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Back to the block and frame. I’m not looking forward to this next step but can’t think of a way to put it off much longer. Those two little 2-56 cap screws are not going to hold this together so my plan is to braze it.

460 Block and Side Rails (Medium).jpg


470 Clamp up (Medium).jpg
 
I have a ton of experience with aluminum, as in I did it once. Ok. Technically twice resulting in one successfully brazed part, and one melted blob of aluminum. With everything clamped up and the MAP at the ready . . . . I’m wondering how much it would cost me to get someone to do this for me. But it’s Sunday and the long weekend . . . .

480 Welding (Medium).jpg


490 Welding (Medium).jpg


500 Welding (Medium).jpg


510 Welding (Medium).jpg


520 Welding (Medium).jpg


530 Welding (Medium).jpg
 
Sorry no pictures of the fire show. I had one torch just aimed through the cylinder hole in the block and another to apply more heat where I was working. It came out pretty go (for me). The only bad blob is up on the inside where it can’t be seen. I bashed it a couple of times and nothing broke so I happy. Cleanup with a file and a little Bondo and paint it should be fine.
 
I was feeling a bit nervous when I started to read about you brazing it together, but it all came out fine. I have seen the aluminium brazing rods demonstrated at various shows, but have never purchased any. It appears that they work very well.

Paul.
 
Hi Paul
YOU where nerves!:eek:
It would not have been a good time for the Doc to be checking my blood pressure. I think I used up almost all of my small scraps of aluminum and 2 rods before I got up the nerve to do it. The stuff does work though if you follow the instructions, like I did the second time I tried it.
You have to use a stainless steel brush to clean everything. I tried a steel brush once and things did not go well.
Hey I have scraps left


Braze 001.jpg
 
It does not work with acetylene (too hot?) but propane and map are recommended. One of the problems I have is keeping everything lined up. It’s not like I can slap a big magnet on the parts and clamps act like heat sinks.



http://youtu.be/oB_TfY9uLIY

I'm doing something wrong. How do you get the YouTube video to show up in a posting?


Braze 002.jpg
 
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The connecting rod has to be split or it’s not going onto the crank. This means I have to make a split bushing for the big end. I also want an oil hole in it so bolting from the back isn’t going to work. This is what I came up with.

535 Con Rod.jpg
 
I got started on the connecting rod by milling a blank down to size.

540 Connecting rod Blank (Medium).jpg
 
After a little scratching and a lot of checking to make sure I had this right in my head I got the blank mounted in the vice at 150 deg. Milled .4440 off the top then spotted, drilled, and counter bored for the two #4x40 screws.

550 Connecting Rod (Medium).jpg


560 Drilling Connecting Rod (Medium).jpg


570 Counter bore (Medium).jpg
 
Now that I have the feeds and speeds figured out I really like using a slitting saw.

580 Cutting off (Medium).jpg


590 Nice (Medium).jpg
 
Tapped the holes as deep as I could go with the 4x40 tap, I want as much screw as I can get here.

600 Tapping 4x40 (Medium).jpg
 
Cleaned up and screwed tougher I drill out the holes that mark the radius for the big and small end of the rod.

610 Bolted tougether and Drilled (Medium).jpg
 
The radius holes are also used to set the angle to mill the rod to width.

620 Setting The Angle (Medium).jpg


630 Cutting The Angle (Medium).jpg
 
With that done I finished up the rod by rounding of the ends on the rotary table. A little more cleanup needed but all that’s left is to ream the two ends to size. Tomorrow I’ll have to tackle the split bearing.
All for today. Germany vs. Algeria starts in an hour and that damn grass just won’t stop growing. :rant:

640 Rounding the Big End (Medium).jpg


650 Connecting Rod (Medium).jpg


660 Connecting Rod (Medium).jpg
 
For the bearings I have some bronze bushings with the correct ID. I picked these up at Princess Auto a while back in their surplus section. Bag “O” bushings for 6 or 7 dollars, I can’t remember now but I could see 2 I wanted at the time and thought I’d use the rest someday. I centered it in the 4 jaw indicating off of the inside. Sorry it’s a bit out of focus.

670 Big End Bearing (Medium).jpg
 
As I started to true up the end I realised this was an Oilite bushing. I’ll have to go with hard brass. Didn’t’ take any pictures. I set it up in the 4 jaw, drilled it undersized (I’ll ream them after everything is together. The plan is to basically make 2 bearings and mill half off.

680 Big End Bearing (Medium).jpg


690 Big End Bearing (Medium).jpg


700 Big End Bearing (Medium).jpg
 
Luckily they both finished spot on .75 so no funky decimal points to get the center.

710 Big End Bearing (Medium).jpg
 
It’s not that I don’t trust digital calipers but when I want to be sure I’m getting an accurate measurement I use a micrometer. I do trust these calipers. My old cheepo set . . . . That would have to be a separate thread.

720 Big End Bearing (Medium).jpg
 
I actually spent a lot of time trying to decide how to hold these in the vise. I’m not sure why. Used a test indicator to make sure the bearing was sitting in the vise correctly and marked the top with a felt pen.

730 Big End Bearing (Medium).jpg
 
Brought the head down until the cutter just scratched off the ink and zeroed my the Z axis.

740 Big End Bearing (Medium).jpg


750 Big End Bearing (Medium).jpg
 

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