G540 running under EMC2 and Linux #10 - Somerville MA USA

[bradm]

I've started my build, pictures to follow soon.

So far, I have rails cut and ground, the beams cut and capped, and the Y car welded up. I've also cut the carrier beams for the gantry, and begun on cutting the bed supports.

Why the odd order? I used the 20' major beam as a work surface for the rail cutting and grinding (also in 20' form). To take it easy on my grinder, I'd run for about 15 minutes, then put a freezer pack on it and do something else for 30 minutes, then go back to grinding.

The Steelmax saw is truly amazing. Ripping the Angle for the rails was easy.

The rail cutting car worked well with the Milwaukee grinder I ended up with. I started out with a left over 4.5A grinder I had lying around, and although it worked, it would have taken ages to finish. The Milwaukee did all 80' (20 + 20, two sides) of rail with one disk, easily.

[Gerald D]

Glad to hear that things are going well!

[domino11]

Brad,
Welcome to the forum! :) Maybe you could post some pics of your progress. :)

[sailfl]

Pics are a requirement to a build.

[bradm]

I have been taking a few pictures, one of these moments I'll sort out how to post them, honest.

With two jobs, and two kids, and winter coming, I've been more focused on getting the work done in the little two hour windows I get.

I've built a bolt-together, 50" x 98" capacity table. Welding is all done, rails are done, all three axis assembled and gliding when pushed. The table disassembles into 2 beams, 2 X axis leg and brace units, 2 Y axis brace and table support units, and the spoil board and table supports except for the two end supports.

I've relearned welding after a 20 year hiatus, and some of the welds don't stink, especially after getting cut and ground out and redone.

My G540! and motors ( PK296A2A-SG7.2 ) arrived today, and I have one motor running reliably on a table at speed. I haven't seen any prior reports on using a G540, so I thought I'd mention it's looking good.

When grinding my rails using a skate, I discovered that a little paraffin lamp oil (kerosene) was the wonder cure to keep the height bolts gliding smoothly. I tried all kinds of bolts: stainless, galvanized, zinc; the combo of the paraffin and galvanized seemed to glide the best.

Unfortunately, it's supposed to rain hard the next two days,so the next progress report will be a while out.

I've also made at least a dozen mistakes, which I'll pull out of my logbook and write up after I'm sure I'll have the beast painted and inside before it snows.

[Gerald D]

Thanks Brad - there's tons of good info in that post!

[gmessler]

Dozen mistakes? I think I passed that after the first week of work.:D And I'm sure that I have MANY more to make. What a great learning experience this project has been.

Have to side with Nils.....Pics Pics Pics....

[bradm]

Okay, I let's see if I can figure out this picture thing:

Here's the start of day one, setup to run the steelmax. This picture shows me ready to cut 2.5" by 2" channel into 2" x 1.1" channel (Ooops!) I went back and did it again, to get 2.5" x 1.1" channel.

Three weeks later, here's me and my nearly finished table. The X axis cross braces aren't in place yet. If you look closely, you'll see that the gantry stiffener bracket for the cable chain is on the wrong corner! I've since cut it out and swapped sides.

Gerald, what's the weight limit on the car? :D

[Gerald D]

Nice picture! You look well within the weight limit. :)

[Marc Shlaes]

Very nice and...

Another beard :eek:

Increasingly strange correlation between MM and beards.

[gmessler]

lightning fast build!:D

[Greg J]

Nice build Brad.

Don't worry about the mistakes (lessons). If your not making mistakes, your not doing anything. :)

[bradm]

I took the gantry out for a stroll on its motors last night.

I'm a linux guy, so I'm using EMC2 ( http://linuxcnc.org/ ). If anybody needs help with it let me know, I've been driving my little tabletop mill with it for years.

The charge pump feature of EMC2 is perfectly compatible with the Gecko 540, once you remember to set your parallel port to EPP mode in the BIOS. That little mistake cost me some hours to figure out.

As the X racks aren't taped down yet, I only ran the gantry slowly from one
end to the other, and then a brief at speed test for a foot near one end. It ran at 660 IPM just fine, which was an impressive sight, and unbelievably satisfying.

As you may note, the G540 uses standard DB9 connectors for its motors.
There's a current setting resistor for the drive across pins 1 and 5; pins 2-4 are grounded for the cable shield, and pins 6-9 are the four leads for the two motor phases. I decided to extend this idea, and so I've placed a DB9 at the end of each motor lead, with the current setting resistor for the G540 so the motors can be tested on the bench. For the mechmate, I've made DB9 extension cords, a female at the motor end that the motor plugs into, and a male at the G540 end. Since my motor cables only have four wires, I placed a duplicate current setting resistor in the male DB9 at the G540.

Now it's time for the big disassemble, then paint, and final assembly. I'll take pictures of the whole thing during this process. If the weather holds and the paint dries, I might be surfacing a spoil board on Sunday!

[Gerald D]

Congrats on the movement!

Now, you have some explaining to do....
Your first post here was only 5 weeks ago. I don't recall you asking one serious question. And you want to cut by Sunday!!! Do you sleep? Who has been helping you? Do you want a job in the most beautiful city in the world? You are hired! :D

[Marc Shlaes]

Brad,

I'm curious, what motors did you find that are powerful enough for the MM and still fit the parameters of the G540??? BTW: Well done!

Thanks,

Marc

[javeria]

Hi Brad, amazing progress and like Marc, even I am surprised the G540 can pull a mechmate - interested to know more of your electronics.

RGDS
Irfan

[bradm]

See above, the Oriental Motors PK296A2A-SG7.2 ( http://catalog.orientalmotor.com/item/stepping-motors/pk-series-stepping-motors/pk296a2a-sg7-2?&seo=110# )

Wired unipolar, you get 3A at 3VDC 1ohm 3.5mH (I actually wired half phase, but close enough). Coupled with a 24V toroid based power supply, I'm running at about 37 VDC (measured).

The G540 ( http://geckodrive.com/upload/G540%20REV3%20MANUAL.pdf ) wants 2.5 to 3.5mH for "maximum wattage output", but remember that the limiting factor on this motor is the gearbox, anyway, and I'm awfully close to that spec on the half phase wiring.

The other G540 specs are up to 3.5A (almost perfect match), and up to 18-50VDC. I'm comfortably in the middle of the range.

I did spend a bunch of time reading and rereading those specs, because it seemed too good to be true. It's part of why getting that big gantry to dance at almost a foot a second was a big test for me.

[Riz]

Hi Bradm this is riz from Lowell ma just found this webb site.I have always wanted a cnc mech but to be able to build one would be even more impressive.One thing if you could give me some dirrection on where to get the materals to build this mech. thanks riz from lowell

[bradm]

Hi Riz. Sure. I used http://www.turnersteelcoinc.com as my steel supplier; they turned around my orders in a day, and delivered at convenient times. I tried two other local vendors, and neither one could even furnish the beams and angle.

I have a great local hardware store here, Tags, so I was able to grab the majority of the hardware from there, including everything metric, and the usual big box home improvement stores supplied boxes of basics, like 5/16"-18 1-1/2" hex head and carriage bolts.

http://mcmastercarr.com is a convenient source of anything you can't get elsewhere, although you pay a premium. I estimate I could have saved around $200 by getting parts like rack elsewhere, but it was very convenient and stress reducing.

Looking around the forum, you'll find the other suppliers, like Superior Bearing, Oriental Motors, GeckoDrive, and the laser cut parts, which I got from Alabama. In fact, if it hadn't been so incredibly easy to get those laser cut parts, I might not have started my build.

Good luck, and if you start the project, let me know, I'm happy to help. The best thing though, is to print and study the drawings, and then read these forums until you suspect you've read everything. They were unbelievably helpful to me.

[Kobus_Joubert]

Nice going there Brad ...with the beard... you did well and when you do your first cut you will be in heaven...MM heaven..:D

[bradm]

I'm doing a full disassembly to paint. It's slightly disconcerting that it only takes one two hour session to take apart what took some 40 two hour sessions to build (one a day, plus bonus sessions on weekends).

I think I'm going to paint the rails, and not paint the racks. After the paint, I'll sand the working surfaces of the rails as part of final finishing. Then I'll surface prep the racks as if to paint, and use the magic tape to attach the racks (unpainted) to the (painted) underside of the rails.

Does that make sense, or should I paint the racks too? Or mask the working surfaces of the racks and the rails and paint?

There, I've asked a question ;)

[spank]

Brad,
My partner and I are about to start our Mechmate up in Portsmouth, NH in the next couple of months. We are busy messing with our frankenrouter that we rebuilt and are happily cutting with at the moment, but we are pumped to start on the Mechmate. I would love to check out your build this weekend if you're around, and so too would my partner. Let me know. Great to see someone else local going for it!
Eli

[bradm]

... My Mechmate is now in it's constituent pieces, getting prepped for a big paint day Friday. If all goes well, I'll do a rebuild Saturday into Sunday. If not, there might not be all that much to see :)

Let's check in Friday, I don't want you guys to waste a trip.

[Gerald D]

Brad, we have left our racks completely unpainted, It is the only part of our machine that gets an occasional touch of lubricant, so rust is not an issue.

[spank]

Will do. In all honesty, we are pretty into all aspects of the machine, so anything will be interesting to us! What are you planning on cutting with it?

[J.R. Hatcher]

I laid my racks teeth down, put masking tape on the bottom, where the tape goes, and sprayed the side with stainless steel color rattle can paint, no rust problems. When I sprayed my rails I also put masking tape on the ground area. It was easy to just let the tape go down the sides then remove the unwanted pieces with a razor knife. Let the knife lay almost flat and ride the corner angle.

[domino11]

Gerald,
Do the V-Wheels need any type of lubricant over time as well? Mine seem to have been shipped with a white lithium type grease on them, is that factory greasing sufficient over the long term?

Brad, we have left our racks completely unpainted, It is the only part of our machine that gets an occasional touch of lubricant, so rust is not an issue.

[Gerald D]

I guess an oiled felt wiper would be great for cleaning and anti-corrosion, but ours run bone dry here in a coastal city and we don't see a problem with that.

[bradm]

The machine is painted and indoors, and it jogs in three directions.

The router isn't mounted, the proximity switches aren't in yet, the estops
aren't on, and I'm out of time for the weekend. I'm also scheduled for a very busy week, so the next chance will be next weekend.

Hopefully Gerald is warming up a nice serial number :)

And pictures to follow as I get a chance.

[Gerald D]

If it already jogs in 3 directions you have done extremely well!

[Riz]

Hi again Brad thanks for the info will be calling tommrow about the steel.One other quick question ? Have you found a shop around the area to do the laser cutting and bending.I been reading about some shops down south I have been trying to contact some of the other guys to get their contact info but have not heard back yet. Thanks again Riz

[bradm]

I got my parts from jbmclain in Alabama. It'll probably be tough to beat that deal.

[bradm]

It's been a fun weekend. Errors I've corrected include failing to locktite the grub screws on the pinion gears, and not plumbing the Z axis in both dimensions.

I made a couple of little V bit name signs for the kids, and then fired up the table surfacing. I'd been thinking that I'd surface the table, then start cutting wooden parts for the dust foot. Trust me, you don't want to surface MDF without dust collection. I did wear a mask, but it took less than ten minutes to surface the table, and over two hours to mop up the mess.

Has anyone considered cutting out MechMate logos on their Mechmate?

[Gerald D]

Well done Brad. Only about 6 weeks from start to finish and you sound like a happy camper. :D

[kn6398]

Bradm,
What model Milwaukee grinder did you use? I bought two grinder already and returned both becasue it didn't fit the laser cut skate.



The rail cutting car worked well with the Milwaukee grinder I ended up with. I started out with a left over 4.5A grinder I had lying around, and although it worked, it would have taken ages to finish. The Milwaukee did all 80' (20 + 20, two sides) of rail with one disk, easily.

[bradm]

I'm reasonably sure it was 6148-6 (the approx $99 one that Home Depot stocks in their stores), I'll verify when I get home tonight. I'm blessed / cursed with 2 Home Depots within 2 miles of house, and I bought it in the second store, since the first had "3 in stock", and the second had "5 in stock" and between the two, they had exactly one in a damaged box. <sigh>.

One of my two grinders would only align with two of the four holes in the skate, but worked just fine. I don't recall which was which.

[bradm]

Yes, it's the 6148-6. You can't change wheels while it's in the skate, and on my skate, it was originally close enough to the rounded corners of the cutout that I had to grind away about 1/16" before assemble to have the wheel clear.

After that, the performance was great. Note that I ended up using lamp oil(*) to lubricate the rail, which didn't seem to affect the grinding performance, but greatly helped the skate to slide. (*) Liquid paraffin, which to my understanding is highly refined kerosene.

[kn6398]

What hole size is your skate? My skate hole is about 1.71 and I think the lastest version skate has bigger hole size I believe 1.85.

[bradm]

That's correct, my skate has 1.85" hole. The 6148 grinder bolt holes are in a 1.75" grid. My skate is going to be idle for a long time, so I suppose we could arrange a loan if you wish, unless there's someone in a more adjacent location that could do the same?

[kn6398]

Thanks for the offer but today I went to Homedepot again and brought my lase skate cut and disassembled the grinder cover and measured all the grinders they had on display. I was determine to get the right one and was able to find the bosch 1375 which fit the hole with just some minor grinding on the end to get fit flush through. Even those only two screws would lineup it seem to hold it very sturdy.

[bradm]

I owe many pictures, so here's a few. First, the pieces all over the yard getting paint. Then three attempts at cutting some contact paper I glued to a piece of MDF. First with a 45 degree V bit, next with a micro end mill, and finally with a specialized roundover. The latter two both pulled the material
upwards and ate it, so to my surprise the 45 degree V bit did the best job.
None of it was particularly good though, so I'm still thinking up other schemes. Maybe I'll cut a stencil and then paint through it.

Could I be considered for a provisional Serial Number while I keep playing? ;)

[lunaj76]

Brad,
Congrats, good work!

[domino11]

Brad,
That logo looks really good. Congratulations on your build. :)

[bradm]

Gerald, thanks for the number, thanks for a great design, and thanks for operating a spectacular forum. I'm thrilled with my MM, and I had a wonderful time building it.

[Gerald D]

Brad, I think I enjoyed your build as much as you did - All that I had to do was to sit back and watch it happen in a very short space of time! :)

[bradm]

Just to confirm the correlation in another thread:

[YRD]

I love this engine R.

It would be a 1.150 ?

[bradm]

Yes, that's a '99 R1100RT. I've taken it from Boston to Washington DC. Maybe next time I'll try to stretch down to Orlando and say hi to Sean. :)

[Kobus_Joubert]

Nice bike...I had a R 1100 RT until my son managed to T-Bone a Fiat Uno at 08:00 on a Sunday morning....Son OK, Uno and Bike not so OK...Insurance decided to scrap the bike....does not look like it, but damages were close to book value they said.:mad:

2666

After 171 000 km on the clock without a hickup...it came to a sudden death

[Kobus_Joubert]

2668

This is the Uno.....why is it so difficult for cars to stop at STOP signs ?:mad:

[Robert M]

Glad your son is OK... Feel sorry for your toy !
Amicalement, Robert

[DocTanner]

Just finished reading your build.
Not many things more exciting than seeing a MechMate run for the first time.
Congratulations on a nice job and extra points for using Linux.

Donald Ross

[bradm]

Hmm. I haven't updated this thread in quite a while. Here's what I've been up to:

I upgraded to a chinese water cooled spindle. The flow through the spindle itself involves very small apertures, so it's difficult to get a strong flow, regardless of how large the fittings or tubing outside the spindle are. If you're willing to just waste water, it's pretty easy to get flow using a fraction of standard water pressure, but it definitely bogs down small pumps, ranging from various aquarium models to 1/6 HP sump pumps.

Something to watch out for with sump pumps: They dump their waste heat into the water (duh!), so it's pretty easy to end up with hot water after a bit of runtime.

If anyone has found an inexpensive pump that works well, please let me know.

I've written a plugin for Sketchup that outputs GCode. I'll be looking for people to test it on their own drawings and objects soon.

I've been thinking about playing with vacuum hold down at some point soon.

Today, I bumped into a rather obvious mistake I made some time ago: I snapped the head off a screw I was using as a hold-down. The break was below surface level of the spoilboard, so I just forgot about it and moved on. Today I resurfaced the table (for the second time since that break), and I found the buried screw shaft, rather violently. It jogged my memory rather effectively.

My Hitachi VFD (purchased separately from the spindle) is wired to report faults back through the G540 to EMC2, so when it detected the increased current draw / sync problem on the spindle from the crash, it shut itself down, and that shut down everything else (that was nice!). I was lucky, the bit survived.

So, the obvious moral of this story is: If you lose part of a fastener inside your spoil board, dig it out immediately.

[Gerald D]

Thanks for the interesting feedback.

[javeria]

Brad - let us know how you have wired your VFD to get to activate teh estop, I have a relay on my Delta and sure know that i can use that - what parameter on you hitachi r u using to - is it the increased current consumption one?

RGDS
IRfan

[bradm]

Irfan-
Just the run mode one. If it drops out of run mode for any reason (like faults), it will stop EMC2.

[javeria]

Ok then even if the VFD is powered down a estop is in place right? does that not form a infinite loop - meaning while switching on if the VFD needs to power up - but we still have the relay on the vfd not letting it off the stop status???

i am hoping you are understanding what I am trying to tell here -

if I have understood you properly - you are trying to say that the estop request is just communicated to EMC but not exactly triggering a hard estop by letting the contactor off?

RGDS
IRfan

[lumberjack_jeff]

Hi Brad, sign me up to beta test your sketchup script! :)

[smreish]

Brad,
I would be glad to add to your beta testers.
Thanks for thinking of us!
Sean

[bradm]

Irfan, good question! I actually have a series of contactors for everything heavy in my shop. It allows for one disable key switch, as I have small to medium children running around, and I want to know FOR SURE that my shop is OFF when I'm not around. You wouldn't believe how attractive a green ON button two feet off the ground on a table saw is to a little person. Some of the control logic for those contactors interlinks with the mechmate.

On the mechmate, I have effectively a 'soft' and a 'hard' estop. The soft is low voltage, and disables the G540 and the spindle. The hard drops the contactor out and kills the power. The computer keyboard, and a spindle fault will both trigger a
soft estop, which maintains power. The red buttons on the mechmate trigger a hard estop. So what I described above triggered the soft estop.

More specifically, the VFD is configured to go automatically to run mode when powered on, with the speed controlled by the G540 (default is zero). The G540 enable is controlled by the VFD run mode output. So any spindle fault disables the
G540 (and informs the PC). The PC has a PWM enable for the G540, so it can kill the G540 and with it cause the spindle to go into a controlled decel to zero. So both the PC and the VFD have to be alive and happy before the G540 goes to enabled state.

Now, as for those other contactors: The digital outputs of the G540 operate low voltage relays that trigger the contactor for my dust collector, and future vacuum holddown. That is one of several possible trigger points to turn on dust collection.
The vacuum holddown is going to exceed the maximum available power in the shop, so it is interlocked with my compressor. If the vac holddown goes on, the compressor can no longer be on. I have an overall shop power budget of 40A at 240, 1 Phase.

[javeria]

Thats a very nice explanation Brad, and that is what exactly I had in mind too.

RGDS
Irfan

[javeria]

Brad just one more thing - do you have a optoisolator in between the VFD and the BoB (G540) or just have it directly connected.

RGDS
IRfan

[bradm]

I have optoisolators in between the VFD and BoB, but they are furnished by the design of the G540. The G540 optoisolates both the parallel port, and the spindle speed control output. For the estop, I'm running that via the relay on the VFD, which is then programmed on the VFD to provide the 'run mode' output; the relay provides isolation.

[bradm]

bradm: So therefore a kind of --Back to basics -- :) I´v like to know how G540(+motors) and Linux has worked on your MM over time.
( Im a Mach3 and G203 person.) The reason why is simple I decided to go "THAT path - G540 and Linux" on one of the slanted machines I´m building:D. was asked over in another thread. (http://mechmate.com/forums/showthread.php?p=39010#post39010)

The answer is that it's been working beautifully for my weekend warrior projects. It's currently configured at 420 IPM rapids on X and Y, 180 IPM Z; homing runs at 180 IPM X,Y and 30 IPM Z.

I've had zero problems with the G540, the OM7.2s or with EMC2. I had a cold solder joint in one of my DB-9s that eventually failed and was redone. I had some misery with getting waterflow through the chinese spindle with long tubes running through the cable chains.

[oopz]

Good to know.

Nice info..!!

I have just downloaded this package
UBUNTU-8.04-DESKTOP-EMC2-AJ13-I386.ISO,

And I will use the DIY belt drive gear.

Later on when I "understand :)" EMC2 the G540 will be ordered.

Thanks again.!!

/oopz

[riesvantwisk]

Brad, how is your g-code project going?

Ries

[bradm]

Very well for basic stuff; it's just the usual defending against weird cases that I'm wrestling with. For example, cutting sloped faces, and dealing with models that have uncuttable geometry (like voids underneath solid surfaces). I should spend a little time and package up what I have so far.

[KenC]

Brad, I would love to sign up your beta version.

[oopz]

[QUOTE=bradm;39013]was asked over in another thread. (http://mechmate.com/forums/showthread.php?p=39010#post39010)

The answer is that it's been working beautifully for my weekend warrior projects. It's currently configured at 420 IPM rapids on X and Y, 180 IPM Z; homing runs at 180 IPM X,Y and 30 IPM Z.

I've had zero problems with the G540, the OM7.2s or with EMC2.

Do understand your statement above. To be frank I have not paid attention
to EMC2..and Im the one who lost on that. (I Love MACH3 don´t think otherwise) ....

But Today
I could manage true EMC2 my 5+-axis card in all directions an with a bad but functional tool.. change message.. more to do and understand maby only 5-axels motion BUT THATS NICE... !!! even with out toolchange ! Like IT !!

THANKS BRADM guy's like U and ALL U Others U make it so NICE !!

/oopz