Warco Major CNC build log

[Robin Hewitt]

Next, tramming it 'cause it ain't square

I chucked up a dti on a 9cm radius and measured to the bed at 4 points of the compass. Plus is a dip, minus is a bulge.

North 0.0"
East -0.004"
South +0.0035"
West -0.0087"

As I measured each point I drew a circle around the DTI tip so I could measure all four points moving the bed rather than the dti...

North 0.0"
East +0.002"
South +0.001"
West +.0025"

Yes, my column is out of square and the bed is a ski jump :nope:

RS do pre-cut shims with a MOQ of 10, so I ordered the 0.05mm (0.002")

Never tried this before, think I need 8 of them and a bed skim :whistling:

[BillTodd]

Did you use a parallel or similar between the bed and the DTI? It helps to smooth out bed irregularities.

My base was shimmed from new. The shims are brass coloured and less than 1 thou" (fitted near the bolts).

BTW Don't get too carried away - the head on these things can be flexed a few thou" with not too much trouble.

Next, tramming it 'cause it ain't square

I chucked up a dti on a 9cm radius and measured to the bed at 4 points of the compass. Plus is a dip, minus is a bulge.

North 0.0"
East -0.004"
South +0.0035"
West -0.0087"

As I measured each point I drew a circle around the DTI tip so I could measure all four points moving the bed rather than the dti...

North 0.0"
East +0.002"
South +0.001"
West +.0025"

Yes, my column is out of square and the bed is a ski jump :nope:

RS do pre-cut shims with a MOQ of 10, so I ordered the 0.05mm (0.002")

Never tried this before, think I need 8 of them and a bed skim :whistling:

[Robin Hewitt]

Did you use a parallel or similar between the bed and the DTI? It helps to smooth out bed irregularities.

I measured it two ways to compensate for the lumpy bed, but seem to have cocked up :nope:

I reckon my -4 mils East measurement was actually a +4 mils, giving a +-6 mil East West tilt. I mean the tilt has to show even either side, doesn't it? :whistling:

6 mils over a 9cm radius translates to nigh on 0.3mm of packing at the column base, it's around 0.1 degrees out. I could see it was a bit bent when facing with larger endmills but didn't think it was that far out.

New plan. I have some 0.47mm brass sheet, I'll put a strip of that down the West side of the column base then shim the East side until it comes true(ish).

Not much of a plan, but hey, it's a plan. Now where did I put my piercing saw? :naughty:

[Robin Hewitt]

BTW Don't get too carried away - the head on these things can be flexed a few thou" with not too much trouble.

How anal is too anal? :naughty:

It is now 0.005 degrees out east/west and 0.002 degrees out north/south. Trying to resist going for better but whaddya do.

Started on attempt #2 at a faster spindle because the bearings are unhappy if I try to run the main spindle up to credible small tool speeds.

The fast spindle is an ER11 chuck fitted to the honking plate and driven using a 1:3 timing belt off the main spindle.

Same axial bearings and Belleville washers that have served me well so far, but less than the 1/4 ton preload this time.

I've been looking at those splendid tool location doo-dads based on an electrical contact between tool and workpiece. As featured on this very site

To that end I have added Tufnol insulators to the shaft housing. No electrical contact between tool and machine body until it hits the workpiece.

[Robin Hewitt]

Spindle housing now bolted together and impossible to assemble :nope:

Have to add a bit of internal clearance so the pulley can get past the belt :whistling:

Measured the resistance top to bottom, slightly worried when I found 8 million Ohms then realised I was in the circuit. Moved fingers and it went away

[Robin Hewitt]

Stuck waiting for bits

Did add an air driven spindle lock, now working on the suds nozzles.

Bill says it's a z axis lock and he's right

[BillTodd]

Stuck waiting for bits

Did add an air driven spindle lock, now working on the suds nozzles.

Is that a spindle lock or a Z axis lock?

Have you a picture of the whole 'honking plate' z axis? (looks good :))

[Robin Hewitt]

Is that a spindle lock or a Z axis lock?

Have you a picture of the whole 'honking plate' z axis? (looks good :))

By Jingo you're right, I used the wrong word :heehee:

You want a picture from a different angle?

Have to fix a front gate this afternoon. Strict instructions, on pain of nagging :naughty: