Forum Replies Created
- February 22, 2019 at 12:20 pm #90351
I wanted to say that this was an exhilarating ride through the tuning of this machine. I’m planning my build (I’ve posted some renders on the Facebook page) and the information I just garnered from your experience will no doubt save me both time and aggravation. And since my work area will be 33″ square (so that 32″ won’t be pushing it) I expect that with properly tightened belts, verified frame lengths and some careful squaring, I too will be able to achieve sufficient perfection.
Awesome. I did not realize what I did here could be exhilarating reading! Really glad it can help you have a smoother build.
1 user thanked author for this post.February 6, 2019 at 3:31 pm #87795
Why not just run with the extruded aluminum?
I had the machine finished before I realized how much play there would be in the X axis. Rather than spend a month redesigning and printing I just modified one part, spent $150, and used an hour of labor to install. I do plan on my next one being all extruded aluminum, (spending around $3k) but this works for now. $150 and a few hours and I have a 6′ MPCNC that I think is probably as rigid as a 3′ version.
1 user thanked author for this post.February 6, 2019 at 11:25 am #87753
Approximately how much did the rails and wheels cost with shipping?
Around $150February 6, 2019 at 11:11 am #87745
Doubled up 2040?
Night and day difference in rigidity. I’d say at least 5 times as rigid judging from some simple flex measurements. I know I was asking for trouble with a 6′ X axis to begin with but it’s a relitivly easy and inexpensive improvment to make once I got myself in this situation.
Attachments:February 6, 2019 at 8:21 am #87694
A preview of my current lower XYZ Winged Burly print. Any guesses at what my machine looks like now?January 12, 2019 at 4:32 pm #83543January 7, 2019 at 4:20 am #82388
Much better. I suggest cutting or drawing a 3″ square or circle, and also a rectangle or square as large as your machine can make and see how far off they are in X, Y and diagional dimensions.January 5, 2019 at 10:32 am #82139
I’ve got a nifty idea for a pretty simple, unintrusive, inexpensive way to stiffen the X and Y axis. I’m going to draw it up, but before I go through the painstaking process of upgrading my old Solidworks assembly to the new version, just wondering if anyone has gone though the trouble of remodeling the latest version of the STL files into STEP or SW part files that they wouldn’t mind sharing for a good cause.
Obligitory current project image below:
Attachments:December 14, 2018 at 5:37 am #79338
The totality of what you are asking for does not exist as a easy solution, because you should never have to do this sort of thing. If you need to do it something went wrong you will have to edit some Gcode, and be using dual endstops.
Think of it this way, if you break a mill while cutting, typically the work is damaged and you need to restart anyway, or any other number of things. If you are using Dual edstops you can just home, edit out the part of the code you have already finished (just delete it) and resume after homing.
If you want an air pass take the extra 10 seconds and program it in.
Maybe I’m bad at describing what I want to do, but when you tell me it can’t be done I get extra determined. Lol. I got it! I hope I wasn’t just asking wrong and this is totally obvious but Ill describe what I wanted and how I’m getting it now.
So the issue was that once I jog over to the workpiece and set all my zeros, I want to be able to go back there anytime and restart the job without having to home the machine and enter in the coordinates I’ve written down as the work offset. Sometimes I have to use the upper left corner of the work because because of how a certain piece is fixtured, so when doing a lot of testing it takes a long time to repeatedly rehome and jog there.
I know some of this is due to being new to Repitier and working in mm and being new to what this machine can handle. This leads me to do a lot of air cutting to make sure everything is set up right and I’ve got correct speeds and feeds for the material. I’m also testing out a lot of different types of wood, so sometimes I need to immedialty change things once I see how the new stuff is cutting. Again, I don’t want to home and jog back to the work zero point. I just want to go right back to the corner of the work, make some adjustments and start cutting from the beginning again.
So I finally figured out that if you zero everything when you get to your work origin, start a cut, then hit pause, wait until it finishes the current paths, then hit kill, it will then let you go to the work zero without losing that position. Then you are free to make your changes, escape the paused state and totally restart the job without homing.
I have no idea why it took me this long to figure it out, but the time ill save not having to rehome and slowly find the workpiece again is worth it. Hope this helps someone else too.
1 user thanked author for this post.December 10, 2018 at 6:18 pm #78960
In Repetier-Host you can hit the Pause button… … then start cutting at the correct depth. (I hope!)
Thanks so much for the detailed write up this looks very useful in certain situations. However, it doesn’t quite solve my issue. I’m not looking to resume the job. The issue is that I can’t make it not try to resume. I want to be able to dry run a bit of my path at a high z in the air, then stop the cut, return to zero, then restart the cut from the beginning. Not resume from where I left off.
I suppose I could have a section of code that does this, but that won’t account for times when it’s an emergency and I need to stop the cut to make a code adjustment, then restart. This could also potentially be solved by using a work offset, but right now I don’t have the job fixtured at a repeatable spot.
In short, I’d really like the ability to completely stop the job at any moment (at the end of current lines of code), return to zero, start the job from beginning.
Right now if I want to stop and restart I have to return to home, then move to X Y position that I’ve written downDecember 10, 2018 at 9:49 am #78895
Are you manually pausing the job or using the M0 command in your gcode? If you are using M0, then you should be able to click the dial on the LCD to restart the job.
I’m trying to just use Repitier to stop the cut when I need to on the fly. I could alternaly send and M0 from one of the presets. The issue is that once the job is paused, I can’t get out of the pause state. You mentioned I could do this on the LCD.. I haven’t hooked one up because I am using Repitier. Can I use an LCD and Repitier at the same time? I like having the computer hooked up because I make frequent changes and don’t want to shuffle the SD card. Also the LCD seemed tedious to jog the gantry.December 10, 2018 at 9:45 am #78894
Is the mount strong and rigid? Are the stl files available?
Hi Trev, This setup is farily rigid, although I’m probably going to change it in the future.
Right now these items are working at an acceptable level. Still need to make a new skirt for the shoe.
1 user thanked author for this post.December 10, 2018 at 7:04 am #78878
Shamelessly bumping my question from the weekend since it didn’t get much action.
“Having an issue where I would like to be able to pause or stop a cut in repitier and then return to zero point (not home). I am unable to do this without pressing estop. I need it to get out of the paused state so I can restart the job. I do a lot of test runs with the Z up in the air and then need to stop and go back to zeros. Any ideas?”December 9, 2018 at 8:24 am #78666
Here’s a few pics of the updated vacuum attachment. Getting a little more refined. Of course, endless tweaking to go.
Having an issue where I would like to be able to pause or stop a cut in repitier and then return to zero point (not home). I am unable to do this without pressing estop. I need it to get out of the paused state so I can restart the job. I do a lot of test runs with the Z up in the air and then need to stop and go back to zeros. Any ideas?
Attachments:December 6, 2018 at 5:45 am #78295
Updated the vacuum hose bracket. The cable tie was touching the pulley. Also moved pulley adjustment window.December 5, 2018 at 10:10 am #78220
Nice! Mounting the hose to an X or Y stepper will help.
I have been sketching and trying to mock up a dust shoe I am okay with, tough problem for sure. Combine the two and we have a winning combo.
Thanks! I printed this one yesterday. Going to see if I can make it work along with this bracket tonight.December 5, 2018 at 5:54 am #78202
Now that we’re cooking with gas I realized that it really sucks to either sit there for an hour and hold the vacuum, or have everything get covered in dust. Trying a few different things. Drew up a bracket for the vacuum hose that attaches to one of the motor brackets. Hopefully allows the hose to gently arc and not stress the Z axis, then direct hose down to the vacuum under the table.
It uses the two top motor screws for attachment. So longer M3 screws will be required. There is a hole in the top to allow for pulley adjustment, and the hose is held clear of belts. Also supplied the Solidworks file if anyone wants to mess with it.
1 user thanked author for this post.December 3, 2018 at 5:41 am #77963
New people! Repeat after me..” BELT * TENSION * HAS * A * HUGE * EFFECT * ON * MACHINE * TOLERANCE”
So after struggling for the past two weeks with attempting to get my large axis machine to be accurate when both drawing a small 3″ square as well as a 20″ x 50″ rectangle; It finally occurred to me that some of the veterans here may have been laughing at me from behind their keyboards this whole time.
After a particularly frustrating day, I went out the next morning for one more try. As I stood above the less than sufficiently perfect beast it suddenly dawned on me that this whole time I’ve been repeatedly tightening my X axis belts in an attempt to fix the problem, when the opposite needed to happen. I grabbed the scissors and snipped the cable ties, new ones in hand. I tensioned them to just barely take the roundness out of the cable tie. As soon as the sides went straight I stopped.
With all my step per mm settings back at default 100 I cautiously drew another 50″ rectangle. The 1/8″ over tolerance condition disappeared. It was actually under 50″! Quickly I gave the ties 2 more clicks to bring it right around exactly 50″, then excitedly drew the 3″ square; it was barely off tolerance as well! And in the same direction! After that it was only a matter of setting steps to 99.9 for the X axis, and then FINALLY both the 3″ square and the 50″ rectangle drew properly.
Also of note: I slowed down my acceleration in firmware from 400 to 300, and slowed Jerk from 3 to 2.5. After these adjustments I was finally able to bore my insert holes, although they were still 1/4mm too small no matter how slow I went, or how many finish passes I took.
I know these tolerances will not matter for 90% of what I cut, but I think it does for these insert holes. Now every fixture or part I put against them will be square and properly spaced.
So to me, it seems the key to setting up your belts on a large axis machine is to use the tension to generally dial tolerances in, getting them proportionately off between a large drawing and a small drawing, then a small tweak to steps per mm should dial it in the rest of the way.
(Hopefully, I don’t follow this post up tomorrow with the pen back on my machine. That would be embarrassing)
Attachments:December 3, 2018 at 5:19 am #77957
Sounds correct. I drew and output paths for a 3″ square. That converts to 76.2mm
You are using a fusion PP I have never used, the Code looks okay but has a lot of extra stuff in there and only works on my very newest firmware. It has sticky speed commands.
I think I grabbed version 10 of the Fusion PP. Also I believe I’m on latest firmware. Anything I should be aware of? Ill take a look for the speed commands.
Either update your firmware or stick with estlcam for a while. I highly suggest testing with estlcam as it is proven. For a square you can easily just hand code it.
I’ve got so much time invested into Fusion it would be rough to go to estlcam. I’ve probably watched 300 fusion videos and output at least 3000 toolpaths for my Taig Minimill in the past year. It’s really nice to be able to CAD up a part, then keep making changes and the CAM updates along with it.December 2, 2018 at 7:52 am #77764
What happens when you draw the crown (know good gcode)? Lets see your squares gcode to look for obvious errors.
I’ll draw the crown when I go out in a bit. Looking for exactly 150mm wide?
I’ve attached the code I’ve been using to draw the square. It comes out perfect on Y, but off every time in X unless I mess with steps per mm. What’s crazy is that if I put the firmware back to 100 it now is more off than it was the first time I drew it. And I seem to have to adjust the steps excessively to get the proper dimension. Then that puts the 60″ rectangle off by 1/2″ too large.
Thinking of going out and flashing brand new firmware and setting up again.
Could this possibly be a board issue?
Could this be an issue with motor drivers? I’ve never adjusted them.
Attachments:December 1, 2018 at 5:20 pm #77720
Went out to bore insert holes, when I noticed that one of my end stops was missing. Went ahead and put the pen back on, found the end stop, and squared everything back up.
Started drawing 3” squares to start. One drew fine, and then I swear the next one I drew was short by 2 mm in X axis.
Been troubleshooting for hours. Can’t figure what caused the jump. Now when I set my X axis steps per mm to 100 the 60” rectangle draws 1/4” too big on X. In order for me to get a 3” square to draw correctly I have to put the steps up so high the 60” draws half inch too big.
It’s got to be mechanical right? I’ve checked and adjusted everything I can think of checked for loose pulleys, belts, tight bolts, motor issues everything
cant yet find why all of the sudden the X axis startes drawing short
any ideas? Feeling pretty bummedDecember 1, 2018 at 7:03 am #77653
To make sure I understand, the bit is supposed to spiral down into the hole, and then do a full depth finishing pass. The gcode looks like it does that. Have you measured the diameter of your bit and made sure that your fusion 360 setup matches it? If the hole diameter is consistently 0.25mm smaller, then your bit size could be the reason (if it was 3mm instead of 3.125mm, for example).
Is the diameter at the top of the hole the same as the bottom?
Yup, that’s what it does! The endmill was the first thing I checked. It is .002″ undersized. Even when I accounted for that, slowed way down, and did two finishing passes, the hole is still small. About to go out and check for play in the mechanical.December 1, 2018 at 5:13 am #77648
Is there any play in the mount between the router and the z-axis? Or between the z-axis and the gantry? Is the g-code correct or does it contribute to the issue? These are the things I’d look at. Can you post pictures or your g-code?
Ill be able to check for play in the components in a bit. I’ve attached a file that should bore a hole out to 10.135mm
Attachments:November 30, 2018 at 7:34 pm #77635
So I finally returned to the router after two weeks of pen. Tried boring some 10mm test holes and no matter how slowly I went, or how many finishing passes I took, they all came out .25mm too small. Is it just a case of any slop or play in the machine adding up when it tries to do that small helical motion?
Do I just need to manually increase the hole size in the file?November 30, 2018 at 2:12 pm #77598
Everything is sufficiently perfect
I love this statement, I will be borrowing it frequently.
Yes! The Last section of the instructions has not been updated in a very long time. Seeing your original issues I went through them again and obviously need to do some revisions to make this more clear. I was teaching a friend how to use the CNC and he kept leaning on the rails and setting material on them and realized I need to make it clear that is not a good idea and why as well.
Thanks! Glad you approve. Don’t think I’ve ever used that phrase before, but I also like it.
So my joy was short lived. I got home and decided to do a final test before I bored insert holes. I went back to drawing the 3″ square. It came out over 2mm short on one side. So it looks like I’m stuck with it being only dead on at one end of the machine. It will either be perfect at 3″ and 1/8″ off on 60″ Or perfect at 60″ and way under at 3″
I can’t see a way to accurately bore inserts over the span of the entire table now… :/
EDIT: False alarm. My motor pulleys were loose. Getting faster at finding the root cause tho.November 30, 2018 at 8:07 am #77522
I think we’re finally there. Last night I got the machine calibrated enough that I could not detect any errors in the large rectangle pen test with a tape measure.
I first measured the 3′ Y tubes and their lengths were spot on, so I loosened up the parts a bit and bumped the side with the longer dimension in 1mm. This immediately fixed the issue. Then I used a height gauge to test and set leg lengths, I guess there might have been some remaining support or issue with the parts because the far end was significantly higher despite having the leg tubes the same size. Then I used the height gauge on each end of the 6′ X axis to set the end stops and make it parallel to the X rails. Then used a square to set the Y axis end stops. After that, I didn’t even need to adjust the auto squaring settings. I also adjusted steps per mm with m92 using the formula (100*length programmed)/acutal length = new steps per mm) Everything is sufficiently perfect at the moment. Ready to bore the table for inserts tonight. Thanks for your help everyone.
Almost seems like a “pre-flight” checklist would be handy with items similar to what I listed above all put in order. I know it’s mostly written in the instructions, but I was just listening to a podcast about how checklists, even for seemingly simple straightforward procedures drastically reduce errors. It’s easy to miss something buried in a paragraph of text. (or a lot of things in my case. Lol) This would cut down on forum support as well. It seems like what took me weeks, could have taken days. But that could just be because it takes me a while to catch on.November 29, 2018 at 11:00 am #77429
Was your legs off??
I cut the legs to within .001″ of each other. I’m going to check if there is a height issue when I get the chance.November 29, 2018 at 10:42 am #77426
Thanks! I’ll be checking all these things tonight. Already extremely happy with how accurate and precise things are.November 29, 2018 at 9:57 am #77419
Just to make sure, that side isn’t longer is it?
Hmm, I’m sensing some humor here? You mean the X vs Y axis, or the far side of the rectangle? Far side is 1mm taller in Y direction
Are the Y and X rails the same length as each other…you can see if you are 1mm off well the square will be 1mm off.
Are you talking about the Y rails being the exact same length as each other? Actually, I never checked this due to them being a stock 3′ from McMaster.
With those corners drawn, how are the diagonals measuring?
Diagonals are measuring perfect due to me offsetting X 1.5 in the auto squaring firmware.
Yes, the direction of travel can have that small/large of an effect with a pen.
Ill correct this and test again. I think I did last night but I was getting tired.
Also from that video your home corner pushes the pen down 5mm or so, and the far corner barely seems to touch, that suggests the corners are not at the same height.
You saw my original Z tubes were cut on a lathe to within .001″ of each other. Then I bottomed everything out, supposedly setting the height. I’ll look into this as well. Thanks!November 29, 2018 at 9:08 am #77406So as promised I recorded a video last night of drawing a rectangle. (See previous post) The results were the same, with the far end of the rectangle being about 1mm larger in Y direction than the side close to the home area.As I was thinking of what you guys would say or think a possible solution to the issue occurred to me. Turns out that since I’m drawing just the corners of the rectangle, and the first corner is drawn the opposite direction from the rest, is it possible that the slight enlargement of the far end of the rectangle is due to some slack being taken up as it moves in the opposite direction to draw?Please let me know if you think this is the case, or see anything else that raises a red flag. Really interested to see what you think about my machine travel and such. Could I go faster, despite having the slight jerking motion as I travel? Is this normal? How do the motors sound? Don’t mind the unclipped cable tie ends or the frayed wires, that will all be tidied up soon.I’m having a really tough time posting the video. Any tips? My post keeps not submitting..