 Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me. |
Forum Index : Electronics : Would this drive a F& P?
Page 1 of 2   |
|||||
| Author | Message | ||||
| KiwiJohn Guru  Joined: 01/12/2005 Location: New ZealandPosts: 691 |
HI folks, it is quite a while since I check in here but I know this is the right place to ask this question! 
Would this controller drive a F&P? 
http://www.trademe.co.nz/Browse/Listing.aspx?id=819793102 http://www.leadshine.com/UploadFile/Down/3DM683m.pdf Cheers |
||||
Gizmo Admin Group  Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
Maybe, but not very well. The F&P is 3 phase, while most stepper motors are 2 phase. Instead of a stepper driver, you might be better off using a servo driver. Many servo motors are 3 phase AC, and use a decoder to get the drive position. I have some memory of Silicon Chip magazine doing an article on a F&P driver a couple years back. Some one else might be able to help. Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
||||
| KiwiJohn Guru Joined: 01/12/2005 Location: New ZealandPosts: 691 |
Thanks Glenn, this one claims to be 3 phase and there is a pair of them being offered. This is an extract from the manual (which is the second link in my opening post) [quote]5. Connecting the Motor The 3DM683 can drive any 3 lead or 6 lead three phase hybrid stepping motors. The connection between the driver and 3-phase stepping motors includes two different kinds of connections, namely delta-connection and star-connection. Using delta-connection, the performances of the motor under high speed condition are better, but the driver current is higher too (about 1.73 times the motor coil current); while using star-connection, the driver current equals to the motor coil current. [/quote] I suppose another way to ask my question is does the F&P behave the same as a 'regular' 3 phase stepper? |
||||
| Gizmo Admin Group Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
Interesting, it might work. The F&P has a fair bit of back emf, but most modern stepper controllers can adjust for this. I guess the F&P should be able to step, using its natural cogging, and hold, just like a regular stepper motor. Dunno, would be a interesting experiment. The SC web site shows the article about the F&P motor driver was published Feb 1012, but you need to pay to get any more info 
I have a copy somewhere, but maybe someone else can put their finger on it quicker, the make/model of the controller would be handy. Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
||||
| KiwiJohn Guru Joined: 01/12/2005 Location: New ZealandPosts: 691 |
Thanks Glenn, I might give it a miss as there does seem to be a lot of unfinished projects on my bench! John |
||||
| Gizmo Admin Group Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
Found it! 
The controller was $149, and you need to email contact@energy1000.com.au to buy one. Now it looks like its just a motor driver, and not a stepper, so did you want to step the F&P or just run it as a motor? Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
||||
yahoo2 Guru Joined: 05/04/2011 Location: AustraliaPosts: 1166 |
From memory his was designed for a mobility scooter or a golf cart 50 amp by 36volt and was quite sluggish with standard 240v series wired motor. The bit I remember is that the wiring for the hall effect sensors was made easy because the unit could self calibrate the phases as it was rotated, I thought that was pretty neat! I'm confused, no wait... maybe I'm not... |
||||
| KiwiJohn Guru Joined: 01/12/2005 Location: New ZealandPosts: 691 |
The 3DM683 driver arrived and yes, it does drive a F@P motor, sort of! 
I have a 36V power supply and set the driver to 5.7A (peak). Using EMC2 I can get the motor to run with bags of torque but acceleration is very slow and top speed is, estimated, 150rpm. I am hoping to use this for the X axis on a CNC router table. |
||||
| Gizmo Admin Group Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
Hi John Back EMF might be the problem with speed and acceleration. Same thing applies to any stepper motor. Do you have a F&P stator modified for a windmill? The parallel windings will drop the inductance and therefore you should be able to get more speed out of it. Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
||||
| KiwiJohn Guru Joined: 01/12/2005 Location: New ZealandPosts: 691 |
Hi Glenn I am a bit uneasy about damaging the driver from back EMF so thanks for reminding me of paralleling the windings. 
|
||||
| Gizmo Admin Group Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
No problem John, let us know how it goes. I did a similar mod on some stepper motors for my own CNC. The steppers were 8 wire types, so you had 2 windings for the A phase and 2 for the B phase. The 2 A's could be connected in series or parallel. Same with the B phase. In series, it had more torque but less top speed. In parallel the torque was reduced, but speed improved. I would see if you could reduce the 5.7 amps, at 36 volts its a lot of watts your pumping into the stator. Some stepper controllers have a running current and a holding current, so you may get away with a much lower holding current, and just reserve the high currents for motion. If you using micro-stepping, you may need to keep the holding current high to fight the F&P's natural cogging. Lots to play with, you'll soon see why they call it stepper motor tuning. The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
||||
| KiwiJohn Guru Joined: 01/12/2005 Location: New ZealandPosts: 691 |
Hi Glenn, I quickly changed the stator to star winding to see what difference I could see but nothing really to report there. The current does sound high but neither the stator nor the driver heatsink is getting wam, maybe this power supply is not living up to its label! 
First thing tomorrow I will cut the winding and make each phase 7+7 in parallel. |
||||
| KiwiJohn Guru Joined: 01/12/2005 Location: New ZealandPosts: 691 |
Dang! I meant to say I have changed to Delta wiring! 
Holding current is set for 50% and after one second drops to 30%. |
||||
| Gizmo Admin Group Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
Yeah good point about the power supply, might pay to throw a analogue multimeter or cro across the output to see how it holds up under load. The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
||||
| KiwiJohn Guru Joined: 01/12/2005 Location: New ZealandPosts: 691 |
While I have your here.. What do you think of the idea I see online of linking PC power supplies in series (after isolating the black wire from ground)?
|
||||
| Gizmo Admin Group Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
Yeap easy way to go if you have a few PC power supplies handy. I did the very same on my CNC rounter, see this page http://www.thebackshed.com/cnc/RouterA2.asp, though its a bit out of date, been a few changes to the cnc router since then. As you say, got to isolate the -ve output from the power supply case. Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
||||
| KiwiJohn Guru Joined: 01/12/2005 Location: New ZealandPosts: 691 |
Thanks, I know where there is a stack of power supplies waiting for the day they might be needed for something! This tuning of the F@P motor is proving quite a challenge! |
||||
| KiwiJohn Guru Joined: 01/12/2005 Location: New ZealandPosts: 691 |
============NEWS FLASH!============ If you want to use a F&P as a stepper motor the number of steps per revolution is 112. I cant understand why it is that number except that it is 8 times the number of windings. |
||||
| Gizmo Admin Group Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
Did you try the rewired stator? The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
||||
| KiwiJohn Guru Joined: 01/12/2005 Location: New ZealandPosts: 691 |
Hi Gizmo, it is the same number of steps with rewired stator. I have one stator wired each phase 7+7 and one with has 3 phases of 6 coils each with the rest of the coils cut away with a jig saw! They all operate on 112 steps per 360 degrees. |
||||
| Page 1 of 2 |
|||||
 Print this page |
