up grade

[dan_nelson]

I have a prt standard that im going to upgrade using the rbk drivers, can anyone tell me what to expect as far as overall preformance goes? Im currently using mach and a assension controller and cant cut faster than 180 in/min without a motor dropping out. thanks as always dan nelson

[Brady Watson]

Dan,
With the RBK you should be able to move (meaning cut - depending on the material) up to 360 IPM and Jog up to 500 IPM or so (some can Jog as fast as 900 IPM reliably) - It boils down to how fast your computer is and how good your USB communication is...The limiting factor may be your router in the end, since a spindle won't bog down.

-B

[dan_nelson]

Brady do you have a recomdation as to how fast of a computer I need to reach these speeds. and I dont quite understand the usb communication as to tell how good it is. Also im cutting with a 5hp spindle. If im upgrading I can afford a new deticated control computer, I just want it to be right when all is said and done. Dan

[Brady Watson]

You should be fine with anything that came with Win7 installed on it...That covers a lot of ground, but ideally you should be 2GHZ or faster with 4GB of RAM(cheap these days).

Some hardware is better than others in terms of USB. Roll with what you can get your hands on & if it proves to be less than ideal, a PCI to USB expansion card is just the ticket.

See how it goes when you get the RBK hooked up.

-B

[GlenP]

Morning guys. Brady the new RBK can cut at speeds of 360 ipm (6ips) and jog at 8.3 ips? My current PRS circa 2007 can only cut at 2.5ips and jog at 6 ips. I do use a PC router and hope to upgrade to spindle someday.
Dan do you mind me asking how much the upgrade costs?

[Brady Watson]

Glenn,
Speeds of 4-6 IPS when cutting and 6-10 IPS when jogging are reasonable, provided that your computer is up to par. The router is the limiting factor on a number of jobs, but it also matters what you are cutting. It's hard to tell you how fast 'it will go' without knowing the specific part to be cut.

-B

[dan_nelson]

Glen, as quoted from shopbot total with shipping is $2960 that includes an extra driver for a indexer to be added in the future. Im using my current motors.You can trade in your old box for a credit. I cannot because it is a ascension and I run mach 3. but not for very much longer.

[jerry_stanek]

Is the 4g upgrade still available

[Brady Watson]

Yes, the 4G upgrade is still available. The RBK box uses Oriental drivers, which are beefier and offer a few advantages over Geckos on the 4G board.

-B

[Steve M]

Which version of Mach are you using?

If the Ascension controller uses Gecko drivers and you are using Mach3, you should be able to easily and reliably jog at 600 IPM and cut at up to 400 IPM, depending on cut parameters.

Brady is probably correct in that your control computer is too slow or your Mach settings are incorrect.

Check the speeds on the motor tuning screen as a start.

[richards]

Oriental Motor makes excellent motors and excellent controllers. Some people do not realize that many motors have basically the same specifications, meaning that they can be expected to do the same job if driven by equal stepper drivers at equal voltages.

A case in point is the PK296-03, the PK296-F4.5 and the PK296A2A-SGxx motors. If you look at the "fine print", those motors have the same characteristics, differing in the number of exposed wires or leads and ratings limited by attaching a gearbox. Now compare the PK296DAA motor to those other motors and see that the ratings are almost exactly the same. The PK296DAA motor is used with the RDB stepper driver.

The other motors that I listed can be used with the Geckodrive stepper drivers (G203v or similar).

The RDB driver has many more options when compared with the Geckodrive stepper driver. I have never used the RDB driver, but I have used many other Oriental Motor stepper drivers, including the Alpha drivers that Shopbot supplied with my PRT-Alpha. All of Oriental Motor's product have been excellent.

If the correct power supply is used, the correct pulse stream is used and the correct ramping is used, there is no reason to expect any of those motors driven with the Geckodrive or the RDB drive to greatly outperform the other. Because the RDB driver has more options, the operator would have more opportunity to experiment, but he would still be limited by the resolution required and the number of pulses per second that his controller could produce.

A fatal flaw in the Ascension controller design was in re-using the original stepper motors instead of requiring/furnishing motors with lower inductance. The G202 stepper driver could drive the high inductance motors, but those motors were not suited for high-speed use. In addition, most of those older motors came with only four wires or leads, so that they had to be wired bipolar series instead of half-coil or bipolar parallel. (Check the differences between the specifications for the PK296-01A and the PK296-03A motors to see what I'm writing about.)

The RBK upgrade seems to me to be a very good option for those who don't want to design their own control box (and take responsibility for that design). When asked how much it would cost to build a new control box using PK296-F4.5A motors, G203v stepper drivers, a good power supply and all of the other parts and pieces required in a fairly minimal control box, I tell them that the price for parts would start at about $2,500 and rapidly increase, depending on options and "do-overs". (Believe me when I tell you that there will be "do-overs" if you design your own controller.)

Ignoring the "alpha factor" obtained with the use of "Alpha" drivers, both the Gecko and the RBK is able to drive a non-alpha motor at the same speed as the Alpha IF the motor is suitably geared. For example, the 7.2:1 geared Alpha motors that Shopbot sent me to upgrade my PRT were rated at 80 in*lb of holding torque. The PK296-F4.5 motor is rated at 440 oz*in holding torque. With a 3.6:1 belt-drive that is just under 100 in*lb of torque. Ramping may give a slight edge to the Alpha motor, but if proper ramping is used with the PK296-F4.5 geared to 3.6:1, it will not miss steps when running at similar speeds and depth of cut.

(I'm not trying to "bad mouth" the alpha factor, but if you've read some of my earlier posts you'll know that I threw out a tremendous amount of material that was ruined when an axis went into "alpha mode" and left a divot in the cut. Slowing things down slightly so that the motor never missed steps and therefore never needed "alpha mode" solved that problem for me.)

[jerry_stanek]

I have the 4g box and an old pentium computer with only 2 gigs of ram and I can cut at 400 ips real easy with the new software with no comm errors. My setup is a 2008 PRS standard with a 2.2 HSD spindle and 2 Fein vacs for hold down I have a HF 2 hp dust collector. I surface the table at 600 ips

[dan_nelson]

to all, maybe you can tell me more about the motor tuning and what they should be set at in mach. I have A6497-9412KT6 motors 2 phase 0.5 step on x and y on z the step is .25 as stated these are of the 4 wire variey the gecko drivers are G202 Im more than willing to try to get my machine running like it should so I thank you guys in advance Dan Nelson