I’ve been wrapping my head around a super easy way to set the Z home since it’s a bit of a pain. Decided to design a jig today that holds the router bit with a magnet at a 10mm offset — happy to report it works really well!
Basically, you pop the bit into the jig, the encapsulated magnet holds it in place, and you slide it under the Maslow and into a loosened chuck.
Move the Z axis up or down based on where you want to grip the bit.
Tighten the chuck (you can hold the bit with needle nose pliers so it doesn’t move).
Now you’re exactly 10mm above the home position — jog the machine down 10mm and set your Z home.
Super easy!
Need to tweak a few things with the design then I’ll share for others to test out. Also, kinda hard to see it in action since I chose to print the prototype in black -_-
The only issues that I would think may arise are: 1) Getting it under the rig while the M4 is tethered to the frame may be a tight squeeze. I use a horizontal frame, and the few times I’ve had to lift up the machine while tethered is not a walk in the park. 2) Some bits may have trouble. Some bits are really short and some bits are really long, so at either extreme, this may not work. 3) If you use different diameter bits, you’ll need a different mount for each. 4) Tightening the chuck with such little clearance may be pretty difficult. This could maybe be solved by simply adding to the gap. E.g., using a 20mm gap instead of 10mm then just jogging 20mm down instead.
Lastly, I could be wrong, but I think I remember seeing an offset setting somewhere to account for a z-probe. Assuming I’m not misremembering and that the setting is functional, I believe you could just enter 10mm in that setting and then home immediately after getting the bit tightened and the 10mm would be automatically accounted for. Would eliminate the need to jog the machine down after getting the bit in place. That would also provide an added bonus of not needing to raise the bit back up after homing and before cutting (before cutting, I always raise the bit back up a little so that when the router turns on, it doesn’t immediately cut into the material at that spot).
Appreciate the extra insight @Andith! Seems like 3-4 versions would cover most use cases:
This original 10mm version
An alternative 20mm version
A bore-less version for non-traditional or > .25" bits
A zero offset version
Getting it under the rig while the M4 is tethered to the frame may be a tight squeeze. I use a horizontal frame, and the few times I’ve had to lift up the machine while tethered is not a walk in the park
I was concerned about getting it under the Maslow while mounted, but the bore is wider than the bit which allows it to move and sit at an angle. Tested the setup last night with fully tensioned belts and was able to get the homing jig under the Maslow with a ~2" bit in it. Alternatively, you could put the bit in the chuck first, then slide the jig under.
I’d be great to have someone with a horizontal frame test it out, do you have a 3D printer?
Some bits may have trouble. Some bits are really short and some bits are really long, so at either extreme, this may not work.
A really long bit might necessitate a 0 clearance jig instead of 10mm. I think the 10mm would work with a normal range of bits, if it’s too long you could slide the bit into the chuck first. I tested with a 2" bit, and not sure you’d want to use anything much shorter than that.
If you use different diameter bits, you’ll need a different mount for each.
I was thinking about this as well as a 45° or 90° bit — maybe an alternative version without the bore that the bit sits in, so the magnet is exposed at 10mm height. Bit would go in first, the you’d use the jig as a stop basically.
Tightening the chuck with such little clearance may be pretty difficult. This could maybe be solved by simply adding to the gap. E.g., using a 20mm gap instead of 10mm then just jogging 20mm down instead.
Totally agree, but my wild-ass-guess of 10mm worked pretty well. I had to use needle nose pliers to stop the bit from pulling away from the jig when tightening — maybe with 20mm you could just hold it with your hands.
If anyone knows how to set the offset so it’s always 10mm, please chime in, that would make things even easier.
I likely will for longer bits, but with this 2" long bit you wouldn’t be able to hold it while you tighten the collet. If you look at the image with the jig in the Maslow, 10mm lower with this bit would mean the collet is about flush with the vacuum plexi surface which would be pretty difficult to tighten and there wouldn’t be enough room for the button pusher. A 3" or longer bit would work though.
Seems like having a few of these jigs would be the way to go based on what bit you’re using. I’m going to print the offset on the jig for quick reference.
I had a chance to look. If you are on your maslow.local page, click the four lines in the upper right corner. Click on “Preferences”. Then go down and click “Show probe panel”. I don’t know how all of the settings play out, but I believe those are the relevant settings. It’s under “Show GRBL panel” so I’m not sure if the settings are currently active or are a fossilized legacy setting.
I had a chance to look. If you are on your maslow.local page, click the four
lines in the upper right corner. Click on “Preferences”. Then go down and
click “Show probe panel”. I don’t know how all of the settings play out, but
I believe those are the relevant settings. It’s under “Show GRBL panel” so
I’m not sure if the settings are currently active or are a fossilized legacy
setting.
I think that is what Z gets set to if G38.2 or G30 are used. But that isn’t
what’s happening here.
@bar has been too busy working out the problems with the current maslow 4 to
implement the probe-to-z-touch that would be needed to do that
that would be where you put the bit in at whatever distance, then put a metal
plate (say a metal ruler) under the bit, connect a probe to the bit, and run Z
down until they touch.
Will any of the settings at least work to automatically add in an offset when the Z-Home is set or do those settings do nothing without G38.2/G30? The offset is all I’m really curious about here. If anything, it shouldn’t be very difficult to add a setting that applies a user-inputted offset.
Made the four versions from @Andith’s feedback with labels in the design. Posting the STL files here and would love some help testing if anyone has a 3D printer. They use a 10x3mm magnet, you’ll have to pause the print with gcode and superglue it in there, then resume.
Will any of the settings at least work to automatically add in an offset when
the Z-Home is set or do those settings do nothing without G38.2/G30? The
offset is all I’m really curious about here. If anything, it shouldn’t be
very difficult to add a setting that applies a user-inputted offset.
I believe they do nothing if you aren’t doing a homing operation
what would be needed for a user-inputted use is a new button similar to set Z
home = 0 that sets Z home = 10mm instead
Pretty easy to drop it 10mm and home, then raise it 10mm. Not sure an extra button would save much time or effort. Especially compared to the belt retract and extend song-and-dance. No dig on the design, I’d much rather save the space of a gantry CNC router and deal with the Maslow cables!
This is a stellar concept!
You know… I bet this would work just as well with my old chain maslow from 2018.
And… I have a 3D printer that might just work to print a prototype.
Have you posted the CAD somewhere for someone to download and tinker with?
It probably would work if the bore inner diameter was about the same as the M4. The M4 is a 32.8mm bore ID and this jig is 30mm. So if your sled has an opening greater than 30mm it should work.
Here’s the STL file if you want to play with it. I can also adjust one for you if you want. Disclaimer: I’m still learning Fusion 360. Maslow4 Z Homing Tool (v1).stl (2.1 MB)
No worries OR judgement. I’ve been doing most of my work in FreeCad (because I am a glutton for punnishment). I’ve been able to crosssection that STL to separate your (pretty awesome) tool from the sled. Should be able to make the mods I need to fit my current maslow sled. Will share everything with you direct. You can then post/share as you see fit.
It worked!
I printed one of the 10mm offset tools without mods for testing and it works great even on the temporary sled. The top surface of the large disc makes contact with the bottom of the sled, and since the top of the magnet is also parallel to that top surface… The bit is set to zero automatically.
Also took your advice on stopping the print and gluing the magnet in place. Worked like a charm.
Thanks for the help!
