Mr1 spindle taper

Wondering how the spindle is designed.
Is there a taper in the spindle that the er20 collet holder mounts too?

Yes that is correct, the spindle shaft has a 16* taper to accept ER-20 collets.

Sure but is there a secondary taper in the spindle.
For instance a Bridgeport has a manual tool changer design using a r8 taper so that u can remove the tool and holder with the r8 shank using a long threaded rod through the center of the spindle.
So is your spindle one piece with the er20 taper or is the er20 holder removable in some way.
I love the machine for the price and will being ordering one on the 26th but the one thing that bothers me is the lack of a removable tool holder
As resetting tool height every time is inconvenient.
I know the goal was keeping the price and I think we can all appreciate that but to me that spindle says I’m a router not a mill.

1 Like

Brochure says ISO20 so the holder is a ISO20 which holds er 20 collets ? ISO20 Tool Holders ISO 20 ER20 Collect Chucks for CNC Machines

All your videos shows it cutting , But nott a single one showing the softwear?

There is only one taper in the spindle that secures ER20 collets only. One could build toolholders that have a male taper for insertion into the spindle and a female ER20 taper for holding tools. The problem is that doing so reduces precious spindle to baseplate clearance and also reduces rigidity from extended stickout. Correcting those two setbacks would require design changes elsewhere that would increase overall cost quite considerably.

If you purchase the toolsetter, tool changes become quite easy. It will automatically set the Z offset for you so that all you need to do is load the tool and press cycle start.

Check out this video showing how the toolsetter is used: Under 60 Second Tool Change on the MR-1 CNC Gantry Mill - 'Chip to Chip' Time Test on Steel - YouTube


So basically it is a 2.5 KW Router spindle. Nothing more nothing less.

That’s not true at all. Read this to get an understanding how the MR-1 spindle is superior to a generic router spindle in the context of metal cutting: Spindle Design | MR-1 CNC Gantry Mill | Langmuir Systems

In short, router spindles are high revs low torque which is fine for cutting wood and plastic. Milling spindles are low revs high torque which is mandatory for cutting steel, stainless, titanium, etc.

You’re not going to do a cut like this with a 24,000 RPM 2.2kw router spindle: Rough Milling Steel at INSANE 4 MRR on the MR-1 CNC Gantry Mill - YouTube


You mean this Servo 240v the torque is 5.4 FT lbs.

Yes, MR-1 has a very similar servo motor that drives the spindle shaft through a 1:2 timing belt drive. The motor spins 0-4000 so the spindle can spin 0-8000. Excellent torque curve on these motors.

1 Like