UNIMATS ARE NEAT BUT???

[Ulma Doctor]

Trying to blame the machine again.
There is no hunt it just do the job right. A operator may time to get uses to lathe but he can maintain ±0.000,2" on most work.
If using a turret lathe this can be even closer.
Do not wast time on making ever part ±0.000,1" unless you are doing for fun.

Dave

please perform these tests and report your findings, on a Unimat DB200 or SL1000, we were mot in discussion of more capable equipment

 

[Ulma Doctor]

Thanks, the hunt for the tenths is great fun.

chasings tenths is great fun, i will agree.

 

[Pylonracer]

It's amusing to view such a comversation.

I started out by saying in essence with extra work (and tricks) tolerances greater then the lathe specs are obtainable. The skill of the operator also comes into play. I severely doubt someone can hold a toleramce of .0001 on a Unimat (any model). Judging by the U3 I had, I doubt anyone could hold .0001 repeatedly.

But not all lathes are equal. The typical engine lathe is not made to the same specifications as say a Hardinge HLV-H. Or a Levin. Much more is capable repeatedly. The old Rivetts were reknowned for their accuracy. There was an article on the net over 20 years ago describing how a guy modified a Rivett 608 to cut 100,000 threads per inch. Creating what was called a diffrection grating. I imagine you can still look that up.

Is stuff like that doable on a Chinese 7 x 12? Go ahead and try. I remember a guy saying years ago it's nice when you can make 2 "identical" parts on a lathe. But with those you couldn't make 1!!!. I am not knocking people's machines. It's just that there is a wide variation in quality. And that's just the way it is. A very well made machine is capable of higher tolerances - repeatedly. The cheaper machines require more work/tricks/skill to achieve better results.

Wise words.

 

[Smithdoor]

please perform these tests and report your findings, on a Unimat DB200 or SL1000, we were mot in discussion of more capable equipment

If perform test them you adjust or shim. They use round bars for bedway. Back to machinist to do work.

Dave

Ods are some did made adjustments before you.
FYI
I would upgrade to 7x12 mini lathe with cast iron bedways. You find for qbout $420.00 on Amazon and Walmart. Look for belt drive the quit like your lathe.

 

[Smithdoor]

please perform these tests and report your findings, on a Unimat DB200 or SL1000, we were mot in discussion of more capable equipment

Look for a mini lathe I would look for metal feed gears the plastic does not last long.
They are 60 to 80 pounds to move around.
The biggest problem with most lathes is tail stock is every one tries making a tapper then pain to get right again.

Dave

 

[CraigH]

It's amusing to view such a comversation.

I started out by saying in essence with extra work (and tricks) tolerances greater then the lathe specs are obtainable. The skill of the operator also comes into play. I severely doubt someone can hold a toleramce of .0001 on a Unimat (any model). Judging by the U3 I had, I doubt anyone could hold .0001 repeatedly.

But not all lathes are equal. The typical engine lathe is not made to the same specifications as say a Hardinge HLV-H. Or a Levin. Much more is capable repeatedly. The old Rivetts were reknowned for their accuracy. There was an article on the net over 20 years ago describing how a guy modified a Rivett 608 to cut 100,000 threads per inch. Creating what was called a diffrection grating. I imagine you can still look that up.

Is stuff like that doable on a Chinese 7 x 12? Go ahead and try. I remember a guy saying years ago it's nice when you can make 2 "identical" parts on a lathe. But with those you couldn't make 1!!!. I am not knocking people's machines. It's just that there is a wide variation in quality. And that's just the way it is. A very well made machine is capable of higher tolerances - repeatedly. The cheaper machines require more work/tricks/skill to achieve better results.

Amazing how 10X the weight and 10X the price can help - by extension 20X the price and 20X the price helps even more.