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View Full Version : Using Unimat SL as a tool post grinder



chuckinnc
12-29-2009, 09:54 AM
I picked up a 7 x10 mini lathe last night to replace the small SL so I am thinking of using the Unimat as a tool post grinder for my 12" lathes, old craftsman & new import. Both have BXA quick change tool post, so I need a idea for mounting the Unimat headstock on a quick change block.
If any one has done this or has good ideas or tips it would be a big help. Photos
would be even better, anyway I need to convert the little SL to something usefull. I could install in on the milling stand and use it as a mini mill but I think
a tool post gringer/drilling head would be more usefull, I am open to any ideas
as how to use the SL for something besides lathe operation.

Doozer
12-29-2009, 10:47 AM
What project do you need to do cylindrical grinding for?
Toolpost grinders get grit all over your lathe and it is hard to clean.
With surface grinding, if one knows grinding real well, you can get away without coolant.
With cylindrical grinding coolant is almost a must.
Buy a cylindrical grinder if you need to do cylindrical grinding.
One is on my wish list.
I have a surface grinder, and it will not meet my needs for cylindrical grinding, hence a real one is on my wish list.
I guess in a super pinch situation, a toolpost grinder could be helpful.
But the mess cleanup and fiddling around is not worth it. If you get a project that needs cylindrical grinding, sub it out and pay for it. If rigging this thing up is a novelty, just to say you have capacity to do cylindrical grinding, it might not be worth it. If say you want to grind a 6" long hardened shaft straight in your lathe for example, you are going to have a hell of a time achieving this with no taper. I have used a 5000 pound cylindrical grinder, and getting at dialed in does take a bit of doing. Trying the same thing on a mini lathe, the odds seem stacked against you. Not trying to be a buzz kill, just saying there are a lot of factors involved in cylindrical grinding to get good results. I am only OK at grinding, and wheel selection still blows my mind a little. There are so many grits, bonds, materials, and hardnesses that ones needs to be familiar with for different grinding conditions, it is a lot overwhelming. If you do make this toolpost grinder and get poor results, try not to get discuraged when things start not working out. Investigate rubber-bond wheels as they are more forgiving. That is what swing-grinders use, popular in England. Learn all you can about the different wheels available. Rig up coolant if you can.
--Doozer

Dawai
12-29-2009, 11:03 AM
I... well... in the spirit of compadre..

Took a piece of one inch tube, found some 5/8" bushings.. a piece of 5/8" rod shafting.. Mounted a dc motor on the end of it, drilled the end for a 1/4" mandrel. Dc drive from another project.

built a inside tool post grinder.. Less than $20.

What can you do with it? refinish cylinders.. bore.. on the lathe.. polish inside a bore.. I am building a harley cylinder adapter, cut out part to fit a chuck adapter for my L00 chuck mount. Still tinkering with the idea of lateral adjustments to compensate for out of center previous boring jobs..

Most shops just bore it big enough to do away with any set up errors. (egged cylinders). it ain't theirs.. f-it.. time is money.

chuckinnc
12-29-2009, 11:04 AM
I don't, not at this time. All my machinist activities are just hobby and never
any critical measurement stuff. Instead of having two mini lathes setting around I was trying to come up with something usefull, not that I need it for anything yet as its just another hobby project. Tool post grinder would just
be a learning tool more than anything.

vpt
12-29-2009, 11:16 AM
I have been kind of thinking about doing this same kind of thing. I was looking into getting an atlas 6" headstock machining it just a bit and mounting it to my 10" cross slide swivel. I measured it out and the 6" would be perfectly on horizontal center line of the 10". My thoughts were that I could use the 10" backgeared as a somewhat rotary table and use the 6" to hold endmills, cutters, etc.


I had this thought when I was trying to figure out how to do the recess seen on this QCTP body:

http://home.inter.net/mthomas/qctp-6.jpg

Mcgyver
12-29-2009, 12:12 PM
i second the keep the grit away from the lathe sentiment.

besides, you could probably sell that unimat for quite a bit more than a good Dumore tool post grinder will cost....and if the dumore is in good shape, its bearings will be up to the task of grinding which i doubt the unimat's are

Paul Alciatore
12-29-2009, 01:39 PM
I have done this. Here is my Unimat on my SB grinding an internal taper.

http://img.photobucket.com/albums/v55/EPAIII/GrindingTaper1.jpg

The Unimat headstock has a piece of 3/8" square stock screwed to it's bottom to allow mounting in my QC tool post. It's location there was chosen to put the spindle axis on the lathe center. The height adjust on the QC tool post easily allows precise centering.

As for results, it did work. I was grinding an ER11 collet holder in the photo and it worked. The finish did show some pattern, probably from vibrations but it is not clear if it was due to the Unimat's bearings or just the overall setup. I can see a lot of room for vibration with all that mass hanging above the SB's compound slide. But the finish was certainly a lot better than a turned finish.

I plan to get some bags filled with lead shot and try them for dampening the vibrations the next time I try something like this.

Also, I did not use coolant and I suspect that it would make a much better finish.

Here's another picuure of the Unimat combined with the SB:

http://img.photobucket.com/albums/v55/EPAIII/P02.jpg

I was milling a flat on a boring bar I was making to bore out a 25mm hole.

And here's another:

http://img.photobucket.com/albums/v55/EPAIII/P09.jpg

This setup allowed drilling a hole in that same boring bar while it was still in the lathe.

I have 60 indexing holes on my SB chuck's backplate so I can easily index drilling or milling operations in the lathe. You can see these indexing holes in the second picture.

In these two photos the Unimat is mounted on the compound slide with a rectangular block I made to replace the original Unimat casting used to mount the head on the vertical post for drilling and milling. I simply added a 1/2" hole through it to allow clamping it down in place of the tool post on the SB. The fact that it is rectangular instead of a casting makes such mounting easy. That block is where I needed to bore the 25mm hole to fit the Unimat's vertical post so it is actually helping to make itself. You can see this partially finished hole toward the back of the block in both pictures that show it.

I find the Unimat is very useful on the SB lathe. And all of these operations were suggested in the original Unimat manual.

Dawai
12-29-2009, 01:44 PM
I had one of the old german unimats.. never occurred to me to make a end mill sharpener out of it.. Till after I sold it for a song..

with a lil mod.. Nice use on a lathe..

chuckinnc
12-29-2009, 01:44 PM
I must be missing something in the previous post by VPT his photo came through just fine but I am not getting photos on your post?

Paul Alciatore
12-29-2009, 04:13 PM
I must be missing something in the previous post by VPT his photo came through just fine but I am not getting photos on your post?

If you are referring to my post, try again. I was editing when you posted.

vpt
12-29-2009, 07:31 PM
Awesome! Because of the smaller size it looks as those the unimat is easier to mount in different positions than the 6" atlas would be. I'll have o start looking for a complete unimat headstock now I guess.

Thanks for the pics Paul!!

Paul Alciatore
12-29-2009, 08:23 PM
It's not only the smaller size, but also the fact that it is designed to rotate 360 degrees on it's mounting pin. The drilling or milling jobs I have shown could have easily been at an angle to the lathe axis.

vpt
12-29-2009, 09:12 PM
When I originally thought about getting a lathe head I looked into the unimat and even watched a few auctions on ebay. But than I found some measurements of the unimat and thought it would be to small to handle endmills and small cutters and whatnot. So than I started watching for a 6" atlas. But after the pics you posted and the info I am glad I didn't get the atlas yet.

Now the unimat prices are going to go up because of you. :p

Astronowanabe
12-30-2009, 02:03 AM
unfortunately going to school takes away details ... not unlike sandblasting your brain . so I apologize for not remembering the name of who on this forum I blatantly stole this idea from.

http://ix.cs.uoregon.edu/~tomc/images/unimat-toolpost.jpg

base mounted in the toolpost

http://ix.cs.uoregon.edu/~tomc/images/unimat-compound.jpg

base mounted in place of the compound


at some point I expect I will make another mount point off the edge of the disk but I haven't needed it yet.


edit. it is on a 10x24 Logan in this case

Circlip
12-30-2009, 05:24 AM
Instead of screwing up a perfectly good lathe, why not try this:-

http://www.hemingwaykits.com/acatalog/The_Quick_Step_Mill__.html

"Model Engineers Workshop" did a couple of constructional articles on the quickstep, so as the Chinese copyists haven't brought one out yet for everyone to have a tool gloat about being so cheap, you could try making your own.

Alternatively, you could always mount a Sheerline on you toolpost.

Regards Ian.

Bguns
12-30-2009, 06:04 AM
Thats the beauty of the Unimat..

For 645 UK Pounds (~ $1031.00) for that quick step mill, or the time needed to make it...

I could buy a old Bridgeport Mill.... (don't need 2 tho...)

Or buy 3 or 4 Unimats...

No modifications needed at all to it...

It is already designed for light milling and flexibility.

Especially flexibility :)

With care, it will do decent light work...

A couple adapters for Compound slot and done ...

I have most of the attachments, and will sharpen some end mills on it, when I get a couple more dull ones..

vpt
12-30-2009, 10:38 AM
it is cheaper to get a unimat than to build a head, shaft, pulleys, and buy a motor.

Circlip
12-30-2009, 11:35 AM
But a Sheerline would be MUCH better suited and accurate for bolting to the toolpost. Heck, you could even CNC it.

Regards Ian.

oldtiffie
12-30-2009, 11:59 AM
I loved it - I just could not help myself!!!

Using the "Unimat" on a lathe - a very good idea by the way - is turning (sorry) a USA-made "good old American iron" lathe into a dreaded "3-in-1" and so apparently cloning or "knocking off" an Asian (read: Chinese) product - "puny round-column mill" and all.

And all with the approval of the "good old American iron" Brigade.

I can see the iron(??) of it all.

This has truly made my day (New Year's Eve) and my year (2009 going into 2010).

It doesn't get better than this.

Circlip
12-30-2009, 12:35 PM
:D Thanks Tiffe, a "Pat" on the head.

Evan
12-30-2009, 01:36 PM
As further proof that I don't post everything that I do in the shop there is this:

:D

http://metalshopborealis.ca/pics3/4thaxis.jpg

Paul Alciatore
12-30-2009, 03:05 PM
Instead of screwing up a perfectly good lathe, why not try this:-

http://www.hemingwaykits.com/acatalog/The_Quick_Step_Mill__.html

"Model Engineers Workshop" did a couple of constructional articles on the quickstep, so as the Chinese copyists haven't brought one out yet for everyone to have a tool gloat about being so cheap, you could try making your own.

Alternatively, you could always mount a Sheerline on you toolpost.

Regards Ian.

My Unimat is still completely usable in it's original form as a lathe, drill press, mill, circular saw, and all the other tools it is. My mounting of it's headstock on the SB lathe in no way harms the original machine. It's just pieces in a set-up. This is versatility.

I am also working on a T&C grinder design that will use the Unimat headstock for it's first generation spindle. If it works well, I may look for a E-bay headstock to modify permanently with better bearings and if not I will replace it with a dedicated design.

That being said, the milling head at that link looks like a very nice accessory. But $645.00??? My Unimat was purchased new (in the 60s) for less than 1/5 of that and I already had it. So cost wise it is a natural choice for me. Perhaps others here have that kind of money. But again, I spent about three times that and got a real (import) mill that is full sized.

Bguns
01-01-2010, 06:52 PM
Feeling ignored here..

That was 645 POUNDS ~1030.00 US....

That is 3 or 4 ebay Unimats... or an old bridgeport...

Not going to buy a sherline, as I already have a FREE unimat.

And after running Monarchs, SB's, and 12 in Clausings, Sheldons, Atlas's, Chinese... Why would I need 2 tiny lathes around? .... I don't do watchwork, or micro models...

Many milling spindles have been fitted to lathes before... An attachment that comes in handy once in a while. And as Evan has done, can add a new axis for CNC

darryl
01-01-2010, 07:44 PM
I've used my Unimat like that on the lathe- sometimes I can't perform a needed operation in any other way. If it works for you, do it.

My major dislike was the round rod ways, and the ensuing lack of rigidity on down the line. My second dislike was the inability to get a real return to parallel if you swiveled the head to cut a taper. Sure there's a locating pin, but it doesn't ensure a perfect re-alignment. To solve both these problems, I have found a cast iron dovetailed structure which I want to mount the Unimat head onto, then make up a new crosslide, etc. While I'm at it, I'll raise the head about an inch, equivalent to what the accessory riser block does.

This new bed is built in such a way that it will be easy to make a sort of pedestal stand for it. I'll probably change the motor to a dc one as well, since I'm already set up to operate dc motors at variable speeds. The original motor has had a lot of use and needs either some work, or replacement. I can't fault the spindle bearings- only the relatively small spindle bore- but this is a Unimat after all. I'd love to have it set up again as a tool for higher speed, smaller work, with at least this improvement in its functionality.

I will not be making any changes to the headstock which would prevent it's use as a lathe accessory with the existing adapters.

dian
05-03-2012, 02:05 PM
i coudnt resist to exhume this.

"I have done this. Here is my Unimat on my SB grinding an internal taper."

paul, are you really using a drill chuck for grinding it? looks like the 0.3 mm runnout variety. did you somehow grind it in or did you dress away most of the wheel?

laddy
05-03-2012, 04:14 PM
I love my Unimat, in fact I have two. I don't use them often since I have a 9" South Bend, a 6" craftsman and two milling machines a large and a small. It is always a pleasure to use and visibility is pure, finish is always excellant. Size is the only limiting factor. Fantastic for a ton of operations. I never thought of the above uses but they sure make sense. Good job! Fred

uncle pete
05-03-2012, 04:53 PM
Very,very handy to have a system for lathe Headstock dividing and Live Tooling on the cross or top slide. Sherline also offer two types of powered headstocks. One will do I think 10,000 rpm.

Pete

jkilroy
05-03-2012, 08:15 PM
I think the Taig head stock would make a better adaption given the ER collet spindle.

vpt
05-03-2012, 10:36 PM
Since I posted earlier in this thread I got one as well, made the mount, and have done ALL kinds of otherwise impossible operations with it!

http://img62.imageshack.us/img62/9714/texas056.jpg

http://img97.imageshack.us/img97/4499/gear001c.jpg

http://img535.imageshack.us/img535/1456/gear002.jpg

yes thats allot of room to flex but light cuts still work fine.

http://img41.imageshack.us/img41/9648/excursionfpr015.jpg

vpt
05-03-2012, 10:38 PM
http://img704.imageshack.us/img704/2088/texas061.jpg

http://img18.imageshack.us/img18/7315/qctp018.jpg

http://img717.imageshack.us/img717/9049/qctp016.jpg

Paul Alciatore
05-04-2012, 03:42 AM
i coudnt resist to exhume this.

"I have done this. Here is my Unimat on my SB grinding an internal taper."

paul, are you really using a drill chuck for grinding it? looks like the 0.3 mm runnout variety. did you somehow grind it in or did you dress away most of the wheel?

Wow, quite an old thread that was drawn up.

Yes, I really did use a drill chuck, I didn't have a collet holder and was making one in the photo. So I used what I had, the drill chuck. If I recall correctly, I did dress the wheel after it was mounted. It worked and I now have a collet holder for my Uni.

If you think that's bad, you should try holding a milling cutter in a three jaw. Sometimes you do what you have to do to make the cut.

dian
05-04-2012, 04:46 AM
in a post from 2007 i see you used a diamond burr in the drill chuck. now im really surprised. you didnt dress it, did you? how come it worked? that chuck must be a real treasure.