up and running
Posted by
Peter Smith
on 2000-02-09 15:01:43 UTC
5amp Board
Hello all
At last the board is up and running, I have run a few programs and all seems to be well, the mill runs comfortably at 50 ins per min, though I have had it running faster than this, but slowed it to allow a little bit of a safety margin, the setup is rock solid and loses absolutely no steps at all, cross axis interference is nil, chips barely get warm.
As someone said recently, (stepper/versus/ servo) there is a lot to be said for a well set up stepper system, run within its limits it will turn out part after part, day after day, exactly the same.
For any non electronic types like myself building one of these boards, just a note of some of the changes made during this journey
As a precaution DO NOT do any switching on the DC side of the transformer, do all on and off switching on the AC mains side.
Before any assembly starts, fit a suitable resistor or bulb accross the 15000 uf cap terminals to bleed away any charge left in the cap after switching off the supply, ( a bulb is handy to show when the system is on, this can be mounted in the front of the case) there is a lot of energy in there which is looking for a victim, or the nearest vulnerable electronic circuit, either way you or your wallet will get a nasty shock.
The onboard 36v logic supply to the 7805 was removed and an unregulated 12v 1amp external supply fitted.
All the motor grounds on the board were separated from the chip grounds, and the logic supply and 555 timer grounds with a knife, making sure that the 3300 caps remained grounded with the motors and the non inductive 3w resistors, (this being recomended by someone else assembling the same board), I had made a separate power supply enclosure, which included the 15000uf cap, transformer and rectifier, I moved the cap into the enclosure with the board and joined all the separate ground leads at the negative terminal.
Wherever possible use screened cables, especialy for the motors, earth the screen to the mill at the motor end only, earth the case or enclosure back to the normal household socket, solder the screen of the signal cables which go from from the computer to the 4 pin headers on the board, to the outer case of the par/port plug at the computer end only. Keep the tails of these leads as short as possible where they come out of the screening and into the 4 pin header plug at the board end.
Lastly make sure you go over all your solder joints with a magnifying glass at least twice, I had some joints which looked perfect but wern't, if in doubt re-solder them,
Now for the next project
I have had a Sherline mill standing on the bench for a while now, at a car boot sale I bought 3 small steppers for �10.00 and wondered if might do the job on the mill
they are STEP-SYN type 103-77061 5.1 v 1 amp Sanyo Denki Japan, body dia 56.4mm 200 step rev 1/4 dia shaft both ends,
Would these run the mill OK, has anyone got any info
Best Wishes
Peter Smith
[Non-text portions of this message have been removed]
Hello all
At last the board is up and running, I have run a few programs and all seems to be well, the mill runs comfortably at 50 ins per min, though I have had it running faster than this, but slowed it to allow a little bit of a safety margin, the setup is rock solid and loses absolutely no steps at all, cross axis interference is nil, chips barely get warm.
As someone said recently, (stepper/versus/ servo) there is a lot to be said for a well set up stepper system, run within its limits it will turn out part after part, day after day, exactly the same.
For any non electronic types like myself building one of these boards, just a note of some of the changes made during this journey
As a precaution DO NOT do any switching on the DC side of the transformer, do all on and off switching on the AC mains side.
Before any assembly starts, fit a suitable resistor or bulb accross the 15000 uf cap terminals to bleed away any charge left in the cap after switching off the supply, ( a bulb is handy to show when the system is on, this can be mounted in the front of the case) there is a lot of energy in there which is looking for a victim, or the nearest vulnerable electronic circuit, either way you or your wallet will get a nasty shock.
The onboard 36v logic supply to the 7805 was removed and an unregulated 12v 1amp external supply fitted.
All the motor grounds on the board were separated from the chip grounds, and the logic supply and 555 timer grounds with a knife, making sure that the 3300 caps remained grounded with the motors and the non inductive 3w resistors, (this being recomended by someone else assembling the same board), I had made a separate power supply enclosure, which included the 15000uf cap, transformer and rectifier, I moved the cap into the enclosure with the board and joined all the separate ground leads at the negative terminal.
Wherever possible use screened cables, especialy for the motors, earth the screen to the mill at the motor end only, earth the case or enclosure back to the normal household socket, solder the screen of the signal cables which go from from the computer to the 4 pin headers on the board, to the outer case of the par/port plug at the computer end only. Keep the tails of these leads as short as possible where they come out of the screening and into the 4 pin header plug at the board end.
Lastly make sure you go over all your solder joints with a magnifying glass at least twice, I had some joints which looked perfect but wern't, if in doubt re-solder them,
Now for the next project
I have had a Sherline mill standing on the bench for a while now, at a car boot sale I bought 3 small steppers for �10.00 and wondered if might do the job on the mill
they are STEP-SYN type 103-77061 5.1 v 1 amp Sanyo Denki Japan, body dia 56.4mm 200 step rev 1/4 dia shaft both ends,
Would these run the mill OK, has anyone got any info
Best Wishes
Peter Smith
[Non-text portions of this message have been removed]