Unimat SL1000 Lathe Modifications and Improvements

[prjones76]

I want to share some photos of the recent improvements I made to my Unimat SL1000 lathe which has a 3" swing. I bought this lathe new in 1970, used it for a few years and then put into storage. I recently started to use the lathe and decided it needed a make-over after being inspired by the book series "The Shop Wisdom" by Rudy Kouhoupt.

As part of the lathe improvements, I built a storage platform with a single drawer, added a permanently installed milling/drilling head and more intermediate pulleys for slower spindle RPM, raised the whole lathe up in riser blocks and add threaded holes for future attachments (yet to be designed), added dial indicators for the x, y and z directions (I usually work in inches), and added adjustable carriage stops to the x-direction. It took several iterations to align the x, y, and z axis to each other but everything seems to be in tram with each other. Along the way I replaced the motors with continuous duty U-100 motors. Yesterday I replaced the stationary lathe handles with ones that rotate (not sure why I waited all these years before doing this). There are many more future features I want to add such a longitudinal power feed for the x-axis and a dividing plate for the lathe spindle. Some of the most fun I have is designing the parts before anything is machined and then making a hard copy or recording my changes as the parts are built (and then making these changes on the original drawings).

Eventually I want to start building stationary steam engines but I am having too much fun with the Unimat.

I hope to be able to post my photos as things progress.

Paul Jones

 

[Tin Falcon]

Nice work brings back memories. My older brother purchased a unimat in the early 70s still has it. And I miss seeing Rudy at the shows he was a great guy.

The senf minikin and the river queen engines should work well on that setup.
looking forward to seeing more of your work.
Tin

 

[gerritv]

Well thought out additions, many would help to improve any lathe.

Gerrit, ex Unimat DB owner

 

[prjones76]

Thank you for the compliments and for the miniature steam engine recommendations. I have also started building some of the lathe tools shown at http://watchmaking.weebly.com/toolmaking.html, the website "Adventures in Watchmaking". It seems as if we can never have enough specialized tooling when machining small parts.

 

[spurgear]

I have 2 Unimats, you'r improvements are inspiring & looks great.

 

[petertha]

I have also started building some of the lathe tools shown at http://watchmaking.weebly.com/toolmaking.html, the website "Adventures in Watchmaking"..

Thanks for the link, some really nice tool ideas there.

 

[deverett]

Nice set up you have, Paul.

There was a book by Rex Tingey called 'Making the Most of the Unimat' dated from the early 1980s, which described numerous modifications to the original bar bed machines. Later chapters went into mods for the Unimat 3. Well worth reading for Unimat lovers.

For anyone wanting to see what R.T. achieved, join the Yahoo group for all Unimat lathes and download a copy from there.

Dave
The Emerald Isle

 

[goldstar31]

I have a MJ-189 which is a Unimat3(or4)) clone and there is some articles, I think- still from Geral Wingrove who built model cars.

Digressing( apologies for stealing the thread) but has anyone a successful CNC conversion or can point to where I might refer?

Nice topic- thank you

Norman

 

[nevadablue]

Nice work! I'll be appropriating some of your ideas. I'm working on a mill post similar to yours. I just got the bed casting to use, yesterday. I have a chunk of 304 stainless that will become the column I hope. I'm still trying to snag a reasonably priced headstock or complete lathe off of ebay for parts for this project.

 

[prjones76]

Dave,

Thanks for the compliment and tip for the book by Rex Tingey. I too have a copy and enjoyed reading about his tools and modification. In addition, I own a 7"x14" mini lathe and a 12"x37" geared-head lathe and now limit the small 3" swing Unimat to special jobs too small for the other lathes.

After my initial posting of the Unimat SL modifications, I have added more improvements including indexing plates for the lathe head and milling heads. I included a few photos of this work. More details are posted on HomemadeTools.net at

http://www.homemadetools.net/indexing-plate-for-unimat-sl-lathe
http://www.homemadetools.net/lathe-modifications

Thank you, Paul Jones

 

[prjones76]

Hi Ken,

I recognize you from your work on HomemadeTools.net. I too post tools and tool modifications/improvements at that website as "Paul Jones" with the link http://www.homemadetools.net/builder/Paul+Jones

Good luck with your Unimat build.

Paul

 

[deverett]

Paul

I once owned a Unimat 3. Great little lathe except for one failing: The motor was only rated for intermittent use. From memory 2 minutes on and 10 minutes off. Also a bit weak at 120 watts if any real machining was required. The motor could have been changed, but I decided to get a larger (and more powerful) lathe.

Dave
The Emerald Isle

 

[prjones76]

Since my last posting of photos to the Unimat SL 1000 lathe improvements, I have several more tool additions and posted the thread at http://www.homemadetools.net/lathe-modifications . Below are more photos of the Unimat.

Photo 1 shows the lathe as of April 2016
Photo 2 shows an extension arm I made for using a Noga adjustable arm for using a DTI near the headstock.
Photo 3 shows the parts machined for the extension arm.
Photo 4 shows an ER16 collet chuck made for Unimat SL M12x1 spindle threads and uses a Shars collet nut.
Photo 5 shows the ER16 collet chuck details.
Photo 6 shows M6X1 lever action clamping nuts I made for the Unimat headstock, milling head and tailstock. Very useful for quickly moving the tailstock into position.
Photo 8 shows a slotting saw arbor made for Unimat SL M12x1 spindle threads.
Photo 9 shows the slotting saw arbor in action making the lever action clamping nuts.

Thank you for looking,

Paul Jones

 

[ddmckee54]

Paul:

I've heard, from the Yahoo Unimat group, that leaving the Uni set up in the milling mode will eventually cause the milling adapter casting to sag and the head-stock to droop. You went through a lot of trouble to get it set up properly and trammed in, aren't you concerned about that droop?

Don

 

[prjones76]

Don,

Great question regarding the Unimat milling head moving out of tram over time. I was not aware of this happening so I measured this morning the front-to-back tram. I had originally added to the milling support base a 0.0015” thick shim to bring the vertical column into tram front-to-back. Today's measurement has the front-to-back tram out by 0.0003" over a 3" distance across a 1-2-3 block and much better than I expected. This may be a slight droop over a two year period but well within the tolerances of this machine because the 25 mm vertical column can flex +/- 0.0005" during milling operations with heavy cuts.

However, I did find the side-to-side tram along the long axis of the Unimat to be out by 0.0015". This has always been problem with the milling head because it can rotate slightly even with the locking screw and locking pin in place on the Unimat headstock assembly. It took about 15 minutes but I now have the long axis trammed to with 0.0003". This is an operation that should be done ever 3 to 6 months but I usually put it off.

I included a few photos of the Unimat milling head tramming operation including a photo of the dividing plate removed for access to the milling headstock locking screw.

Thank you Don for the question and my Unimat is now in better shape for the next project.

 

[ddmckee54]

Paul:

I must confess that had an ulterior motive when I asked the question. I've been thinking of doing something similar with my Unimat. I was worried that I'd have to come up with some kind of parking fixture to would take some of the weight off the milling adapter. It's nice to have some real world numbers that show the milling head droop after a couple of years is not really that bad.

Don