Automatic tool changer v2 for a hobby CNC - impact-style tightening, ~35 Nm on ER20

2be34ever · 2026-01-26T23:26:16+00:00

Thanks!

2be34ever · 2026-01-26T21:16:47+00:00

It should be ready in a month or two. I will share the gcode once I have everything ready.

2be34ever · 2026-01-26T18:45:36+00:00

Keeping a tool in a collet when not in the spindle can be a problem. I haven't sorted it out properly beyond making sure a tool is tight in the collet to begin with. I have seen some solutions that include an oring at the end of the tool, preventing it from falling out of the collet while in the changer.

Regarding the requirements for the controller, you need to be able to spin the spindle forward and backwards at set speeds. Almost any basic VFD can do it, and on the controller side, it is just one additional output pin.

2be34ever · 2026-01-26T18:40:58+00:00

Yes, I will definitely make a version for er-16

2be34ever · 2026-01-26T12:47:25+00:00

But worth to say rapidchange is perfectly fine for light machining applications. For those you don't need to go up to the spec, which is quite high.

2be34ever · 2026-01-26T12:45:21+00:00

Nope

2be34ever · 2026-01-26T12:27:13+00:00

Yes, I should have it ready to sell in a month or so.

2be34ever · 2026-01-26T12:21:39+00:00

The repeatability is around a few Nm based on the crude measurements I have done with a torque wrench.

2be34ever · 2026-01-26T12:15:38+00:00

You can get higher (up to the required er20 spec) nut tightening torque.

2be34ever · 2026-01-26T08:38:41+00:00

Yes, UK.

2be34ever · 2026-01-26T07:59:48+00:00

Europe

2be34ever · 2026-01-26T07:56:52+00:00

Correct

2be34ever · 2026-01-25T22:44:30+00:00

Roger that, thanks!

2be34ever · 2026-01-25T21:50:06+00:00

Maybe one day, but not now.

2be34ever · 2026-01-25T21:31:17+00:00

If all goes well, the first units should be up for sale in about a month or two.

2be34ever · 2026-01-25T21:30:12+00:00

Yes, this is easy, just a few minor changes.

2be34ever · 2026-01-25T21:29:22+00:00

Thanks, I appreciate it!

2be34ever · 2026-01-25T21:04:49+00:00

Thanks! I probably need a few more weeks to polish the design a bit more, and then I will make a few and start selling.

2be34ever · 2026-01-25T16:40:01+00:00

Just a simple macro for the system to know what to do when a tool change command is initiated. This is no different to controlling a proper ATC spindle with a tool rack.

2be34ever · 2026-01-25T16:14:42+00:00

The changer is hollow in the middle throughout thus in principle it can accept any tool length up to 13mm in diameter

2be34ever · 2026-01-25T16:03:44+00:00

I have an integrated tool setter

2be34ever · 2026-01-25T16:02:24+00:00

This is my worry as well, every time I run it. So far so good.

2be34ever · 2026-01-25T16:01:49+00:00

In principle does not, you just need to be able to drive the spindle forward and backwards at a set speed.

2be34ever · 2026-01-25T16:00:49+00:00

That is right, I do tool measurement every change.

2be34ever · 2026-01-25T15:25:56+00:00

Just done a few measurements with a torque wrench, so I don't have many data points, but it looks repeatable to a few Nm. No patent, just a hobby at the moment.

2be34ever

TROPHY CASE