Not sure what forum to put a troubleshooting question, but this seemed like a good place. If not, feel free to move.

Well I finally have my Phlatprinter built and am working on the tuning. X obviously is no problem. Z is working just fine, but I can' get the Y past 11IPS. I took it apart ( built it so I could remove all the important goodies) , re-ran a tap in the T-Nut and Die across the rod a few times. Got a few shavings on the first pass, and none on the next. I also checked the rod to ensure it is straight. Actually I was amazed how straight it is. The hose was a little out, but I took care of that. There is a bit of run-out in the rod when spinning (about 1/16")
No change in the Y-axis.
When I loosen the hose clamp, I notice it is preloaded. That is the rod snaps out a little.
Motor is very slightly warm to the touch, same w/ the heat sink. I set the V-ref with a volt meter before starting and turned it up a little, but that seemed to make it worse. I've also sent the Y back and forth by using the calibrate function to send it to the left, and home to return while occationally spraying with lubricant. FWIW, at 11IPS it appears to loose no steps as the measurements are the same each time and it sounds fine. At about 12 IPS I can hear it missing steps

Any ideas?

THANKS in advance.

 

I don't know of this will be of any help to you, but I'm gonna give you my 2 cents worth anyway.

The motors that came with the Premium Kit, and I'm assuming that's what you have, are certainly of varying quality - the results are all over the board! Many builders of this machine have reported slower Y axis speeds as your machine is exhibiting. I got lucky with mine as I was able to get 20 ipm from the get-go, and now that the machine is starting to break in, I am getting 22 ipm. Mark reported that his original prototype, after a great deal of use, finally yielded speeds of 40 ipm plus.

You have two choices from what I can tell:

1. Run the machine at the slower speed you have now and hope that it will break in over time and allow you to realize some higher run speeds down the line. Hey, it may be slow but if it's not missing steps then it's still better than the old way of fashioning your foamie from paper templates. I would imagine that at your speed, you'll prolly be able to run your Dremel at half-speed to reduce the noise level.

2. Continue to run the machine for now at the slower rate, but start looking to replace that Y stepper with something a little more substantial. Several people here have already replaced their motor(s) and have achieved much better results. I'm certain another 'Club member will chime in soon with some direction of another motor choice. I scored a set of JVL MST001A motors cheap on ebay ($57 for three including shipping) that offer up 169 oz-in torque - much better than the 90 oz-in that the stock steppers are 'supposed' to provide (I haven't replaced mine yet tho - these are spares in case I need them). I think it was RayClark that reported good results from this particular stepper. Another one to look at might be the $38 steppers from HobbyCNC.com. The smaller ones are supposed to put out 130/185 oz-in depending on how you wire them up.

Be advised that there seems to be a balancing act from what I understand with stepper motors. Motor choice is important so that you end up with something that provides the necessary torque to effectively move the gantry, but not so much that you don't get any speed out of it.

I hope that this offers you some insight.

 

Thanks for the replies. I like the idea of the coarser, better quality drive rod, but mine is VERY free now when turning by hand, so I'm going to stick with that. My plan was to go with option 2 as Crash outlined, but I think I am forced into getting another stepper sooner than later. I just had a chance to come down to the basement today, and was going to try and cut a simple box I made to test the machine as I don't have the full version of Mach yet, so I can't cut the Phlat table.
After about 3 or 4 seconds of running at 50% the Y axis stepper just chatters. I disconnected it from the drive rod, still chatters. Swapped X and Y, and the Y motor still chatters. Looks like the stepper has expired already after about a whopping 15 minutes of run time.

Looks like now I'll have time to install Linux, and try to get that working as opposed to using Mach.

 

Yep, I set them to 1.2 and the other setting (TP2) to what the manual said ( I forget the value now). When I wasn't getting the speed, I bumped the Y axis up to 2.0. In the video in the build log Mark said he ed his up to about the 3 o-clockposition. Mine at 2.0 was about the noon position. When 2.0 didn't help, I backed down to 1.2. Ran it a few more times at 1.2 last night. After swapping motors around earlier today, I checked the voltages on TP1. All were within a few hundreds of 1.2

FWIW, I checked the hobbycnc site, and they are out of the steppers until mid Jan. Don't really know what I'm looking for when surfing E-Bay.

 

Dorsal; Thanks for the links... I'll be ordering one of those. For $23 it's worth a shot.

 

No I haven't, but will do now that you mentioned it. I am guessing the port is fine as I am using an old heavy duty Compaq.

 

Now there's a trick I would have never thought of! Great advice, TV!

 

I know the layout/design is aligned, and the cuts from the manufacturer should be fine(+or-), But in saying that there are a couple areas that this can get off . Because this is an area of the build where the build of the Y/Z gantry comes together (at last) with the build of the cabinet. During the build of either of these components there are a number of variables that have to be considered, amount of glue used, clamping of parts, material thickness variations, etc. All of these things are going to attribute to variations in the alignment of these two components working together. Even the slightest misalignment will be compounded over the build of the component itself. Where being off by 1/16" on two of the top pieces can throw you off an 1/8th in no time. I have noticed that this usually plays a small role and it will normally go together with little trouble in this area.
One other thing that has also happend to me on my builds is that the Y/Z guide rods can be slightly bent over the cabinets span. It may not be much but over the span it can make a difference. This is the one that is usally the culprit in the misalignment problems.

One way I have learned to fix this is by moving the Y/Z gantry over to the Y motor side of the PP and spin the guide rods top and bottom until I see that it is lined up with the motor shaft. I also check this by looking at where the bit sits in the top cabinets cutting trough.
This is an area in the build where you have to do your best to try and center and level the bit along its cutting path.
Moving the Y/Z gantry down to the center and check again spinning the guide rods until I get the best center/level I can.
Finally I move it to the end of it's run (away from the Y motor) and try again. Because of all of the factors involved in bringing these two components together it really is a case of doing the best you can to make it work the best it can.

I hope this helps
MnT

 

TV, nice tip for the tubing. Mine is really straight... I used an arbor press to load it the opposite way. Seems to be holding.
FWIW, my Y alignment seems really good. When I put it back together the Y gantry was between the middle and far end form the stepper. Stepper w/ hose on it slid right in with no persuasion needed. Also when it was spinning, the run-out was very slight....maybe 1/16" along the length.
I was wondering about the accuracy of the assembly giving it is glued together with some pretty viscous glue, so I made sure to use the glue sparingly on the parts I thought would matter.

Mark, like the TS section.... Thanks

 

I think you are right it would be a better idea to wait on the tnut install until after it is on the guides. As a matter of fact in my old prototypes I would mark the motor tip with a marker and press the gantry against it to see where to drill my hole for the t-nut. But that was no help for where it would sit as far as alignment on the far end of its travel. One way we could overcome this is to have some type of a floating mount? That would allow the t-nut to move up/down and front/back while always connected to the YZ gantry. Coming up with a simple cheap way of doing this is the hard part.
Mark

 

dorsal, i am building my z-axis, and i see exactly were your coming from....the z-axis hole spacing is messed up, its like 1/16 off. i was thinking they did that for that plastic pipe bearing thing to get the slop out. also i see what mark is saying about the wood fit, glue errors. i seen on mine that the stepper motor mount was "out of square" .010in. it doesn't seem like much to someone that dont understand Mechanical alignment. like you said, ya better check your centerlines on the screw alignment, as the coupler is not for any gross misalignment. people that dont understand these fundamental principles will be going thru alot of wd-40 and will be very disapointed. randy.

 

Well I did get 7/16th bushings from McMaster for the Z and Y. I put them in the Z as the alignments appeared to be just fine there with the bushings, but really sloppy with the plastic. On the Y axis sitting in the cabinet with the plastic pipes it seems to ride really nice,( I can give it a gentle nudge, and it will coast along the axis slowly stopping) and since the pipes had some slop when testing outside the cabinet, and the bushings didn't I figured I would try with the plastic pipes first. If I remember correctly some guys had sloppy Z axis, and some didn't. I'm guessing the assemble tolerances came into play for them.
As far as T-nut alignment; yes I can see this as a problem and last week some engineers I work with were starting to hash out a home made solution during lunch, but they're off site the next few weeks, so we'll pick up that discussion when they get back.

FWIW, when I turn my Y axis rod by hand (with the hose still on the Y stepper, but not tight) it is VERY easy to turn everywhere on the axis that I tried it, so I am guessing that all is well on mine. I did this before the stepper crapped out to see if there was any binding, and used the stepper to position it randomly along the axis, then loosened the clamp, then tested by hand.

 

Well I'll have to replace the stepper as I'm getting 0 IPM now I'll be sure to post the results. I was going to order the stepper yesterday, but just way too much going on getting ready for the holidays and such. Hopefully tonight.
I also plan on getting EMC fired up while I wait. I read your thread and it seems pretty straight forward. You already did the hardest part by supplying the settings for the machine. THANKS

As far as the replacement for the T-Nut... Was thinking something along the lines of a floating nut so it will "absorb" any side to side/up/down play, but still keep square to the gantry. Not sure if that would amplify any run-out as the drive rod is flexible. After I get new the stepper, and see how it works, I'll explore it further.

 

Run for the hills... Ha I dabbled in Linux back in the old Red Hat 3.x days. Had it dual booted on the family PC, but I couldn't get the wife's Citrix client to work w/ Linux, and she needed it for work, so when that PC died, I just installed Windoze on the new one, and forgot about Linux.... Downloading the ISO now. Hope to get the PC going after watching the Pens (hopefully) come from behind and beat those pesky Sabers.