I just added another version, maybe something got messed up in the downloading process?
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Neat. Cheers!
@bar, I noticed the Diag pins from both TMC2209 chips are tied directly to each other. Is that intentional? They don’t connect to anything else, they’re not connected to ESP32, which makes sense since Diag pin based StallGuard triggering isn’t being used by firmware. Was expecting the Diag pins to be left separate and floating, or trace to test pad or unused through hole if you were intentionally leaving an opportunity for someone to use in the future, related AI chat.
I didn’t look at all the TMC2209 pins and trace clearances, but thought it’d be helpful to check given some of the forum questions about the stepper motors, especially if you’re seeing a cluster of issues for specific TMC2209, e.g. closest to the USB port.
Are you happy with the trace thickness and clearances of the TMC2209 closest to USB port? I have to Alt+S disable/toggle Snap behavior to allow better precise placement of outline edges/points for those copper filled traces.
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It is intentional, but it’s a bit of a legacy thing. I had those tied to the ESP32 so that we could detect faults that way, but I never really saw them produce faults in practice and we needed the ESP32 pin for something else. I don’t think it’s doing any harm, but there is no reason for them to be connected at this point.
Good call that we could improve that area. Those copper pours should really be as big as possible since the motor drive current has to flow through there.
I’ve enlarged them a bit to take advantage of all of the space that we have.
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Large copper pours/traces for large currents make sense.
But… Noticed some posts about TMC2209 components needing reflow on a few boards, I don’t have full context, but was wondering if the PCB Fab company’s tolerances were a factor, in which case, would more precise trace placement and larger clearance at the TMC2209’s pins help reduce Fab related risks? Looked at a few connectors on the board, looks like the default “Snap” behavior results in less ideal placement in a few spots.
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I’ll check in with them and see if they think that could be a factor!
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Really like the direction you went with this.
What materiel would you be thinking about making those T-shaped braces with? My brain goes straight to making it out of some pieces of standard aluminum T-track extrusion, which wouldn’t be expensive for an individual to source, and would also provide a lot of freedom for mounting things to it, as you suggested.
In my case, as an example, it would make my intent to mount it on some rails to float the sled a lot less complicated and I’d feel a lot more confident about the strength of what I am connecting to. As it stands, I’m designing something that attaches to the current arms and the sled, so I won’t be worried about it breaking at the connection point.
What materiel would you be thinking about making those T-shaped braces with?
I was thinking plywood, but anything can be used.
In my case, as an example, it would make my intent to mount it on some rails
to float the sled a lot less complicated and I’d feel a lot more confident
about the strength of what I am connecting to. As it stands, I’m designing
something that attaches to the current arms and the sled, so I won’t be
worried about it breaking at the connection point.
IMHO, if you are going to go with rails and a gantry, you will be far better off
using a conventional movement system (corexy or similar) rather than using the
maslow belts to the corner approach.
the maslow approach is far more compleax and hard to tune accurately compared to
conventional systems. It’s advantage is being compact and avoiding the
difficulty in making a gantry that is stiff enough to cover the large area.
David Lang
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From what I’ve been looking into, I just need the gantry to be stiff on the Z axis. Other than different values for forces, it should be effectively the same as putting it on casters. The belts should be able to move the two moving rails and the carriage, and maintain the x y. What I’m also interested in is seeing how different things are when it can’t tilt.
I have secondary uses for the rails if this doesn’t work out, and the concerns you raise are very present in my mind. As I’ve noted each time, though, I’m mostly interested in seeing how well it does. If it works out, then I need to buy more rails for the other thing, lol.
Same time, if it doesn’t work for hard materials, but improves pen plotting and 2# XLPE/EVA foam carving by removing sled friction and doesn’t have issues because of the super low resistance from the material against the toolhead, then I still end up with a good solution for those.
I have a mostly-assembled 3x5 MPCNC as backup. Just have to cut the pipes, design a tool holder, and assemble it.
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hi Bar, I hope all is well, great update (17 Sept 2025)! ,
adding to the great suggestions by MD8N , and going on from previous suggestions, is there still on going development to separate the z movement from the X and Y movement , I realize its potentially a significant change to the existing design of the sled and the way the router is mounted onto the sled but it will potentially simplify some of the math but, more importantly, make changing router bits way more practical , it’ll remove the need to detatch the bit everytime (for z to be at zero) we need to calibration/anchor positions.
I dread having to remove the bits currently… the hole for access to the ‘locking’ button on the router is a real issue
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I totally agree, I would love to make it so that the belts don’t move up and down with the z-axis.
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ignuf wrote:
adding to the great suggestions by MD8N , and going on from previous
suggestions, is there still on going development to separate the z movement
from the X and Y movement , I realize its potentially a significant change to
the existing design of the sled and the way the router is mounted onto the
sled but it will potentially simplify some of the math but, more importantly,
make changing router bits way more practical , it’ll remove the need to
detatch the bit everytime (for z to be at zero) we need to calibration/anchor
positions.
once youg et the anchor positions correct, you should not have to find them
again. They are stored in the maslow.yaml file.
I am timkering with improvements and will try to get the firmware to support the
Z not moving the spools. I need to get a 3d printer that can print arms/spools
before I can do that.
I dread having to remove the bits currently… the hole for access to the ‘locking’ button on the router is a real issue
what is the full process you are going through from your last cut with one bit
to the first cut with the new bit?
David Lang
I created allow for arms that don't move when Z changes · Issue #325 · BarbourSmith/FluidNC · GitHub to allow this
making the hardware to test it is going to be another effort.
David Lang
Bar wrote:
I created a version of the top post clamps that are stronger and have more space for longer rods, print with petg with 50% infill.
ReplacementPostTop.stl (86.1 KB)
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Hi David, thanks for the reply,
Unfortunately I’ve yet to get past the calibration/anchor locating phase. Ive got to the point where I would attempt to make a cut and hit accuracy issues etc. which meant that i would have to go back to square one and recalibrate again and again requiring me to remove the router bit repeatedly to zero out the z axis, hence my being very keen on improving the overall z axis issue a) to remove its incorporation in the calibration phase and b) I’d like to be able to swap-out bits easily.
meanwhile I managed to over tighten the fastners on mounting assembly for the router, so I ended up creating a CAD model to 3D print a replacement, I took the opportunity to make some modification to incorporate a fast-clip tensioning setup, in the hope I can just unclip the top and bottom parts of the assembly to release the Router. I’ll need to relocate the circuit board from the top of the router to somewhare else on the sled , is there anyway I can source longer connecting cables ?
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That quick clip is AWESOME!!
The connector is a JST-XH connector, I don’t have a source for longer cables off hand, but the connector is pretty common at least.
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you do not need to recalibrate every time you disconnect the belts. only if you change the frame
Bar wrote:
The connector is a JST-XH connector,
are they 2.54mm between pins or 2mm between pins?
David Lang
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Scott wrote:
I created a version of the top post clamps that are stronger and have more space for longer rods, print with petg with 50% infill.
ReplacementPostTop.stl (86.1 KB)
The version I have here
doesn’t care how long the rod is.
There is little infill on this one, I print it solid
David Lang
JST-XH is all 2.54mm spacing I believe. It’s the JST-PH which is 2mm. We used those on the stepper motors to make sure they couldn’t be plugged into the wrong spot by mistake
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