Spindle holder for 1.5kw Chinese spindle.

[Web Goblin]

I see. Are the jaws on your 4 jaw chuck long enough to hold both pieces at the same time or did you do them seperately? I wanted to do both at the same time but my jaws arent long enough to hold two bits of 20mm alu. My plan after milling them was to cut the inside out with a 70mm hole saw then bore them on the lathe.

Ian

[Jonathan]

I see. Are the jaws on your 4 jaw chuck long enough to hold both pieces at the same time or did you do them seperately?

The jaws on my chuck a long enough to hold a few mounts... I thought the same to start with then realised it wasn't going to hold them securely enough due to the uneven clamping pressure. I think when you tighten the chuck up it grabs the one nearest the face of the chuck (since that's closest to where the scroll applies the force) which causes the jaws to be at a slight angle and therefore not put much force on the next part out. It would have held both with the chuck done up pretty tight ... but that would make 4 horrible marks on the part from the jaws, and I doubt it would actually be any more accurate than doing them separately as long as your centre mark is good.

To make things quicker (for the spindle mount pictured fixed to the spindle) I made it so around the 80mm hole there is a 100mm square. That enabled me to put it straight into the 200mm 4-jaw self centring chuck (the main one I use on the lathe). I used the normal jaws as the external jaws would get in the way of the boring bar.

On a related topic ... I wonder how many tram the spindle on their CNC router? I've had to do it with mine as aluminium highlights the error.

[Jonathan]

Oh also, here's some pictures of yet another one:





It's 188mm wide if I recall correctly.

[Web Goblin]

Nice bit of work Jonathan.
I like the second design with the clamp at the side, nice and tidy.

Ian

[Peter.]

Nice design, but I don't think you were going to have any problems with the originals apart from the sharrp corners. These are tidy though.

[Jonathan]

Nice design, but I don't think you were going to have any problems with the originals apart from the sharrp corners.

I agree entirely, but most people immediately point out the sharp corner and start complaining - I though it would be best to rectify it.

Nice bit of work Jonathan.
I like the second design with the clamp at the side, nice and tidy.

Thanks...I wasn't so sure about the clamp at the side as the clamping pressure is probably less even, and if the spindle is a little too big it won't open up much. Still it's marginally quicker to cut so no problem there!

[HankMcSpank]

Sorry to hijack, but as it goes, I'm presently knocking up spindle mount in CAD for my spindle which has a 43mm throat (or collar?)

What diameter should I make the spindle holding hole in the mount - bang on 43mm ....or is it standard to say add a 0.5mm, 1mm to the diameter etc?

Also if adding a little bit to the diameter (to aid getting the actualy spindle into the mount), what 'gap' do you then allow to pinch the bolt onto the spindle?

[m_c]

I'd personally go for bang on, that way you get more even, and better clamping force. The more undersize/oversize you go, the more the collar has to deform to clamp, resulting in a less uniform clamping force on the spindle.

As for the slot, if you get it bang on, then a hacksaw blade cut should be more than enough, and if needed wedge the slot open a bit with a plain screwdriver until you get the spindle in.

[Jonathan]

I'd personally go for bang on, that way you get more even, and better clamping force.

I agree entirely. I generally bore it on my lathe (to get an optimal finish and accurate circle) using my spindle as a gauge. When my spindle only just slides in I stop. Next I machine the slot with a 1mm slitting saw and on one occasion 0.5mm as the 1mm broke. Doesn't make a difference. Next I put my spindle in the two mounts with one at either end with them resting on surface plate. Then use height gauge to measure difference between centre height at each end and put one or both of the mounts in mill and skim the measured amount off so that the spindle will be held precisely parallel to the Z-axis plate.

[D-man]

Hmmm im torn between the 2 now, is there any sort of difference? apart from the obvious size lol