PM932 CNC Build

[ncf250sd]

Excellent! I will be envious of your extra Y travel!

I'm happy to share but you will have to confirm they will work for your mill. PM me your email and I will send what I have.

What type of motors will you be using? My Z is driven by a 42 size stepper with a 2005 ball screw and nut so parts were made accordingly.

I appreciate you sending the dimensions it will certainly help seeing a design that works and I will most definitely confirm dimensions on my machine. I'm pretty sure I will be using a 2005 screw and I am concidring a Nema 34 / 1700 oz-in servo but I am open to any suggestions. I will send you a PM.

 

[jbolt]

I would recommend the the 2005 on the Z as a minimum. It could easily take a 2505.

I would check out this thread. http://www.cnczone.com/forums/benchtop-machines/122462-cnc-cad.html

He did a servo system. It is a long thread but worth the read.

I pull together what drawings I have and send along tonight. I also have most of my machine parts in 3D models. If you have a 3D CAD program that can open Parasolid files I can send those too.

 

[ncf250sd]

I look forward to seeing your drawings, thank you. I read that thread, very jealous of the machine he ended up with.

I will put the largest liniear bearing I can without going excessive. Not yet fully decided on the axis motor but leaning toward the servo. It's all new to me, other then lots of reading, so please if anyone has recommendations let me know.
Are you happy with your z axis performance? I'm starting with the z conversion first as a learning experience and because if it doesn't perform well I will keep the machine manual and just use the z conversion as a power down feed.

 

[jbolt]

The Z has worked very well. I'm still chasing a few thou of backlash but that is due to I went with 2 single ball nuts on each screw vs a double ball nut. It gives me more control over the preload but takes some time to get adjusted. The way my mill is placed it is not easy to get to so I have not done done any tweaking in a while. The 4200 oz-in stepper moves the head like it is not there. I have some plans in the future to correct the typical head nod on a dovetail column mill.

I went with a stepper system based on cost and ease of setup. I figure I can't turn a $2400 Chinese bench mill into a high end VMC so steppers were good enough.

What are you looking at for controls?

 

[ncf250sd]

The Z has worked very well. I'm still chasing a few thou of backlash but that is due to I went with 2 single ball nuts on each screw vs a double ball nut. It gives me more control over the preload but takes some time to get adjusted. The way my mill is placed it is not easy to get to so I have not done done any tweaking in a while. The 4200 oz-in stepper moves the head like it is not there. I have some plans in the future to correct the typical head nod on a dovetail column mill.

I went with a stepper system based on cost and ease of setup. I figure I can't turn a $2400 Chinese bench mill into a high end VMC so steppers were good enough.

What are you looking at for controls?

The Z has worked very well. I'm still chasing a few thou of backlash but that is due to I went with 2 single ball nuts on each screw vs a double ball nut. It gives me more control over the preload but takes some time to get adjusted. The way my mill is placed it is not easy to get to so I have not done done any tweaking in a while. The 4200 oz-in stepper moves the head like it is not there. I have some plans in the future to correct the typical head nod on a dovetail column mill.

I went with a stepper system based on cost and ease of setup. I figure I can't turn a $2400 Chinese bench mill into a high end VMC so steppers were good enough.

What are you looking at for controls?

 

[ncf250sd]

Jbolt,
I received the drawings, thank you. I haven't really decided on a controller, in fact I am reconsidering steppers or servo. I will do my research this weekend and hopefully have made up my mind.

 

[jbolt]

Jbolt,
I received the drawings, thank you. I haven't really decided on a controller, in fact I am reconsidering steppers or servo. I will do my research this weekend and hopefully have made up my mind.

Yes there is lots to think about. For the stepper system with Mach3 I have been very pleased with the PMDX products. I use a PMDX-126 BB with a 107 spindle controller and an eithernet smooth stepper otion controller. Very robust combo tho Mach3 has a few quirks. I'm still waiting to see more feedback on Mach4 before I make the leap. If your a Linux person LinuxCNC is widely used and free. Mesa makes some really nice interface boards. We are using those on a servo based CNC router/mill I helped build for the high school. I'm not a Linux person so I don't run that machine.

 

[Boswell]

I also am using the PMDX products with the Ethernet smoothstepper on stepper based machine. I loaded up Mach4 the other day but I was not happy with the user interface. I was surprised that I could not find hardly any user generated UI's given the focus on Mach4 (and Mach3) on supporting user developed interfaces. Anyway the result is that I am still very happy with Mach3 using the MachMotion screen set.

 

[jbolt]

I also am using the PMDX products with the Ethernet smoothstepper on stepper based machine. I loaded up Mach4 the other day but I was not happy with the user interface. I was surprised that I could not find hardly any user generated UI's given the focus on Mach4 (and Mach3) on supporting user developed interfaces. Anyway the result is that I am still very happy with Mach3 using the MachMotion screen set.

Have you actually run Mach4? I'm curious if the M4 plugin for ESS is working? My only real issue with M3 is it does not always turn the spindle on. I should try reverting to a previous version, just need to do it.

 

[Boswell]

I loaded Mach4 but I can't remember now if I actually loaded the Smoothstepper driver. I think so but I know I have not cut any parts using March4. I have never had any issues with the spindle not turning on using Mach3