Messages

71

General Mach Discussion / Re: Stepper motors that shudder.

« on: April 02, 2019, 03:48:39 PM »

I have been using a machine that jogs on 900mm. After blowing up my PC, and plugging in an old Mach 3 I have installed on another PC I noticed the motors jogging at 1200mm which would have been day one commission. I have been decreasing that speed as the machine has gotten older. And I kind of liked the faster speed.

So on Monday I tuned my motors up to 2000mm, all the axis's will run on that speed except for the heavier Y gantry which will run for a period only to slip or brrrr out. What is the term for that? Its like a stall.

Looking further, with a 5mm pitch it appears I am asking the steppers to run at 400rpm and that seems to be the limit with the torque dropping right off yes? If I was able to run the steppers at 1800mm or 360rpm is that a reasonable request of a Nema 23?

I will say, the lower speeds have served me very well over the years. Its just a long time to jog the length of the table lol

72

General Mach Discussion / Re: Stepper motors that shudder.

« on: April 02, 2019, 02:36:26 PM »

Gerry is that a fact? I have been using the same machine, with the same setup from day one. Its been running fantastically for over 5 years until I put voltage where voltage should not go.... But I have been running the motors slow, quite slow in fact.

So am replacing my $10 BOB along with the DQ543ma drivers. I will try out the improved Chinese BOB board, and purchase 2 of them they are so cheap.

If I am to look at running 100V, with the fact I dont have any money to purchase anything but Chinese what are the recommended stepper drivers out there that people have had successes with? The MB450A looks the same but is still a 50V input. I wonder if I need to revisit my setup.

73

General Mach Discussion / Re: Stepper motors that shudder.

« on: April 01, 2019, 03:43:51 AM »

Really? Cool ok will do. Have a license. Thanks

74

General Mach Discussion / Stepper motors that shudder.

« on: April 01, 2019, 02:25:55 AM »

I have a router, running it with Nema 23 425lb motors on screws. The Y axis has double motors. If I set the speeds any higher than 1800, whilst jogging my Nema 23s will stop, with a corresponding brrrrr sound. Kind of like the sound my Milwaukee driver makes pushing in a screw.

The jog speed with a 5mm pitch screw is about 1800, anything above that I will have the above fault appear. But am unsure if I am asking too much of these motors or do I need to troubleshoot them? If I slow everything down it all becomes good and happy.

Or, is it just I should upgrade to Nema 34 motors?

Also I see my drivers are up to 50V and I am supplying them with 36V. Is it better for the drivers to be receiving the higher voltage?

What do you think?

75

General Mach Discussion / Re: We live to learn from small steenky explosions. Now what?

« on: March 31, 2019, 11:25:01 PM »

Hi Guys,

Ok ahem. This is where I need to let everyone know where I went wrong, and perhaps might save someone, or to less worry some equipment. When I knew nothing about CNCs, the very first one I built I put the 4 lead wire to the motor inside an earthing sleeve. You know, one of those expensive stainless steel woven sleeves that may have ended up in my toolbox when I worked for an airline. But I put it there thinking there may be noise generated by the inverter/spindle, best shield it, earth it.

Ok. So. My mistake was not putting a megga on my new connection to the new spindle plug (4pin instead of 3pin). A tiny unseen little hair piece of the sleeve was touching one of the connections inside the plug. Well thats what I assume, I couldnt see it, or find it, but I had a few ohms between a phase and the sleeve and now since I pulled it off and resoldered it, this time test with a megga, its all good.

I wanted to repost with something else, but best you know.

76

General Mach Discussion / We live to learn from small steenky explosions. Now what?

« on: March 29, 2019, 10:53:00 PM »

Looking at Youtube for a bit of disassembly info to change out the bearings in my Chinese 2.2kw spindle motor I noticed how quickly the guys spindle would start. I wanted the same. So I set the inverter to make the spindle go waaarrrp!!! Starts in a few seconds. Nice.

Ok so the problem with that, is the huge surge of current, and I may be wrong here so correct me if I am, but once the motor reaches a speed, it no longer needs all that current being delivered so it surges for a small amount of time back into the supply phase? Anyway, the PC, the CNC breakout board, power supply and all 4 drivers went up in smoke. This because all of them were plugged into the same socket. Oh, and it had that steenky burnt electrical smell.

I have 3 phases in my workshop so have dedicated the inverter to its own phase now.

I need to replace my gear. Question. I currently have a normal DB25 breakout board for my 3 axis router. Looking at replacements they are $10. Does anyone think I should upgrade to a better breakout board? Like, is it worth while doing this or do I just stick with the cheap reliable same same?? Be good to hear thoughts please.

77

General Mach Discussion / Re: I burnt out my lathe motor today. So have a few questions.

« on: March 01, 2019, 09:42:13 PM »

Thanks for the words. Its why we belong to these forums huh?

The controller is from Jinan Keya Electronics P/N MMT-115/230RT10AL I dont see a PWM input on it.

The motor I burnt out was a 750w single phase reversible motor. I actually dont know what happened. I had cut several items of the same out and was using a loud machine in the background. The reason I knew something had happened was when the breaker in my shed popped. For some reason the tool decided to bury itself thus stopping the workpiece. It didnt do this on the previous runs. Also, the overcurrent device inside the lathe did nada. Ha.

I will check the motor, I reckon its reversible which is only necessary for a few operations.

The PWM to voltage converter I dont have the part number for. I bought it off one of the Gurus on one of these forums to control a spindle.

Hey so Mach 4. This is a recommended upgrade yes? I am so into keeping original working software but should look into it. Infact I still have an XP disc unused. On that subject, I am a ROV supervisor. It was only in the last few years we stopped using XP as the platform to run the very expensive ROV spread. Yep. XP.

78

General Mach Discussion / I burnt out my lathe motor today. So have a few questions.

« on: March 01, 2019, 02:42:35 AM »

One of those days where we are busy, out cnc machinery is working in the background, the tool goes where it shouldn't on the lathe, stops the workpiece, pop goes the nice single phase motor - and it was a reversible one at that! Anyways I have had a DC treadmill motor sitting on the shelf to put into this lathe, just means I need to do it now. But a couple of quick questions if someone could please answer with a yes or no?

I know I am not supplying all info here and am just keen on hearing opinion in a general sense.

1) I plan to control the speed of this lathe DC motor with mach 3. And am actually going to use a PWM to 0-10VDC converter I bought off someone in this community. I have a speed sensor on the lathe already for threading. Does Mach 3 read this speed input and then decide what output to send to the motor controller?

2) The Chinese motor controller has the three connections for a 10k pot for the speed control. Its plausible I can plumb my PWM converter into these connections to control the speed?

3) The DC motor has CW written on it. I thought all DC motors were reversible? Wondering if this one is reversible or is there something mechanical that would make it unhappy going in the other direction. Its a 2hp treadmill motor.

Fun fun fun!

79

General Mach Discussion / Couple of itchy problems can someone please help.

« on: November 02, 2018, 02:41:25 AM »

Home built CNC Router.

I use it in my door making joinery business. Man. I dont know how I got by without it! Ok. I am using the 2010 screenset Gerry built. Two problems:

1. When I probe for an edge, and I do it lots so I can set my machine perfectly on the side of a work piece. I just use the end mill I am using at the time, and probe it against the moveable plate that I use for auto depth. Obviously I make sure I put the diameter of the milling bit into the program. So no probe but it works great. The problem is, that if I do an edge probe, it sets all my machine coordinates to zero, not just the coordinates. So this corresponding action throws out all my limits etc requiring a homing to get my limits working again. I just want it to zero on the edge, not everything.

2. One operation I do, is I physically rotate my spindle 45 deg. This is so I can mortise into the edge of a door. Great for installing a lock and rebate set. I do this by just swapping the pins/outputs for the Z and the X inside the program. It works great. But, if I try to save this XML file and rename it, the probing, and the auto depth setting no longer works. I just cant work out what I am supposed to do. All I want is a "router" profile, and a "side router" profile that I can load on the program start. I have even tried just copying the file and renaming. Currently I am having to swap out the software pins each time.

Small things. Please help. I am not saying I have spent hours trying to work this out. Just, you know, if someone knew what to do here???

Boydage

80

General Mach Discussion / Re: Mach turn. Very very, very slow.

« on: July 30, 2018, 04:35:06 PM »

Thats some good info on the initialization string. I will change that. One problem I encounter with Mach 3 is if I hit stop, it defaults to a feed of approx F50, and just wont speed up requiring a restart. Also the feed override does not work at all.

But as for this job. I ended up working out how to program Ecam properly. Its a good program and I would recommend it to anyone on a budget needing a CAD/CAM program. Although I didnt have much to do with the CAD