Re: Spindle motor drive belts MAXNC 10 UPDATE

John,

Do you know of any web sites with Compumotor drivers?

Paul Devey
-----Original Message-----
From: Jon Anderson <janders@...>
To: CAD_CAM_EDM_DRO@onelist.com <CAD_CAM_EDM_DRO@onelist.com>
Date: Thursday, November 04, 1999 10:35 PM
Subject: Re: [CAD_CAM_EDM_DRO] Spindle motor drive belts MAXNC 10 UPDATE

>From: Jon Anderson <janders@...>
>
>Hans,
>
>I moved from the wimpy stock steppers to some approx 120 oz/in motors
>and CyberPak drivers. I've only seen one or two ads for Cyberpak. They
>make a nice little driver that retails for about $110, a bit less in
>quantity. They much prefer the OEM market however. These will half step,
>and I was happy with the performance, but ran into a lost step problem.
>Went to 198 oz/in PacSci motors which ran quieter and cooler, but still
>lost steps.
>Then went with Compumotor OEM 650 drivers I got on a close out deal.
>Much much better setup. At 1000 step resolution the motors are very
>quiet and smooth. Power supply is 40 volts at about 8 amps. I have a PS
>out of some medical device that I can pull at least 50 volts/10 amps out
>of, trying to get that set up now.
>Even getting drivers and motors surplus and cheap, that all cost me
>almost $500. Not to mention the cost of the Sherline spindle and motor.
>Good thing my dad's a dealer...<G>
>I think it's a good frame to start with, but I just saw the latest HSM
>and Sherline now sells a CNC ready mill and lathe. Their brackets with
>thrust bearings are exactly what I've done for mine, they just have the
>bucks to make a real slick looking casting instead of fabbing from
>plate.
>I was about to go for Dan's drivers when I ran across the Compumotor
>drivers. That's not to knock Dan's stuff in any way whatever, and I'd
>recommend if you are going to really step up that you take a good look
>at what he's got. Hunt around for at least 140 oz/in motors, build a PS.
>Ebay the MAX and get a Sherline...
>
>Jon
>
>hansw wrote:
>>
>> 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.
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