ATC module for ER20 spindles

**Daz** · 4 Weeks Ago

My project this weekend is to upgrade the tool rack cover. I will post a video once I have it running.

**dh42** · 4 Weeks Ago

registration done ;)

++
David

**JohnHaine** · 4 Weeks Ago

Daz, that's very cool! Could you show more of its workings please? Will you publish the design?

**Daz** · 4 Weeks Ago

Hi JohnHaine, yes, I will share some more details. I have a nice slow-motion video of the impact mechanism in action. I will upload it to YouTube over the weekend.

Re your second question, I won't be sharing the detailed design, as I am making and selling the modules.

**needleworks** · 4 Weeks Ago

I'd love to know what software you are running to achieve that ! eg, how do you get a 20k spindle to run slow enough to start the threading process of the collets ?

**Daz** · 4 Weeks Ago

Originally Posted by needleworks

I'd love to know what software you are running to achieve that ! eg, how do you get a 20k spindle to run slow enough to start the threading process of the collets ?

I am running LinuxCNC with a Digital Dream EC300 controller that was originally for March3, but I have converted it to LinuxCNC with Remora firmware. I have 2.2Kw spindle that goes up to 24k RPM. I don't remember exactly the RPM resolution, but it is better than 50RPM around the 1k RPM range I am using it for tool changing. The inverter is Huanyang 220v 2.2kw. With this setup, I can run the spindle backwards and forwards, from I think around 300 RPM (I would have to confirm that) all the way up to 24k RPM. After moving from Mach3 to LinuxCNC, the setup is rock solid. I had lots of problems with Mach3.

**JohnHaine** · 4 Weeks Ago

Well I could be interested except I use ER16 on my mill.

**Daz** · 4 Weeks Ago

Originally Posted by JohnHaine

Well I could be interested except I use ER16 on my mill.

It is very straightforward to modify the ATC module for ER16. Just a simple change to one part, and I would be happy to do it.

The main challenge will be around the torque your spindle can generate. This is mostly a problem for the unlocking step where the spindle needs to overcome the module's initial resistance from the standstill. In case of my spindle, and with the current module setup, I had to increase the acceleration setting on the VFD to give the spindle a bit more torque, as it was stalling from time to time.

If you could let me know your spindle model, I can check its specs and let you know if it would work.

**JohnHaine** · 4 Weeks Ago

I have a Novamill which uses a DC commutator motor, about 375W. Max speed is 5000 rpm. At the moment I only have manual speed control and no reversing so that would need to be added. The table is also quite small so at the most only room for 2 modules - what size are they?

**Daz** · 4 Weeks Ago

The module external dimensions are: 95mm X 95mm footprint, and 88mm height.

Checking your spindle, I am afraid you most likely won't have enough torque to operate it. I might consider making a lower torque version in the future, but I will need to modify some internals.