ON 20060613@10:03:31 AM at page:
http://www.piclist.com/io/stepper/linistep/lini_wks.htm#38839.5674537037
James Newton[JMN-EFP-786] removed post 38839.5674537037

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I don't see the small transistors in this discussion above, what do  they do?  I look on a scope and don't see the small transistors getting any base drive from the pic...  Also I don't see the pull up resistor Rp on the actual schematic?<BR>
<BR>
Greg<!-- 38839.5674537037 EOR -->

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ON 20060613@10:04:28 AM at page:
http://www.piclist.com/techref/io/stepper/linistep/lini_wks.htm#38369.9821875
James Newton[JMN-EFP-786] Published and replied to post 38369.9821875 by rmustakos

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<A TITLE="P-70.32.213.106" NAME="38369.9821875" HREF="mailto:rmustakos@att.net">rmustakos@att.net</A> asks: <BLOCKQUOTE><A NAME="70.32.213.106">
</A> 
Very nice!  I have a question about the tuning of the linearity of the C-R2 circuit for different stepping speeds.  If I put a digital pot between the C and the Base junction with R2, will that vary the charge time and let me tune on the fly?  R(digital pot) would vary with step time and inverse with step size (longer time between steps == lower R, smaller steps == higher R).<BR>
Thanks<BR>
RM</BLOCKQUOTE>

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ON 20060613@10:08:05 AM at page:
http://www.piclist.com/techref/io/stepper/linistep/lini_wks.htm#38457.811099537
James Newton[JMN-EFP-786] Published and replied to post 38457.811099537 by jacknjean

|Insert 'While your 555 mod should be possible, I would think this would be better supported via the PC software. Turbo CNC and others support joystick or mouse interfaces that run the motors under your manual control. 

Limit and home switches are also best supported by the software.' at: '<!-- 38457.811099537 EOR -->'

<A TITLE="P-63.226.201.202" NAME="38457.811099537" HREF="mailto:jacknjean@wilkins.net">jacknjean@wilkins.net</A> asks: <BLOCKQUOTE><A NAME="63.226.201.202">
</A> 
Hi,<BR>
	I really like your way of thinking on stepper motor control.  I started out getting involved in model railroading, but my eyes have gotten so poor at age 66 that I decided to convert my small Myford lathe into a mill so I could drill holes more accurately.  Then I started thinking about adapting CNC to it.  This would allow me to program for repeat hole patterns etc.<BR>
	What I want to know is if it is possible to adapt a 555 timer chip so I could have manual control for a small mill job or just to have a rapid traverse?  This would also require direction control.  Also, what provisions do you have for limit switches and home position?  Thanks so much.  Jack<BR>
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ON 20060613@10:14:00 AM at page:
http://www.piclist.com/techref/io/stepper/linistep/lini_wks.htm#38540.4627893519
James Newton[JMN-EFP-786] Published and replied to post 38540.4627893519

|Insert 'You would need an accurate timebase such as a clock, and then a divider that would produce one step pulse every so many clock pulses. For example, with a 1 second pulse from the clock, a 200 step / revolution stepper motor, and the controller set for 1200 step (or 6th microstepping) you would need to divide the clock pulse by 72 (producing one step pulse per 72 clock pulses) in order to turn the stepper motor one revolution per day.

Since the linistepper is an open source project, if are yourself or you have access to an experienced PIC assembly language programmer, these functions could be added to the chip in the linistepper itself.

Or they could be developed externally in hardware or in software using existing programmable hardware.' at: '<!-- 38540.4627893519 EOR -->'

<A TITLE="P-210.212.125.2" NAME="38540.4627893519">
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how to design a stepper motor that would complete one revolution in one day(24 hrs)?
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ON 20060613@10:15:10 AM at page:
http://www.piclist.com/techref/io/stepper/linistep/lini_wks.htm#38757.2132291667
James Newton[JMN-EFP-786] Published and replied to post 38757.2132291667

|Insert 'That depends on the size of R2 and the ramp you wish to create.' at: '<!-- 38757.2132291667 EOR -->'

<A TITLE="P-84.24.158.151" NAME="38757.2132291667">
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How big must the capicitator over r2 be???
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