How many motors use mechmate in the long axis
 

Hi, I'm gonna build a mechmate and I want to know how many motors use mm in the long axis, 1 o 2?, Right now I have 3 740 OZin Stepper motors, thank you for the help and sorry for my bad English

Alberto

2 motors on long axis. You need 4 motors total.

Well it depends on which is the long axis. Commonly 2 but if your Y is longer then your X (mine is) then the answer is 1.

Alberto, those sound like powerful motors for a MM.

Well, this is because it applies creative engineering, but you can see the design of the PlasmaCam has done it with one motor Link

One tube inner the granty and a big motor is the secret.

Attachment 8740

Hi
 

So, do you think that 2 stepper motors of 740 oz-in are to big for my long axis??, I have 4 stepper motors of 740 oz-in, what do you thing about my motors??, sorry for the english jaja
Kind Regards

Alberto

Alberto, do you have any of the electrical data for the motors. We can help you better if we know exactly what you have. Normally, a 740 oz*in motor should work fine. It is probably very similar in size and capability to the Oriental Motor PK299 motors that I've tested.

Hi Richard

the motors are RHT34-740 from http://www.homeshopcnc.com/RHTstepperMotors2.html

The data information that I have is:

Motors are 4 Lead parallel configured, 2 phase, 1.8 degree step angle

HOLDING TORQUE Nm 5.2 (740 oz-in)
Rated Voltaje 2.0
Rated current per phase (amps DC) 6.0
Resistance 0.33
INDUCTION mH 2.7
Rotor Inertia g-cm2 1400


I hope that you can help me with this information, thank you!

Kind Regards

Alberto

Besser read 3740 oz.in per motor, instead of 3 motors at 740 oz.in each.

Looking at the homeshopcnc link, the motors are 78mm long and weigh 2.3 kg. That immediately suggests single stack, and a rotor inertia of 1400 g.cm^2 confirms it. (equivalent Oriental Motor is the PK296 series). It is highly unlikely that the 740 oz.in is possible from these motors on a permanent basis without damaging them. These motors will not be suitable as direct-drive motors for the MM, but with 3:1 belt reductions, you could be okay.

Hi Gerald,

Thank you for your quick response, I don´t speak English very good.. sorry XD, single stack is a bad thing?, I don´t understand this:

"It is highly unlikely that the 740 oz.in is possible from these motors on a permanent basis without damaging them"

Could you explain me this with single words jaja, I understand that I need a 3:1 belt reduction system but I don´t understand why

and I have one question jaja, my MM with that motors and the 3:1 belt reduction gonna works fine and fast or it gonna be slow???

Thank you!

Kind Regards

Alberto

Sorry Gerald I don´t ask you one thing..

Can I use the RHT34-740 Oz-in on direct drive with a ballscrew?, because my Z axis gonna be with ballscrew.. or I need belt reduction in the Z Axis too?

Thank you

Alberto, I have no experience with those motors, and I have no direct experience with ballscrew drives on router tables, so I can not answer all your questions.

Simple language:

I do not believe the specification of 740 oz.in that is given by the supplier. I think it is a lot less. (maybe 500 oz.in max?)

If you fit a pinion gear direct to that motor, and run it direct on the rack, then the performance will be bad.

If you use belt-drives with that motor, I think you will be okay. I never make promises of speeds.

2 motors on X axis
 

I know ive read somewhere regarding keeping the 2 steppers working together on the x axis but cant find it anymore...can someone please point me in the right direction.

thanks