything that holds the Piston Rod to the Beam Links. On page 17 zone A2, "Cylinder Rod End Bushing " is shown that would make that connection, but can't find a drawing for it. The "Cross Head Link Bushing" (actually our item #33) (note that names are different on page 17 vs the rest of the pages) is what we need except shorter. I would suggest that each builder make their own. Same as #33 except instead the length of .808", it would have a length of .510" or more then face off the excess so that there is just a little overhang when assembling.

Comments?

Pat H

 

[dreeves]

Worked for about 3 1/2 hours getting the rockers cut but when I was done I notice something was wrong:wall::wall:. Something must have changed when I flipped them over to cut the pockets. Looks like I have some new parts to make.

 

[chrispare]

Nice setup.
So what is eying with them?
Also how what cnc controller you have that communicates with the laptop?

 

[ninefinger]

Dave,

Could you enlarge the pockets a bit to even the sides out? Might be worth a shot to save remaking them (it is just a cosmetic feature you're dealing with)

Mike

 

[dreeves]

I was thinking about trying to open up the pocket. I have 2 extra pieces to try.

I am using the smooth stepper in the box to allow the use of the laptop along with mach3. Ron ginger could answer questions on the control box. I went to the cnc build in Ann Arbor mi to build the mill

Dave

 

[dreeves]

I think I saved the Rockers. I opened up the pockets by .010 and recut them and looks much better.

I also got the bases mostly done with a little cleanup on them.

Dave

 

[blighty]

looking like a great team build gents......... as i have only just seen this thread i'll have to wait for the next team build.

 

[joe d]

Dave:

Nice save! If you had not mentioned it, none of use would have noticed....
bases look good, too.

I'm still waiting for material to arrive. Patiently. Really, patiently.

Joe

 

[ninefinger]

Dave,

You're too keen - all done already! What are you going to do for the next 3 months while the rest of us get our butts in gear?

I need to go get more material. I've had a change in plans on how I'm making the eccentric strap and need some more material. Thank goodness its only steel and is about as cheap as it gets....the other stuff I bought will just go into the pile of stock material for use whenever. I didn't have any known good steel anyways.

Plus an excuse to visit the metal store is always nice (but costly)!

Mike

 

[dreeves]

I have 70 more parts to do. 30 pins for the rods. 30 center pins and 10 pivot pins. I have to wait on material for them as we'll. I got lucky on the rockers I fixed it the way I should have done it in the first place. Like I said in an earlier post in still on the uphill on the learning curve of cnc.

Dave

 

[chucketn]

I'm working on the rod clevis on sheet 7. I don't see a dimention for over all length. Does this mean it's not critical?

Chuck

 

[Path]

I'm working on the rod clevis on sheet 7. I don't see a dimention for over all length. Does this mean it's not critical?

Chuck

Yes ... I came up with an overall dimension of .707" by scaling up.


Pat H.

 

[chucketn]

I'm working on the rod clevis on sheet 7. There is no overall length dimention given as I can see. Or am I missing something? Is this dimention critical?

 

[chucketn]

I don't see where you came up with that dimention, Pat. Could I trouble you to explain?

Chuck

 

[Path]

I don't see where you came up with that dimention, Pat. Could I trouble you to explain?

Chuck

Sure ...

There several ways to come up with the overall dimension ... all of which will be approximate.

The missing dimension is the distance from the left edge of the .282" and the left edge of the part. Find that and we know the overall length.

One way ... eye ball, the .282 is almost the same distance as the missing, but a little smaller ..guess at say .3" now the overall is .707" could be .7 or so etc.

Another way ... measure the actual distance of the .282" using calipers and eye loop. Measure the missing actual distance then using ratios calculate the missing distance. I used this method then rounded to .3". You may very well come up a different number but close.

Now with that distance you can look at the other parts of the Crankshaft to see how it fits. Using the .707" I came with a few threads showing when I put all the pieces together using SolidWorks.

We will need to adjust the location of the Rod Clevis when tuning the Engine.

Hope is helps ...
Pat H

 

[chucketn]

Thanks for the explanation, Pat.
I guess I'm making this a lot harder than it needs to be. Plus, even though I worked as a draftsman 40+ years ago, and the last 17 as a computer tech, I never got into CAD/CAM or 2d/3d rendering. Experience has taught me not to trust scale in a photocopied or printed drawing.I am probably trying for much tighter tolerances than necessary.
Anyho, I have most of the materials cut except the brass for the bearing.
How would you guys tackle the bearing? Cut 2 pieces and solder together (will soft solder work for that?), drill/bore the bearing hole, and separate? Or drill/bore solid piece and split with slitting saw.

Chuck

 

[ninefinger]

Chuck,

I have on my list of parts 2 sets of bearings to make so I'll tell you how I plan on making them.

I'm going to flaten the mating surfaces of the top and bottom of the bearing (ie cap and base) - this will be the datum from which the other measurements are taken. Then I'm going to clamp them together and drill, then ream the bearing hole. Before removing from the clamp I'll mark them as a matched set (ie 1T and 1B, 2T and 2B, etc), then I'll proceed to work on the profile, and other features.

I guess I could do the profile and other features 1st, either way the "split" is done 1st, then the hole is made with the 2 parts held together. You shouldn't need any solder to hold the parts while making the hole, and the solder won't clean up properly after - leaving you a job of reworking the surfacces and then also re working the hole....

Mike

 

[chucketn]

Thanks, Mike. You guys make this seam so easy.

Chuck

 

[chucketn]

Next question...
So far, the rod clevis's are done, and the rods proper are cut to length and threaded. I'm working on the plate at the end of the connecting rod. It is easier for me to make it as a separate part and either silver solder it myself or have a team member do that for me. I've made the first one, tapped it 2-56 and it just press fits on the end of the rod proper. My question is, is this press fit o.k for silver soldering? Or do I need to open up the fit a bit? (I have only silver soldered 1 part in my life)
BTW, I found a local distributor for Silver Solder, and a hose for my Dad's 60 year old Prestolite torch, so I'm going to have a go at soldering it myself. Still have to go get the solder, flux, and hose. I have my Dad's torch kit, and his acetylene bottle. Hope there is some gas left in it!
And, another first for me, I made and used my first filing button for rounding the ends of the clevis arms. They came out pretty good, if I do say so myself.
Time for happy our with SWIMBO, I'll take some pictures tomorrow of the parts I've got done so far.
Thanks for allowing me to take part in this build. I have learned so much, and accomplished much more than I thought possible already.

Chuck

 

[dalem9]

Hi all Chuck it sound like you are having a good time at this ,that is what this whole team build is all about. Glad that you decided to come along. What size did your rods turn out to be . Pat what are we going to use ,a packing or an o-ring ,and what persent squeeze will their be on the o-ring. Also on the cyl. the exhust hole it shows a 1/8 hole .375 deep also a 5-40 thread . The hole for a 5-40 thread is a number 38 drill .which is .101. Please advise as to what we will use. Thanks Dale