Need help for design 5 Phase stepper motor driver

[bb_ss_oo]

Hello

i bought used oriental 5 phase stepper motor , 6 wires , star connection , i design circuit like in project link

http://www.geocities.com/dsaproject/.../cnc_ctrl.html

the motor move but it very slow related to uniploar one and it torque is very weak even it big motor " 2.1 ohm and 0.4A per phase " so it cant used well for CNC work, so i need suggestion,, to solve this problem,

what is the good idea to design the driver for this stepper motor and have max torque and speed?


Thanks ..

[Konstantin]

The good idea here is: DONT
Usually designing a drive is a huge task, even if you have a reference design provided by a drive IC manufacturer which in 5phases you do not. Unless you are electronic engineer and up for the task.

My 2$ here
a) buy some drives from ebay, Vexta 5 phases. If you get lucky $20-$30 +shipping.
b) get some regular 2phase motors and build a drive using one of many open source drive designs.

"B" option here is the cheapest by far. Almost all parts are available easily and there are plenty of experience from forum members to help sort things out if anything.

EDIT:
There are some options from Sanken, namely this trio of IC are designed to drive a 5phase pentagon connection, SI-7502, SLA6503 and SLA5011.

[bb_ss_oo]

Thank you Mr Konstantin, i will build linistep uniploar microstepping driver it seems more easy ..

[Konstantin]

Remember to check out the www.pminmo.com site. Phil maintains a forum on his site where they discuss some open source drive boards. Plenty of boards there. Drives and also parallel port interface boards. I have used his designs quite a few times.

His Bulletin Board (forums) link does not work for me, use http://pminmo.com/phpBB2/index.php

[bb_ss_oo]

THanks Mr Konstantin

But i would ask you, from your experience is the following microstepping controller is good for milling PCB CNC machine? I mean about accuracy..
i design my first CNC machine and used this controller and it was very good with milling wood ,

so i would ask about rules i must follow up before build PCB milling CNC machine ?

http://www.sxlist.com/techref/io/ste...p/lini_wks.htm

Thank you ..

[Konstantin]

I have no experience with linistepper.
I have made my pcb miller out of a bed of old Agfa Scanner.
I guess you need a tight machine (no backlash) and I think microstep is very good Idea, I run mine on 1/2 step and I guess there is a place for improvement.

YouTube - Cnc pcb mill

YouTube - Cnc pcb mill

Milling area 100 mm on X and 260 mm on Y.
I think there is more room on X but my lead screw had only 102mm travel.

What else can I comment, the X axis is belt driven and I think that it would be better to use a leadscrew. Because calculating travel of a belt on a pulley is not as precise as having a set travel on a lead screw. I can never get a round integer like 40 steps per 1mm , its always something like 14.23steps per 1mm.
I think if you are to mill in inches its better to get an inch leadscrew and use metric leadscrew if you mainly machine in mm.

In the video I am milling mdf board but later I have milled a 3 axis bob, gcode generated by Eagle script called pcb-gcode. Eagle is great for pcb design, I confess I know very little about Eagle, just enough to make a simple board and generate milling code and drilling code. It is a joy to watch it mill and to change drills for different hole sizes. I can never drill with such precision.

A lot of consideration goes into the spindle. In my machine I ve tried to hold a Dremel 300 series and results were quite poor.
Then I machined a metal rod to be able to use Dremel collets and the drill chuck which secures the tools better. The less runout the spindle has the smaller the milling dot is which helps in milling tight spaces.
There is a Dremel like tool called Proxxon IB/E, it has very acceptable runout and it has a metal cast body which helps with precision, it is quieter than a Dremel and has very precise collets. Also it can be run for prolonged periods of time. If you can get it, do it. It is widely known in Europe, maybe it is available in your area.


And please call me Konstantin (no mr.)
Thanks.

[bb_ss_oo]

Thanks alot Konstantin ,,,