techno-retro

[advt001]

I have a 10 year old 4896 with the servo system and the dos control.Can anyone reccomend a "diy retrofit" for this machine?
thanks again

[cabnet636]

i am partial to wincnc as a controller, i went from dos to wincnc in 07 and have been glad i did ever since,, you can go mach as well contact tom caudle at candcnc.com

[Pplug]

Another option is to replace the servo amps and card with Gecko drives and mach3. If I was doing a retro of my lc4896 I would go with this solution.

[advt001]

Thanks for the replys guys.Can one of you tell me how large the servo's should be? I am almost positive the machine is equipped with 1/4" shaft nema 23's.This machine has a little over 18" in z travel and has a brake on that servo.Is the brake actually needed ?I have looked at some sites offering kits but have not seen any info on brakes?As always I appreciate your time and knowledge.

[Pplug]

The break is always a problem for every retrofit I have seen. I heard people use air springs to offset the weight of the spindle and mounting plate. If you go the gecko route I know you can use the same motors. All you have to do is tune the drives to the motors.

[advt001]

Pplug you have convinced me, gecko's and mach are the way to go.Now my mission for the weekend will be comparing prices and comments on dealers.

[cabnet636]

mcmaster carr has the adjustable arms for counter balance however since i went gecko and mach i have not needed them

jim

[g2x2y2]

Typically you don't need a counter balance on a stepper system. when you turn your machine off with steppers, the z doesn't drop like the servo system does. but also the stepper sytem is much easier to setup and less expensive. if you you do go with steppers. i recommend that you wire them in parallel. 2 sites to check out. kelingcnc.net and homeshopcnc.com

[TOTALLYRC]

Originally Posted by advt001 Thanks for the replys guys.Can one of you tell me how large the servo's should be? I am almost positive the machine is equipped with 1/4" shaft nema 23's.This machine has a little over 18" in z travel and has a brake on that servo.Is the brake actually needed ?I have looked at some sites offering kits but have not seen any info on brakes?As always I appreciate your time and knowledge.

If you keep the existing servos as suggested by another poster, The brake on the Z is only really needed in a power off situation to keep the head from drifting downward. If the brake is on when there is no power and releases when power is applied, it should be easy to wire it using a relay so the power gets turned off when an e-stop is applied.
If the main power supply to the drivers is below 80v, then go with the new G320x drives from Gecko and keep the motors. Servos, when setup properly, rock. If you need new encoders, I am extremly happy with the amt-102 from digi-key.

The other poster was right that steppers have enough holding torque in the non moving stated to keep the head in place, unless the weight is really silly.

There is
another option to look at, depending on your budget.
If your existing servo amps are still working well, and all you want to do is go to Mach3, and they use +-10v analog input, take a look at the DSPMC from Vital systems. You will also not have speed limits like the pport has.

Most likely it is overkill for your application, but it is a nice way to run analog servo amps using Mach3 for the CNC frontend.

Mike

[dmauch]

I have retorfitted about 10 of the techno systems. Only 3 were servos. The 3HP router will cause the Z axis to drop if power is lost or the output of the servo amps are not engaged. The XY axis servo are bout 300 oz in and the Z axis is aboutn 400 oz in peak.
I used an airsping from Mcmaster car as the simple solution. I can get you the part number. I drill and tapped for a 5/16 hole on the bottom of the plate that hold the router. Then I made a L bracket that fit on top of the Z axis and connected the top of the air spring to that. I used Gecko drive G 320 servo amps.

Dan Mauch
www.camtronics-cnc.com

Originally Posted by advt001 I have a 10 year old 4896 with the servo system and the dos control.Can anyone reccomend a "diy retrofit" for this machine? thanks again

[advt001]

Guy's thanks for the input. I will look at "dspmc".Dan this machine came from the factory with a hydraulic type dampener. I need to make sure it will hold up a 5hp. Colombo.I guess I could put one on the opposite side if needed. Good ideas guys.
Thanks again,
Scott

[joejared]

Originally Posted by advt001 I have a 10 year old 4896 with the servo system and the dos control.Can anyone reccomend a "diy retrofit" for this machine? thanks again

Funny thing about Techno controls. They're all basically the same, from ISA bus to pci bus. The older machines are based on the lm628 chipset, the newer ones on the lm629, and from a programmer's standpoint, well, one object model covers all units. My own application works on LC anything, and ISA anything, with only minor port reassignments for the newer models. Timewise, you may be better off contacting Techno for a new control card. If you ever feel like selling the thing, it's a bit on the bulky side and I prefer the smaller LC3024 series but I may have a buyer.

OreTek