Aluminium Kress Spindle Holder

Material and setup
I opted to use 12MM aluminium for this. It is 95MM wide and over 100MM long.
The spindle holder needs approx 85MM * 85MM, so allow for the extra being cut out.

http://www.overunity.org.uk/cncdudez/kressstep1.jpg

I already had a bit of levelled MDF still on the bed, so simply drilled 4 holes in each corner of the aluminium block and secured it nice and tight to the bed.

http://www.overunity.org.uk/cncdudez/kressstep2.jpg

As you can see the usual yellow pipe for extracting the waste is attached but also this time I have attached an airline coming from the compressor. I am hoping the airline will help keep the cutting bit cool and also blow any waste away from the cutting area.

The cutting bit I am using is a 3mm carbide 2 flute slotted drill. The flute on these nice little cutters should clear the waste away and also be tough enough for the job.

Artwork
Find the design and Gcode below, that you are more than welcome to use.
http://www.overunity.org.uk/cncdudez/kressstep3.jpg

The design above has a 44MM hole in the middle which can then be clamped up a little by the two top tabs.

This design will fit the Z-Axis on our machine just like the normal spindle holders we supply for the Mini Spindle.

It will cut down at 0.30 MM a step and run at 50MM per minute.
Okay so not the fastest cutting speed, but I am in no hurry and do not want to overload the small Mini Spindle.

I have no doughts about cutting Aluminium with the machine as the frame is more than rigid enough, my concern is with the Mini Spindle being man enough and this is one of the reasons I am choosing to upgrade to the Kress.

Also the 3mm 2 flute bits have a 12mm cutting flute length, so it gonna get tricky near the bottom.

It will go all the way down to 13MM, so just Zero the X and Y to the bottom left of your workpiece and the Z-Axis on top of your workpiece.

Please right click and choose save to download the Gcode.
Please Click here to download the Gcode

Milling the Aluminium block.
http://www.overunity.org.uk/cncdudez/kressstep4.jpg

Above you can see it cutting with the airline doing the job of keeping it clear.
My little compressor tends to overheat if left running all the time, So I kept the air flow to as small as I could, so it would not empty the tank too fast.

http://www.overunity.org.uk/cncdudez/kressstep5.jpg
As you can see the 3mm 2 flute cutting bit does indeed glide through and leaves a nice finish with dry cutting.

Finished piece.
Well here it is, the finished piece. It did struggle a little after getting past 10MM deep with the noise increasing, but it did it.

I do not think I would attempt again to cut aluminium this thick with the Mini Spindle as too slow, but watch out for some new examples of aluminium block now I can use my Kress Spindle!
http://www.overunity.org.uk/cncdudez/kressstep6.jpghttp://www.overunity.org.uk/cncdudez/kressstep7.jpg
Top of finished Workpiecebottom of finished Workpiece
All I need to do now is drill a hole through the top clamp and two holes in the bottom so I can connect it to my machine.

http://www.overunity.org.uk/cncdudez/kressstep8.jpg

http://www.overunity.org.uk/cncdudez/kressstep9.jpg

Above shows the Spindle holder in place and it is more than secure with no play.

This was pulled from: http://www.cncdudez.co.uk/

One note.
The Kress has a 43mm spigot at the end not 44mm.

John S.

True they will but why not do it right in the first place and not reply on a two point contact that can rock and induce errors into the work ?

The problem with the Internet is the speed it transmits information, good or bad and in most cases it gets to stay permanent.

We now have two sites [ at least ] saying a Kress has a 44mm spigot when it doesn't.

John S
[ who makes commercial Kress holders with the correct size hole and no it's not sour grapes as I don't sell them privately, only to larger OEM's ]

Yes i noticed that as well john, i'm redesigning a mount today in the right sizes. can you help me with any formulations and/or mathmatics that i should be using to make a spindle mount.

I was hoping to use 16mm Thick ali, 6082T6 grade. i will post up some art once i get started, what i'm concerned about is how much matrial i should leave for the area around the part that clamps to the spigot on the spindle.

also john would you be ok posting your design for our review, would be nice to see how you have gone about designing yours.

Thanks,
Lee

As long as you are working on the right size hole, 43mm, the the shape doesn't matter as it has to deform only very slightly to grip the Kress.

My ' design' is based on a piece of 20mm thick 100mm wide alloy split thru into the hole at the front and a clamp screw fitted.
Even though this is very substantial it still grips the Kress hard, if it was 1mm oversize then I don't think it would deform enough to hold it securely hence getting it right to start with.

My design will not suit many as it's purposely over length as it has to reach on the OEM machine.
It also doesn't bolt onto the Z axis but fits on a quick release mounting so the original machine has a choice of three spindle alternatives.

Ok john ill crack on with the one i'm designing and post it up for your review. Thanks mate, Lee

John, is there a standard centre size for mounting holes on a spindle mount?

I noticed MD is selling spindle holders with 52mm centres and also 90mm centres for the mounting holes.

The spindle mount on my machine has 60mm centres.

Thanks,
Lee

Wickes used to sell those Kress Spindles (model FM 6990 E) as their "own brand" routers, you can sometimes get them cheap on E-bay. I got two for my CNC router, and some extra collet nuts and collets from http://www.cncplus.de

Quote:

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Originally Posted by Lee Roberts

John, is there a standard centre size for mounting holes on a spindle mount?

I noticed MD is selling spindle holders with 52mm centres and also 90mm centres for the mounting holes.

The spindle mount on my machine has 60mm centres.

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I assume that has a lot to do with fitting the extrusions they use on their machines.

Quote:

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Originally Posted by skittles

Hey, did you build the JGRO machine on guitar-list?

If you did, it is awesome :D

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Yes that's mine. I just moved house and It's been sitting in the garage under a pile of stuff for a year. I got it going again last week and I was going to use it cut out a new machine, but I think I'll just stick with this one for a while. Making the machines is so much fun that you can easily get caught with making the next one, rather than using it to make something useful!

Quote:

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Originally Posted by CLaNZeR

Could you also point me to another set of G-Code that is posted free that other people can use for a Kress holder ? :)

Cheers

Sean.

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Looking at mine which was another thread, it wasn't done by CNC. The design is so simple it was done with a drill, hacksaw and the 43mm hole was put in with a boring head or could be done clamped to a faceplate on a lathe.

The fancy shapes do nothing only remove metal that is better staying attached to act as a heat sink.

http://www.stevenson-engineers.co.uk/files/kress1.jpg

.

That's true Sean, I was just pointing out a way for the many folk who haven't got to the working machine stage and are still reliant on hand tools or limited power tools.

An old recent thread, but I found it because soon, I'm going to need to buy a 43mm mount (audioAndy has kindly lent me his Proxxon BFW 40/E which has a 43mm ring...he lent me the mounts too - but I'm going to need my own soon!)

So, where's the best (read best value!), place to buy such a beast?

I found this one....

http://www.cnc-plus.de/product_info....lder-43mm.html

Which they kindly shown the dimensions, so I've quickly CAD'ed it up (exact same dimensions, but I've just rounded a corner or two)...but I'm not sure my CNC is really up to milling such chunky Aluminium....

http://img44.imageshack.us/img44/8016/43mmmount.th.jpg

I'm fairly new to CAD/CAM, but if anyone wants the G-Code just drop me a PM - I guess all you'd need all you'd need to do is change the feed rate & the Z depth to suit your own CNC machine & material. (I've assumed 20mm & a feed rate of 10mm per minute at a depth of just over 1mm per take ...as I've never milled Aluminium, so hopefully have err'ed on the side of caution!)