# Tricking out a Unimat



## mklotz (Jul 22, 2008)

My first machine tool was a Unimat and, while I've gone on to larger equipment, I still use my Unimat as a dedicated miniature milling machine and precision drill press.

To that end, I made a number of modifications to the machine to make using it easier. 








I added a 3/8" square rail parallel to the spindle on the wooden base. An adjustable bracket can be slid along this rail. It carries a 2" DI that allows measurement of the carriage position.

Said rail also carries an adjustable bracket to which is fixed a 1" DI for measuring cross slide motion. This bears on an elongated aluminum jaw fixed to the vise which is mounted on the carriage. (The rounded castings don't provide flat reference surfaces - hence the elongated jaw.)

Sitting in front of the base are two important accessories. The one closest to the base is a length of 1/4" stainless rod. It can be slid down the spindle, emerging from the opened chuck. On one end is a conical point for centering holes. The other end has a turned 0.2" precision tenon used for edge finding.

Aside: For those not familiar with the Unimat, it has very little spindle travel - about 0.6". Furthermore, the support column is round and unkeyed so, if you raise/lower the power head you lose all registration. Hence the need to do tooling changes via the aft end of the spindle once the head is located.

In front of the locating rod is a thin rod with a magnet at one end. This is used for tooling changes once the spindle is locked in place. A drill/mill/rotary file is attached to the magnet and lowered into the spindle until it emerges from the chuck. The chuck is then locked onto the tooling and the magnet withdrawn. Reversing the procedure allows the removal of tooling via the aft end of the spindle.






On the top of the column that supports the motor/spindle assembly I installed a fitting that supports another 1" DI used to measure Z motion of the tool. This DI bears on a piece of square aluminum tubing clamped to the pulley support bracket






In this view you can see one of the clamps that secures the square aluminum tubing. An identical clamp is out of view on the other side of the pulley bracket.






The motor/spindle assembly is rather heavy and adjusting it side-to-side is somewhat awkward. I made a substantial clamp that mounts to the motor support column and bears the weight of the assembly while it's tweaked side-to-side around the column. This also works as a safety feature preventing an accidental drop of the motor/spindle onto a delicate workpiece.






Once the spindle is properly extended for milling, it needs to be locked in place. On the original machine this was done with a SHCS that needed an Allen wrench to tighten - very awkward when doing precision work. I replaced the SHCS with an extended locking handle that requires no additional tooling be juggled while making adjustments.






The final improvement is electrical. As delivered, the Unimat has a switch mounted inline on the power cord. Another bit of awkwardness. (I guess the Austrians just don't know or care about ergonomics.) I took a 10 amp relay and wired a receptacle through it. The low voltage relay trigger contacts are brought out to a jack into which I can plug a (low current) foot switch of the type once used on dictation machines. Perfect for Unimat control, it can also be used to control other, larger power tools. It works a treat for the Dremel.


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## Bernd (Jul 22, 2008)

Nice improvements on the lathe Marv. Gives a whole new meaning to "manual CNC" machine. (running and ducking) ;D

BTW, is that a rope I saw on one of the pulleys?

Bernd


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## Mcgyver (Jul 22, 2008)

still use mine for very small, light stuff. they are in high demand it seems - can't believe ebay prices for them. Bought a second one last week - had all the wood working accessories that i didn't have. I'm embarrassed at what i paid for it. It popped up on craiglist and I pounced. immediate "I'll take it" email, 20 minutes after the ad appeared. I was there in an hour and he said he'd received 10 emails wanting it, mine was the third but the first two didn't commit wanted to look first. 

i have tooooo much stuff....but its fun


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## BobWarfield (Jul 22, 2008)

I fondly remember as a young boy going through the Unimat catalog and dreaming about all of those attachments and what I could make if I had the complete setup!

Cheers,

BW


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## itowbig (Jul 22, 2008)

ya is that a rope belt of some kind we see there


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## mklotz (Jul 23, 2008)

Bernd,

Manual CNC. I call it HAM - Human Assisted Machining.

Many years ago, I bought some back-up drive belts from Blue Ridge. They claimed that their new braided, multi-strand belts were much more durable than the standard poly round belts.
The one you see in the photo has been in use for twenty years so I guess their claim was justified. While it is rope-like in appearance, it's made of some synthetic material that I can't identify.

Bob,

I had the same experience reading the Unimat catalogue. In fact, I can say that drooling over the Unimat advertisements had a lot to do with getting me into machining as a hobby.


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## greenie (Jul 24, 2008)

There is a method for rising and falling of the head, to enable changing of different tooling AND keeping it aligned to the original spot. A bit of machining is required, this mod is not for the faint of heart.
If anybody's interested, I'll take a few pics of the modification that I've done to my U3, this same mod could be done to the DB/SL as well.


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## Mcgyver (Jul 28, 2008)

hey greenie, lets see some pics of the mod.....


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## mogogear (Sep 2, 2008)

Thanks Marv and I second the call for Greenie to show his mod's - I am very newcomer to suing a lathe and my only lathe is a very lightly used and fully tooled UnimatSL..also a lucky find on Craigslist and a fast pounce.. I see the low speed adapters almost going for what I paid for the whole kit...

I am almost tempted to sell it and split off most of the major accessories and then grab a Chinese import 7X12 from Harbor Freight.... and still put some money in the bank...tell me I am stupid to think that way...??....


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## mklotz (Sep 3, 2008)

Mo,

If your finances allow, hang on to the Unimat. When you buy larger tooling, you'll quickly discover that most anything you buy won't be able to generate the high spindle speeds needed by truly tiny tooling. This is where the Unimat shines - both in lathe and mill configuration.

Also, I mount my Unimat on my 12 x 30 lathe for impromptu toolpost grinding and other specialized operations. Its small size makes this an attractive alternative.

If there's any way you can manage it, don't give up the present and future flexibility that the Unimat offers.


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## mogogear (Sep 3, 2008)

Time will tell -thank you Marve....


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## mogogear (Sep 3, 2008)

So on you gentleman's Unimats--- do you use a end mill holder like this when doing ?small scale milling?

http://cgi.ebay.com/UNIMAT-1-4-END-MILL-HOLDER_W0QQitemZ260280576666QQihZ016QQcategoryZ13876QQssPageNameZWDVWQQrdZ1QQcmdZViewItem


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