Re: CNC upgrade

-----Original Message-----
From: Tim Goldstein <timg@...>
To: CAD_CAM_EDM_DRO@onelist.com <CAD_CAM_EDM_DRO@onelist.com>
Date: Friday, July 16, 1999 8:15 PM
Subject: Re: [CAD_CAM_EDM_DRO] CNC upgrade

>From: "Tim Goldstein" <timg@...>

Hi Tim
Sorry Iv'e been so long in replying, but I work for a local Brewery and the
job I am on requires 24hr cover, so there are some long weekend shifts
involved.

1 I think the computer would cope ok generating faster signals, but
anything over 7"pm the motors sound rough and start missing steps.

2 It would be nice to have the ability to see the cutter paths generated
on screen before I switch on the hardware and do any cutting , at present I
get an X Y Z print out on screen as the job is in progress, but as you can
imagine this is difficult to see at times due to the speed, never mind
follow the program.
I quite like the sound of DeskNC or Supercam, which of these do you
prefer ?

3 I would not mind upgrading the computer side of things to a pentium if
this was required.

4. I took a look at Dans website directly after sending the 1st Email
out, and I was very impressed, how difficult is it to build one of these
boards up, as I am more at home with a hammer and chissel than a soldering
iron, how is the voltage controlled for various types of stepper, are there
resistors fitted to cope with this,
Has anyone built a one who could advise of the pitfalls, if any ?
having the do's and don'ts to hand can save a lot of time and effort.
What would come naturally to you electronics experts, has to be
drummed into Joe Bloggs, to avoid the disasters and expense of blown
components ( always happens when you think you are doing just fine, then you
switch on, smoke appears from whatever you are working on, and you think
well how did that happen, many tears, kick the dog, off to the bar to
contemplate, many drinks later, off home , get up next day, into workshop,
count the cost and start again)

5 As I said earlier I do like the sound of Linux and EMC, I am going to
try to get hold of a copy of Ver 5.2 maybe for future use ( after everybody
else has beaten the track and sorted the problems)

Best Wishes
Peter Smith

>
>Hello Peter,
>
>Seems to me that 7 IPM is pretty slow for the motors you have. It that low
>feed rate caused by your motors losing steps or by your computer not being
>able to step at a faster rate?
>
>I initially had DeskNC running on a 486 SX25 and it was not capable of
>driving the motors beyong about 8 - 9 IPM. I could put in any faster rate I
>wanted, but that was as fast as the motors would go. I upgraded to an AMD
>K-7 2D 350 and now I can reliably get about 25 IPM and the limitation is

the

>motors and machine, not the computer as it is happy to try driving the
>motors much faster, but they protest.
>
>I am not quite following what you mean by "I would like to upgrade the
>programming department "?
>Do you mean that you would like to find a different program than the
>Compucut HPGL to drive the steppers electronics? If so, you may want to

look

>at as I know it has the ability to drive unipolar 'phase' systems. I don't
>think though that the 386 will cut it.
>
>Have you considered changing to a bipolar stepper electronics? You will get
>a lot more power out of your motors and can run a much higher voltage which
>will help to bost your feed rates. I would suggest looking at Dan Mauch's 5
>amp chopper driver kit. Then you will have a much greater range of programs
>you can use as it seems more of the software supports the step and

direction

>signaling.
>
>Tim
>[Denver, CO]
>
>---original message-----
>>>>Hello to all you professionals
>
>I have been following all subjects for about four weeks now, I find it very
>interesting but I must admit a lot of the electronic & technical stuff

goes

>over my head.
> I am running a far eastern mill 13" X 5" travel with 3 type 34

steppers

>2 1/2 volts, 4 1/2 amps (27 amps total running) with 2R0 50 watt resistors,
>10tpi leadscrews direct drive, unchecked ( no encoders) max speed 7"p/min
>and using a compucut program (HPGL) and interface in unipolar mode, I had
>loads of problems with missing steps and interference between axis when I
>first set it up, until everything was screened and a good interface cable
>was used. It has been very stable, and has ran successfully for about 2
>years, At 10 volts I can run all day and the motors just get warm, but I
>can push it up to 12 volts for a couple of hours or so if I need the extra
>power. It has served very well for the type of work I have been doing.
> I would like to upgrade the programming department ( at present
>running on an old 386 SX 33 with DOS 6.22 ) , are there any packages that
>would run with this interface, or would I have to upgrade to a bi-polar
>device, I would prefer 4 axis if I had to change the interface, to include
>the dividing head (any idea of costs).
> If I had to change the interface, I would use the old one on a
>Sherline Mill which I have standing idle at the moment, so it would not be
>wasted.
> I like the sound of linux and emc for the future, but it does seem

a

>bit complicated to set up, I priced linux 5.2 locally here in the UK, it
>came out at �39.50, but I think I can Get it cheaper as a friend got

version

>6 for �25.00
> I have no other experience in electronics, computing, or
>programming, other than creating the above conversion, but learnt a little
>in the process.
>
>Yours Faithfully
>Peter Smith <<<
>
>
>--------------------------- ONElist Sponsor ----------------------------
>
>Get $20 off all MotherNature brand products!
><a href=" http://clickme.onelist.com/ad/mothernature1 ">Click Here</a>
>
>------------------------------------------------------------------------
>Welcome to CAD_CAM_EDM_DRO@...,an unmodulated 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.
>bill,
>List Manager
>