Hey. I recently bought a mini lathe but it arrived with minor damage. The change gear cover was broken into bits and the plastic gear on the auto feed screw was also broken in bits. The power box was broken at the bolt holes so was hanging off.
Instead of sending it back which was a real hassle I contacted the company and had replacement parts sent as I felt it was just superficial damage.
After fixing it up and using it a few times I noticed a wobble. I thought it was runout but looking at the spindle from behind after taking off the change gear cover I noticed a slight wobble in the spindle. The gear on the back end of the spindle seems to mesh tighter with the gear under it at one point in a single revolution.
Now I am thinking that it was dropped during transit obviously but as the feed screw gear was broken it must have caused a shock up the gear train and maybe bending the spindle?
Im not 100% sure tho as the bearings seem to move slightly during revolution also.

Anyone have any recomendations?

Its a 7 × 12 (300mm between centres) apex mini lathe.

wrote in message
...
Hey. I recently bought a mini lathe but it arrived with minor damage.
The change gear cover was broken into bits and the plastic gear on the
auto feed screw was also broken in bits. The power box was broken at
the bolt holes so was hanging off.
Instead of sending it back which was a real hassle I contacted the
company and had replacement parts sent as I felt it was just
superficial damage.
After fixing it up and using it a few times I noticed a wobble. I
thought it was runout but looking at the spindle from behind after
taking off the change gear cover I noticed a slight wobble in the
spindle. The gear on the back end of the spindle seems to mesh tighter
with the gear under it at one point in a single revolution.
Now I am thinking that it was dropped during transit obviously but as
the feed screw gear was broken it must have caused a shock up the gear
train and maybe bending the spindle?
Im not 100% sure tho as the bearings seem to move slightly during
revolution also.

Anyone have any recomendations?

===============

https://www.precisebits.com/tutorial...dle_runout.htm
You'll need a dial indicator anyway to center work in a 4-jaw chuck.
I've found expensive high-quality ones second-hand and can't suggest a
source for an adequate new one.

On Thu, 16 May 2019 04:55:15 -0700 (PDT), wrote:

Hey. I recently bought a mini lathe but it arrived with minor damage. The change gear cover was broken into bits and the plastic gear on the auto feed screw was also broken in bits. The power box was broken at the bolt holes so was hanging off.
Instead of sending it back which was a real hassle I contacted the company and had replacement parts sent as I felt it was just superficial damage.
After fixing it up and using it a few times I noticed a wobble. I thought it was runout but looking at the spindle from behind after taking off the change gear cover I noticed a slight wobble in the spindle. The gear on the back end of the spindle seems to mesh tighter with the gear under it at one point in a single revolution.
Now I am thinking that it was dropped during transit obviously but as the feed screw gear was broken it must have caused a shock up the gear train and maybe bending the spindle?
Im not 100% sure tho as the bearings seem to move slightly during revolution also.

Anyone have any recomendations?

I'm only an untrained hobbysit with basically no training. A "real"
machinist, or engineer, might disagree/advise you differently... I'm not
an expert; but this is how _I_ tend to approach problems like the one
you're having (with the assumption that I want to fix it myself rather
than ship it back the seller).

1st, I would very carefully check that the headstock wasn't
cracked/broken. I might even pull the spindle and bearing races to give
me more visual access to look for cracks. I'd also look for cracks where
the head attaches to the bed. Carefully looking over the major parts of
the late for fractures. If I find any cracks - it's "game over" for me.

My intial look at the spindle: it's push, pull, spin the spindle by hand
- just feeling/listening for any sign of obvious damage; that the
preload is properly set, etc; and looking for any other obvous physical
damage.

If all the above seemed OK, I would look for an inspection record for my
lathe. The inpection record will have diagrams for the tests that done
on the lathe at the factory. East test on the sheel will have a maximum
acceptable deviation for that test. I would repeat each test on that
sheet - and make note of any that were out of tolerance. They're the
ones that will need further diagnosis to sort out the cause of the
deviation. If you can't find an inspection record for your lathe - you
might find one "close enough" on the internet. One for another 7x12
should be comperable.

Let's say you did all that, and the conclusions you come to a the
spindle is possibly deformed/bent. To confirm, I would pull the
spindle, set it in vee blocks on a surface plate and carefully evaluate
it using a dial test indicator. That setup can usually dectect bends
& out of round conditions - it just takes care and patience.

That's the general idea how I would approach things.

Bill


--
Email address is a Spam trap.

On Thu, 16 May 2019 14:02:09 -0400, Bill wrote:

On Thu, 16 May 2019 04:55:15 -0700 (PDT), wrote:

Hey. I recently bought a mini lathe but it arrived with minor damage. The change gear cover was broken into bits and the plastic gear on the auto feed screw was also broken in bits. The power box was broken at the bolt holes so was hanging off.
Instead of sending it back which was a real hassle I contacted the company and had replacement parts sent as I felt it was just superficial damage.
After fixing it up and using it a few times I noticed a wobble. I thought it was runout but looking at the spindle from behind after taking off the change gear cover I noticed a slight wobble in the spindle. The gear on the back end of the spindle seems to mesh tighter with the gear under it at one point in a single revolution.
Now I am thinking that it was dropped during transit obviously but as the feed screw gear was broken it must have caused a shock up the gear train and maybe bending the spindle?
Im not 100% sure tho as the bearings seem to move slightly during revolution also.

Anyone have any recomendations?

I'm only an untrained hobbysit with basically no training. A "real"
machinist, or engineer, might disagree/advise you differently... I'm not
an expert; but this is how _I_ tend to approach problems like the one
you're having (with the assumption that I want to fix it myself rather
than ship it back the seller).

1st, I would very carefully check that the headstock wasn't
cracked/broken. I might even pull the spindle and bearing races to give
me more visual access to look for cracks. I'd also look for cracks where
the head attaches to the bed. Carefully looking over the major parts of
the late for fractures. If I find any cracks - it's "game over" for me.

My intial look at the spindle: it's push, pull, spin the spindle by hand
- just feeling/listening for any sign of obvious damage; that the
preload is properly set, etc; and looking for any other obvous physical
damage.

If all the above seemed OK, I would look for an inspection record for my
lathe. The inpection record will have diagrams for the tests that done
on the lathe at the factory. East test on the sheel will have a maximum
acceptable deviation for that test. I would repeat each test on that
sheet - and make note of any that were out of tolerance. They're the
ones that will need further diagnosis to sort out the cause of the
deviation. If you can't find an inspection record for your lathe - you
might find one "close enough" on the internet. One for another 7x12
should be comperable.

Let's say you did all that, and the conclusions you come to a the
spindle is possibly deformed/bent. To confirm, I would pull the
spindle, set it in vee blocks on a surface plate and carefully evaluate
it using a dial test indicator. That setup can usually dectect bends
& out of round conditions - it just takes care and patience.

That's the general idea how I would approach things.

Bill

Good enough. Id spin the spindle between centers myself and check
but...shrug.

__

"Poor widdle Wudy...mentally ill, lies constantly, doesnt know who he is, or even what gender "he" is.

No more pathetic creature has ever walked the earth. But...he is locked into a mental hospital for the safety of the public.

Which is a very good thing."

Asun rauhassa, valmistaudun sotaan.


---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus