Bridgeport Boss 6.1 Retrofit

[ttlehto]

Hello everyone,

I just placed an order for Acorn board and next thing is to get the stepper/servo motors and a VFD.

I am on a tight budget for now so what would people recommend for the size of closed loop steppers and drives? I mean torque in NM and the frame size.

The plan is to upgrade to servos later and use the cheaper stuff to some other project.

P.S. If anyone knows where to sell all the 1980 electric stuff, it is still in place but not used since 2002..

[martyscncgarage]

Welcome to the club.
What motors are on the machine now?Large steppers? If so they could be reused. Pictures?
Marty

[ttlehto]

Thank you Marty for the quick reply, because of your videos i decided to get Acorn instead of some Mach4 board

Pic of X-axis motor attached.

[martyscncgarage]

Thank you Marty for the quick reply, because of your videos i decided to get Acorn instead of some Mach4 board

Pic of X-axis motor attached.

You could likely reuse those steppers at a cost savings as you indicated.
Use the search box upper right corner of the page and search Bridgeport Boss

I suggest Gecko 201X or the 203V. Stepper drivers.

Marty

[ttlehto]

So, now i know that my steppers are Sigma and wired in series.

I can even keep the original cabling, i assume.

What i started wondering is that have anyone installed encoders to these motors to create a closed-loop system? Like investing a little more on the drives and installing separate encoders? Too risky or little advantage? Or is it even possible at all? This would add about 100-200$ to the budget, if it works

I understand that Acorn is not a closed-loop controller but if the drives and motors are, then there would be less risk of lost steps.

[martyscncgarage]

So, now i know that my steppers are Sigma and wired in series.

I can even keep the original cabling, i assume.

What i started wondering is that have anyone installed encoders to these motors to create a closed-loop system? Like investing a little more on the drives and installing separate encoders? Too risky or little advantage? Or is it even possible at all? This would add about 100-200$ to the budget, if it works

I understand that Acorn is not a closed-loop controller but if the drives and motors are, then there would be less risk of lost steps.

Can not be done.
You mentioned you were on a budget and would eventually change these out to servos. This will get you going and your feet wet with Centroid Acorn and CNC12 at minimal cost. It looks like all you would need to do is buy the stepper drives, and maybe a 80VDC 7A power supply if you want reasonable rapids after the conversion.
http://www.antekinc.com

You would have to figure out how much current each stepper motor draws depending on how its wired and make sure they can take up to 77VDC.
I am not sure what the original Bridgeport power supply was rated for. Maybe that info is on the motor cover or check the other Boss conversion thread.

Get the 77VDC with the 24VDC for Acorn, and a 5VDC in case you need it for your drives. Its an option on most of their power supplies

If you want to go AC servos, I would suggested DMM Technologies 750W motors and drives. DYN2 is a little easier to wire, but requires a separate 60VDC power supply while DYN4 drives can be wired directly to 220VAC

[ttlehto]

Ok!

I knew it is better to ask than assume

I found some more info on the Sigma steppers and even how to wire them with Gecko Drives from here --> http://www.improvedparts.com/blog/bridg ... ii-buildup

On that project they use LinuxCNC but as a Linux user (for the last 7 years on my laptops), i really dont want the additional pain of setting everything up the "open source way". Also, a decent buffered, ethernet control would cost more than Acorn. I am going to install CNC12 to a Lenovo Thinkpad X230 Tablet. It is a 2013 i7 machine so i think it is powerful enough for this purpose.

[martyscncgarage]

Ok!

I knew it is better to ask than assume

I found some more info on the Sigma steppers and even how to wire them with Gecko Drives from here --> http://www.improvedparts.com/blog/bridg ... ii-buildup

On that project they use LinuxCNC but as a Linux user (for the last 7 years on my laptops), i really dont want the additional pain of setting everything up the "open source way". Also, a decent buffered, ethernet control would cost more than Acorn. I am going to install CNC12 to a Lenovo Thinkpad X230 Tablet. It is a 2013 i7 machine so i think it is powerful enough for this purpose.

All you need is about a 2.9GHZ Intel processor, whether it be a Celeron, Pentium, i3, i5 or i7. SSD preferred, Running Windows 10
You can check minimum requirements here:
http://www.centroidcnc.com/cnc_pc_perfo ... ments.html

[ttlehto]

A little update here,

As my Acorn board got stuck in the customs , i did a little more research on where to get Geckodrives.

It seems that in order to get those to where i live (Finland), I have to a) pay taxes and customs if i make a purchase from USA or China. Or b) pay additional 30-40% for an european distributor.

So, the price per a Gecko driver goes up by 50-70$ per unit...

As my budget is limited at the moment, i did some digging in ebay and found some Wantai Motor 80V 7A drives and power supplies. Three drives and three power supplies will cost me about 300$ including shipping and because the seller is in EU, no taxes or customs are added.

I really really would get decent AC servos & drives but anyway it may not matter what motors my mill has when i am learning the basics of CNC12