I'm building a pen lathe

[Nevadablue]

So, for today's progress. I've worked out the design I think. Here are some views. Note, the Chinese version of this machine are NOT exactly the same as the Austrian one. Of course... tiny size differences. I'll be able to use what I have, but not without modification. The T-slot in the extrusions is just slightly smaller at the narrow part. Milling machine will fix that.

This gives me a good solid, low profile machine.

 

[Nevadablue]

I will post one more on the pulley building process. I probably won't use this pulley on the Unimat 1, since I've discovered that it has plenty of power with the small pulleys and they will give me the speed ratios I need. This larger pulley will probably become a drive pulley on one of my DB200 machines. I just eyeballed the whole thing, no drawing or measuring, but it looks like it will work fine. I will need to machine the bore, face the inner side flat and install a set screw. This piston material is very gummy and sticky and doesn't machine nicely. I'm not a machinist, just a wanna-be. I managed to finish the pulley with only a couple of wrecks and no spilled blood.
I discovered that I couldn't properly support the pulley to part it off of the piston scrap. But, I tried... and this resulted in a crash when the parting tool snagged, and popped out of the holder, which also pulled the pulley out of the 3 jaw chuck. Sigh... dings in the grooves, but nothing that can't be lived with. My live center wouldn't reach inside the piston, so I tried to part it without support... DUMB MOVE. Anyway, I just thought... I should have found my dead center. But, I didn't and decided to use the small bandsaw to part it. Broke the blade!!! Finished the cut off with a hacksaw and finished the basic pulley machining on the big lathe.

Here are some pics. The piston in the pic is the same style as the one that the pulley came out of. The head is domed, but this one is faced off for the index center project. Note the ratty finish, nasty stuff. Anyway, here it is...

A little work with a jeweler's file will fix the dings good enough to work.

 

[Nevadablue]

Oh, I left the thick rim on the large side of the pulley to give me room to drill index holes directly in the pulley.

 

[donwatson]

Very good Ken. this is coming along nicely

 

[Penpal]

Well on the way mate like the thicker face to form the indexing on.

Peter.

 

[Penpal]

I salvaged this out in the open in a blokes back yard gave up on the project a guy called in to give it to a guy 400 miles away eight yrs ago to help complete his unit.(Unimat 3 Austrian).

Peter

 

[Nevadablue]

Thanks for the support guys.
Peter, those little lathes are worth salvaging for sure. They are just neat machines.

 

[Jim]

Good to see you are still at it Ken, each day more progress ..

 

[Nevadablue]

My replacement bandsaw blade arrived today. (I couldn't find my spare of course) So, I cut a couple of pieces of the aluminum extrusion, for making a spare tail stock and the countershaft housing. The flange bearings also arrived, giving me an excuse to work on this. (just finished laying the hardwood flooring in my son's bedroom... finally)
So, after cutting the bits for the housings, I turned a section of 12mm shaft... twice... . I forgot to make the first one LONG enough to put on the pulleys. So, I have a short section of shaft for something else.

I will have to tap the holes in the extrusions for 8-32 button head screws to hold the bearings properly. I discovered that I can mount the bearings either way, if I tighten the lock screws before installing the shaft in the housing. Now to make the pulleys and mill the lock screw flats on the shaft.

 

[Penpal]

Like the way you used that extrusion Ken is it made for the purpose or a separate extrusion on the market. I also like the strength of the shaft. Tomorrow we are installing double glazing in our main room so I am up to my ears in furniture clearing, getting ready. Its our coldest area and this year is miserable cold so I hope this will help. We have air con in here as well as a gas hydronic series of heaters through the house plus we pull hot air in the roof space through 7 inlets through the ceiling. With Solar Panels that give us a relief on Electricty Bills but gas pricing has gone sky high.

Kind regards Peter.

 

[Nevadablue]

Thanks Peter, the extrusion is cut from the bed section of one of the chinese clones of the Unimat 1, sold by Harbor Freight some time in the past I think. I got it, a spare headstock and tailstock off ebay for cheap. I got it for just this purpose. I'm copying the basic design of the Unimat 1 headstock, with more readily (and cheaper) bearings. I think I'll drill and tap both ends of the countershaft for versatility too. I have several feet of the .5" round stock that I made the 12mm shaft from. I may try a making a hollow shaft with 12mm threads on the end one of these days.
Oh, I also received the aluminum stock I ordered. I intend to make replacements for the plastic end caps on the modules that make the lathe. The 'metal line' version of the little lathes comes with the metal ends.

 

[wm460]

Thanks! The pistons are out of a Deutz engine. I saved several thinking of using them as raw material for casting, but now they have turned out to be useful in other ways.

The good old Deutz, I spent many an hour on a Deutz tractor when I was younger.

 

[wm460]

Very nicely made Ken, like your thinking and planning.
I have been trying to get that extrusion in Aust, but no luck.

 

[Nevadablue]

Keep an eye on ebay for the extrusions Mark. It looks like they sell a lot of the chinese clones of the Unimat 1 and most people seem to hate them. There should be used parts showing up somewhere.

 

[Nevadablue]

I tapped the mounting holes for 8-32 button head screws, and rounded the ends of the bearing mounts for a better fit. I wanted the ends of the mounts to be inside the square profile of the extrusion. I used 12mm bearings and shaft so the parts will be compatible with my Unimat DB200 machines. Now to make the pulleys.

I may thread one of this shaft for use as an auxiliary power tap. I also discovered that mounting one bearing 'inside-out' wasn't a good idea. There's no way to tighten or loosen the lock screws so the shaft can be moved.

 

[Penpal]

Apart from Authenticity or miniaturising I question the use of such tiny motors I find conventional motors effortless or perhaps you want or looking for superspeed? Model making groups could be helpful to Mark in his quest.

Peter.

 

[Nevadablue]

I tried the sewing machine motor on the Unimat DB mill and found it to work OK. I wanted the lathe to be small enough to move around and still be useable also. I have a spare dental engine but the motor on it is fairly large too. By the way, the dental engines (the old rope drive ones) are just the berries for lots of model and wood working chores. I outfitted mine with a selection of headpieces and use it a lot.

 

[wm460]

Ken how would a motor out of a washing machine go, some are quite small.?

 

[Nevadablue]

Mark, I think one of those would probably work fine. Many of them are reversible and variable speed too.