Brain trust needed, can it be done? Homing and repeat cuts

the level of involvement of this community makes this product really something else. I hope someday I can give back.

So I have a project in mind that requires repeated cutting into a material that is centered in a jig. If I understand the process after homing I could jog over to the jig, set zero and go from there.

My question is will the accuracy relative to the jig be dependent on the homing switches being consistent? if so would upgrading them make it possible to repeat a cut after setup within a close tolerence?

second question, I haven’t dabbled with g-code but is it possible to move the machine to a set position with out homing.


1 - You perform a homing sequence ONCE at power-up only - or you think the machine has lost its sync
The precision of Homing is determined by the precision of the switches, for general wood work most switches will suffice precision wise but for intricate metalwork an upgrade may be viable (provided the machine is proper rigid in the first place, no point in 0.001 switch precision if the machine have 0.1 flex)

2 - No, moving to a set position require a reference point which is what Homing establish.

I do not use the homing feature. I do it manually. I do not reset xy for multiple cuts. I have several videos on it. Here is the link to one.

1 - I used to do that, but enabling Homing have been a real asset in combination with G28/G30. Well worht it for me. I have not measured the precision though.
2 - Me neither, only Z require re-zero or using a known Z position as reference.


I made this jig/fixture for using on a bunch of different signs that all were the same length and width. I set the X/Y zero once and then just homed the machine every time (and squared the gantry the same way pre-power up) and it worked like a charm. Did 50+ signs over the course of a few weeks with no problems.

If I didn’t have/use homing switches, it would have still been possible using a 3 axis block but the time would have been increased slightly every time I would go to the machine.

I use two bump stops to slide multiple projects for small pieces. Xy is set only once

Can’t tell you how much I appreciate waking up to answers to my late night forum digging in six hours.
exactly what ideas hoping for.

it seems you have all spent enough time with the machine to get close to the results you are looking for. this should probably be a new thread but since I have you here.

to get the machine to cut square I have been adjusting the belt tension since the distance it travels is dependent on how tight the belt is. using weights and a gauge didn’t quite get it right. I matched it to the grid as close as possible and then did test cuts. bump the gantry and start over, help a little but not too much.

are you able to match the grid on the waste board or is that something you abandoned?

how do you get the Y travel to match on start up. the block method is dependent on the rail stands and the screws which aren’t exactly perfect?

it’s a great machine for the price but it seems I’m not the only one fiddling around trying to get what the design lacks in a reference point and a way to guarantee especially on the 1000 version a way to get it parallel. any advice could save me hours and much appreciated.

Don’t try to get the grid on the wasteboard to match. As soon as you skim it once the grid is gone anyway

I made a nest for engraving aluminum fill-caps for car engines. Worked great by just probing for Z after loading a set.

I just my bump stop as part of a jig for turkey calls I do for a call maker. G28 is set, and is always dead on no matter what. Has to be precise when the diameter of the call is 3.85” and the blocks of wood are somethings only 4” squared, or a hair under. Haven’t been off yet.


fantastic, do you have a second home switch on that side? It seems getting both Y motors equal is the real struggle. i have wondered if there was a way to hack the homing to run the Y servos independently for a while.

what’s the chance of running both Y axis off a single motor? flip the Y plates, move the wire tray and use one servo.

I think Elias is doing that in his B-carve build, and he seems to know what he’s doing.

One of the problems with NOT shutting down the steppers between some tool bit changes is when you have a very long carve, like multiple hours. I still do some tool bit changes “live”, but, I still don’t trust my machine enough to NOT stay near it for hours. And, it’s loud and boring. What I have done is to make the 3D printing block shown in the picture to allow me to more easily set the homing screw positions for X and Y zero repeatability.

I attach my workpiece where I want it and use a laser cross mounted to my spindle to line it up parallel to X and Y axes machine axes. Then, I manually move the spindle (power off) until a bit in the spindle is over the lower left corner. Then, I move the X and Y " homing switch stop blocks" until I hear the homing switch “click” (closed). Next, I back off the stop block position until the switch just clicks again, “opening”. This is where the machine will home to and is repeatable as long as the stop blocks don’t move (which they don’t). The blocks I made aren’t absolutely necessary for this procedure, they just making setting the stop easier for me.

Although I have Charlie’s calibration block, I ONLY use it for Z. Reasons why:

  1. For X and Y, you need a separate macro for each size bit, cumbersome.
  2. X and Y calibration for a non-straight bit, e.g., a round over, is somewhat more difficult.
  3. Even if you’ve calibrated in X and Y, there isn’t any guarantee that the X and Y axes of the material to be carved are parallel with machine X and Y axes. This may not be a problem for small carvings or when you cut the carving completely from a larger workpiece (which is what I always do since I “screw down” the workpiece rather than use clamps).

Furthermore, for me, it isn’t even critical that X and Y zero line up precisely with the lower left corner. I just want X and Y zero to be repeatable for multiple power ups (as long as I don’t move the workpiece, of course.)

Once I have fixed the stops and screwed down the workpiece, powering up again and again (if needed) is simple. This is what I do:

  1. Manually, with power off, move the spindle away from the lower left corner in both X and Y (to ensure I get a “good” homing.
  2. Start UGCS and power up the machine. Usually, UGCS initializes X, Y, and Z to “0”, But double check this as sometimes “non-zero” values are brought up. If you home with non-zero values, you will likely find the steppers “banging away” at the stops and have to chop power. I’ve had this happen several times in the past without damage. But, now, I’m more careful.
  3. Do a Z cal with Charlie’s block and a simple macro I wrote for UGCS. One macro is good for ALL bits.

Usually, I don’t readjust the homing stops unless I have to because of a significant material size change. Other photos show calibrating Z with Charlie’s block and my laser attached to the spindle.

1 Like

Thanks for these tips, phil, I’ll try them. You’re correct that if you don’t turn off the machine or move the spindle manually, you can change the bit and run the next toolpath without homing or jogging the spindle. I only home after a re-powerup.

I haven’t had any movement during “live” tool changing so far. Perhaps that’s because I’m using a Makita router that requires only one wrench to change the bit - a push button on the spindle, when pushed, prevents the spindle from turning.

Here’s how I do it. Repeatability is within the length of one step on any axis stepper motor.