looking to upgrade steppers & drivers.

I'm running a 5x10 torch mate 8020 table and want more speed for cutting thinner gauge and I want to add a z axis as a router. My current setup is a flashcut 501a with a separate motor driver box that has applied motion 2035 drivers that are maxed out @ 2 amps running 262 oz nema 23 steppers. The sutup works great cutting thicker material but stalls @ higher feed rates.
I'm wanting to keep the 501a and software and only change the stepper driver box and steppers, the new flash cut setup is all built into one box it appears to use applied motion str-8 drivers with a 501a inside also. Would it be better to stay with nema 23 steppers or go with bigger 34's? My setup uses rack and pinion and belt reduction.

modelaratrod

You have a number choices which mostly depend on your ability to do the integration your self. I was in your position last summer with my TM2 table. I ended up converting it to dual stepper drive on the X axis with new motors in a configuration similar to a TM3 table. Open your driver box and make sure that the drivers are set to maximum output (mine weren't) as a first step. Also check your tables mechanical assembly, these tables require constant adjustment to keep them running true and tight. I kept the old driver box (same as your's) and used higher powered steppers so effectively had about 320 oz/in of holding power with the original driver box. You didn't mention which table configuration you have. If you have the TM2 configuration I highly recommend making the changes I did as a minimum. I can post photos if you want. I am not sure that any of the TM 8020 based tables will be ridged enough for serious router work. First replace your stepper motors with 4 stack ones to get more drive power on the X for plasma only and Y if trying to use a router. I used ones from Automation Technologies. For a turnkey upgrade buy a system from CandCNC, you won't need the ethercut option or their torch height control if you want to keep using the TM (Flashcut) software and box. The next choice in complexity is to buy a Geko 540 based stepper driver box and some new steppers and do the integration your self, this should increase available torque and speed by about 1.5 at a minimum.

John

It's a TM2 and it would be great to see your upgrades you made to yours.

My drivers are turned up and maxed out at 2 amps so I can't run any bigger steppers unless I upgrade the drivers.

I'm planning on using the current setup to cnc a grizzly mill so my TM2 will be plasma and light routing in plywood and plexiglass.

modelaratrod

The design of the TM2 X drive is really crap as anyone that own's one knows, cheap to build but high wear/short life. My excuse is I bought mine second hand and knew nothing about CNC plasma cutting when I bought it. The only saving grace was that I only paid about 10 cents on the dollar compared to list including 5,000lbs of steel sheet. The racks and stepper are in the worst location for getting covered with slag and debris from cutting. So along with needing more speed I decided that the racks needed to be moved to the outside of the the 8020 frame like the TM3. At first I agonized over copying the older belt reduction TM3s and then found two 5:1 23 frame gear reducers on Ebay for a good price and bought them. Life got really good when I figured out that with the exception of two holes the parts for both sides are the same. The main plates are plain old cold rolled .25" thick 1018 plate. The gear box and motor mount to a .5" 6061 T6 plate that bolts to slots in the first plate for adjustment. Sorry I didn't take photos of the parts before assembly as I did this in my busy season. The cable chain supports where also lengthened and mounted to the inside of the 8020 frame. The extra brackets in the first photo are part of the water tray supports. Parts sources:

Ebay Gear reducers, 8020 hardware
Amazon New 24 tooth 24 pitch spur gears (makes drive math easy)
Automationtechnologies Stepper motors
Mouser Connectors to match existing ones
McMaster Carr Cam follower bearing

The only bad is that I lost about .0005" resolution per step with the combination of gear ratio and larger spur gear. This is not a big deal for the garden art that I make. I still don't run my table real fast but now I get almost double the acceleration from stock, which is good for all the curves in my work. I think that I can find sketches of the parts if you want.

John

I don't see how you can deal with flashcut, I tried getting some basic information from them since fabtech with not much luck, email and calling I never got a salesmen to call me back about either turnkey mill or retrofitting my mill and CNC router/plasma table

ttm

I don't deal with Flashcut at all! They will not support equipment purchased through Torchmate. I got a quote on a new system once because I had no idea what the parts cost and about fell out of my chair when it came. They also sell through Grizzly Industrial for the common small systems now. I have actually found their software quite simple and good, I am running the TM3 software which is an older version. I knew nothing about CNC or plasma cutting when I got my system (used) and was able to get up and running with very little help from TM, the manuals are generic but complete. The TM email support has been pretty good if you ask the correct question, the guys there aren't mind readers and I did ask newby questions that weren't relevant to the real problem some times.

John

Islander how did you configure the two motor x axis? two motors, two driver cards with one motor rotating in the opposite direction?

Also why did you pick 5:1 for gear reduction? as opposed to 10:1 etc...

Here's some progress pics. Attachment 264970 Attachment 264972

Quote:

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Originally Posted by islander261

modelaratrod


The only bad is that I lost about .0005" resolution per step with the combination of gear ratio and larger spur gear. This is not a big deal for the garden art that I make. I still don't run my table real fast but now I get almost double the acceleration from stock, which is good for all the curves in my work. I think that I can find sketches of the parts if you want.

John

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did you figure out why you lost resolution? and do you recall the user on ebay for the gear boxes? I got my new controller and am looking to go gear box 10:1 with my dual gantry drive servo's on my plasma, and im probably just going to use CandCNC for the router build too I already have 4 extra 850 ox servo motors, and they sure are customer friendly, (I had been thinking of going with a complete conversion from someone)

modelaratrod

Your setup looks nice! I wish I had found right angle gearboxes at a good price. The straight ones I used are OK on cable carrier side but really stick out on the other side.

ttm

I don't remember the ebay vendors I bought the gearboxes from. I do remember I bought them from two different vendors.

The lost resolution is just a mechanical fact from the gear ratio and pinion size. It is the difference in distance covered by one step of your stepper motor. If I built a table with what I know now I will use the CandCNC controller.

John

Thanks for all your help islander. :D

New power supply just showed up. Is big! lol

Attachment 265778

Now to figure out the enclosure.
Attachment 265784

modelaratrod

Find attached screen shots from my setup. Can't attach to PMs.

John

Here's where I'm @ driver is 3.5 amp micro stepping set to 1/10 or 2000 steps per revolution, 2:1 gear reduction gear heads running on a 14.5 pressure angle 24 pitch R&P with a 24 tooth spur gear with a OD of 1.083"

I told the axis to move 16" and it moved 41"

16/41=0.3902439 and divide Pi by the gear ratio? 3.14/2=1.57 so 0.3902439x1.57=.612682

I see you have your gear ratio set to 5.0 and your screw thread is .31833

modelaratrod

Check the settings on your stepper driver, from the distance moved and your other entries it may be set to 4 microsteps per step instead of 10.

If your rack and spur gear are 24DP then the pitch diameter is 1" or pitch circle of PI for a 24 tooth spur gear.

So the screw thread that Torchmate or Flashcut wants is Screw Thread = rack teeth per unit length/ tooth pinion = (24/PI)/24= .31831, mine is not set to the theoretical number because that is how I fine tuned my motion.

Check and fix the settings on your stepper driver or enter 4 microsteps per step in the Torchmate or Flashcut SW.

Mine worked by the book for getting close. I measure the gantry movement with a dial indicator then and adjusted the screw thread number until 1" commanded gave 1" on the indicator.

John

I have the gear ratio tuned in and can run 600 ipm rapids. :-D
https://plus.google.com/photos/11304...06183670155932

Here's the almost finished product, I used a different enclosure.
Attachment 326100

Quote:

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Originally Posted by modelaratrod

New power supply just showed up. Is big! lol

Attachment 265778

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The power supply is from Antek
PS-15N70R5R12

Did you get your machine up and running?

Yes it's been up and running for a good while now and working good.

Nice! I'm interested in the speeds you are getting. I built a 5x10 heavy duty gantry router, I use a router, mill head, drag knife, ..., and have an outrigger to hold a plasma torch out over a water table that connects to the main table. It has worked great for ~15 years. I want to build a 5x12 dedicated plasma table with a light weight gantry to get the speeds up for light stuff. I cut from heavy 1" down to rusty .020" roof metal.
If you don't mind a few questions,
Did you use 23 or 34 motors?
What oz rating?
Looks like you have 2 motors on the gantry travel?
What drivers did you use?

I'm running str8 drivers and ht23-603 motors from applied motion technologies with two motors for the x "long" axis.

Thanks modelaratrod, what is the max speed you can cut at, does it do corners at a good speed?

The issue I have is the torque sensing AVHC, with the plate flexing I've had to slow down. I'm currently waiting for my shipment of a flashcut stingray height control and version 8 software to give me ohmic sensing and corner lockout/lookahead. I'm currently cutting 14g at 150 ipm.

Thanks, I program at 300 ipm, but mine also slows to about 150 on tight corners. I'm thinking I should go with 34 motors.

I'm also changing the cam roller set up with Parker cassette's, should be a big improvement.

If that doesn't get me cutting at cut chart speeds 34's will be next!