I hear ya. I still need the stepper for my indexing axis. Trying to sneak that one in somewhere.

Yesterday afternoon and some time this morning I cut the rails to height everything went well. I'll set up for the bevel and wait until I can get the additional time required. Snail's pace... I know.

Can anyone tell me the tolerance range for the rail height? I've got the first one at .06mm total variance. Is that okay or should I keep trying to get closer?

Tom, 0.06mm is excellent!

Gerald, I thought I should get it better when no one responded for a while, so, I went back to touch up and got it within .03mm. But that doesn't mean the next ones will be that close, that took a lot of time. I was only able to do that because I did the final passes at night (outside he shop), that way I could really see if material was coming off. Once the sparks were nearly nonexistent, Voila! I don't recommend doing the rough cuts in the dark (safety reasons) just maybe the final passes that don't require man-handling equipment.

Hey Folks, does anyone have experience with Longs Motor 34HS5850 steppers http://www.longs-motor.com/productin...12_25_120.htmland their driver DM860A http://www.longs-motor.com/productin...12_80_137.html? These seem to be the same manufacturer of the some of the other Chinese companies. I got a very favorable price from them, enough of a difference to really consider starting with these.

Sorry Tom, I have never used them. I have only used Oriental Motors and AMCI steppers and drives. Maybe someone else can chime in.

their model numbers 9840 and 9850 correspond to 9801 and 9802 models from other manufacturers we use.
Recently I got some ACT Motors 34HS9840 and they happily spin at 1000 rpm with 2M982 or DM860 style drives at 60V DC.

Great, thanks Danilo, that info saves me a lot of dough. :D

Tom,

There are a lot of good motors available. Personally, I would recommend the Oriental Motor PK296A2A-SG7.2 for a geared motor or the PK296-F4.5 for a motor that you would use with a belt drive. For direct use (non-geared), I would recommend the PK299-F4.5 motor. I would recommend the Geckodrive G201x or the G203v drivers.

Contact Mike (Metalhead) for his recommendations. I think that he has a kit that uses another motor that was thoroughly tested that is very similar to the PK299-F4.5 motor.

The problem with using other motors is that you, the designer, have to do all the testing to verify that those other motors and drivers will do the job. I enjoy doing that kind of test. In fact, I have a "test bench" all set up to do that very thing, but I doubt that most of you would want to spend $2,500 on a "test" setup just to check low cost motors. It kind of defeats the purpose.

I know that Oriental Motor products are more expensive than other options, especially in places where buying those motors requires that you buy them through a reseller. In that case, if I were to buy some other motor and driver, I would buy one motor and one driver and then do some testing on that motor and that driver. If it performs as expected, then I would buy the other motors and drivers (and at least one spare).

Mike, I value your input and will take under advisement. I would prefer to purchase the pk299-f4.5 and the geckos (which I probably will in the end) but when the cost of the drivers and the motors are under $600 delivered I can't see not taking the risk. I know there are others using the same steppers and drivers with little know problems. Worse case scenario I waste some time and I learn about what not to use and purchase the geckos and OM's anyway, that I don't mind so much.

Tom, unless you are using a direct drive to pinion the 299 would work but is not needed unless your working torque load is really high. The recommend power supply if memory serves me correctly is 50VDC using Mariss's formula Vmax=32*√L. Most here recommend a little higher than what the formula calculates out. Here is a post that Heath showed me.

I used the PK296A2A-SG7.2 (motors) and the PK296-F4.5A originally on a 35VDC power supply. The functioned well but recently I upgraded to a 56VDC power supply and they do run better. The A2A are wired half coil and the F4.5A is parallel. The both have identical ratings so the Vmax calculation was 39VDC. With the 299 and a Vmax of 50.6 you would be at 60VDC for a power supply.

I hope it helps you out in some way.

Pete, you are correct about the PS voltages. I think what I'll do is direct drive to cut the belt drive plates then switch to belt reduction. Based on the formula you mention the 34hs5850 require 72vdc but I think I'm going to 70vdc which falls within the mfg drive specs as well. I've ordered just about everything except wire at this point and maybe a few odds and ends.

Does the single core processor PC still apply? I didn't see anything in the forum that says any different but wanted input/anyone's 2 cents worth. I got a few old pc's laying around and wanted to open them up to see whats in them.

Update: working out a schematic layout so I have a layout reference for table top testing, working out proxy setup and push buttons, received PS, PDMX-126, estops, proxies, most junk in control box (and maybe too much) motors and drives will be here Tuesday, ferrules and wire from Mike today. Haven't flipped the machine right side up yet (waiting for available time and assistance). Still need to grind 45's on rails, been reading mach3 and pmdx-126 manuals repeatedly (lots to absorb, the schematic will give better overall sense), z plate at the machinist's, still need to weld-up the gantry (going to wait to verify measurements when more together).

Pete, Thanks for your assistance.;)

Almost any computer will do if you don't use large toolpath preview

Should I not view it at all or only during certain functions/activities?

Pc is the least problem. Even a Pentium2 has more computing power for Mach3. The current issue is having overly powerful pc not the other way round. Relax mate :)

So you're saying the PC is not the problem and mach 3 is, at least in part, the problem...great I'll find the best pc of the bunch and use it.

Tom,
I have a little experience with this. The current CPU of my computer is 3GHz Xeon. It does not like a large toolpath so I have to shut it off. It's brother computer was the first one I tried and Mach hated it. Caused jittery motion of the steppers because the pulse rate was crap. I have read enough to know it is more than just horsepower of the CPU. It is a combination of the CPU, GPU and the motherboard. If you are using parallel ports it can add another complexity to the process. I would say that your chance of picking a computer that will run Mach3 fine is in the greater than 95% range. Mach3 does have some downfalls but it is a great piece of software. We (hobbists) find them more because we are trying to push the envelope on cost and sustainability. An OEM puts a lot of time into finding a setup and design that is almost bulletproof. Their reputation relies on it. Therefore every piece is designed to work seamlessly together to give the end user a great experience. That is why proprietary parts cost so much more. Mach 4 hobby looks to be solid replacement but only time will tell. In all of posts I read I have people I have seen people using 733Hz PCs and Mach runs fine on them. It is more than muscle. Most likely you will be just fine.

I know my buddy Greg (bradyaero) in Smiths Falls, had a similar issue and solved it by just upgrading the video card to something with a better GPU. But like Pete said, the combination is the key.

Thanks fellas. First thing first, put it together then find the bugs.

With original mach screen the toolpath is rather small and does not affect performance as Mach2010 screenset which some of us use.

Well dug through the pile of old PC's and found nothing that will work, will have to outsource the PC.:( On a more positive note, the steppers and drivers I ordered are finally here.:cool:

When building my kitchen table project, any suggestions where to start?

one motor, one drive, power supply, breakout board on a rough piece of ply with crude wires . . . . give yourself the confidence that you can create motion.

Minimal table project
 

Tom,

It depends. If you are relatively confident in your electrical skills and you have new or "tested" parts, the only items you need to checkout in the kitchen table project are: motors, drivers, bob, power supplies and a PC. The other items in the control box can be checked out after final assembly. Temporarily wiring the motors, drivers(with resisters), bob, power supplies and a PC together will allow you to "spin" the motors using, say MACH3 and verify that your system will move the motors. It's a good idea to put a piece of light colored (coloured) tape on the shaft of the motors so that you can see them spin. This will not test the motors under load. To test the motors under load, I simply held the shaft of a motor between my "gloved" thumb and forefinger while securing the body of the motor, to simulate a load. I setup a repetitive routine in MACH3 to spin the motors continuously. I tried "slow", "medium" and "fast" speeds for each motor. My motors were used, so I spent extra time in checking them out.

Of course, I bow to others with greater experience who may differ with my opinion.

Let us know what you do and how it comes out. This will be helpful to others who are at a similar stage of their build.

The 1st thing I did when I started my Kitchen Table Project was finding a flat horizontal surface which were not clutter by stuff.... :)

I did not do that part of the build as I just assembled and tested everything with the pinions not engaged in the rack. Like John stated it really depends on your comfort level.

If you're running a "standard" configuration then download and install the configuration from Mach3. Then it's just wire things together, apply power and follow the steps in the Mach3 and BOB manuals. Worked to get my ply / spaghetti wiring kitchen table project running immediately on power up.

I will try to stress reading the MachMill Install and Config Guide thoroughly. It cannot be read enough. I lot of good information there.

I don't have a working PC yet(for the most part), so, based on the manual for the bob (pmdx 126) I can run the on-board test just to see if the steppers operate.

Yes you can do that with the 126

I've read a large portion of the mach 3 manual but I Know I'll have a bit of a learning curve, needless to say. I'll post my progress starting tomorrow. Thanks guys.

stepper wiring
 

As some of you know I chose to purchase my steppers from china at a good price (we'll see). However trying to communicate with them has a 12 hour delay. My question is how to wire these steppers bipolar-parallel. I'll try to attach the docs they sent me, see if you can make heads or tales of what I think is parallel.

Tell me if I'm on the right track. Red to Blue, Yellow to Black, White to Brown, Orange to Green- @ driver +a (red) -a (black), +b (white) -b (green). Is this correct or is there something I don't know about? Sorry but I can't figure how to show a pdf

I was correct but is expressed = Red-blue +A, Yellow-Black -A, White-Brown +B, Orange-Green -B. Finally, I can run this test. One other question, is there a preferred safe way to discharge the PS? (safety first) Anyone... anyone... Bueller... Bueller...

Tom,
A 20 watt ( or more) power resistor around 100 ohms or so makes a good bleeder for the power supply. You could also use an old incandescent bulb with some clip leads in a pinch. Use a volt meter to make sure you know what the capacitor bank is at and always remove your bleeder before you do any work. That way you will not power up the supply with the bleeder still hooked up. :)

Leave a drive connected to the power supply - that will act as a bleeder.

Are there any issues with an AMD dual core processor?

I prefer Intel , recently installed mach3 on a windows 7 starter preinstalled machine, no problems what so ever.

This is the configuration, you can see the list of components, if you need translation be free to contact me :)

http://www.winwin.rs/racunari-i-komp...dvd-win-8.html

Thanks Danilo, I found another PC with single core Intel which I think I'll be happier using.

i have change mi pc to an intel d2500 atom itx motherboard. have a lpt port and no cooler on the cpu. works well on xp with mach3 1gb ram..
and the best part .. they are cheap.