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Winner Pm Research Engine #7
- Thread starter tomw
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- Oct 21, 2014
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- 2,163
Nice work on the cross heads and the cross head slides, I did get my slides done, Then have been to busy to do many things, Did get my now z axis in and installed What a difference the extra inches make. Now I just have to tram it, so I can use it. But will have to wait a week or so. As I have a trip to Ohio starting tomorrow. You are going to be finished before I get the base finished. at this rate.
- Joined
- Jan 24, 2015
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- 239
Jumps4, thank you for the nice comments. The primary reason for the B & W photos is to reduce their file size without reducing clarity. Color takes up lots of bits. But, I also like the look.
Ken, congrats on getting the taller column. It really does make a word of difference. Not only can you do taller set-ups, but you can use a co-axial indicator. Have fun in OH.
Cheers,
Tom
Ken, congrats on getting the taller column. It really does make a word of difference. Not only can you do taller set-ups, but you can use a co-axial indicator. Have fun in OH.
Cheers,
Tom
- Joined
- Jan 24, 2015
- Messages
- 239
Today's post will be short and about the drive, or crank, shaft.
The first order of business was trimming the shaft to the correct length. The 1/4" round stock provided was only 60 thou or so over, so I just faced it off in my lathe and put on a bit of chamfer.
Next was machining the flats. There are two flats on each end of the shaft. They are placed 90° from each other. In other words, when you machine the second flat, you have to rotate the shaft 90°, or half a pie. Mmm, pie...Anyway, upon these flats ride the grub screws that secure the crank throws.
To accomplish this, I used a set of two v-blocks and my vise. First I used one v-block, with the shaft clamped using the outer clamp position on the block. This was placed in the vise with the block positioned so the shaft was against the fixed jaw of the vise and the v-block clamp was beyond the edge of the vise. I then machined the flat to the specified dimensions.
Milling the flat on the crankshaft. Note the v-block clamp extending just beyond the fixed jaw of the vise.
I then released the v-block from the vise and rotated 90° so the v-block now faced up. I left the shaft clamped in the v-block this entire time. A matching v-block and block camp was now added to the set up to support the end of shaft that needed machining, and the whole set-up was re-clamped in the vise. The flat was then machined.
Here I have added another v-block (part of a matching set) and am milling the other flat.
This process now seems really obvious. Unfortunately, it was only obvious in hindsight. I spent much time pondering (in the shower, while cooking, petting my weasel, etc.) how I was going to accomplish the 90° indexed rotation. I had ideas about using my rotary table and collet blocks, or making various jigs. And it was while pondering the rotary table option and how I would support this long shaft poking out that I pulled out my v-blocks. And like lightening on golf course it hit me. Riiiight, v-blocks are perfectly square!
Thus I admit to all and sundry what a flipping dunderhead I am.
The final product of much mulling and a tiny bit of milling.
Finally, we have the machine to date:
The first order of business was trimming the shaft to the correct length. The 1/4" round stock provided was only 60 thou or so over, so I just faced it off in my lathe and put on a bit of chamfer.
Next was machining the flats. There are two flats on each end of the shaft. They are placed 90° from each other. In other words, when you machine the second flat, you have to rotate the shaft 90°, or half a pie. Mmm, pie...Anyway, upon these flats ride the grub screws that secure the crank throws.
To accomplish this, I used a set of two v-blocks and my vise. First I used one v-block, with the shaft clamped using the outer clamp position on the block. This was placed in the vise with the block positioned so the shaft was against the fixed jaw of the vise and the v-block clamp was beyond the edge of the vise. I then machined the flat to the specified dimensions.
Milling the flat on the crankshaft. Note the v-block clamp extending just beyond the fixed jaw of the vise.
I then released the v-block from the vise and rotated 90° so the v-block now faced up. I left the shaft clamped in the v-block this entire time. A matching v-block and block camp was now added to the set up to support the end of shaft that needed machining, and the whole set-up was re-clamped in the vise. The flat was then machined.
Here I have added another v-block (part of a matching set) and am milling the other flat.
This process now seems really obvious. Unfortunately, it was only obvious in hindsight. I spent much time pondering (in the shower, while cooking, petting my weasel, etc.) how I was going to accomplish the 90° indexed rotation. I had ideas about using my rotary table and collet blocks, or making various jigs. And it was while pondering the rotary table option and how I would support this long shaft poking out that I pulled out my v-blocks. And like lightening on golf course it hit me. Riiiight, v-blocks are perfectly square!
Thus I admit to all and sundry what a flipping dunderhead I am.
The final product of much mulling and a tiny bit of milling.
Finally, we have the machine to date:
Cheers,
Tom
Tom
Last edited:
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- Jan 24, 2015
- Messages
- 239
Another short-ish post. This time I made a few rods.
The first rods to make were the stainless steel piston rods. I had not yet machined SS. I don't know the grade of SS provided. I do know that is was harder to machine than CRS.
I used my carbide insert tools to turn the small end of the piston rod to the correct diameter and for the correct distance. My first few cuts were "big" at .01. My last few cuts were clearance cuts taken without changing the cross slide position. In between were some .002 cuts. Eventually I got the diameter needed for the 3-48 thread.
Using my carbide insert tool to machine a stainless steel stock for the piston rod.
I then threaded this with a 3-48 threading die and my die holder. I could do this threading under power, because my lathe is powered by a 90V DC motor with variable speed. This aspect of my lathe is really handy when I have to make a lot of male threaded parts.
Threading the small end of the piston rod 3-48.
Once the small end was done, the other end was simple threaded using my 5-40 die; no turning was necessary.
The finished piston rods.
The eccentric rods (valve drive rods, valve movers and shakers, etc.) come as brass round stock that requires splitting in two, a bit of shortening, and then threading.
The finished eccentric rods (valve push rods).
The last bit for now is making a bunch of nuts. The kit provides 3/16" and 1/4" brass hex stock. The nuts are made from the 3/16" hex stock, the 1/4" stock is used for the gland nuts (not done yet). Two of the nuts are 3-48 and the rest are 5-40. So, two nuts worth of hex stock were drilled for a 3-48 tap, tapped, and then cut off to the correct size. Before cutting of my nuts, I would chamfer the exposed side. The rest were were treated likewise but for 5-40 threads.
After I cut off my nuts, I had to clean up the burr left over from the cut off operation. To do this, I mounted each nut back in the three jaw chuck and used a sharp lathe tool to trim off the burr. Then I used a small file to chamfer the edge. Or, I would forget to do the chamfer, remove it from the chuck, realize my mistake, remount it in the chuck and then chamfer the edge. And then realize that I did not remember to chamfer the other side prior to cutting it off from the hex stock, and ......
De-burring my nuts using a very sharp HSS tool bit.
The slowest and most painful part of the process was getting my small nuts into the chuck with my over-sized hands. Otherwise, this all went quite smoothly.
My nuts and shafts.
Until next time.
Cheers,
Tom
The first rods to make were the stainless steel piston rods. I had not yet machined SS. I don't know the grade of SS provided. I do know that is was harder to machine than CRS.
I used my carbide insert tools to turn the small end of the piston rod to the correct diameter and for the correct distance. My first few cuts were "big" at .01. My last few cuts were clearance cuts taken without changing the cross slide position. In between were some .002 cuts. Eventually I got the diameter needed for the 3-48 thread.
Using my carbide insert tool to machine a stainless steel stock for the piston rod.
I then threaded this with a 3-48 threading die and my die holder. I could do this threading under power, because my lathe is powered by a 90V DC motor with variable speed. This aspect of my lathe is really handy when I have to make a lot of male threaded parts.
Threading the small end of the piston rod 3-48.
Once the small end was done, the other end was simple threaded using my 5-40 die; no turning was necessary.
The finished piston rods.
The eccentric rods (valve drive rods, valve movers and shakers, etc.) come as brass round stock that requires splitting in two, a bit of shortening, and then threading.
The finished eccentric rods (valve push rods).
The last bit for now is making a bunch of nuts. The kit provides 3/16" and 1/4" brass hex stock. The nuts are made from the 3/16" hex stock, the 1/4" stock is used for the gland nuts (not done yet). Two of the nuts are 3-48 and the rest are 5-40. So, two nuts worth of hex stock were drilled for a 3-48 tap, tapped, and then cut off to the correct size. Before cutting of my nuts, I would chamfer the exposed side. The rest were were treated likewise but for 5-40 threads.
After I cut off my nuts, I had to clean up the burr left over from the cut off operation. To do this, I mounted each nut back in the three jaw chuck and used a sharp lathe tool to trim off the burr. Then I used a small file to chamfer the edge. Or, I would forget to do the chamfer, remove it from the chuck, realize my mistake, remount it in the chuck and then chamfer the edge. And then realize that I did not remember to chamfer the other side prior to cutting it off from the hex stock, and ......
De-burring my nuts using a very sharp HSS tool bit.
The slowest and most painful part of the process was getting my small nuts into the chuck with my over-sized hands. Otherwise, this all went quite smoothly.
My nuts and shafts.
Until next time.
Cheers,
Tom
Last edited:
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- Jan 20, 2013
- Messages
- 285
Nice write up, Tom. I've never worked with casings, they do present some interesting challenges. I'm looking forward to seeing your progress and seeing this engine run.
B
BRIAN
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Hi Tom
When making small nuts for clocks I put a stud in the chuck with a short length of thread showing , and thread the nut onto it up to the chuck jaws, the facing cut keeps the nut tight against the chuck, this is ideal for doing repetitive jobs.
Brian
When making small nuts for clocks I put a stud in the chuck with a short length of thread showing , and thread the nut onto it up to the chuck jaws, the facing cut keeps the nut tight against the chuck, this is ideal for doing repetitive jobs.
Brian
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- Jun 17, 2011
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- 2,069
My #7 kit arrived today. For those who may be wondering, there aren't any real instructions. Just a good set of raw parts and some really good drawings. The how-to's are up to you.
It looks like a great winter project. At least if I can keep my pea-pickin' paws off it that long. This thread will be a real asset to all who are doing one of these kits.
It looks like a great winter project. At least if I can keep my pea-pickin' paws off it that long. This thread will be a real asset to all who are doing one of these kits.
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