Help Servicing My Lathe.

Topics regarding professional record cutting.

Moderators: piaptk, tragwag, Steve E., Aussie0zborn

Post Reply
User avatar
concretecowboy71
Posts: 569
Joined: Mon Mar 08, 2010 10:13 am
Location: Cleveland, Ohio, USA
Contact:

Help Servicing My Lathe.

Post: # 12105Unread post concretecowboy71
Thu Jan 13, 2011 11:08 pm

I am having the first issue that I cannot seem to deal with on my own.

A couple weeks ago my lathe began cutting deep "double" grooves and it seemed like the issue was solved by cleaning and lubrication.

Today the problem came back about ten times worse. I have cleaned everything, re lubricated the slide, the bearings and even the pulleys that the guide wire runs on at the back of the machine.

I cleaned the lead screw and made sure no lubricant dripped onto it.

I rearranged my hose so nothing is binding.

Any other ideas?

I am beginning to think I made need professional service help. Does this exist for these lathes? Who do you trust? Albert has spent a lot of time on the phone with me, but somebody may need to look at this to figure out what is wrong.

Thanks
Cutting Masters in Bristol,Virginia, USA
Well Made Music / Gotta Groove Records

andybee
Posts: 702
Joined: Mon Aug 14, 2006 2:12 pm
Location: Germany

Post: # 12106Unread post andybee
Fri Jan 14, 2011 4:18 am

Hi!
Maybe the feed nut is full of dirt?
You have to demount the cutting arm.
normally, there is a plate at the right side, there
are 2 screws, then you can loosen the plate, remove the
screw and slide the arm out to the right side (don´t forget
to disassemble the "direction wire" before.
Then, you can see the feed nut under the arm, and clean it
with some fine sand paper.
Good Luck!
Andreas

User avatar
concretecowboy71
Posts: 569
Joined: Mon Mar 08, 2010 10:13 am
Location: Cleveland, Ohio, USA
Contact:

Post: # 12109Unread post concretecowboy71
Fri Jan 14, 2011 8:37 am

I believe I have found what you are talking about. Late last night I removed that panel and saw the two bolts that hold that on. I did not remove it because it was late and I tend to make my worst mistakes when I am tired.

That might be my project for today.

Is there any way to adjust the pressure of the feed nut against the lead screw? I see a spring and a nut of some kind in there, but I left it alone, for the same reasons as above.

Thanks.
Cutting Masters in Bristol,Virginia, USA
Well Made Music / Gotta Groove Records

User avatar
TotalSonic
Posts: 227
Joined: Tue Sep 30, 2008 7:08 pm
Contact:

Post: # 12110Unread post TotalSonic
Fri Jan 14, 2011 10:44 am

If you still end up stumped then after Al Grundy the person most knowledgeable about Neumann lathes in the USA who offers repair services is Chris Muth - http://www.taloowa.com/tccontact.html

He's worked directly with Al, spent years as head in house tech for Sterling Sound (including doing all the repairs and mods on their VMS-80 and 70's), and has designed all the Dangerous Music gear as well - so the man knows what he's doing.

Best regards,
Steve Berson

User avatar
dietrich10
Posts: 840
Joined: Wed Jan 16, 2008 2:18 pm
Location: usa
Contact:

Post: # 12113Unread post dietrich10
Fri Jan 14, 2011 11:21 am

I need a Muth session soon as well. Hopefully include finally recap entire rack.

Who upkeeps the vms at chicago mastering?
that tech would be closer
cutting lacquers-vms70 system

User avatar
TotalSonic
Posts: 227
Joined: Tue Sep 30, 2008 7:08 pm
Contact:

Post: # 12114Unread post TotalSonic
Fri Jan 14, 2011 12:17 pm

dietrich10 wrote:I need a Muth session soon as well. Hopefully include finally recap entire rack.

Who upkeeps the vms at chicago mastering?
that tech would be closer
That would be Shea Ako. Probably could get his contact info from BoB Weston or Jason - http://www.chicagomasteringservice.com

Best regards,
Steve Berson

User avatar
opcode66
Posts: 2700
Joined: Sun Nov 08, 2009 10:56 pm
Contact:

Post: # 12121Unread post opcode66
Fri Jan 14, 2011 4:37 pm

I hope your halfnut isn't worn out. That seems to be the kiss of death.

If the carriage moves smoothly on its own then you know that's ok. If the leedscrew seems to be turning ok via the pitch control box then you know that's ok. (Speed of rotation looks normal and consistant). Then the only thing left is the halfnut as you have surmized. If not that then I would focus on the pitch control systems.

I've been trying to track down a spare half nut to have duplicates made. I'm hoping to find one. If not, I'm going to remove mine and have it 3D laser scanned in order to create duplicates.

Let us know what you discover.
Cutting, Inventing & Innovating
Groove Graphics, VMS Halfnuts, MIDI Automation, Professional Stereo Feedback Cutterheads, and Pesto 1-D Cutterhead Clones
Cutterhead Repair: Recoiling, Cleaning, Cloning of Screws, Dampers & More
http://mantra.audio

User avatar
concretecowboy71
Posts: 569
Joined: Mon Mar 08, 2010 10:13 am
Location: Cleveland, Ohio, USA
Contact:

Post: # 12174Unread post concretecowboy71
Sun Jan 16, 2011 10:06 am

Luckily, I have a mechanical engineer/machinist helping me also.

I spoke to Chris Muth at length (what a nice guy) and he had a lot of suggestions.

I was just finishing my new studio anyway, so this also seems like a good time to pack up the lathe and move it to its final home.

When we get it to the new studio we are going to remove the carriage for cleaning as well as to check the thrust bearing at the end of the lead screw and to look at the half nut to see if there are issues there.

My machinist friends seem to think that making a new one would not be too difficult, Chris also suggested adjusting the half nut a little tighter to take up any play caused by wear and tear.

He explained how to do it once and I will call him again to verify, but if anybody has experience adjusting the half nut, could you post some basic directions. I know the two rotating disks at the top are the locking ring and adjustment ring, beyond that, I am still a little unclear.
Cutting Masters in Bristol,Virginia, USA
Well Made Music / Gotta Groove Records

User avatar
mossboss
Posts: 2050
Joined: Sun Jul 01, 2007 8:18 am
Location: Australia.

Post: # 12205Unread post mossboss
Mon Jan 17, 2011 1:58 am

Concrete man
Careful with the thrust bearings
They are unobtainable
They look standard however they are very specific for those machines with a very fine tolerance
They where made for Neumann
If I where you I would leave them alone with only some aerosol spray so as to clean them out followed by a generous application of fine oil
It seems that carriage has slack on it which is easily adjusted
I have yet to hear of the half nut giving grief but possible even though a very remote possibility
I would leave it alone as well as the thrust bearing if I where you
Use cleaning aerosol spray first obtained at any good electronic store as used for contact cleaning and dont be shy with it
Than lubricate everything and try it out before dissmantling anything and after adjusting the slide for lateral movement which is a simple op or you will finish up with more issues than you started off with
It is very easy to check the half nut
Get hold of the wheel and keep it steady while with the other hand get hold of the transport system so as to see if there is any slackness or movement left to right back and forth between the carriage and the lead screw
Same applies fo the carriage get hold of it with both hands and see if there is any slacknes on it between it and the rails which it runs on there should be nil if there is there are adjustments for it
It seems to me that a bit of shit has lodged somwhere in there which makes the transport of the head across the platter jittery
See if you can find where it is before undoing anything
Take you time and find it it does not have to be much of it either
A good blow down with dry compressed air out of another aerosol can would be a good start befor you do anything regardless
Most likely a bit of the chip is in there somewhere (my guess would be )
If the half nut has bit the dust it would be incosistent but from what you describe it is in the same spot like a double cut
Which means that the carriage is forced against something it finds its way back to where it should be once the pressure its off and back again
Any way here you are
Just my experience with 3 of them under my control/command/care
Cheers
Chris

User avatar
concretecowboy71
Posts: 569
Joined: Mon Mar 08, 2010 10:13 am
Location: Cleveland, Ohio, USA
Contact:

Post: # 12208Unread post concretecowboy71
Mon Jan 17, 2011 4:19 pm

We have exhausted the compressed air angle. I spent 10 hours blowing it out with canned compressed air and high pressure from a tank.

I feel very good that my cleaning was as good as it could possibly be. The area in question seems to be one of those spots that is never directly visible.

I feel pretty good that there is something stuck there too.

Al pointed out that a problem with the half nut would not be consistently in the same spot either.

Thanks for all of the input. Me and the engineer are going to work on it tomorrow. We expect to exercise a great deal of caution and will take pictures along the way to document what we are doing. If all goes well I will be happy to share info with anybody having the same problem.
Cutting Masters in Bristol,Virginia, USA
Well Made Music / Gotta Groove Records

User avatar
THEVICTROLAGUY
Posts: 321
Joined: Thu Feb 28, 2013 3:55 pm

Re: Help Servicing My Lathe.

Post: # 29221Unread post THEVICTROLAGUY
Tue Mar 11, 2014 12:26 am

HALF NUT REPAIR : i service Edison cylinder phonographs, the half nut / feed screw set up is identical to a disc lathe. for worn half nuts here is a solution that works quite well. remove and clean the half nut with alcohol. apply a liberal amount of JB weld or any slow setting epoxy to the half nut, reassemble the half nut and lower it on to the OILED feed screw. let the half nut sit undisturbed for 24 hours. the result will be a perfect working half nut that will last for months, longer depending on how rough the feed screw itself actually is. this is an accepted repair for worn half nuts and cost nothing, it can repeated in perpetuity if necessary. THIS WORKS !!!

User avatar
opcode66
Posts: 2700
Joined: Sun Nov 08, 2009 10:56 pm
Contact:

Re: Help Servicing My Lathe.

Post: # 29228Unread post opcode66
Tue Mar 11, 2014 7:12 pm

Actually, the best cure for a worn halfnut is to buy one of my Chris Muth approved clones. Contact him for replacement. He will get one from me and install.

I have absolute perfect clones of original Neumann square and round halfnuts.
Cutting, Inventing & Innovating
Groove Graphics, VMS Halfnuts, MIDI Automation, Professional Stereo Feedback Cutterheads, and Pesto 1-D Cutterhead Clones
Cutterhead Repair: Recoiling, Cleaning, Cloning of Screws, Dampers & More
http://mantra.audio

User avatar
concretecowboy71
Posts: 569
Joined: Mon Mar 08, 2010 10:13 am
Location: Cleveland, Ohio, USA
Contact:

Re: Help Servicing My Lathe.

Post: # 29241Unread post concretecowboy71
Wed Mar 12, 2014 4:06 pm

Whoa! That post came back from the dead! Over three years old!
Cutting Masters in Bristol,Virginia, USA
Well Made Music / Gotta Groove Records

Post Reply