PDA

View Full Version : WANTED: Spindle holder for 1.5kw Chinese spindle.



jcb121
30-07-2011, 12:33 AM
So, I'm in need of a spindle holder or two,

would it be possible for one of you to make one or two for me?

the spindle is 80mm in diameter so it should be simple to make.

I can buy the alu needed and pay postage both ways,

All I will need of you is your time, machine and your skills.

Thanks.

Jonathan
30-07-2011, 12:57 AM
Me again...

I've made a few 80mm spindle mounts (only one picture shows finished mount):

4293

4294

4295

4296

The drawing is just an example - if you want a different size or to draw your own that's fine. I have got aluminium in stock to do up to 150mm wide and 1/2" thick, or 5/8" thick and 125mm wide.

If you're interested send me a PM or make me an offer...

pavlo
30-07-2011, 08:16 PM
Jonathan,

Do you think that mount is strong enough? it looks to be very thin near the clamping bolt (If my maths is right, 4.7mm) and you have a sharp internal corner at this point too. With this stress concentration and the cyclical loading that a spindle typically gets, I wouldn't expect it to be too long before a crack appears.

Jonathan
30-07-2011, 08:20 PM
Yes I thought that looked like a weak point when I'd made it. Once it's clamped on to the spindle it can't bend, so fatigue shouldn't be an issue. It seems perfectly solid.
That's why on the next version (last photo) I rounded off that corner and moved it further from the spindle to make it stronger. Changing the drawing is not a problem.

If it breaks naturally I would replace it free of charge.

Web Goblin
30-07-2011, 11:14 PM
Jonathan,
have you been copying my design ? :smile:
Only kidding. Mine is very similar, basically the same shape but without the rounded off corners seeing as I made it on the milling machine then lathed out the inside.
I have just cut two more alu plates today at work and I am going to make two more spindle mounts and see if I can get two identical mounts that are a better fit for the spindle than the last one I made.
My original plan was to make two as my first job for the cnc machine but I am still having problems trying to get USBCNC to work properly and also my workshop pc died earlier tonight. At least the weather was nice today!

Ian

Jonathan
31-07-2011, 10:57 AM
Jonathan,
have you been copying my design ? :smile:

Not seen yours...


Mine is very similar, basically the same shape but without the rounded off corners seeing as I made it on the milling machine then lathed out the inside.

[QUOTE=Web Goblin;23056]I have just cut two more alu plates today at work and I am going to make two more spindle mounts and see if I can get two identical mounts that are a better fit for the spindle than the last one I made.

I see, same as the one I made with my CNC router then bored on the lathe...last photo in post #2 shows it before boring.

Web Goblin
31-07-2011, 11:05 AM
Jonathan,
I would have loved to make them on the router, that way they would have been identical. Why didnt you mill out the inside completely on the router?

Ian

Jonathan
31-07-2011, 11:09 AM
I did them on my router as it's far quicker than the milling machine. I left small (1mm thick) tabs so that the middle bit didn't go walkies on the final pass. Boring the hole is more accurate (by accurate I mean it's closer to a circle, and better finish) than milling it.

Web Goblin
31-07-2011, 11:38 AM
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
01-08-2011, 12:07 AM
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
14-08-2011, 03:21 PM
Possibly a bit late now, but just in case anyone reads this and is interested in one here's the 'latest version' without the aforementioned weaker point:

4352

One with the clamping bolt at the side:

4353

Web Goblin
14-08-2011, 09:17 PM
Nice bit of work Jonathan.
I like the second design with the clamp at the side, nice and tidy.

Ian

Peter.
15-08-2011, 08:42 AM
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
15-08-2011, 06:52 PM
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!

D-man
13-10-2011, 09:46 PM
Possibly a bit late now, but just in case anyone reads this and is interested in one here's the 'latest version' without the aforementioned weaker point:

4352

One with the clamping bolt at the side:

4353

Hi Jonathan,

I could be interested, ive got one of these spindles sitting on my bench waiting to be fitted!, what sort of price you looking for?

HankMcSpank
14-10-2011, 01:09 AM
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
14-10-2011, 01:46 AM
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
14-10-2011, 02:52 AM
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.

Jonathan
14-10-2011, 02:55 AM
Oh also, here's some pictures of yet another one:

4741
4742
4743

It's 188mm wide if I recall correctly.

D-man
14-10-2011, 03:07 PM
Hmmm im torn between the 2 now, is there any sort of difference? apart from the obvious size lol