An attempt to execute the 400 rpm threading for a G0602 plan

Hello Larry, it sounds like you are making progress. I presume the shifting issues have been taken care of. How about the rotating problem, any new developments there? One other point you mentioned milling a thin washer, I make all of my thrust washers (and others) by boring a bronze rod to the desired diameter, turn the outer diameter and then part it off. I make washers down to about 0.015". They may cup depending on the material but they work well.

Jim
 
Jim - There is no more rotation of the body when shifting. It shifts smartly, even at 700rpm.

Next up is setting up the parts on the back of the lathe.

I didn't get much done today. The lawn needed mowing and I smoked a pastrami. The pastrami smoked for 12 hours, so I had to diddle with my little smoker on a regular basis.
 
I am back to work on the project again. The article calls for a 28 inch long flat to be milled on the trip rod. My mill has a maximum X travel of 18". While trying to figure out how I was going to clamp and mill the flat, I got to wondering if I really needed 42 inches of control rod. So I did some measuring. I would presume that all G0602 lathes would be pretty close.
From the headstock end of the carriage stop to
end of ways - 32.25"
to outside of carriage stop at max travel - 23.25"
to outside of carriage stop at max travel with thread dial - 22.75"
to outside of carriage stop at max travel with tailstock installed 22.25"​
From the headstock side of the carriage stop to the out side of trip linkage B - 10"
2 Shift blocks 1"
Throw length - 0.75"
​
I am thinking that I will seldom, if ever, remove the tailstock or the threading dial to cut threads at the far end of the lathe. I should be using 34.25" of rod, and that would leave 1.75" of rod for the trip rod bracket.

Does this make sense, Jim?
 
Hello Larry, the length of the shift rod was determined by measuring the distance for the end plate (steel plate on the outside of headstock) to the end of the ways. The reason for going to the end of the ways was to mount the supporting bracket using an existing hole. To mill the flat I milled it in two steps, repositioning after the first cut.

Jim
 
Thanks Jim. I hadn't considered using the chip shield mounting hole. I was coming from the direction of saving that 3 foot piece of drill rod for another project. I also want to be able to remove the chip shield without taking the trip mechanism apart. I have had the shield off a few times already to mess with the motor. My belts seem to be the wrong size. Maybe one day I'll do a VFD.
 
Baithog, Really nice work I was considering this mod and had been waiting for Jims article to show up in HSM I had seen it along with some of his other mods on YT. I am highly impressed with you progress rate. Keep up the good work and keep posting. I have saved Jims articles and now have your post to further guide me when I get the guts to attack this project.
Mark
 
Jim, You may not know this but you help me a great deal when first started in this art. You always had good advice for my then new and scary Go602 lathe over on the group for that lathe. Things like the proper set up of change gears, Four bolt compound clamp and the like. A tip of the hat to you.
Mark
 
I have been moving right along on the project. I figured out that I could get away with using just one length of drill rod for the trip mechanism. So I put a 28" flat on one of the half inch drill rods, leaving an inch at the tailstock end round. That would be the part that rides in the support bushing. The bushings ended up being a problem. The only piece of Acetal in my box that was big enough was the stub left over from making the idler gears. I couldn't bring myself to throw away so much stock. A trip to the hardware store and I had a pair of 1/2" bronze flange bearings. They cost less than the shipping for some Acetal round stock, and I didn't have to wait a week to get them. The drill rod slid quite nicely once it had been deburred.

I didn't want to tie the trip mechanism tied to the splash guard. Remember my order tribulations in the initial post where I mistakenly ordered 6 one inch pieces of 2X3 aluminum instead of 1 six inch piece of 2X3 stock? One of those 1" pieces became the support for the control and trip rods at the headstock end. The support for the tailstock end (which by the way is not called out in the materials list) was fabricated in 2 pieces. A piece of 2" X 1/4" aluminum angle acted as the stand-off from the lathe bed. It was mounted with 2, !/4-20 SHCS through slots. The slots allowed vertical adjustment of the tail stock end support. The top part, which carried the bushing, was made from a piece of 2"X1/4" aluminum flat stock. It was mounted to the stand-off with #10-24 SHCS through slots that allowed for horizontal adjustment. My suspicion was that the headstock support bushing was not bored absolutely parallel to the bed ways. It doesn't take much error over 3 feet to cause binding on close fit bushings. I was correct.

The deviation from Jim's design meant that the trip linkage didn't fit as designed. I considered putting the linkage on the drive side of the control rod support, but belts and pulleys were in the way. To put it on the headstock side of the control rod support required an odd double offset shape to fit. I milled it from a 3 3/4" piece of 1" square CRS. I kept the length of the control rod arm as specified, but modified the length of the link to fit. It was interesting to turn the ferrules on the half disassembled lathe. The clutch mechanism drove the lead screw nicely.

The mechanism works in static and dynamic trial. I have the slot in the splash guard and the stop blocks to fabricate. I have a small micrometer head in the "might be useful some day" box. I wonder if that would be overkill for a fine adjuster?


IMG_1114[1].JPG IMG_1115[1].JPG IMG_1117[1].JPG
 
Very nice Larry. Looks like you are on the final leg to threading Nirvana. I used two shorter pieces of drill rod and used a coupler that is underneath the head stock to join them together. If you have everything lined up correctly the effort needed to move from forward or reverse to neutral is very small, a few ounces.

Mark, start by making the gears, something to wet your appetite so to speak. For most the making of gears is what they find intimidating. Start with the Acetal gears, easy to machine and they will give you a good understanding of what is involved. Once you finish the gears then make the dog clutch disc and axle. Once that is done is your more than half way home.

Jim
 
I have spent the last 2 days trying to fabricate the hinge for the trip lever. I'd sure like to know how Jim made those half round sticky-up parts of the hinge. I tried doing a radius with my DRO, but that wasn't very successful. Tomorrow I will bite the bullet and buy a hinge from the hardware outlet. It won't look as pretty as one fabricated from billet, but it will at least work.

Since I'm a very impatient guy, I clamped a block of metal to the cross slide and tested the setup under power. IT WORKS!

The clutch mechanism has really quieted down. I had hoped that that would happen after a bit of run-in, and it was gratifying that it did. Currently the clutch makes some 'ding, ding. ding' noise after it releases, but I think that will go away once I make the detent grooves. I put a dial indicator on the bed to get an idea how consistent the trip was:
toward headstock away
0.4942 0.153
0.495 0.153
0.494 0.153
0.494 0.1555
0.494 0.159

So tomorrow I will make new stop blocks and the hinged trip lever. Then it all comes apart to have a bth, visit the sandpaper bench, and get some paint. More pictures and video to follow.
 
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