[hoss2006]

You'ret 4 posts are showing thru here but I'm on a pc not a phone.
Hoss

[comtech]

Thanks hoss your plans got me going. I guess I can continue to talk about my machine then...

Lets talk about the pendant....got it from Cnc for pc not exactly compatible with Mach 3 I works but I can't get it to step in specific increments have to use he keyboard. Quality o pendant is excellent hope they get the compatibly issue fixed.

[comtech]

As I run my signs I am listing my issues, another issue I have is the z. The z is direct drive no problem right but the 960 oz motor can't move it at any speed. I may gear it down to 1:2 but that is if I need the speed can only jog at around 20 - 25 higher than that it makes wired noises. Don't know a lot about this stuff, I'm only just a shop teacher.

Here are the final setup on the z, not as pretty as I wanted but works for now.....

[comtech]

Lets talk about the pm-30 mv. Gripes the head won't go all the way down to the table. This is a pain have to be careful when cutting things and extend the bit quite a bit. The other thing I can't figure out is the rpm thing.....according to the manual I should be only able to get 2250 rpm out of the spindle but I am hitting speeds up to 2800 with no load what the heck, darn Chinese need to get it figured out. Overall the precision Matthews mill has been a good starting place to build from, the mill is a great base for a Cnc conversion.

[comtech]

To address some earlier questions.....I put a splash guard over the control box to protect it from what ever, metal chips find there way everywhere or so I have found out.

The noise level is pretty low no louder than my lathe.

The gibb on the z has been adjusted but no real change think I need a stronger z motor or need to reduce the ratio no direct drive. Also I need to make a solid mount for the ball nut and head unit, you can see pix of what I made earlier, if I did this I bet I could ge the tolerance down a bit. But, Mach does a good job with compensation.

Over all the machine runs smooth i couldn't be happier with what I did, I'm not an expert nor have I undertaken a project like this before but glad it works. Half the price of a prelate machine and I think is more capable. I'll talk about the cnc4pc touch probe in a bit. Can't get the darn thin to work at all and there are no instructions at all anywhere. Just plug it in and of will work.....yeah right!

[Zaggy]

Hi,
Could you describe the steppers you installed on all axis and the kind of speed/accel they give ?

[comtech]

I bought a kit from cnc4pc the electronics are not my thing but here is what Is installed.

2 nema23 570 oz 5A 3/8 dual shaft stepper motor
1 Nema34 906 oz 6.1A single shaft

Max speed on the z is around 20 with a generous ramp, I think my head is to heavy, but if i run it slow there is no problem.

X and Y I can get up to 40 ipm with out the motors skipping steps.

Any faster on the motors and they cant keep up. I don't know enough about the electronics to tweak it. So far for what I have cut wood, plastic and brass it works fine. Unfortunately Im no expert.

After thought Here....I should have bought bigger motors what was another couple of hundred dollars in the over all scheme of things.....

[Zaggy]

Hi Comtech,

thank you, these are very valuable informations to me as I just received almost the same machine from Weiss Machinery.
Almost because mine has the larger table, and because the saddle is a special higher version I asked them to integrate the ballscrew nut without having to mill a pocket in there as you had to.
I'll start a thread to present the machine.

When you talk of 40ipm and 20ipm, you mean the rapids right ? That's on the very low side of what I intend to get with my heavier table. What is the inductance of your steppers, did you tried to raise the voltage ? The torque graph of the steppers would be informative to know the torque delivered at the max speed you reach.
The head is indeed very heavy, I intend to put a Nema34 12Nm (1700oz-in) direct drive and 8.5 (1200oz-in) for X/Y. Ballscrews will be 0.25 inch (or 5mm) per turn.

I bought a kit from cnc4pc the electronics are not my thing but here is what Is installed.

2 nema23 570 oz 5A 3/8 dual shaft stepper motor
1 Nema34 906 oz 6.1A single shaft

Max speed on the z is around 20 with a generous ramp, I think my head is to heavy, but if i run it slow there is no problem.

X and Y I can get up to 40 ipm with out the motors skipping steps.

Any faster on the motors and they cant keep up. I don't know enough about the electronics to tweak it. So far for what I have cut wood, plastic and brass it works fine. Unfortunately Im no expert.

After thought Here....I should have bought bigger motors what was another couple of hundred dollars in the over all scheme of things.....

[comtech]

Well here are the graphs I think, I'm just learning don't know the in and outs of Mach 3 that well. Here are some photos of the Mach 3 setup x and y are the same. I hope this is what you are looking for if not I will gladly help in any way I can

[hoss2006]

How did you arrive at your steps per?
Set your accel to at least 25, 1 is ridiculously low.
Velocity should be able to reach higher than that.
Are you still running the stock screws?
I should think you could achieve at least 50 for vel with stock screws and these motors.
Hoss

[Zaggy]

What microstepping are you using ? 256 ? More ? You could set it with the swithes around 8 or 10, it's far enough to keep the steppers run smoothly. Lower your "step per" accordingly by the same factor (a lower value probably around 400), raise your acceleration around 50 or even 100 and start raising max speed too. That should do it on X and Y.

[comtech]

Well to answer your questions Hoss......

As per your instructions on your plans I chose to use the Roton ball screws and oversized balls on all axis.

I set the steps according to your video using 1 2 3 block and a starret last word dial indicator.

I changed the speed to 25 and the ramp to 5...... It seems to work fine. When I was fooli g around with the motor tuning and turned the velocity over 40 the motors would make bad noise so I just backed it down until there was no noise.

The z axis is the on that gives me the most problems I, I think the head is to heavy for the motor so I just slowed it down and it seems to work fine. I don't need the speed, I've got plenty of time.

I'm only a shop teacher not an expert

[hoss2006]

ok, setting the drivers to 1/2 step and the steps per to 2000 (run the calibration again)
should give a little better performance.
You might be able to jump the vel up some more.
A counter balance would help the z a lot.
Check out davids.
Hoss

[ame=http://www.youtube.com/watch?v=ijRL68ZXFRE&list=FLjoRKEpk7uE5Wzf4b-IFTFg&index=34&feature=plpp_video]Counterweight BF30 CNC - YouTube[/ame]

[comtech]

Hoss - I hate to say this but I have no idea where to change the settings in Mach 3 to half step. I can't even find it in the manual. What do I need to look under.

Your help and expertise is greatly appreciated

[comtech]

Zaggy,

You are now asking questions of which I have no idea....micro stepping 250? I guess I'm lucky this thing works at all. When I set up the control box I followed the limited instructions that they offered with the control box kit. I still can't get the machine to home off the limit switches but that is not a big deal as long as it will stop the machine if it over travels. The touch probe doesn't work either there are no instructions on how to set it up when it came. The jog pendant I also bought don't work worth a darn, should have use a cheep game controller. When it cOmes to setting up Mach 3 I am way out of my depth I have an idea what some things do and no idea what other things do.

I think my machine runs pretty good but still need to cut some metal parts. I may just draw one up in aspire and see what happens when I cut metal. I have used the machine to engrave some small brass thumb screws for an oiler for a hit and miss engine. The engraving was awesome the letters were 1-16 tall and they looked great. I engraved the plastic signs for the football team and the mill didn't miss a beat ran for over 4 hours cutting over 40 signs.

There needs to be a community where all the machinist get together at each others house or business and help out and have a beer. I only have one friend into machining and he is an old timer but an awesome machinest but only uses manual machines, he worked for an aerospace company here in akron in is good and who I'm learning, I just need to find someone in to the c c stuff.......any way I'm rambling.

I'll see if I can figure out how to change the settings and let you know if it helps but I have nothing to base it on either, so I'll experiment.

[hoss2006]

You need to set the switches on your driver, circled in the pic.
From what I can see you have the current set to software mode and the microstepping to 1/8.
note which way the switch goes for "on" and set them this way and set your steps per in motor tuning to 2000.
set them all to "on" except number 5 to "off".
this gives the full current and 1/2 microstepping plus half idle current for cooler motors.
Noticed the box has a smoothstepper, you'll need to make sure it's setup correctly like the manual says too.
Hoss

[comtech]

Ok Hoss 7,8 are on....if I go switching these will I mess anything up? Will I have to make changes in Mach. The reason I ask is that it is running good now, will I see a marked improvement? With my limited knowledge should I just leave it be?

Here is a competed picture of my finished box.

[hoss2006]

You can leave 7 and 8 alone and stay with your micostepping and mach settigs as is but at least switch 1,2 and 3 to ON to make sure you're getting full power, I bet this will perk things up and you can raise the vel (ipm)
Hoss

[comtech]

Hoss,

Thanks for your help....I will have do give this a shot this week. I have a lot of engineering drawings to grade before midterms come out.....but I will keep you posted and let you know how it is working. I will switch on 1,2,3 and run it and see what happens.

Thanks again for your help........

[comtech]

Hoss,

What a difference in the rapids I have successfully turned it up to 60 for the velocity. The steppers make a whole different noise when switches 1,2,3 are activated. No will have to make a test run but just thought I'd tell you that the thing rapids much faster and the motors don't make that skipping noise.

This is really awesome........now I want to figure out how to set it to half step mode.

Thanks again hoss, your expertise is greatly appreciated.