Bridgeport Series 1 steppers - replacement

[CozyGirrrl]

I have a BP Series 1 was Boss 3-5 controlled, have Gecko G210's and would eventually like to replace the Sigma stepper motors.
My understanding about the Sigma #026744 motors is:
-6 wires
-5/8" keyed shaft

I need to know:
-NEMA size?

What I am looking for is a bolt in replacement bipolar with about 1750"oz torque. I can probably add the keyway using my other mill.
The Y axis has a size limitation of about 8.5" body length. X & Z are not a length problem.
It needs to be the same flange and shaft size though.

When I solve this puzzle I will have 3 good Sigma motors available.

Regards, Chrissi

[Mike Nash]

Look at http://www.kelinginc.net at their Nema 42 stepper motor. The shaft is smaller than the spec sheet says (the spec sheet size would have matched your pulleys) but only needs a new Taperlock bush to mount the pulley. I know it works for the Y axis. I don't recall whether the X and Z use the same type pulleys. The bolt holes match up but the new motor doesn't have threaded holes like the Sigma/Superior so you may have to use nuts and bolts.

A friend was having issues with table jerkiness. The Y and Z were both Sigma and the X was Superior. He swapped in a kelinginc motor on the Y and resolved his issues. The Z is still a little jerky but he is living with it. The Superior motor is smooth. I tried his old Sigma motor on a unipolar HobbyCNC board with various step settings and it was jerky on it also. It would only smooth out if the current setting was set so low it stalled too easily. He has Gecko 201s on his mill.

[cabledude]

Chrissi-
The Sigmas (and Superiors) are 8 wire motors. The original BPT wiring had 6 leads with two jumpers at the motors. I have tested my Sigmas on my BOSS 5 conversion (underway) and would love to know how your Geckos are wired to them. Mine works great unipolar, but I had a problem when I tried them wired in parallel.

Mike-
You're right about the shaft size...Keling's info page says 3/4 shaft, but the spec sheet pdf shows 16mm. Taperlock sounds like the best way.

If the bolt pattern is the same, (Keling vs Sigma), how about inserting 5/16-18 Helicoils on the motor...the 8.5mm holes (.335) are just right for the Helicoil tap drill size.

Rob

[CozyGirrrl]

Thanks guys, sounds like the Keling motors with Taperlok and helicoils would be the way to go. Will have to save my pennies for them =)
The best way would probably put the existing ones up for sale?
Regards, Chrissi

[frog]

I am doing the same project as most of you, I upgrading a Bridgeport Boss 5 with superior Stepper motors, I order a 203 Gecko drive to experiment, I was wondering if anyone has a wiring diagram, I talked with Marris from Gecko, nice guy however I lost my notes, I believe that the center tap on the 8 wire motors is eliminated, however in my conversation with Marris I believe that he said to only eliminate 1 of the center taps, and one of the field wires, I however noticed these motors are 8 wires do I apply the 8 wire diagram or just use the original 6 wire configuration, and remove the jumpers at the motor, I did find a diagram on here for this configuration however it looked like it might be a parallel configuration, it was indicated to me that I might need to use a non parallel application. If anyone has any information they can email me please help, I have pondered every page I can find on this site and the internet as well as the original manual from Bridgeport, I am tired of only 3k lines of code, and blowing transistors often. Need to bring the machine into the 21st century. This is only a hobby of mine, I am also thinking of using the original power supply it seems to work ok, I have the 3 phase rotary converter ballanced within 6 volts across all 3 phases, so I am happy with this, just wondering if the original voltage is ok after conversion? I noticed that the Gecko 203v will take up to 80 volts, I believe the original voltage is close to that value is there anyone who has had continued success, I did read post that people had done it however they were not sure of long term success, I was wondering what the status was? Thanks in advance to everyone. I know the power of this site as I have had many calls to my cell phone for advice of different kinds. I am always willing to help.

[jking]

I am doing the same also.I am using nema 34 that I bought from Keling.These are suppose to have more power than the originals.

I ned to know how do you make the connections from the stepper to the wire cable? The wires are just sticking out of the stepper. Do you add a box? Plug?? Or connect and tape up? That doesnt sound like the best way.

Here is pics of my stepper conversion. http://smg.photobucket.com/albums/v24/ikimjing/

[rogerfries]

Any idea what the stock Sigma or Superior are rated for? How much extra power are you getting with this upgrade?

[jking]

the originals were 800. These are 900 plus. The smaller size will allow faster acceleration and stopping. Less power used and smoother. The mill has a 2to 1 ratio also .Feed power isnt a concern.

People tend to want to over power these mills. What you will get is a a lot of damage to the machine if something crashes.Think about it.Not running 8000 rpms,only a 2 hp spindle,small work envelope,Not trying to hog with a 3/4 endmill.

Jim

[rogerfries]

Jim,

You mention 2-1 ratio. Did you change the pulley size on the motor to get that? Or is your machine a BOSS 6 that already has 2-1 ratio? Mine is a BOSS 5 w/1-1 ratio. How can you identify the difference between a Sigma & Superior motor? Is one preferred over the other. I'm brand new into this stuff and I'm not looking to upgrade today. I'm just taking my notes for the future possible upgrades once I get everything working.

Thanks

[jking]

boss 6 and dont know how to tell.There are no plates on these things.

[frog]

My Gecko Drive came in today, I am looking forward to getting it going tomorrow, I am using a superior stepper motor, I will document my travels with pictures starting from now as well as write an article on it, I have found much useful information however it is all scattered all over, why pay thoulsands of dollars for a hobby machine if you can save the money and purchase Gecko Drives. As for the difference in the drive steppers there is a visible difference when looking at them you can tell I will get a picture of a superior Motor and try and scan the other one from my manual Boss 5 it shows what they basically look like. It is important as I have been informed that these original motors will work but you will not be able to microstep witht them, if you need this feature you will need to change to another motor. For my project it is just a hobby and I will stick with the originals, the machine has little time on it due to comming from a college, however it still may of had a hard life.

[jking]

Will enjoy watching your progress. I have the limit switches rewired and connected. I am running Keling drives. They were recommended by someone who does alot of these cnc machines. New cables ran to the steppers and the steppers fit. Getting there. I still need a computer and monitor.Getting a little excited now. I have had this for over a year. Jim