Re: Spindle motor drive belts MAXNC 10 UPDATE

I was under the impression that repeatability was related
to the tool piece coming to the exact same spot, repeatadly.
Accuracy is how close it comes to commanded postion.
Right, wrong ?

Steve

----------
From: Darrell Gehlsen <darrell@...>
To: CAD_CAM_EDM_DRO@onelist.com
Subject: Re: [CAD_CAM_EDM_DRO] Spindle motor drive belts MAXNC 10 UPDATE
Date: Friday, November 05, 1999 10:08 AM

From: "Darrell Gehlsen" <darrell@...>

Just a note.
Resolution and repeatability are two very different things.
Resolution is the distance the machine is supposed to move for each step.
Repeatability is how close it comes to commanded position.
Darrell

----- Original Message -----
From: Dan Mauch <dmauch@...>
To: <CAD_CAM_EDM_DRO@onelist.com>
Sent: Friday, November 05, 1999 6:48 AM
Subject: Re: [CAD_CAM_EDM_DRO] Spindle motor drive belts MAXNC 10 UPDATE


> From: "Dan Mauch" <dmauch@...>
>
> BTW Maxnc says their system has .000125 resolution. I know this isn't
true
> becuase they must have a lot of backlash in the leadscrews. How much
> backlash does your machine have?
> Dan
> -----Original Message-----
> From: hansw <hansw@...>
> To: CAD_CAM_EDM_DRO@onelist.com <CAD_CAM_EDM_DRO@onelist.com>
> Date: Thursday, November 04, 1999 6:43 PM
> Subject: Re: [CAD_CAM_EDM_DRO] Spindle motor drive belts MAXNC 10 UPDATE
>
>
> >From: hansw <hansw@...>
> >
> >Jon,
> >Thanks for the detailed reply. I looked at your picture, it looks a lot
> >sturdier than the crap MAXNC puts out.
> >The guy had the nerve to tell me " we designed it to be flexible" ...I
> >also notice the carcass of the MAXNC electronics hanging on the back of
> >the mill.... I purchased a complete MAXNC -10 because I needed a mill, I
> >did not want to build one....
> >What kind of electronics are you using to drive the motors ?
> >
> >Well I'm in the middle of making a new motor mount. it will be a four
> >point mount and will allow full adjustment... I'll post the results at
> >my web site when I done...
> >
> >Sure it's a deal, and now that I've re-built over half of it, I regret
> >not doing it from the beginning, the regrets are about $500.- worth of
> >motors and electronics and software.. I ordered 70oz-in motors and
> >realized after a while that they could not be that powerful. My tests, (
> >see my web site how I do it ) tested the so called 70oz-in motors at
> >42oz-in..... When I asked to see the manufacturers data sheet on the
> >motor I was told it was not available and I could get a refund... I'll
> >keep the motors as a reminder that I should not be so dumb fat and happy
> >with everything that's fed to me in brochures... I'm not flaming anyone.
> >I'm just stating the plain honest facts...
> >
> >Would I buy a MAXNC again.... Well no... I do learn from my mistakes...
> >would I recommend it to anyone... Well NO...
> >
> >Jon, I appreciate the help and all the feed back, hope I can repay some
> >day...
> >
> >regards
> >Hans Wedemeyer
> >
> >
> >Jon Anderson wrote:
> >
> >> Hans,
> >>
> >> First mod I made to my MAX was to toss the spindle motor into the
> >> spare
> >> parts bin. I fitted a Sherline DC motor and control. It's a tight fit
> >> betwen the Z stepper motor and the spindle.
> >> Here's a link to a pic of mine
> >>
> >> http://www.prototype-design.com/images/Shermax1.jpg
> >>
> >> You can see here the adapter I made to use a Sherline spindle as well.
> >> If you (or anyone else) is interested in this adapter, I can post the
> >> 3D
> >> wireframe in DXF format.
> >> You can see that I'm only using one bolt on the end plate on each
> >> stand
> >> off, and have no problems with vibration or flex. I think part of your
> >> problem is the standoff isn't seating well against the sheetmetal
> >> case.
> >> MAXNC is getting better at spin control. I seriously doubt that flex
> >> was
> >> engineered! The whole thing is cost driven more than anything, and
> >> it's
> >> a decent bargin alright, but some mods will go a long way towards
> >> making
> >> it more useful.
> >>
> >> BTW, you can see in place of the stock motors, I've made thrust
> >> plates.
> >> There is a custom stub shaft passing through dual ball bearings.
> >> With a nylock nut for adjustment, I can dial out backlash and relieve
> >> the motor of thrust loads. Note, this does nothing for backlash at the
> >> leadscrew nut... The Sherline spindle adapter has a constant force
> >> spring inside that is attached to the thrust plate. I forget, but
> >> think
> >> it's rated for 7 lbs, and it releives the Z motor of some of it's
> >> load.
> >> Can also post a DXF file of the thrust plates and the stub shaft.
> >>
> >> As for your setup, I would suspect that either the V groove angle is
> >> not
> >> right on one or both pulleys, or possibly one of the pulleys V-grooves
> >> isn't concentric to the bore. Does the belt vibrate or flutter a lot?
> >>
> >> Jon
> >>
>
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>

Welcome to CAD_CAM_EDM_DRO@...,an unmoderated list for the
discussion of shop built systems in the above catagories.
To Unsubscribe, read archives, change to or from digest.
Go to: http://www.onelist.com/isregistered.cgi
Log on, and you will go to Member Center, and you can make changes there.
For the FAQ, go to http://www.ktmarketing.com/faq.html
bill,
List Manager