Thread: How to stop the spindle falling

Nice spindle, wheeeeeeere did you get it?
I usually park my heavy router on the surface of the spoilplate. If that is inconvenient I place a block of timber underneath it and wind it down just to touch.

Hi saisay
Yes, I do that too, but I want to have the spindle stay where it is when I turn off the motors so that Mach can remember exactly where it is.

Here is one from love-happyshopping

And another one with VFD but 3Kw

This is the one that I bought

Bob
We used a air spring (not a gas strut) to balance the head on the mill we use. This make the head a neutral weight, it does take a load off your lifting motor when lifting the head, same load up or down.
Fitting will need some thought, i used a air cylinder mounted on the head and a small reserve tank (fire extinguisher bottle) mounted on the wall.

Well maybe not simple but it does work

R

Hi Bob, you can get brakes for motor's, I have a servo in the shed that has a 24v brake, apply power and the brake disengages, power off and the brake is on, basically tie to the enable or motor supply and it all works as you require.

I did find a few a while ago, but cannot seem to find where that was, I will do some more looking around for you and post if I find anything.

I cannot see exactly but it looks like your motor's are dual shaft, so the brake could sit on top without much effort, you will just miss out on the handweel.

Dunno about cost, but I know the servo I got was about $30.00 bucks in total second hand, including brake.

Cheers.

Russell.

possibly something like this :

B30A Pittman Power-Off DC Motor Brake

Hi Russell
That would be a very good way to go if I could buy one for $30, but it appears that they cost about $200 each. A little more than I want to pay.

Hi Bob

What about using a counter weight? It would have advantages when cutting as well - far less effort required for the Z axis motor to lift the spindle head.

Take a look at these sites for ideas.

Sherline CNC Projects

Z Axis Counter Weight

Craig

Hi Russell
I have found a site (Alibaba) that has a set of three motors for $256US. But I only want one. And even then, the current conversion rate means that they are $272 for the three. 272/3=$90.66 each. I would like to find some a lottle cheaper.

Craig
I will have a look at counterweighting. That would be the cheapest way out. The big problem with that is that the whole counterweight would need to move sideways with the Z axis as it moves across the table, so unlike the systems shown, I cannot have a fixed point of dependence screwed to the ceiling. I may also be limited with my headroom due to ceiling height. As the weight stops and moves, it could exert a fair amount of side thrust with the extra motions. I will check it out.

Just tossing ideas around - what about sticking a small (40mm diameter?) gear on the other end of the stepper motor shaft? Then you could use a ratchet or latch to stop any rotational movement. just move the ratchet out of the way again after power up.

Further to the wooden block under the spindle, I put an adjustable leg (like under a fridge) under the block and screw the block upwards to the spindle instead of the other way around.
Works somehow like a mini jack

Originally Posted by foobillious

Just tossing ideas around - what about sticking a small (40mm diameter?) gear on the other end of the stepper motor shaft? Then you could use a ratchet or latch to stop any rotational movement. just move the ratchet out of the way again after power up.

I am not certain that this would give an exact stopping point. If it did, then I could use the existing round aluminium part on the extended shaft and just drill a few holes in it.


saisay
I don't want to put a bit of wood under it and then move the motor gently down to it; I want it stop in the air where it is when I turn off the power.



I have been thinking that a small hydraulic lifter from a car rear window or bonnet might do the job. So long as it has a stroke of about 150mm and can hold about 10 kilos then this may be a good way to do it.

I have ordered one of these. With 10Kg of spring lift, it should be able to hold the weight without lifting it either.

Thanks for the ideas everybody, I will let you know how it progresses.

I used to use a few early Multicams and they did exactly what you said. The first day on the job and the guy said to use the piece of mdf just the right size that was already prepared for when it goes home it sits at it's free height and the mdf was about 6mm less so when we turned it off for the day it slowly sank down on it. Not on the cutter but the block that the spindle is bolted to. Works every time.

Originally Posted by Bob Willson

Hi Russell
That would be a very good way to go if I could buy one for $30, but it appears that they cost about $200 each. A little more than I want to pay.

I will sell you mine for $195.00