Messages

11

Show"N"Tell ( Your Machines) / Re: My first CNC (plasma) machine

« on: July 24, 2015, 07:36:58 AM »

Just wanted to give everyone an update. I am under power now and starting to test it out. I was messing with it a little bit last night and realized I didn't have something set right with the slaving of the A axis to the X axis. I'm sure its something simple, I just ran out of time. Its starting to get more exciting the closer it gets to being completed. I also have been thinking about an upgrade I might want to make down the road. Has anyone had any experience with the hybrid closed loop steppers that are on eBay? I'm confused as to how they communicate to mach 3. Or is it a self contained system outside of mach?

12

Show"N"Tell ( Your Machines) / Re: My first CNC (plasma) machine

« on: April 17, 2015, 09:35:36 AM »

Just thought I would stop in and give an update. Ive uploaded more pictures to the build album. Ive got the gantry back together and am now going to start building the Y axis plate. I think I might be able to do that tonight. The house shopping is done, so Im trying to get as much done as I can before settlement and its time to move in. I cant wait to tinker around in the garage. I managed to find a house with a two car, 3 story garage. That should be enough room to house future projects.

13

Show"N"Tell ( Your Machines) / Re: My first CNC (plasma) machine

« on: March 24, 2015, 04:44:24 AM »

Ok stirling, I will do that. I havnt had much time lately to work on it. Between a full time job, being a full time studenand house shopping with my wife, theres been little free time. But, I have the sheet metal for the enclosure, and the 3/16" plate for the new lighter gantry. I did find the time to start cutting it apart. This is why I only had everything tacked together. I eliminated the channels and now have the rails mounted to the much lighter square tubing. I figure changing the gantry plates from 3/8" to 3/16" will shed quite a bit as well. All the rest will be aluminum as far as the Y axis and z axis, so that shouldnt add too much weight. Im hoping to find some time throughout the week and this weekend to get some work done on it.

14

Show"N"Tell ( Your Machines) / Re: My first CNC (plasma) machine

« on: March 14, 2015, 02:52:48 PM »

Chaoticone- That is an awesome calculator. I am definitely bookmarking that tool for future reference. Thanks alot. according to that tool I should be alright when it comes to the motors.

Stirling- I have emailed longs motor and asked about the rated current, and if it is RMS or peak current thats listed. My driver allows me to go up  to 7.8A peak / 5.6A RMS. But, that would mean I would need bigger power supplies, as they are only rated at 5.6A. I emailed longs motors and asked about the specs on it. They do not have this model on their website.

15

Show"N"Tell ( Your Machines) / Re: My first CNC (plasma) machine

« on: March 14, 2015, 01:15:13 PM »

I was hoping that myself. I hope to also attach a spindle to this machine and route wood as well. That and I knew that my gantry was going to be heavier then most, judging by the materials I had available. Also, do you think I have the driver dip switches set properly? I think I do but, a little reassurance would help calm my nerves a little bit. Thanks again to everyone answering my new guy questions.

16

Show"N"Tell ( Your Machines) / Re: My first CNC (plasma) machine

« on: March 14, 2015, 11:46:26 AM »

Nema 34 motor size converted to inches.

17

Show"N"Tell ( Your Machines) / Re: My first CNC (plasma) machine

« on: March 14, 2015, 11:44:56 AM »

Ok, and thank you for the help. Before I post the info, I just want to mention that I purchased them from Longs Motor off of ebay. It was a 4 axis Nema 34 kit including the motors, drivers, power supplies, and Breakout board. Also, note that the drawing of the motor has been converted to inches. I have a bigger version of this saved and will gladly send it to anyone that would like it. It was a big time saver when I was designing my machine.

Motor(s):

http://www.longs-motor.com/
Part No.:                    34HS1456
Frame Size:                  NEMA34
Step Angle:                  1.8 degree
Voltage:                       3.08V
Current:                       5.6A/phase
Resistance:                  0.55 Ohm/phase
Inductance:                  5.5 mH/phase
Holding torque:            8.4N.m           1232oz.in
Rotor inertia:                2700g-cm2
Number of wire leads:  4
Weight:                        3.8 kg
Length:                        118mm
The stepper motor is single shaft, the diameter of axle is 14mm,and the length of shaft is 37mm with 25mm length flat.

Drivers:

http://www.longs-motor.com/
DM860A
Details
Features:
l High performance, low price
l Average current control, 2-phase sinusoidal output current drive
l Supply voltage from 24VDC to 80VDC
l Opto-isolated signal I/O
l Overvoltage, under voltage, overcorrect, phase short circuit protection
l 14 channels subdivision and automatic idle-current reduction
l 8 channels output phase current setting
l Offline command input terminal
l Motor torque is related with speed, but not related with step/revolution
l High start speed
l High hording torque under high speed
 
Electrical specification:
Input voltage
24-80VDC
Input current
＜ 6A
Output current
2.8A～7.8A
Consumption
Consumption：80W； Internal Insurance：10A
Temperature
Working Temperature -10～45℃；
Stocking temperature -40℃～70℃
Humidity
Not condensation, no water droplets
gas
Prohibition of combustible gases and conductive dust
weight
500G

I have the dip switches set up as such:
Current: 5.7A peak 4A RMS
Pulses per Revolution: 2000

Power Supply:

The only info I could find is the power output is 350 Watts 60 volts/5.83A

18

Show"N"Tell ( Your Machines) / Re: My first CNC (plasma) machine

« on: March 13, 2015, 09:21:22 PM »

So, I started the gantry weight reduction phase. Unfortunately I forgot to take some pics before I left. I'm going to be working on it some more on Sunday. Ill take some pics then. I should have more to show by then. I eliminated the two steel channels that the rails were mounted to. I drilled and bolted them to the square tubes that were that the rear part of the original design. I found some 3/16 plate I might be able to use for the gantry plates, instead of the current 3/8" plates as well. I think that might be enough. Any input on this from anyone? Think that will be light enough for two 1232 oz. In. Steppers to move around?  Stirling, could you nudge me in the right direction with the 23 vs 34 topic? Ive searched but cant seem to find anything on this forum comparing the two.

19

Show"N"Tell ( Your Machines) / Re: My first CNC (plasma) machine

« on: March 11, 2015, 05:59:50 PM »

I did not use servos because of cost. I would rather have torque than speed. Like I mentioned in a previous post, the fastest I will ever have to cut is about 150 (ish)ipm. This machine is not going to be a full out production machine so I dont need the fastest rapids etc. But, when I am cutting and change direction at 150ipm I dont want to stall or lose steps. That is why i am totally starting from square one on the gantry. The motors are not in yet. But, I have them hooked up at home to get everything working. When I am jogging it with the pendant and change direction very quickly I can hear the motor losing steps. I dont think i will know until I get them mounted on the machine and try it with weight on them. I might even have the speeds and acceleration set wrong. My plans are to (re)build the gantry as light as possible. And hook everything up and see what happens. Does anyone have any suggestions other than what I just mentioned? Is there a way to measure or test tis before hand?

20

Show"N"Tell ( Your Machines) / Re: My first CNC (plasma) machine

« on: March 11, 2015, 02:32:59 PM »

Could you elaborate a little please? How would nema 23s give me better performance? And thanks alot for your input on the direct drive. What size gearing were you using? My gears are 20 pitch 20 pa and 1" pd.