Potential upgrades

[sawkerf]

I have a 2004 PRT Alpha and I am wondering what would be a worthwhile enhancement or upgrade other than gears and rails. Are there control box upgrades that might improve performance? What about the retro Z upgrade, is that worth it? Please share your thoughts. Thanks, Kip

[bob_reda]

Kip, I upgraded a 1997 prt with the rbk control box, 7.2 motors, new hardened rails, didn't do the z I have to look at that. Don't know exactly what that involves and how much better it would be than i have right now. I did all my upgrades over a two year period. runs like a prs!

Bob

[bleeth]

If you have the 1:1 motors changing to geared ones or adding belt gear drives would make a huge improvement in resolution. A much stiffer gantry would allow you to cut and jog much more quickly. The new Z is an improvement over the old.

[davidp]

Hi Kip,

We have a 2004 PRT Alpha.

We have upgraded to 7.2 motors on all axis, X,Y & Z. We replaced the rails with BWC hardened rails on both the gantry and the X Axis and all of the rollers with larger rollers. We replaced the Z Axis with the retro Z, we have also installed a 5HP HSD Spindle with Auto Tool changer and 8 tools on the tool bar. Our last modification was to replace the springs on the X axis motors with longer springs. We now have a machine that cuts beautifully and reasonably quickly.

We have not touched the electronics or the control box. There has not been a need. In fact our next modification we are planning is to strip another brand CNC and replace all of its electronics with the shopbot gear. We will probably do that in the next year or so.

Regards,
David
Sydney

[gc3]

Hi Kip,

We have a 2004 PRT Alpha.

We have upgraded to 7.2 motors on all axis, X,Y & Z. We replaced the rails with BWC hardened rails on both the gantry and the X Axis and all of the rollers with larger rollers. We replaced the Z Axis with the retro Z, we have also installed a 5HP HSD Spindle with Auto Tool changer and 8 tools on the tool bar. Our last modification was to replace the springs on the X axis motors with longer springs. We now have a machine that cuts beautifully and reasonably quickly.

We have not touched the electronics or the control box. There has not been a need. In fact our next modification we are planning is to strip another brand CNC and replace all of its electronics with the shopbot gear. We will probably do that in the next year or so.

Regards,
David
Sydney

the other brand cnc have linear rails?

[sawkerf]

I've seen these 7.2 motors mentioned here before. Where do you get them? How much do they cost? How difficult is the changeover? Keep in mind, I'm more of what's known as a "power user". For example, when I read a book, I read the first few pages, skim the middle and then skip to the end. Thanks for the info gentlemen.

[davidp]

Kip

The 7.2 Motors are from Shopbot. They simply bolt on to the bot, you do have to change the drivers in the control box and change the unit values in the control software a couple of hours all up max. The hardest part is re running the cables. One of the best upgrades you can do IMHO

Gene

The proposed machine has BWC rails and rollers the same as the one we upgraded to, with rack and pinion drives.

David
Sydney

[blackhawk]

David - What are the major differences with the Retro Z axis? Shopbot's description on the website is pretty vague.

[Brady Watson]

The RetroZ uses a PRS style Z axis, but is made to fit onto a PRT. It uses 3 rollers per side that sit in a profiled track and an aluminum extrusion instead of the T-rail.

I'm not sure how much interest there is, but I was thinking of fabricating replacement T-rails for PRTs since I could use a couple on my own machines. If I am making some already, what's a few more? If interested let me know. FYI - these will be out of A36 steel, precision ground - NOT that soft malleable CNC bent steel that wears out very quickly - which you probably have on your machine now.

One thing that really makes a huge difference in longevity on the PRT T-rails is running 8 V-bearings opposed to 4. 4 bearings was the original setup, but 4G PRT & later PRT Alpha machines had 8 of them. It makes a BIG difference not only for wear, but for stiffness. Combine 8 bearings with good steel with higher Rockwell hardness & it will outlast the soft steel by a factor of 3:1 or more. At least this has been my experience.

-B

[danhamm]

Here is a pic. of the one Brady mentioned, can be mounted in many ways.