CANDCNC on Torchmate Table

[Stanmyers00]

Has anyone run the CANDCNC G5 system with stepper motors on an older Torchmate table? I have the table with the turnscrew drive on the gantry and rails. I am wondering what kind of feedrate\cut speed I can go up to. The original Torchmate set up was maxed at 175 IPM. Thanks.

[dodom]

This was a torchmate upgrade

CandCNC G5 bundle
Post by regpattee » Thu Jul 15, 2021 7:53 am

I upgraded my 10 year year OLD table to the G-5 bundle with the RS-485 kit.
I would highly recommend this CandCNC upgrade for two reasons, first of all the, plug and play system, and outstanding Tech support.

I was so ingrained in having to do all settings by hand, Tech support was a great help in getting me started.

Thanks CandCNC.

[weldguy]

I have heard nothing but good things about the C&CNC Torchmate retrofit kit. Flashcut also has a Torchmate specific retrofit kit but I believe it is a little more costly, both are longstanding reliable brands.

[cutnweld]

I have Cand system, Works well. I saw my cousins Torchmate and decided almost anything could beat it on gantry power and speeds etc. I am working on switching to linux QTplasmac with clearpath servos as I have time, just another option if you like to fiddle.

[Stanmyers00]

Thanks everyone, I do have the system installed and running. I am trying to figure out what cut speeds I can run with the new system. I regularly cut thinner metals, so with the old Torchmate system I had to manipulate the amperage to get good cut quality because of slow cut speeds.

[tcaudle]

What you wil find is the higher torque motors you got with the upgrade system will allow you to get better speeds before you experience the dreaded lost steps . The beeter toolpath tracing and dynamic trejectory control will let you cut at faster speeds and while Real time Anitdive on corners an d turns will stop torch dives . You should be able to approach the required cutting speeds on the chart and use the integrated cut charts if you have a Hypertherm of any type. You can raise the Preset voltages if you want to cut a slower speeds to maintain the proper cut gap height).

Note to cutoweld: We have a new G5 XL servo system that uses the Clearpath servos and our CommandCNC version of LINXUCNC . You can choose between the 34 servos or the 23 and mix and match them. Servos are not cheap but they offer some advantages if geared correctly for a rack and pinion table. The G5 Xl controller has all of the power features to run the Clearpath with centralized overload shutdown and servo fault shutdown if any axis faults . Panel indicators show which servo casue the shutdown.

[Stanmyers00]

Thanks everyone.

I posted this on the CANDCNC forum and was told 600 RPM's was an ideal working range for these stepper motors. According to my calculations I should get 200 IPM, a 25 IPM increase over what I had. Thanks again.

[tcaudle]

What did your steps per inch end up being ? The best way to find the operational point is to keep raising the Max Velocity unitl its starts to lose steps on detailed cuts then back a off by 20%. Also lower the acceleration some and you will find you can hit higher IPM . You can get by with lower acceleration due to the tracking giving preference to accuracy over constant speed . Down side is corner slowdown but VAD takes care of torch diving .
200 IPM is marginal for thin material . I have reports taht the original tables would start to have poor perfomenace about about 120 to 150 which really caused issues. You can't get step up gearheads I am aware of so chanign the raio with pulleys and offset motor mount is th eonly way I can think of to get more speed. ^20 steppers will do 1000 (actually as high as 1200 ) RPM with no load but tha tis not USABLE RPM in most cases. We have found that on a leadscew Z with ballscews and low friction guides that we can get up 900 RPM or more .

[weldguy]

And there you have, solid info above direct from Tom Caudle at C&CNC, how can you go wrong with attention like that!

[Stanmyers00]

Tom, I missed this reply.

Steps ended up being x- 1995.58, y- 3991.16.

I am considering upgrading to a ballscrew drive versus the leadscrew and plastic nut being used now. Also considering linear rails and guides versus the bearing system. Hoping this will help with accuracy and speed. 400 IPM would be ideal for the thin material we run.

[cutnweld]

Mind me asking why not rack and pinion?

[Stanmyers00]

I have considered that as well. Actually was my first choice. I would have to engineer the mounting of the gear racks and stepper motors. This machine is in production so I can't afford to have it down too long.

[adbuch]

Both of my AvidCNC tables use rack & pinion, as do my three Plasmacam tables. These have proved to be quite reliable and trouble free. I did use lead screws with the delrin anti-backlash nuts on my smaller diy table and this worked pretty well also, but are more trouble to adjust to minimize backlash/slop. AvidCNC sells the stepper motors, racks, and drive components here.

David

https://www.avidcnc.com/pro-rack-and-pi ... 47_49.html

avidcnc racks and drives.jpg

[Stanmyers00]

Thanks David this is the sort of stuff I am trying to research.

[adbuch]

Thanks David this is the sort of stuff I am trying to research.

You are quite welcome! Let us know if you need more information.
David

[Stanmyers00]

After doing some research, I have noticed that using belt drive for speed reduction is the popular way of doing it on rack and gear systems. I wonder why direct drive gear reduction boxes aren't used more, any thoughts? Seems like less hassle, adjustment, things to go wrong.

[cutnweld]

i have those. Noisy. expensive. wont last as long as belts, unless you spend a pile a get really good ones. You have to keep backlash in mind on a cnc appplication.

[TJS]

I have and older PPLC V rail set up with rack and pinion with no gear reduction. Have been using it for quite a while. So far so good. At the time the gear reduction upgrade in my mind was expensive so I did not do it. I check my backlash all the time and even take the pinion gear off (un-locktite) and re-do them about once a year with the correct loctite 271 and make sure the set screws are perfect on the shaft flats.

[Stanmyers00]

Thanks for the advice. I had a set screw come loose from one of the drive pulleys, cut a belt, and ruin an entire sheet of material. Inspecting the set screws and using loctite on a some sort of schedule seems in order.

[cutnweld]

I key all my shafts and put roll pins in my motors. I don't trust a set screw to hold anything by itself. Set screw with keyways along with Loctite sleeve retainer has worked well for me, no backlash and zero slipping.

[Stanmyers00]

Good idea, thanks Cutnweld. I had never heard of the loctite retainer, I will check it out.

[adbuch]

I key all my shafts and put roll pins in my motors. I don't trust a set screw to hold anything by itself. Set screw with keyways along with Loctite sleeve retainer has worked well for me, no backlash and zero slipping.

That's good information! Thanks for sharing. With some stepper motors, it is not possible to drill the shaft for a roll pin due to the size of the shaft. But for the larger ones, great idea.
David

[cutnweld]

That's good information! Thanks for sharing. With some stepper motors, it is not possible to drill the shaft for a roll pin due to the size of the shaft. But for the larger ones, great idea.
David

You can get pretty small roll pins...
My theory is to overbuild then you wont have problems. For my new setup I have 3/8 keyed shafts on my motors, running a 1" wide L pulley down to another 1" keyed pulley on my 5/8 pinion shaft, connected with a 1" wide belt. I don't expect to have problems. When you are flinging a 100 lb gantry around at up to 1400 IPM you want something more than friction holding things together, Unless you shrink fit everything, which is harder than sinking a keyway. My $.02 if its worth that!

[TJS]

I key all my shafts and put roll pins in my motors. I don't trust a set screw to hold anything by itself. Set screw with keyways along with Loctite sleeve retainer has worked well for me, no backlash and zero slipping.

Cool idea. I will need to check this out. I wonder what size roll pins I will need to use on this shaft. I have a Bpt/DRO, so setting up and being accurate is not the big deal. Just wondering if a "too large" of a hole will compromise the shaft integrity. There is a roll pin PDF out there that denotes what size hole and such is needed for said roll pin. I imagine the roll pin will have to be perpendicular to the flat of the shaft. The more I am thinking I am not sure cause the set screw hole in the pulley is taking up that landscape.

T.J.

[Stanmyers00]

That's good information! Thanks for sharing. With some stepper motors, it is not possible to drill the shaft for a roll pin due to the size of the shaft. But for the larger ones, great idea.
David

You can get pretty small roll pins...
My theory is to overbuild then you wont have problems. For my new setup I have 3/8 keyed shafts on my motors, running a 1" wide L pulley down to another 1" keyed pulley on my 5/8 pinion shaft, connected with a 1" wide belt. I don't expect to have problems. When you are flinging a 100 lb gantry around at up to 1400 IPM you want something more than friction holding things together, Unless you shrink fit everything, which is harder than sinking a keyway. My $.02 if its worth that!

Cutnweld, Sounds like a good setup, could you post a picture?