use ramp 1.4 for driving nema 34 in combined reprap lasercutter

Hi,

I am new to this forum and am planning to build a maxi reprap combined with a lasercutter.

Because the footprint is a lot bigger then the standard printer (aprox 1m x 1,4m x 0.75m) i will use stronger (heavier) material. Also the dual extruder will be heavier because it will also have the possibillity to extrude with a bigger diameter. (aprox 2mm) and a normal extruder. Because of this requirements i will need stronger steppermotors. I was wondering if it is possible to drive strong Nema23 or nema34 steppermotors with the ramp 1.4. And in case this is not possible, which is the best way to go?

thanks in advance.

try sanguish ,,, it can power motors upto 2 amps and also it is cheap..... or you can use cheap tb6560 driver boards from china in combination with ramps......

One other option is to use high(er) voltage large motors and to run the Ramps board off of 24 to 35 volts. The small motors run fine on 12V, so you can have 3X the "smoke and fire" than normal. This takes a bit of care on the details (supply to the Mega is one). Weather you will get enough torque probably depends on just how much you really need. That will be a function of your weight and your speed.

Thanks for all the replies

@ ekaggrat: Is it possible to connect for instance gecko drivers to the ramps? I was looking at the fineprint of the ramps and it looks like it should be possible to connect other stepperdrives directly to the ramps. But the fineprint is just not readable on the wiki.

@ Uncle_bob: Running the electronics at a higher current is an option, but only a last one. If i can manage to get everything within specs, then i prefer that option, but in case... i come back to you :-)

When you go to buy motors, it's not a single axis decision. I can get the same motor with the same torque in the same package with a number of different winding options. Some are very low voltage and very high current. Some are very high voltage and very low current. Since energy is amps x volts that makes sense. You can get the same energy many different ways. Instead of tripling the current, you can triple the voltage.

So why do this?

You need to do some very simple mods to the ramps board (mainly remove / replace a diode).
You need a +12 and a high voltage supply.
You can use a very normal control board
You can use standard un-modified firmware

The high voltage supply probably isn't going to be expensive. I'd guess less than $20. You need the 12V supply no matter what. Given the total cost of the project, that's not a lot of money.

I just found the pibot; was wondering if this is a better solution?
Pibot; ramps alternative?

I don't think it's a better solution for what you want to do. It's more integrated, so customization will be harder to do. I don't believe it's compatible with as wide a range of firmware as the Ramps. It's main focus seems to be lots of power into the extruder hot ends. That does not seem to be part of what you are trying to do.

Edited 1 time(s). Last edit at 11/13/2013 06:20PM by uncle_bob.

I'd use Mach 3 and breakout board. I built a large repstrap using nema 34 motors 6 AMP 70 volt I have built many machines useing stepper motors higher voltage is the key

Edited 1 time(s). Last edit at 11/18/2013 09:27AM by cnc dick.

So let's see, 2 windings per motor times 6 amps per winding times 70 volts times 6 motors .....

Time for that new power line