Alpha upgrade and Columbo speed control

[bleeth]

Just finished the next upgrade to Old Blue. Alpha 7.2's and new Alpha control box. She flies!! This sure ain't grandpaps old PRT standard no more.
Question:
Does anyone with a modern Alpha (RBK driver setup) have the SB3.xx software properly controlling a 5HP Columbo spindle? Having a bit of an issue.
e-mail or private message me.

Thanks

(PS: I just may use those PK99's and gearbox parts to build a laser one of these days!)

[danhamm]

http://www.talkshopbot.com/forum/images/icons/icon10.gifFinally....

[bobmoore]

Dave that sounds great. I am hoping to start mine next spring if funds permit. Would you start with hardened rails and larger wheels for the first modification? I have a 2003 prt 4896 with 4g upgrade.
Thanks Bob

[bleeth]

Well Bob, my first modification was a Gecko driver control board before SB came out with it's 4-g version.
IMHO the power of a current Alpha driver/motor combo is wasted on an original PRT chassis. My last upgrade was changing the rails and redoing the entire gantry and Z car. Although mine is not exactly like a PRS Gantry it uses some of SB's parts and at first glance appears the same.
Without increasing the rigidity of the PRT gantry you just don't get the results out of the increased power and torque that the motor package is capable of giving you.

[bleeth]

The reason I asked regarding the speed control is it seems to be the only part of the new system I can't get to operate correctly and SB support seems stumped also.

[Brady Watson]

IMHO the power of a current Alpha driver/motor combo is wasted on an original PRT chassis....
Without increasing the rigidity of the PRT gantry you just don't get the results out of the increased power and torque that the motor package is capable of giving you.

If you have a 3G PRT gantry, then you'd do best to weld it up & replace those horrible unistrut pieces. Original PRTAlpha tools had a much stiffer gantry than your 3G does and table gussets that really beefed things up. The PRT gantry has better mechanical advantage to the tall PRS gantry. A well tuned PRT will perform just as well as a PRS. I just ran a job @ 12 IPS in solid maple for 5 hours (3D finishing pass on slow curve) without a hiccup.

Don't know about your spindle speed control. Your VFD may be older than when the interface was implemented or the pigtail isn't wired in correctly or you don't have the SSC settings right for the Hz scale etc or the VFD type in the SSC drop down doesn't match your spindle. I use a 15' extension cable that mounts the keypad for the VFD where I can control it manually - so I don't even use SSC.

-B

[bleeth]

All the settings in control software and VFD parameters are correct and device manager sees the control. Support spoke about the cable end having been wired wrong in the past on some but say that issue is long solved. I gave them the wire color order on mine and am hoping to hear back soon to verify the pigtail wiring.

For me, I'm so used to running the speeds myself anyway it's not a big deal but I'd rather control it for employees who have been know to break bits because they forgot that thousands have 3 zero's before the decimal and not two!

[bobmoore]

Thanks Dave and Brady. I think I will start with the rails and rollers, but weld up the Y car while I am at it. Also a new Z will help, the 2003 is getting a little worn I think.
Bob

[curtiss]

Somewhere on the ShotBot site it might be nice to have a bit of a "photo history" of the various models and when they were released.

Key upgrade features could be listed so everyone could understand what has been done to improve the machines over the years and what upgrade steps they might want to take.

[cip]

Dave:

I did the rpm controller thing and finally after 4 months of trying to get to work sent it back for credit. Wasn't worth the aggravation.

It caused my machine to stop and start movement as well as skip steps producing parts that were the wrong size and out of square. Even knocked the gantry rollers off the rails once.

Tried everything, Shopbot couldn't even figure out the problem.

[bleeth]

Thanks for the info Mike. Someone told me that several of the "older" Delta VFD's have not worked with speed control from the screen.
You'll have to stop by and visit the new digs. It's nice being in Delray and so close to the house.