#91
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Awesome...one milestone down ;-) out of the "planning" stage...
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#92
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Welcome to your new home!
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#93
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Would rather move into that "Mechmate's already cutting" home :-)
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#94
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Soon, grasshopper.....
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#95
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Another bite or 2 down...
Well...progress happens sometimes. Was waiting on some wire to finish up the kitchen table project, so decided to get in the shop and weld some of the smaller parts.
(tacked the spacer ring into the universal motor plates (for the Metalhead gearbox setup)...the ID on the ring is pretty snug...had to "hone" it out a bit with a rat tail file chucked in a drill. (I know...real machinist would pass out at the thought of that...sorry)) (Same plate cleaned up with a quick pass on a wire wheel) I elected to assemble the gearbox a bit different from the instructions. I cut the tab off that was to be bent over completely. This allowed the top plate to be put on (temporarily) rotated 180 degrees. This allowed for easy marking of the cut location for the tab that has to be cut fairly accurately (see the "blue and scratch" step on Metalhead's instructions" The other thing is that the flanged bearings lift up the sprocket and give it a bit of "wobble" when you are clamping it together with the 1/2" bolt...this made me a bit uneasy. I took a few of the 12mm washers and spaced them out around the sprocket to lock it down. These washers are a few thousandths thicker than the lip on the flanged bearing so they add a tiny bit of margin to help reassembly of the whole mess after welding and painting. (The tab that I cut off is recut to the right length and welded back in. I am TIGing these parts, so weld spatter is very unlikely...So I left everything clamped in place to ensure alignment during/after welding) (Please don't grade the welds...I haven't TIG'ed in a couple of years...I had to clean the dust off the machine...kinda sad actually) (The Z-gearbox) (Read in an old post where Gerald said the countersinking of the holes in the Y-car end plates wasn't a critical issue...just a clearance issue, and he used a drill bit. Since I didn't have a countersink handy, I just used a 5/8" bit...definitely crude...but economical) (One side of the main Y-car plate wasn't bent quite enough...quick clamp in the brake and give it a nudge) (Got everything aligned and locked in place with threaded rod (Suggestion from the forum...worked like a champ)) (weld up the idler holddown bearing support) (Start making puddle welds) (Y-car welding complete. Let it cool and touch-up with the grinder. First coat of primer and caulking seams this weekend) Last edited by 1planeguy; Thu 06 March 2014 at 13:29.. |
#96
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Good amount of work!
Ps. You might have a clearance issue with the weld on the idler, see drawings. |
#97
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Quote:
That is a great reason for posting build pictures here...experienced eyes back checking things ;-) (This is still at the "oops" stage...quick work with a grinder to clear it up...after it is painted and being final assembled...then that is the "OH s$*t!!! stage...I like to avoid getting into that one.) |
#98
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Is that a Syncro 200 tig? I have the same box. Your welds still look better than mine !!
Good progress, did you get your wire ? |
#99
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It is the Syncro 200...it's a nice unit. That said, I took a weekend class on welding thin chromoly a few years ago and spent 12 hours in 2 days working with a Lincoln precision TIG 185...it was soooo easy to lay beautiful beads on .035 tubing...and hardly ever blew holes in it.
Wire is here...waiting on a pack of resistors to get here to make the kitchen table project turn...fun stuff! |
#100
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Looking very professional, is this your first ?
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#101
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First MechMate...not first CNC. Been fabricating homebuilt airplanes for years (the REAL reason for building this machine...not the made up stuff about craft projects that convinced my wife to let me spend all the extra time in the shop ;-)
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#102
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Verification please
Getting close to wiring my motors to the Geckos for a kitchen table test. According to what I've read in the "sticky" threads in the motor section, I intend to run these motors Unipolar. This is basically using 2 of the 4 coils in the motor. The motor has 8 wires coming out of it, of which I will use 4 of them. There is a + and - for both the A and B side...and if I am understanding this correctly, if I use the A+ I BETTER use the B+...or bad things will happen...conversely I could use A- and B-...so long as I use both +'s or both -'s...does this sound right?
Looking at the attached spec sheet...let's say I want to use the + coils. I would wire the blue/A+ to the Gecko 203V terminal 3, and the red/A comm to the Gecko terminal 4. Then the brown/B+ to the Gecko terminal 5, and the Black/B comm to the Gecko terminal 6. Sound close? If I do this, is there a reasonable expectation that the magic smoke will stay in the motors? |
#103
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Not to confuse you but a unipolar driver is different than a bipolar driver. I think you are suggesting half coil. Unipolar normally indicates a 6 lead motor. I personally would opt for the higher low and high speed torque and wire parallel. I do not know how an 8 lead motor would perform wired Bipolar half coil
Reference http://probotix.com/stepper_motors/unipolar_bipolar/ http://mechatronics.mech.northwester...per_intro.html |
#104
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Was using the terminology from the thread here
http://www.mechmate.com/forums/showt...13&postcount=1 And from the motor spec sheet. Have already got the power supply voltage sized for the amp draw of it wired unipolar...so committed that route. Just need to verify the proper wiring. Quote:
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#105
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I know, the terminology thing is hard to get by. Unipolar and Bipolar half coil work out to same in calculated values. For some reason everyone say Unipolar for wiring but if you call a manufacturer and tell them you are wiring unipolar, they will assume a 6 lead connection. Trust me, I have been through it. You want to wire half coil, ok. The scenario you list will wire fine. If one is reversed, so will the direction. Make sure you calculate the current limiting resistor and terminated before powering up and tape of the remaining leads individually.
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#106
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When you say "one is reversed" are you referring to the "-" side instead of the "+" side?...I guess I really want to be sure I am correct with saying "use both +'s or -'s but don't use one of each..." and I'm referring to on the same motor...ie use A+ and B- coils
Last edited by 1planeguy; Mon 10 March 2014 at 19:15.. |
#107
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I have always used Mach to reverse motors, not the wiring. The advantage of that is if you run into a problem you can move a motor anywhere on your machine to test things out. Don't know what anyone else thinks of that but I have never had a problem doing it that way.
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#108
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If you use mach you are doing the same by changing the step or direction signals.
Reference Here and read the section header 'Plug it into the stepper driver' |
#109
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You put one coil from A side on the terminals you listed. You put one coil from B side on the other set of terminals. Whether it is
A blue A- red B brown B- black or A red A-blue B brown B- black is up to you. Only changes the rotation. But you do not want to have A wired half coil and B wire Full Coil (series). |
#110
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The plus or minus you refer to is actually phase not polarity.
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#111
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Roger...think we can keep the magic smoke inside. Time to wire Thanks for taking the time to answer Pete
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#112
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Quick update
Quick update. Went to a local steel supply to get the gantry tubes. They had a nice saw that I was assured would give me a good square cut...not so much. Loaded a 20' piece and cut the first one an inch long so we could stack it on the leftover piece...do an accurate measure and gang cut to the final length. ASSUMING the saw would cut square, this would assure 2 tubes, both square and equal length. Well you know the old saying about what "ASSUMING" does? Well, it did... I didn't notice the blade was probably last changed sometime right before WW2...it was so dull it wandered all over and made a mess of my tube. I didn't even realize that (because I didn't bring a square) till I got the tubes back to my shop. I clamped them together and started checking things out and realized the problem. The blade wandered to the long side of the cut (thankfully) so my tubes were still salvageable without having to make adjustments to my table dimensions. Buuuuuuttttt since making another cut with a bandsaw would be next to impossible without moving back far enough for the band to have some metal to bite into, I pulled out a file and started whittling away...
Well that got old REAL quick, and since I have a friend with a full-on machine shop...I called in a favor. I tack welded the 2 tubes together and headed over to said friends milling machine. Now this mill is circa 1940, and as such is hell for stout. He chucked up a 7/8" endmill, clamped the tubes in the vise and started whittling down till he got both ends dead on square. Problem solved... Since I had to order a tap to make the clamping strips for the inside of the tubes, I went ahead and went back to finishing up the kitchen table project...and figured I might as well watch the motors spin the "close to finished" gearboxes. So I reassembled one that I welded up a few days ago and was very happy with the ease it went back together...everything stayed put during the welding (and cooling) so it lined back up with no issues...life in the shop (today) is good ;-) |
#113
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...you will thank yourself for the care of those 2 cuts! If you are wrong on that dimension, the shimming of the Vee wheels becomes a long challenge.
Thank you for documenting for the forum...pictures are everything! |
#114
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I kinda suspected the "long challenge" part of that :-) In my mind if those 2 tubes were not dead on even there would be a LOOOONNGG day of shimming wheels in my future.
No problem with the documenting...I have already benefited from the experienced eyes back checking me for errors... |
#115
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It's ALIVE!
at least the motors turn from the PMDX 126 test :-)
I'm just tickled that sparks didn't fly. Checked all 4 motors thru the PMDX test. On to the Smoothstepper next... Link to video here |
#116
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Wow Man your going to be done before I even get my serial number
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#117
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Gantry assembly
Already had the gantry tubes tacked together, so aligned the clamp strips on the tubes and just tacked them to the top. I measured off the bolt holes and center punched all of them at once.
Moved the whole mess over to the drill press and worked my way through all the holes. Cut the tacks loose to separate all the pieces and carefully ground down the remainder of the tack welds. Up drilled the tube holes to 17/64 to pass a 1/4" bolt. I clamped the clamp strips to the work table and started threading them all. This little bit works MAGIC...it is a drill tap deburr bit made by Greenlee. Like the name says it can drill-tap-deburr all in one shot, but since I had the strips and gantry tubes stacked to match drill at once I used a separate bit. Once ready to tap though, drip a little oil on that bit and let it rip...when it bottoms out and the deburr edge hits, reverse the drill and back it out. 26 holes took 3-4 minutes. Gantry shimmed, squared and welded... |
#118
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Gantry and Y-car down...
On to the rails (ominous music plays...)
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#119
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Nice build!
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#120
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Getting there!
Nice work! |
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