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View Full Version : Emco Unimat SL 1000:- No guts



BIGRR
09-11-2014, 09:14 AM
Hi (from down under),

I was given the above hobby lathe. I consider in very good order.

I did a fitting and machining trade 1964.

What I would like to know is should this lathe drill a 1/8" hole in mild steel OR has the electric motor failed.
It took me about 10 minutes and the (brand new) drill bit only drilled the hole about 3/16" deep. I pulled the bar out of the chuck and finished the hole through the center of the bar with a portable drill in the vice.

I stripped the motor for inspection and it appeared brand new?!

I have read countless posts on the internet regards SL 1000 having "No guts", however I would have thought with a new drill bit and a gentle feed that it should have been achievable (although near its limit).

Thanks

Robert

PS Hope I have posted this question in the correct place. :)

flylo
09-11-2014, 11:18 AM
Welcome to the forum! I have one with the later plastic moter & it does fine for it's size. I keep it in the house for small jobs. Looks easy to replace with a bigger motor. Good luck!

mars-red
09-11-2014, 11:42 AM
I've never used one, but the SL1000 appears to have stepped pulleys going directly from the motor to the spindle. If you ran it through a countershaft to really gear it down, I'm sure that would make a big difference. Even my delicate little watchmaker's lathe will drill 1/8" through steel with the speed stepped down through a countershaft. It's not really the reduction in speed that will help you, but the increase in torque.

Paul Alciatore
09-11-2014, 12:50 PM
Been using a Unimat for close to 50 years and it should have no trouble drilling holes up to 1/4" in mild steel, aluminum, brass, plastic, etc. None at all. 3/8" may need a bit of technique, not much, just a bit. I have no hesitation to drill 1/2" in steel, but technique will be a lot more important. Never tried any larger ones on it.

Check your drill bit. "New" does not mean sharp.

Check your belts. They may be old or too large. They should be a nice stretch fit on the pulleys. At 1/8" you should be going fairly fast. And do use some cutting fluid or oil.

Is your motor stalling? You should be able to tell from the sound of the motor. If it is stalling with a sharp, 1/8" bit, then something IS wrong with it. Is it the original? Mine has brushes: check them. Perhaps you need new brushes.

Paul Alciatore
09-11-2014, 12:58 PM
The Unimat is always run "geared down". You can find the appropriate speeds for different diameters in the manual, which you can find here:

https://groups.yahoo.com/neo/groups/UNIMAT/files/Unimat%203%20manual/

And yes, this machine does require a bit more attention to using the proper speed than a 1 or 2 HP drill press.



I've never used one, but the SL1000 appears to have stepped pulleys going directly from the motor to the spindle. If you ran it through a countershaft to really gear it down, I'm sure that would make a big difference. Even my delicate little watchmaker's lathe will drill 1/8" through steel with the speed stepped down through a countershaft. It's not really the reduction in speed that will help you, but the increase in torque.

ahidley
09-11-2014, 01:34 PM
You are spinning the chuck in the correct direction. ?

mikem
09-11-2014, 02:15 PM
Ahidley--good question!

JCHannum
09-11-2014, 03:03 PM
Ditto Ahidley's question. Unless you actually stalled the spindle, you have some other problem. If the spindle stalled, check the belt, these used a drive belt which is difficult to locate for replacement. Often O-rings are substituted with less than satisfactory results. If the motor stalled, it is the problem, but should be capable of the task.

Frank Ford
09-11-2014, 03:36 PM
Eh, could it be the drill bit? I've run into some new super-cheap ones that didn't have any relief at all, and simply didn't work. My life improved a fair bit once I discovered split point drills and jettisoned my old ones.

flylo
09-11-2014, 05:24 PM
Not a left handed drill bit by chance? I do have a set.

loose nut
09-11-2014, 07:06 PM
Unimat belts stretch or age over time and tend to expand out from the pulleys (sometimes they flip off the pulleys) at higher speeds so they probably are slipping if they do so.

Paul Alciatore
09-11-2014, 09:31 PM
The Unimat design does not have any provision for reverse. Unless a reversible motor has been substituted for the OEM one, he is going in the correct direction.

Assuming the steel was not hardened, check (in order):

0. spindle speed (2,000 to 4,000 for 1/8" in mild steel)
1. drill sharpness
2. belt tension
3. motor brushes (if any)
4. motor itself

One more thought. You stated you used a "gentle feed". At 1/8" diameter, there was absolutely no need for that. Perhaps you work hardened the steel.




You are spinning the chuck in the correct direction. ?

BIGRR
09-11-2014, 09:48 PM
Been using a Unimat for close to 50 years and it should have no trouble drilling holes up to 1/4" in mild steel, aluminum, brass, plastic, etc. None at all. 3/8" may need a bit of technique, not much, just a bit. I have no hesitation to drill 1/2" in steel, but technique will be a lot more important. Never tried any larger ones on it.

Check your drill bit. "New" does not mean sharp.

Check your belts. They may be old or too large. They should be a nice stretch fit on the pulleys. At 1/8" you should be going fairly fast. And do use some cutting fluid or oil.

Is your motor stalling? You should be able to tell from the sound of the motor. If it is stalling with a sharp, 1/8" bit, then something IS wrong with it. Is it the original? Mine has brushes: check them. Perhaps you need new brushes.

The above is the answer I was looking for Thanks Paul.

AND thanks to all the other posters for your ideas and comments. I have not had the Unimat out since the 1/8" hole episode (sort of lost interest in it).

I will have to get the thing out and have a fiddle it testing all the advice received (last time I was in one hell of a hurry to make a new steel yoke for my clutch cable). The lathe was stalling under very light feed via the tail stock. I think although the revs for a 1/8" drill should be around 2000, I will gear it down and see what it will do. Otherwise I may fit a hand drill motor or similar to the Unimat.

Thanks to all again. :-)

Robert

Sydney

Australia

tlfamm
09-11-2014, 10:05 PM
re: "Otherwise I may fit a hand drill motor or similar to the Unimat."

A better alternative might be to locate a Unimat "slow-speed" attachment - they occasionally appear on the used market:

http://www.tomstoolstore.com/servlet/the-47/Unimat-Slow-Speed-Attachment/Detail

darryl
09-11-2014, 11:00 PM
I'm reminded of the Taig- another small lathe, but with a seemingly huge motor for the size lathe. It's probably 1/3 horse or so, but the point is that you do have the option to re-motor the Unimat. I did it to mine, and it has way more guts now. I haven't used it much since, and I did also mount the headstock to a way more solid bed-

I'm sure there will be a point where there's too much power and the spindle could become bent or other damage occur, but it's going to depend on how you'd be using it. To drill, the forces are mainly axial and all the balls in the front spindle bearing are taking the load. You should be able to use more power without problems.

But also, I too am thinking that if there's that much problem drilling a 1/8 hole, the bit is probably not sharp, or sharpened correctly.

BIGRR
09-11-2014, 11:30 PM
"EUREKA"

Appears I had forgotten about gearing. When I dropped the speed down to the last and second last available there was no problem. When I read Paul's post I thought 3/8" drill Oh yer!! I appolagize Paul.

I left the machine shop 1971! I did not know you could stall a lathe, the last one I worked on had a 4' chuck with a 16' bed. If you were drilling 2" or 3" hole and having problems, you would just put a 4' bar in the tail stock wheel and give it a tug. I now realize that when I am working a lathe 1/30th the size with a sewing machine motor that you have to take it easy and as an old apprentice instructor said "take a few bites at the cherry".

Thanks again all.

Robert

By the way, I just looked at what came with the Unimat:- 3 & 4 jaw chucks, face plate, vice, collets, steady, 2 x drill chucks, live center, indexing head, mast, countless drills, taps, dies, tool bits, trepanning bar and other gizzmos and the lathe has a long feed set up. Not bad for free!

Paul Alciatore
09-12-2014, 02:33 AM
Well, you probably could stall that 4' x 16' one too, but I don't want to be ANYWHERE near when you try it.

BIGRR
09-12-2014, 03:26 AM
re: "Otherwise I may fit a hand drill motor or similar to the Unimat."

A better alternative might be to locate a Unimat "slow-speed" attachment - they occasionally appear on the used market:

http://www.tomstoolstore.com/servlet/the-47/Unimat-Slow-Speed-Attachment/Detail

Yes that reduction unit is a good thing and would help. Though I doubt a 1" drill would fit in the chuck :-)!

Robert

loose nut
09-12-2014, 03:31 PM
If the motor is gone then a sewing machine motor is a good replacement.