The upgrade is FINISHED - THANK YOU!

[waynec]

I just wanted to say thanks to all the folks here for helping me get my PR upgrade running.

My old PR rack and pinion has been upgraded with a new 8020 aluminum gantry in a vertical configuration instead of the PR horizontal one. It has a heavy duty linear actuator Z axis with ground ballscrew and beefy bearings. And I now roll on Bishop Wisecarver rails instead of unistrut.

I also upgraded my controller from the PR box to an Ascension and now use Mach 3 software. I'm still learning how to get the most of this software. Alan from Custom CNC was very helpful, following up to make sure I was up and running.

The machine is about 3x faster on jog speeds, and at least 2.5 times faster on cut speeds. I havent tested beyond that yet. My early problems with 'gear slipping' were just bad connections causing intermittent loss of two coils. I may need to fine tune the X rails if I want to get more speed. Cut quality is at least as good as the PR box, and improving as I learn how to control Constant Velocity and acceleration settings.

Overall I made substantial progress in the speed and reliability of my Shopbot PR. I think I can get more speed, but frankly the Porter Cable router is as big a limitation on speed as other mechanical issues might be.

I spent about $3K on this project, including several hundred on stuff I didn't really need. I could have used a considerably cheaper Z axis acutator for example and smaller motor and saved at least $500.

Thru all this lengthy process I got great advice from folks here including Brady Watson, Bill Palumbo and 'Motor Mike' and others. Folks at the Mach forum were also over the top helpful. I hope to pay forward some day soon.

Thanks all. I tried to post pics, but ran slam into the size limit. 50Kb. I can post the pics on a simple web page if some are interested.

Wayne C
White Salmon, WA

[davidp]

Wayne

I am about to embark on a gantry upgrade to my PRT Alpha, I would be interested in seeing pics of your gantry. To post photos simply optimise them on photoshop and then post them. They only need a resolution of 72dpi anything much above that is wasted on a forum such as this.

Regards,

David

[waynec]

OK, I think I have these files small enough to post. I may have to do it in two posts.

First is the Gantry. Its 8020 alum, with Wisecarver rails and wheels. The ends are essentially inverted 'T' structures, which I think could be improved. The whole thing is bolted together with 8020 hardware, and is nice and rigid. I have found the wheel brackets to be the weakest link- they need to be very stiff, or any rapid changes in direction can cause flex.

Hope this helps.


Waynec
445

[waynec]

Here's the Z axis. This is an info rich pic, showing the Y rack and motor, the Z axis and router, lots of stuff. The Z is a linear actuator I found on ebay. Its HEAVY, and very beefy, probably more than needed. But it seems to work well.

The dust collector gizzie is from the old PR. I arranged a way to attach it either to the Y car or the moving Z axis. That way I can choose if I wan t it to lift with the router, or stay at the surface of the sheet. Generally I keep it at the surface of the sheet.

All that wood claptrap is just a cheesy bracket for the dust collector gate and hose.

Hope this helps. I am happy to give more detailed pics.

W
446

[drodda]

Thanks for sharing the pictures. I am in the middle of trying to upgrade my PRT alpha to replace my X axis V roller and also to widen my Y carriage. I am trying to see how I want ot go about his. I appreciate you taking the time to show your setup.