Max spindle size, in KW, for the Benchtop PRO 2436?

Currently running a small 1.5KW (120V) spindle. Looking to upgrade to a 2.2~4.5KW (240V) spindle (ER20 collet). I know the physical size limitation of my machine. Is there a power limitation where I will just be wasting money on a spindle that has too many KW? Cutting mostly hardwoods.


I think the ideal spindle for the Benchtop is the 4HP. It’s light enough that the machine can move it around easily, but has enough ooomph for seriously hard wood, aluminum, etc.

Good to know. I will grab something in the 3~3.2KW range (4~4.3HP). Thanks.

Shameless plug:

This one will plug and play right into your machine.

HA! I love the “plug and play” concept, but I do all my own electronics. Pic attached of my control box.

That’s a nice setup!

We can sell you individual parts too if you want. Just. Contact us. I think we have pretty good prices on spindles and such.

What kind of control are you running on that? It’s a very neat setup!

Physically speaking, I think you could run any spindle size on the benchtop pro you wanted, but practially speaking I can’t think of a good reason why you’d want more than 3-4hp on a bentop sized machine.

I have been buildings CNC’s for a little over 25 years. My my first couple of CNC’s were built out of stuff I could get at the hardware store. The Avid Benchtop Pro 2436 is my 13 or 14th CNC. In that time I have gotten VERY proficient in the electronics side. Spent years fighting with Mach3/4 and different motion controller, like the ESS. But I was never able to get that setup reliable and stable. Yes, Mach 3/4 + ESS could get some 1~2 hour long cuts done, but every so often Windows, Mach 3/4, or the ESS would crash out a cut.

At the same time I have been deeply involved in 3D printing and playing with different firmware’s to drive my printers. I fell in love with the Klipper firmware. From there it was a minimal jump to find the grblHAL break out board. That paired with ioSender and I have a setup that is amazingly stable. I normally run ioSender on my laptop, over WiFi. Yes, WiFi!! I would never have dreamed of such a thing with the ESS. So for under $80, I have a controller setup that kicks the butt of a Mach+Motion controller setup.

Sorry for the long story.

That sounds impressive!

That’s an interesting setup. I’ve experienced similar issues with Mach 3/4, ESS, or Windows intermittent drop outs. The migration from Mach 3 to 4 on the Avid platform took away some features that were in Mach 3. I’m sure I could customize Mach 4 to get some of them back, but you have to upgrade from the “HOBBY” version and is not supported by Avid.

So, if you have a reasonable alternative, I’m listening.

I can recommend the grblHAL setup. VERY stable and VERY low cost. It’s worth playing with. But it also has the limitation of GRBL, such as no support for arc’s. ioSender has a handy “Convert Arc’s to Lines” function, but that is less than ideal.

At this point Klipper is my end goal. Stuff like Resonance Compensation would be wild on a CNC. I think its a very attainable goal (within my skill set). But it is going to take me a couple of months to get there. If/when I get Klipper up and running, I will do a full write up/how to and post it on AvidCNC’s Forum.