How fast can an SO3 XXL go, Reallllly?

Hi All,
TL:HR: (too long, hate reading)
I want to know:

  1. How fast can the SO3 XXL can machine things at, for reals?
  2. How much can I change my wood cutting programs by now that I have an HDZ installed?

I’ve done a bunch of searching, and it seems like the consensus is that a stock shapeoko XXL with an HDZ on it can machine at a maximum speed of about 200 ipm, or 5080mm.

Recently I’ve been making some fake tombstones out of pink insulation foam, so I set my speeds at 4900mm Feed rate, and 1270mm plunge, and let it rip. Once it got going, I realized I’d been too conservative, and could go faster. So I hit the speed override in Carbide Motion, and cranked it up as high as it goes: 200%.

But here’s the thing, at 4900mm feed rate the only increase it should have been able to do is 180mm per minute, which is not really a very noticeable difference. I promise you the machine was going MUCH faster than that. The change was dramatic.

Sooooo, how fast can the SO3 XXL machine something, really?

And while we’re at it, how much faster does having an HDZ make machining? I just installed mine, because I do large batches of wooden products, and I’m trying to work out how much to change my existing cutting programs.

I think Winston has cut foam at around 6-700ipm and Ive cut aluminum at over 400ipm so there is definitely some wiggle room for increasing the max feed and I think Carbide actually updated this parameter already. Real world rapids are good around 200ipm for me…mainly because you have to take into account the slowing down and changing directions plus all the weight behind it.

For the HDZ, just start increasing your axial depths of cut until the machine starts to groan


Thanks, Vince.
Do you happen to know where Carbide updated that parameter? Is there a table somewhere or something?

Also, is there some way to make the thing go faster when moving it around the table, like to set zero and stuff? I find the “fast” setting to be painfully slow. Am I just too impatient?

So having an HDZ just gives you the power to go deeper, maintaining the same speeds? That works for me, thanks for the tip!

follow this and look at your 110 110 and 112 settings to indicate max rapid speeds. (and yes, you can increase them)

To speed up traveling around the table, consider using one of the preprogrammed rapid jog points to get you close and then just jog from there. The HDZ is more rigid so depth of cut usually improves and using more of the flute is a good idea anyway. Best bet is to slowly increase feeds and speeds while keeping a log.


Just to make sure I understand, the max rapid speeds are the speeds in between cuts, right? So if I set 110, 111, and 112 to be faster, it will just zip around more quickly as it moves from place to place? How fast can I safely go? 1000? 5000? 1000000000?!!! ok probably not that last one, but for real is there a speed you have found that is fast but not too hard on the machine?

@MrHume maybe take a look at this thread which covers some of this. If I recall Winston was testing this out and it may have actually made it’s way into the latest versions of CM. That said not sure if you’d need to push config data to the controller under settings for it to actually take effect though or if simply updating the Carbide Motion would be sufficient.


Current limits are 10,000 mm/min in X and Y for all belt drive Shapeokos. You can modify the GRBL settings yourself, or re-flash parameters using the latest build of Carbide Motion. These speeds are for rapid moves or “extremely light” cuts, such as foam.

Note, the faster a stepper motor spins, the less torque it has. That’s why cutting moves shouldn’t be done at max rapid speeds. Also, if you’re cutting foam, make sure you have dust collection. Excess foam build up on the rails may cause the wheels to encounter more friction and increase the risk of stalling/missing steps.

Another note: When you’re jogging via CM, the “rapid position” buttons are internally limited to 6000 mm/min. They will not reflect the full, open throttle performance of the machine for safety.


Thanks everyone! Two final questions, one of which is important (you decide which):

  1. I’ve read all the links in this thread, but I don’t understand how one changes these parameters on the board. Can someone please point me in the right direction?

  2. I’ve heard lots of people say GRBL like “Grih-bull” but it isn’t it obviously meant to be Gerbil?
    I mean, it’s a pretty funny thing to call your CNC control software, you know? Like it’s a little creature that scurries around chewing things up, kinda like a CNC router?

From the MDI tab in CM, use the command line to input values for the parameters, for example “$110=500” (without the quotes) and hit send. You should also open the Log window before (from the Settings page), so that you see the change being taken into account. You can send $$ at any time to print out the list of GRBL params and their current value

Also, it’s definitely not “Grih-bull” :wink:

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Gerbil? More like “rabid hamster”

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Ah, thanks! It’s so simple it confused me. I was expecting much more bother.

Thanks again, everyone, as always I love this forum!

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