View Full Version : Auto spindle lock

Robin Hewitt
26-08-2008, 07:29 PM
I want a spindle lock so I can prevent any shift on the milling spindle when I do finishing cuts.

Pneumatic seemed the best bet for CNC control so I just bought a ram (32mm piston, 5mm stroke) and a solenoid valve off fleabay.

Started designing complicated lever mechanisms to tighten the spindle lock bolt, then it occured to me it could be totally simple.

If I drill a clearance hole through one end of an iron bar.

Put it under the spindle lock bolt head, as you would a washer.

Put the ram so it tries to lift the other end and tilt the iron bar "washer".

Surely that would lock the spindle with lots of leverage, be totally adjustable and I can still lock the spindle manually if I feel like it.

So why won't it work? Nothing can be that simple :D

Robin Hewitt
27-08-2008, 07:18 PM
3 questions and no answer ;) :D

1: Yes
2: Yes
3: Yes

Got the dinky rams today, two for 8.50 including postage :D

Lee Roberts
27-08-2008, 07:43 PM
two for 8.50 including postage :D

Nice one mate, cant complain at that price !

Just done a bit of work on the site logo and the white area around it, what do you think?

Robin Hewitt
27-08-2008, 10:54 PM
Not enough power.

My machine doesn't have a cotter it uses a pair of wedge thingies that need pinching together.

The cylinder will give me around 100 lbf with shop air, reckon I need more like 500 lbf.

The idea is to use a crowbar action between the spindle lock bolt and the non-threaded wedge thingy :D

Robin Hewitt
28-08-2008, 10:19 AM
More details needed...or your account has been hijacked :eek: :D

I would hate to get black-balled, have a pic :D

Robin Hewitt
30-08-2008, 08:15 AM
Should work Robin :)

Whether it works or not rather depends on the quality of the bolt. That's the weak link, if the shank bends I will need to think again. May have problems finding a suitable bolt.

I've got the valve, now waiting on the postman for the pneumatic hose and fittings.

Wonder if the solenoid coil is rated continuos, may need to add a fat cap and resistor to reduce the holding current. I bought two coils so I can afford to have a whoopsie :D