Winner A Dividing Head By Wayne

[wayne.inspain]

Today I decided to do the worm. never done one never cut a screw thread on the lathe. I have a piece of 25mm brass for the worm, I know
for every thing to run perfect I either need a worm wheel or set the axis of the worm at the helix angle, but I have neither, I know that the threading tool
when ground to size should be set in the tool holder at the angle of the worm helix but I thought that if I ignore all that it might still work, working on the assumption that if every thing is wrong it might all come right. I got a piece of tool steel shaped about right in the things that came with the lathe, and it is square so I can't set it at the helix angle in the tool holder, I don't know what the helix angle should be any way but surmised that if the tool fit the teeth
exact then it would cut wide and the worm teeth will need to be wider that they should be because the worm shaft will be at the wrong angle, I am not sure if any of that makes any sense I won't know till I start cutting.
I needed a pitch of 4mm or at least that's as close as I can guess measure it, the chart on my lathe finished at 3mm. I search the net to find out how to work it out set the lathe up with the correct change wheels, measured the travel of the saddle after turning the chuck by hand it was miles out, after a lot of checking
and head scratching realized, the drive wheel for the change wheel train didn't come off the main spindle but came from a gear box, with a 4.6:1 ratio.
More head scratching and playing with some numbers I got it to 3.9mm travel and that was the best I can do.

 

[wayne.inspain]

I did some cuts in steel with out the feed to see if the cutter would cut then tried it with feed, the slowest speed on the lathe is 170rpm
boy did that carriage move fast.

I would need plenty of run off. That's my piece of brass in the back ground. Enough practice in the brass when skimmed it clean, cut the run off to the depth of the teeth on the change wheel had a few practice runs a few mill from the work and gradually got the tool closer till it made the first scratched, no frills back
off the cutter reverse the spindle and carriage set a new scratch and go again. 20, stress full, minutes later I had this.

A 8mm hole drill through the center for the spindle, that was out of an old printer, cut off, bit of a tidy and it was done.

 

[JimDawson]

That came out very nice!

 

[wayne.inspain]

I was quite please with my first attempt, needs a grub screw or something, it fits the change wheel quite well barely any play, it's
not quite right it just bottoms out and the teeth are too narrow but they had to be because the worm will not be on the helix angle, it will do till I make the new worm wheel then I will have a go at making a good one. When I re-assembled everything I found the worm will hit the main barrel, I thought it would be close. So I put the barrel in the end plates and base put it all back on the mill and took off the corners.

Bit of a clean up.

The next job is the mounts for the worm spindle.

 

[wayne.inspain]

Hi Jim. Thanks. Didn't see your post there I was busy typing. Glad you liked it I was pleased with the outcome for a first attempt,
and other that those bushes I made, the first time with brass since my school days.

 

[Mark_f]

Wayne, This is simply amazing......and first class workmanship. It looks fantastic in the photos.

 

[wayne.inspain]

Hi Mark, You don't know how much I appreciate your comments, thanks.
Today's project was the worm spindle mounts, I bought some 50mm brass yesterday from the man who has every off cut his shop has
produced, 2 slices 10mm thick drilled for the spindle and milled to the correct height, couple of counter bored hole, fit a new car radio,
couple of hours out on the bike, bar, beer and bed, what a day!. I didn't like the idea of hack sawing the brass bar so decided to make a
parting tool. I have not really done any parting on the lathe looks a bit iffy! I have an old saw blade that I thought might do the job so I got the
grinder out.

I sanded it to fit the holder in my quick change tool post on the lathe.
Put the brass in the lathe cleaned it bored it 8mm then plunged it in!

It went in as fast as I could turn the handle I will have to try it on steel that will be a different matter. The tct end looks a bit skew but it's
the camera angle it is central.
Getting the correct height for the worm spindle was a bit hit and miss, I put the spindle through the worm rested in on top of the change wheel in
situ. and with a couple of 8mm end mills and feeler gauge's got the spindle parallel with the main barrel. A few sums then milled and drilled.

I have to counter bore the bolt holes and a bit of a tidy up. There is a perceivable amount of play between the worm and the change wheel, but it's not much but I think it should be good enough to make a new worm and wheel. I have more of the brass and I think I might hollow it out to fit between the worm spindle supports to make a cover to keep out swarf. Next job? O yes fit the new car radio, never mind bike beer and bed after that!

 

[Steve Shannon]

Very impressive. I'm hoping to be half as resourceful.


Steve Shannon

 

[Mark_f]

What I find amazing is how you make what you need from whatever you can find ...... and make it look so nice. I don't have that kind of patience. In my opinion , this is skill, and you are what I consider a true machinist.

 

[wayne.inspain]

Hi Steve, thanks, for your remarks, I never considered it creativity just desperation, Lol!
Mark you really are too kind. I am sure if everyone had the junk that I'd been collecting over the years you all would make
what you need, If I panned the camera round my shop you would all cringe.!! If I make enough projects perhaps it will all get used. lol
Looking at the projects you make and at the level you achieve you have enough patience to make anything you set your mind too.