Newbie here. Received my M4 days ago and have never CNC’d anything in my life. Throwing myself into cold learning how to do this.
A few quick questions on how to use the corner floor mounts in the Not for Sale. How do they mount to the floor exactly? Am I supposed to just drill 10mm holes in the concrete and the bearings in the pin hold it enough? Should I secure the mounts to the floor as well using epoxy or concrete screws? Is there a height above the floor that the belt should attach at?
Maybe others can chime in with the benefits of the corner floor mounts. Personally, I think it much easier to put in drop in anchors similar to these
https://www.homedepot.com/p/Red-Head-1-2-in-x-2-in-Steel-Concrete-Drop-In-Anchor-50126/100155295
Then just have a short bolt that you can put in to keep out dust, and a long bolt that you use to hook in the maslow. You want your longer bolt to be long enough to firmly engage the anchor, but short enough that it won’t introduce flex and hold the cable close to the ground (recommend a washer against the concrete to allow it to pivot easier. Has been working pretty good for me, but I have only made a couple of cuts so far.
As far as height above the floor, there has been a lot of discussion about pros and cons, but no one has done any actual tests to my knowledge. Having them mounted higher to match the height of the spools should in theory improve the accuracy, however, having them mount higher introduces more potential for flex in the mount so you have to have a more robust mount that holds the top of the pivot point as well as the bottom.
Welcome aboard, my advice, get some anchors that are good enough, there’s lots more to learn about the actual CNCing of stuff, ie, bits to use, feed rates, router speed, materials to use, etc that will make the floor mounts seem less important. If your cuts aren’t accurate enough, you can always revist the frame later. Learn by doing!
I used drop in anchors as @Aggiehouse suggested. I’m using Confast anchors - Drop-In Anchors
They have a great install video. Make sure you have or can find a hammer drill to use. It makes it SO much easier. My frame is 8’x12’
I have just started playing around with raising the belts up to be more in line with the machine. So far my calibration has been too low to use the machine so I’m either introducing more flex, or something else is going on.
Good recommendation on the washer @Aggiehouse . I’ll add that to my setup.
This couldn’t be more important to say. If you try to use a regular drill the chances of getting a good enough hole to have an anchor stay in place are almost 0. Doesn’t have to be an amazing drill, Harbor Freight sells one that is fairly cheap and does the job.
Did you change the .yaml file to reflect belt height change? I can’t remember what the actual variables are called, but I know they are there and that by default they are set to be the distance from bottom of sled to the spools (I think).
No, I didn’t. I was not aware of those values. Thanks for the tip, I’ll look into it.
Here are the value names:
Maslow_tlZ
Maslow_trZ
Maslow_blZ
Maslow_brZ
Much more discussion here:
Also, @bar can chime in for sure, but I could have sworn somebody said that to date these values haven’t been taken into account at all, but is something that will be incorporated in the future. Don’t know who said it, or if I imagined it, but it sure seems like i read that somewhere.
It has been! They are used in the computations now 
Re: Floor anchors: If you are comfortable with drilling holes in the floor then the drop in anchors are 100% the way to go. The other ones are just meant to be glued down with some sort of removable glue if you don’t want to permanently attach anything.
We’re living in the future man!
Yeah I was leaning towards using drop in anchors but was kinda weighing all of the options.
I just ordered 10mm drop in anchors. I went to Lowes and took a belt end with me, I didn’t like the slack from the 3/8" bolts. Probably me just being obsessive.
I have a few different hammer drills and have installed anchors before. Also to note, make sure the holes are cleaned out. Like if you think its clean - clean it one more time. I use compressed air. I used a large SDS drill to put a hole in my house once. Nothing will give you an acute sense of anxiety like the second before you start drilling through your house - ha. It worked out though.
I’m thinking of using smooth 10MM bolts, this way the belt ends will not be riding on threads. Maybe I can use nuts and a washer to keep it at a certain height. Again maybe just over thinking this.
@aggie thanks for the short bolt idea - i wasn’t thinking about crud getting into the holes when removed.
What do we think about securing the spoil board to the floor and the cut piece to the spoil board? Double sided tape? more anchors for the spoil board? I haven’t cut anything yet, but was thinking the boards might travel.
Speaking about spoil boards, should the spoil board be larger than the cut board. IE - if I am cutting 4x8 MDF should the spoil board be larger than that? Like 5x9?
Lastly, are the values in the .yaml files in mm? I haven’t got to the SW part of this build yet.
Yes, another extremely important step. The package makes it look like any idiot can do it, and any idiot can, but using a hammer drill to get a straight hole and cleaning out the hole are 2 steps that I think the common idiot (see me about 10 years ago) will think, oh, I can skip that.
It wouldn’t hurt to have a bigger spoil board, but definitely not necessary, and would probably be a pain to store somewhere. The critical thing is to have a plan for very close to the edge cuts. The sled can’t really hang halfway over the edge because the pulling of the motors along the cut path will inevitably tip it due to the moment arm pulling it down. My last cut I just put my hand on the sled to keep it from tipping, but it required me to be paying attention.
For me personally, my garage has the antifatigue squares that grip the spoil board very well. I do then screw the workpiece to the spoilboard, but double sided tape would work too.
Yes, values are mm.
Do the Anchors on the floor have to be perfectly spaced square? From Corners to Corners?
I drilled and added anchors but the dimensions aren’t perfect. Will that be a problem? Not a perfect square or rectangle.
I believe that a rectangle around ~12’ x-axis and 8’ y-axis is recommended for a big cutting area. I made mine a bit larger than that. As far as being square angles, I believe that calibration can compensate if the anchors are not at perfect right angles (though that may not be the case if the angles are really far off). If the anchors are already in, then I would probably just finish mounting on the frame where the anchors are and see if it calibrates.
Also, when putting the frame size into the Config before calibrating, those numbers/measurements don’t have to be perfect either (I’d still try to get each within an inch or so though).
Def not square. About 148x98 inches. One side is off about 1 or 2 inches.
I need to get a spoil board maybe because i just calibrated on the floor and its not meeting the right fitness values. Thanks for your help.
I think a couple inches off shouldn’t cause issues. The spoilboard helped me as well. When I first tried calibrating, I didn’t put a spoilboard down either. Without it, my M4 was getting a lot of friction resistance and refused to calibrate. Worked fine after putting a board under.
Also, when you go to calibrate, be sure that there is no bit in the router and that the Z is as low as possible.
Thanks so much. I’ll keep you posted.
You’re very welcome. What did you use for you floor mounts? I know you mentioned the concrete anchors, but I see in your picture some sort of metal looking blocks that the pins go into.
So trying to calibrate and still getting fitness too low. Any suggestions?
Can I continue calibration with the values anyway?
Maslow-serial (10).log (16.4 KB)
WARNING FITNESS TOO LOW. DO NOT USE THESE CALIBRATION VALUES!
TimmyZ wrote:
So trying to calibrate and still getting fitness too low. Any suggestions?
Can I continue calibration with the values anyway?
WARNING FITNESS TOO LOW. DO NOT USE THESE CALIBRATION VALUES!
You could modify the acceptable threshold and try to use these values, but it is
not recommended. It would be better to figure out what’s going wrong.
did you change the Z offset values to match your mounts
make sure that the mounts do not flex during calibration, even a few mm of
movement is enough to cause grief.
David Lang
