4g upgrade, no more?

[mjindustry]

I seen it mentioned awhile back that supply was becoming limited, and now I can't find the 4g upgrade on the shopbot site. Am I missing something, or are they really gone forever?

[hh_woodworking]

you need to buy the complete power supply system now I think

[kurt_rose]

I'm currently looking at buying a 2001 prt and would most likely want to do this upgrade. Anyone have an idea on what it would cost?

[Dan Brewer]

Kurt

I'm kind of in the same boat as you. I have a 2002 PRT96 and am looking to upgrade the controller box. Spoke with Frank at SB a few days back and the price was in the neighborhood of $2695. ShopBot does offer a rebate on your current (or soon to be current in your case) controller as well to offset the costs.

While initially I was in sticker shock, after some time to reflect I can understand that the cost is quite a bit more due to the fact that it's an entirely new, more industrial unit, better power supply, beefier cabinet, updated drivers, etc. Part of me (my wallet, mostly) wishes SB still offered the more affordable PRT4g upgrade, but I wonder if there were perhaps some issues with it that warranted the switch to their current offering, e.g. the new board was too much for the old power supply, etc.

Finally, my plug for SB: I can tell you that in the 8 years I've had my machine I've been extremely happy with what it's done. Given its years of dependable service, investing $2700 in it to keep it updated now seems like a no-brainer. Good luck with your purchase.

[gc3]

http://www.mechmate.com/forums/showthread.php?t=891

http://campbelldesigns.net/enclosure.php

http://www.super-tech.com/root/itm.asp?p1=itm-emc-geckopwr

[erik_f]

I have played around with trying out the Gecko 540...which is a complete 4 axis driver and break out board in one unit. Only thing you need is a power supply which can be had from someplace like Meanwell...the 540 is about $250...http://www.kelinginc.net/GeckorDriver.html

[richards]

Stepper motors must be matched to the drivers and both the drivers and the steppers must be matched to the power supply.

The Geckodrive 540 is limited to 50V and 3.5 amps. It works well with the Oriental Motors Pk295A2A0SGxx motors wired half-coil with a 35VDC power supply.

The Geckodrive G201, G202 and G203v stepper driver can handle motors with higher inductuance, but they work very well with the PK296A2A-SGxx motors wired half-coil.

Stepper motors require a constant pulse stream. The Shopbot V201 card can handle a pulse stream up to about 30,000 steps per second, perhaps higher. The PMDX-122 card card can handle pulse streams up to 250,000 steps per second.

The limiting factor is how fast the software can deliver pulses.

I believe that Shopbot can deliver pulses to about 30,000 steps per second without error. Mach 3 can deliver pulses to about 45,000 steps per second without error. Personally, I prefer the Shopbot software that gives me much greater control over the tool-pathing file than I can get with G-code and Mach 3. So, I'm willing to sacrifice speed.

Those who aren't afraid to jump in and design their own controller have no limits. I've designed several controllers that work with and without Shopbot SB3 software. I prefer the controller that work with Shopbot software. It is easier to use and easier to modify.

With all that being said, a stepper motor will move a finite distance each time it receives a step command. When properly matched to a stepper driver and a power supply, the stepper motor can be counted on to perform it's duty properly. The choice comes down to convenience. I prefer SB3 software to Mach 3. Shopbot offers a number of options, ranging from selling the V201 card to selling complete controllers.

Users only have to define how willing they are to handle their own problems before deciding whether Shopbot has the best solution to their 'problems'.

Because the controller is the very center of a CNC machine, no one should think that switching to Mach 3 or EMC2 is a minor option. The SB3 software works very well and thousands of users are satisfied. Mach 3 and EMC2 are both excellent, but neither of them are as 'user friendly' as SB3.

Even though I've just sold my PRT-Alpha, I've always resisted the temptation to move from SB3 to any other software. Shopbot's software has been the easiest for me to use, and I've tried them all. With over 30 years experience as a programmer, I like the SB3 software for ease of use and reliability. A very simple machine running simple tool pathing might fit very nicely with Mach 3 or EMC2, but for those who like to 'tinker' with the software, SB3 is by far the easiest to use.

Every hardware design has limitations. Bob Campbell makes a nice controller that works well with Mach 3, but I would classify his controller as less robust that the controller that Shopbot sells. (There are lots of ways to improve both controllers, but off-the-shelf, the Shopbot controller has more features and a better design than any other controller that I've seen. I would like to see better opto-isolation, but not one in the price range that we're discussing offers good opto-isolation.)

Ungeared stepper motors are going to cause grief (chatter). You can either add a belt-drive transmission or you can use a gearbox, like the one attached to the PK296A2A.SGxx motors. Shopbot offers a motor with a gearbox. I don't like the high inductance of the motors that were supplied with older machines, but the motor works.

In an ideal world, I would use a controller that uses Geckodrive stepper drivers matched to motors that are connected half-coil. The power supply would match the requirements of the drivers and the motors, and the entire package would run Shopbot's SB3 software.

[gerryv]

That's one of the best written, easily readable summarizing posts I've ever read on any of the forums I've followed over the last several years, whether machine shop, Mach or SB. A big thanks for the clarity and insight Mike - it's highly valued.

[gc3]

http://www.mechmate.com/forums/showthread.php?t=1190&highlight=pk296a1a-sg3.6

a ton of info out there from Mike

spend some some time on the search mode...

http://www.talkshopbot.com/forum/showthread.php?t=454&highlight=control+upgrade