New spindle idea for my machine - DC 1HP

[HiltonSteve]

I am now officially out of hibernation now the weather has got slightly better and I have been putting together something I have been thinking of doing for a while now, a new variable speed DC spindle drive.

Gathered together the following parts -

1HP DC Motor - Its bigger than i thought it was going to be and quite heavy but good quality DC motors all seem to of a similar size to this. Max RPM is 2000 which is slightly slower than I wanted but will gear it up to get more speed.

DC variable speed motor control board - This is 240V input and will drive a DC motor at 180V up to 8A which will be slightly more than I need for the motor I have got. This is a very good quality board which has a lot of features that I will probably never use but the ones I will be using are the ramp up and down speeds, forward and reverse, and it accepts 0-10V input for speed control so should be easy to interface with my controller so that I can get it working with Mach3.

AC Mains filter - Apparently the motor speed control board needs one of these to clean up the electricity going into it so I bought a 30A one. Bit overkill but the price was right!

Spindle 2 board - Got this from Roy at DIYCNC, I have used Roys boards for everything on my machine and do rate them. The spindle 2 should allow me to send the 0-10V signal to the motor controller. Not tried it yet but somehow I don't think it will be too difficult to setup.

Spindle cartridge - Found this in a box of stuff that came with my lathe, I have re-engineered it and replaced the original spindle which had some odd size taper in it for an ER16 collet version. Was a pretty straightforward mod and the original bearings are very nice quality German ones so should be perfect for what I want.

Toothed belt drive - Gone for a toothed belt drive because....well.... I wanted to and I got them for nothing! Spindle pulley is a 22 tooth which was the smallest that I could get to fit onto the spindle cartridge and the motor pulley is a 72 tooth. This gives me a 3.27:1 ratio which means I should be able to get the spindle running at about 6,500 RPM max. This should be perfect for what I want to use it for but not convinced that it will provide the torque at low RPM so may need to double up the sprockets later to give me an additional 1:1 option. Just have to wait and see! I will be making provision for quick mounting my original Kress spindle to the machine for when I need a high speed option, trying to cover all the bases.

Electronics enclosure - Once I have everything running then I will put together a nice enclosure for all the electronics, want to make sure that it works first!

Ordered some more aluminum plate today to make a couple of mounts for the spindle cartridge so hopefully next week I should be getting close to putting everything together.

I will update this thread as I go so if anyone fancy's building something similar then you will be able to learn from my mistakes!

Photo's below of the bits and pieces and also a quick screen grab from my CAD software of what I have got in mind.