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Cncparts
02-12-2013, 08:13 AM
So I'm new to cnc and have got a kit machine.

The spindle it comes with is a hi torque spindle, however it only has a 1/8" (~3mm) shank.

I'm thinking of getting a router on amazon and dissecting it and mounting it on the machine to give me up to 1/2" collet size. I'd only really need 1/4" (~6mm) as most decent milling bits come in that size.

my issue at the minute is not making the mounts (I can machine them with the curet spindle) but ensuring the new spindle is straight in the mounts so it cuts straight down and leaves straight edges on pockets etc.

Any tips on how to do this?

And actually how to get the profile of the new spindle for the mount (cut from wood by hand first maybe?)

EddyCurrent
02-12-2013, 05:03 PM
So I'm new to cnc and have got a kit machine.

The spindle it comes with is a hi torque spindle, however it only has a 1/8" (~3mm) shank.

I'm thinking of getting a router on amazon and dissecting it and mounting it on the machine to give me up to 1/2" collet size. I'd only really need 1/4" (~6mm) as most decent milling bits come in that size.

my issue at the minute is not making the mounts (I can machine them with the curet spindle) but ensuring the new spindle is straight in the mounts so it cuts straight down and leaves straight edges on pockets etc.

Any tips on how to do this?

And actually how to get the profile of the new spindle for the mount (cut from wood by hand first maybe?)

You need some slight adustment in the brackets but I would make them as good as you can then mount it all on the machine and with the longest piece of 6mm silver steel in the collet check for square from the bed in X and Y axes using a good quality set/try square. This will show you where the brackets needs fine adjustment with a file or similar.

Something like this will give you the profile or just nibbling away at a piece of cardboard until it fits would also work.
Toolstation > Painting & Decorating > Tiling Tools > QEP Profile Gauge (http://www.toolstation.com/shop/Painting%20&%20Decorating/Tiling%20Tools/QEP%20Profile%20Gauge/d150/sd3286/p41118)

Cncparts
02-12-2013, 05:07 PM
Ah yes I forgot about those profile gauges, very handy things, been meaning to get one!

Would be nice if there was an easy way to get it to an electronic vector...!!

Thanks for the help

EddyCurrent
02-12-2013, 05:24 PM
Ah yes I forgot about those profile gauges, very handy things, been meaning to get one!

Would be nice if there was an easy way to get it to an electronic vector...!!

Thanks for the help


This is how I do it.

Get a photocopy or photo of the profile, fire up Sketchup and import it as a picture, use the scale tool to resize it to the exact size you require, on a new layer use bezier curves to draw around the outline of the picture, print result at 1:1 scale.

JAZZCNC
02-12-2013, 05:27 PM
What your wanting to do is called tramming the spindle and using a Set square with Steel in Collet is not good enough and won't be accurate.

Easy way is to get a Piece of round steel bent 90deg that fits in the spindle, make sure it's stiff and ridged so doesn't flex. Make it has wide has your Bed then mount a dial gauge on the end. Then sweep around 180 deg and see how much it changes, if your spindle is trammed correctly it should hardly move in each Axis direction.

The wider the sweep the more accurate it will be.

Cncparts
02-12-2013, 05:31 PM
Ye thought about scanning the gauge, might be the easiest option.

So Jazz what your saying is put the spindle in the middle of the bed, insert a piece of steel, say a 6mm rod as that will probably be the max shank size. Have this steel rod go down to the bed and bend 90deg and run parallel to the bed, touching it. If its square then the rod should stay flush to the bed along its length, and while I spin it around the bed 360deg..?

EddyCurrent
02-12-2013, 06:56 PM
Yes obviously the longer the piece the more accurate, it depends on your requirement and depth of cut you envisage. For my requirement the first method would work but I suppose it might as well be as accurate as it can be so use method 2.

JAZZCNC
02-12-2013, 07:28 PM
So Jazz what your saying is put the spindle in the middle of the bed, insert a piece of steel, say a 6mm rod as that will probably be the max shank size. Have this steel rod go down to the bed and bend 90deg and run parallel to the bed, touching it. If its square then the rod should stay flush to the bed along its length, and while I spin it around the bed 360deg..?

Yes and No to do this correctly you need a dial gauge on the end, just touching the bed is not accurate enough. The process would go something like this.
Position gauge at say 12oclock and Zero it then rotate to 6oclock. what ever the differance is how much your out of tram in that direction, now adjust the spindle half gauge reads half the amount.
Then repeat at 3oclock to 9oclock and now your spindle is trammed, it may take a few goes but each time the amount will be less.



Yes obviously the longer the piece the more accurate, it depends on your requirement and depth of cut you envisage.

Eddy Spindle being trammed correctly has nothing to do with Depth of cut.!! . . . If it's just tiny amount out it will show when surfacing and on flat surfaces like the bottom of pockets etc. Depending on which direction the tram is out you'll have tiny steps in one direction or the other.

The material your using will play big part to how accurate you want to tram. Wood for instance doesn't need so much accuracy but aluminium,brass and even hard plastics will easily show an out of tram spindle on any flat surface.

Then you have the fact edge angles will never be 90Deg so the longer the Z axis extension and tool Dia/length the more obvious it will be.

GEOFFREY
02-12-2013, 11:53 PM
A router will not be as good as a spindle - much noisier, less accurate and more prone to wear. Far better to get another spindle with a greater capacity. If you machine is quite small, don,t be too put off by the 1/8th collet. I have a spindle and have been using 1/8" down to 0.5mm cutters for years, and I always say "I can make anything" (except money). G.

EddyCurrent
03-12-2013, 12:23 AM
A router will not be as good as a spindle - much noisier, less accurate and more prone to wear. Far better to get another spindle with a greater capacity. If you machine is quite small, don,t be too put off by the 1/8th collet. I have a spindle and have been using 1/8" down to 0.5mm cutters for years, and I always say "I can make anything" (except money). G.

Exactly, my bed is only 600 x 1000 mm but I'm using a 2.2kw Elte spindle with a ER25 collet, I plan to use cutters from 1mm to 12mm mostly

Cncparts
03-12-2013, 10:12 PM
Thanks folks, really appreciate the help.
My bed is 15x13 inches
I worked out with Aspire that a 6x7 inch pocket, .75 inches deep will take almost 10 hours with a 1/8 spindle... That's quite long!

There's a spindle on eBay that has a 1/2 inch collet (12mm) for about $70 delivered. Not sure what the quality would be like?

It says engraver but I think it's ok for milling...

http://item.mobileweb.ebay.co.uk/viewitem?itemId=360667233879&index=2&nav=WATCHING&nid=30124643751


Any other suggestions of larger sized spindles?

JAZZCNC
03-12-2013, 10:27 PM
Nah you must have done something wrong what material you wanting to cut.?

Cncparts
03-12-2013, 10:34 PM
Hardwood.
16 inches per minute (machine max)
1/8in pass depth
Step over of 40%

I increased if there to 90% step over and 1/4 pass depth and dropped it to about 5 hours

JAZZCNC
03-12-2013, 11:05 PM
Hardwood.
16 inches per minute (machine max)
1/8in pass depth
Step over of 40%

I increased if there to 90% step over and 1/4 pass depth and dropped it to about 5 hours

Ok well the Low feed is the killer but even then with your 1/8 DOC and 16" feed & 40%STO it still comes out at 6hr 7mins in SolidCam and thats with Spiral down Entry. 5hrs 27min with 45%STO.

With 90%STO 2hrs 48min.

JAZZCNC
03-12-2013, 11:27 PM
So back to to the spindle then about the best value for money IMO is the Chinese WC spindles, the smaller 1.5Kw would do nicely on a little machine and take cutters upto 7mm.
They have relatively low run out and high duty cycle so can run continuously unlike most cheap air cooled spindles that often have Low duty cycles so will need to be turned off and rested after just an hour or so's continuous running.!! . . . To get anything to even compete you'll be spending lot more money.!!

Cncparts
04-12-2013, 08:04 AM
Sounds good, any chance of a link?

Clive S
04-12-2013, 09:26 AM
Sounds good, any chance of a link?

Something like this - Online Buy Wholesale spindle motor matching inverter from China spindle motor matching inverter Wholesalers |Aliexpress.com (http://www.aliexpress.com/w/wholesale-spindle-motor-matching-inverter.html) ..Clive

Boyan Silyavski
04-12-2013, 10:14 PM
Thanks folks, really appreciate the help.
My bed is 15x13 inches
I worked out with Aspire that a 6x7 inch pocket, .75 inches deep will take almost 10 hours with a 1/8 spindle... That's quite long!

There's a spindle on eBay that has a 1/2 inch collet (12mm) for about $70 delivered. Not sure what the quality would be like?

It says engraver but I think it's ok for milling...

http://item.mobileweb.ebay.co.uk/viewitem?itemId=360667233879&index=2&nav=WATCHING&nid=30124643751



Working voltage :12-48VDC (DC)