The rail is 1000mm, The plates, bearings, delrin vwheels etc was from my original shapeoko hardware kit. I have shapeoko2 plates I haven’t put on yet, mainly because I just got everything level.
I’m only using nema 17’s and just one for the Y axis. I’m mainly cutting wood So this has not been a problem. I ran a brass rod across the gantry to drive the mxl pulley on the non powered side of the gantry to keep the gantry inline.
The spindle is a DrillMaster trim router $30 dollar special from Harbour Freight.
The Electronics started out as an Arduino and some step driver board that went POP and released the magic smoke genie.
Then I got this janky chinese step driver board, where it would start dropping steps or drive the motors off into left field.
Now I got this package from zen toolworks, The same driver chips, but works WAAAAAY better. They run the steppers fast quiet and smooth.
The brains started out as MACH3 but I mounted the PC under the table and the vibration from the combination of spindle and janky chinese driven steppers caused the rotating platter HD to crash and burn. So I put an SSD in it and didn’t feel like reinstalling XP again and bringing it up to service pack 3 AGAIN. So I went with LinuxCNC. So far so good.
The only thing I saw that I didnt like was you dont have your timing pulleys wrapped with your belt very much. You want to have almost a 50% wrap on your pulley to minimize opportunity to slip, or have backlash. Particularly with the small belt pitch/width you are using and the small pulley diameter. You probably wont see issues show up with your 17’s and the speed/torque they can produce but even small 23’s will show it.
@Joe_Spanier I know you weren’t criticizing him, and I’m not you here. I think you’re probably right. But if you look at pic #3, how exactly would he do that? Short of making his own plate I mean. Pretty sure that’s the plate from Shapeoko $9.13 : http://shop.shapeoko.com/products/motor-mount-plates
And you can’t argue with the results from his last post.
@Michael_Bridak_K6GTE Was wondering why most of the V-slot stuff was out of stock. It was a kickstarter funding deal. Most seem to have a problem keeping up with demand. Some, like one 3D printer company have had backers n paid customers waiting for 6 months now I think… At any rate, all the 2040 stuff is out of stock. All they have is 2060 (black), 2080 and 2020…
@Mat_Helm
They wouldn’t have to make a whole new plate. Just drill holes in that plate to relocate the idler wheels. Or use bigger wheels. But like you said it seems to be working for them now. The belt contact does look less to me than I’ve seen elsewhere. I’ve seen people get better than 180 degrees. Then again I’ve seen people run racks too. No one is wrapping any racks.
I was more commenting for future machines. I know those are the shapeoko plates and like I said they are probably fine for the torque output from his current motors too. I just know this game and in 6-12 months I bet he will be building a bigger bad asser machine and wanted to give him something to think about. Like you said cant argue with results. Ive done lots of stuff people told me would never work!
@Joe_Spanier you’re probably right. I’ve seen people remove one of the idlers and snake the belt in a Z fashion around the pulley and the one remaining idler.
@Mat_Helm I got the vslot shortly after they got their big initial shipment. I think they were concentrating on dealer orders shortly after that. I have another stick of 20 40 for when I add it to the new plates to make the z axis more rigid.
@Michael_Bridak_K6GTE I imagine the 2060 black would work for the gantry too. Working on a mock up of it in sketchup as we speak. Having to make all the individual parts is a pain though. Just finished that shapeoko motor plate you have on either side of your gantry…
btw, what was their shipping like? cost, time wise…
@Mat_Helm shipping was not too bad, except the post office lost my shipment… But that was not their fault. Shipping costs were not bad either. But it was a while ago and we have a tendency to forget pain.
Shapeoko sketchup parts: I seem to remember from the wiki there was a library of parts you could use to make mockups.
I like where your tool holder is. That way when your machine goes bonkers, it’s a short trip to slit your wrists! I also think the belt should wrap more. Off the shelf or not, that plate should be designed different.
As far as the “janky” TB6560 drivers go there’s nothing wrong with them if you know what you’re doing. But if is an awfully big word. There are a number of settings with those drives that need to be set correctly to achieve maximum performance out of them. Get any wrong and you’re janked I suppose.
True Don’t get me wrong I have nothing against the tb6560 itself. It was the implementation on the board I got that there was something wrong with.
I still run tb6560’s now. All I had to do was move the power, parallel plug and stepper wires over to the new setup and haven’t had a problem since.
@Michael_Bridak_K6GTE
What is the maximum RPM you can run with good torque and what input voltage do you run too? Also what is the current rating of your motors?
The steppers are ldo-42sth47-1684a, got 'em from openbuilds. from what I remember they are 70oz 1.68amp 2.8v, dunno the maximum really I mostly cut with a 1/16th bit on a 1/4 shank and rarely go faster than 700mm/min. when v-carving with the 90deg .5 inch bit if the tool is down in the part 1./4 inch the trim router will audibly bog down at 700mm/min and i don’t want to stall it. So I rarely go faster than that. But thats more a limitation of the cutter and spindle and not the steppers.
@Michael_Bridak_K6GTE
While not always useful for cutting feed rates faster moves are useful for rapidly traversing machinery into position between cuts. In any event it is not my interest to debate the relative merits of equipment operating at top performance. My curiosity is more focused on your janky board, and why it may be that way.
1.68 amps you say? Have you sized the current sense resistors to reflect that on your drives in any way? Like did you change them yourself, or special order drives for your motors? Because those drive boards typically are not setup to handle that value of current. The boards I’ve seen are either setup to run 1, or 3 amps. This is a weakness of the TB6560 that cannot really be addressed in any easy way.
Fooling around with the Torque logic inputs is not an acceptable solution either. That’s not what those inputs are really there for. At least that’s not why Toshiba put them there in the first place, no matter what those janky drive board manufacturers might try to lead anyone to believe.
Although I know in their instructions they try. Get Toshiba’s data sheet for the drive IC. It explains how to set the drives up right. It is on page 10, subsection 6, of my data sheet here under the heading of, “Calculation of the Predefined Current Output”
Once you’ve done that then run everything at 100% Torque, and Decay. Then you’ll be running at top performance. Anything other than that is just janky.
