Building a New Lathe

[tom osselton]

How about a expandable pulley between the two.

[vtsteam]

Hi Tom, not sure how you mean. 

[tom osselton]

I have a old multilith printing press the drive pulley is spring loaded so as the belt goes in deeper it runs slower

[vtsteam]

Okay, thanks, Tom.  I actually have one of those on a drill press. I guess I meant, not what is it, but how would it work here since this is a toothed belt drive, and also the motor is variable speed DC, so I don't actually need a variable pulley ratio.

I was thinking about adding a countershaft only because I already have a 5 to 1 motor to spindle ratio, and I could probably use a 10 to 1 ratio to better effect, given this DC Motor. But that would mean making a giant pulley for the headstock. As a solution for something more wieldy, if I add a 2 to 1 countershaft to the present setup, that will have the same effect, and I will still have variable speed.

If I turn the motor end for end, and then attach a journal with spindle to the motor case, belt the two together, 2 to 1, and then put the original driver pulley at the other end, belted to the lathe spindle, that would be a simple and compact reduction power unit. In overall form, It would look like the motorized milling spindles people make up for cnc gantry mills.

BTW, one important need for a toothed  drive is that the encoder for the electronic leadscrew has to sync to the lathe spindle. The encoder runs at motor speed if direct drive, or would run at at countershaft speed (if there is one). In either case it runs at 5x spindle speed.

[tom osselton]

My Clausing has around a 14” pulley that I actually like because I can use it to thread up to a shoulder.

[vtsteam]

Well the electronic lead screw is ready to try out on the lathe, but I need a case to house the electrical components and switches. I want to minimize the footprint (this is a tiny shop after all) and also make something that's in keeping with the style of the lathe so far. A  square utility case lying on the bench just doesn't appeal to me.

Since I'm not casting right now, I decided to make a heavy shaped pvc case that attaches to the lathe. In form I'd like it to look something like a typical small lathe quick change gearbox.

So, I hunted up some scrap 4" PVC drainpipe, slit it with a handsaw lengthwise, and popped it into a pot of salted water to boil. This sch 40 pipe is nice and heavy walled -- 1/4" thick. Because I wanted to retain some of the pipe's shape, I only added enough water in the pot to cover the half of the pipe I wanted to bend.

[vtsteam]

After the water reached a rapid boil, I pulled the pipe out with tongs. I had leather gloves on, so I just bent it by hand to about the shape I wanted. You only have a few seconds to work before the pipe freezes.

I couldn't get a reverse curve that way though, so I took the still hot pipe, and applied a heat gun where I wanted the reverse. I kept it moving over the surface, because it's easy to burn or blister an area -- especially with pipe this thick. You have to heat gradually and carefully. In a short time I had approximately the shape I wanted.

[vtsteam]

Since the water was already hot, I figured I'd better make some flat stock for end pieces, so I hunted up some more scrap pipe. I took a 5" long section and slit it into two halves lengthwise. Then popped those into the pot for some more "pipe soup"!

[vtsteam]

When soft, I squeezed each piece between two boards. And stood on them!

When they were hard again in about a minute each, I took the curved piece and trimmed it down some so I could see what it looked like against the lathe. There will be some more needed fitting, but these are the pieces made today, for now.

[NormanV]

When I lived in Kenya I did some building work and a trick I learned from a plumber to join pvc pipe was byheating it over a small fire and when it softened to force it over another piece of pipe. When it had cooled you could pull it apart and apply the glue to make a permanent joint. Much cheaper than buying a special joint and just as effective.

[vtsteam]

Cool method, Norman! 

[russ57]

I remember an electrician showing me something similar for conduit. A Milo tin with diesel soaked rag provides the heat source, put the lid back on when done.

-russ

[vtsteam]

I formerly occasionally straightened PVC pipe into usable flat stock by careful heating with an oven, or for smaller pieces, a heat gun. But these methods are easily susceptible to burning and blistering, and they produce plastic fumes. This is just too hot on the plastic's surface. Heat migration through plastic is slow -- it's a good insulator.

I figured out boiling water works better last year when needing to make a small plastic fitting in a place that had no oven and only had an electric kettle. I poured boiling water over a piece of pipe in a coffee mug a few times, and it worked for what I needed. Using water, heat transfer is slow and even, though actually better than air, and temps never get above the boiling point of water. The salt raises the boiling temp a little, so that's helpful. So, that's my method.

[awemawson]

When I was a youngster they were building a new estate of houses on the cornfields behind us. Loads of off-cuts of PVC  down pipe, gutting and underground pipe to be gleaned and turned into 'things'

I used your method Steve - gently simmering water - pull it out when floppy and let it sit between two boards with a weight on top to flatten.

I remember make an oxy-hydrogen generator - six inches of down pipe, two flattened bit of gutter for the ends, brass screw for the electrodes and a gas tap to release the oxy-hydrogen when accumulated - worked well but goodness knows how I didn't blow myself up as if course the mix is EXACTLY the explosive ratio !

(mind you that pails into insignificance compared to the sodium chlorate and sugar experiments  )

[philf]

..........
(mind you that pails into insignificance compared to the sodium chlorate and sugar experiments  )

That was until the spoilsports put an additive into Sodium Chlorate weedkiller to render it useless for such purposes!

[AdeV]

That was until the spoilsports put an additive into Sodium Chlorate weedkiller to render it useless for such purposes!

The spoilsports have gone even further now - you can't buy the damn stuff at all! I'm hoarding the last of mine.... still got half a tub, must have bought it 20 years ago...

[awemawson]

Well it was not long after that that I went on a CCF (Combined Cadet Force) camp at Wyke Regis to the rear of Chesil Beach - it held the Army Demolition Training School and we were being shown how to use plastic explosives. The instructor knew teenage boys were fascinated by the stuff and went to great lengths to explain that there was no way we could pinch any as their security was far too tight.

It wasn't, and I did  - stupid thing to do but I was a teenager. I got away with perhaps an ounce and some detonator cord, easily enough to kill myself. Easy really - told to go lay a charge, actually squeeze a bit off and hide it in your beret and bobs your uncle. Very fortunately one of my group who I'd bragged to had the sense to dob me in to one of the school CCF officers who didn't dare tell the regular army officers what I'd done for fear of consequences. He took me for a midnight stroll to 'The Fleet' (lagoon behind Chesil Beach) where we threw the offending items. My punishment apart from a heavy dressing down - banned from the next camp - shame as it was visiting the British Forces on the Rhine - oh and the worse headache that I've ever had. PE has oils in it that penetrate the skin and have that effect.

. . . oh happy days of youth 

[vtsteam]

Here's the finished leadscrew electronics cover:

[Neubert1975]

nice work 

[vtsteam]

Thanks Neubert! 

[awemawson]

I reckon that you inherited Rob Wilson’s shiny camera !

Nice job, teasing aside .

[tom osselton]

Nice!

[vtsteam]

Thanks Tom, Andrew!  . Just some 180, 320, and 600 grit sandpaoper by hand, and a rattle can paintjob.
uhhhh......I'm nowhere close to Rob. His work was true art.

I feel like these days I'm going so slowly on the lathe -- must be age, I used to do things faster. Now I hesitate a lot and sort of doubt what I've chosen to do.

Well, enough of that, I do have switches installed on the change box. Though connected to nothing. The left 6 toggle switches are A, B, C , D, E and F for selecting the pitch. The two smaller toggles upper right are Leadscrew ON/OFF and Leadscrew Direction. The big lower toggle switch is 3 position, Spindle Direction, center off.

The two direction switches flip horizontally, the rest vertically.





I've worked out a pitch table. For now it will just have to be a paper label, though I'd like at some point to be able to do a nicer brass plate of it. A few attempts so far at transferring resist from a laser printout on magazine paper to a metal plate hasn't worked out.

[AdeV]

Nice to see my name there next to the finests of feeds! 

I've worked out a pitch table. For now it will just have to be a paper label, though I'd like at some point to be able to do a nicer brass plate of it. A few attempts so far at transferring resist from a laser printout on magazine paper to a metal plate hasn't worked out.

I found that sticky-back vinyl (the sort you put through vinyl cutters) makes an extremely good medium for transferring laser toner to copper sheet. Haven't tried with brass. All I did was stick a piece of vinyl onto some paper, run that through the printer, cut out & stick the resulting print to a piece of copper clad board & run the whole thing through a lightly modified laminating machine (I took the clutch out, so it doesn't jam up) four or five times; I generally got 100% transfer of the toner. It can still be a bit "holey" though, so I'd recommend good thick lines for both the dividers and the numbers, and you still have to go over it with a magnifying glass & touch up with a Sharpie pen if needed.

I've not tried it myself; but I'd consider printing the chart as a negative (i.e. white letters on a black background); etch that, then paint the result & scrape off the top to leave the letters in brass colour, and the background in black (or whatever paint you used) - just for better clarity.

[PekkaNF]

...
I found that sticky-back vinyl (the sort you put through vinyl cutters) makes an extremely good medium for transferring laser toner to copper sheet. Haven't tried with brass. All I did was stick a piece of vinyl onto some paper, run that through the printer, cut out & stick the resulting print to a piece of copper clad board & run the whole thing through a lightly modified laminating machine (I took the clutch out, so it doesn't jam up) four or five times; I generally got 100% transfer of the toner. It can still be a bit "holey" though, so I'd recommend good thick lines for both the dividers and the numbers, and you still have to go over it with a magnifying glass & touch up with a Sharpie pen if needed.
....

Something like this?:

I have been testing lately several transfer papers, laminator, cold transfer (acetone) etc. They all sem to work - sort of! But they are very sensitive for whatever changes on printter settings, color cadridge (got another ink to my laser printter and it does not work with hard transparency and same laminator anymore.

Tired this:

And it works sometimes pretty good with high gloss coated paper (same printer&caridge works more consistelly with hot laminator). It is really sensitive to acetone/ethanol mix, timing and pressure. Too much/strong solvent and lines start to skid all over the places. Too little/weak and image might not transfer.

All transfer methods have some paper fiber stuck on them. It does not matter if the lines are fatty, but with very thin lines and small spaces it does matter.

Chinese yellow transfer paper has worked easiest this far.

My questions: Do release papers (i.e. non standard print or release papers) screw up printer or ink cadridge? Many release papers are siliconized and I will not allow that near anything I want to glue or paint.