Thread: My take on a King Way tool

My lathe lives on a cabinet mounted on hardwood risers which allows me to use a pallet jack to move it when I need to as I store stuff behind it.
Every time I shift the lathe I recheck the bed alignment to be sure nothing has moved.

In the past to do this I used a pair of V blocks, a precision level (0.1mm/M) and a feeler gauge. A V block was placed on each way with the level resting across them. An appropriate feeler gauge was then placed as needed to bring the bubble to an appropriate location. Something like this:

King Way Tool 01.jpg King Way Tool 02.jpg

Starting with the level furthest from the headstock the V blocks were aligned against the saddle and the level adjusted with a feeler gauge.
Using the saddle, the level was then moved to about the centre of travel and the level reading noted before moving to the headstock end.
If necessary the bed adjusting feet were tweaked and the process repeated until the deviation was satisfactory.
This method worked ok but care had to be taken because if the level moved on the V blocks at any point during a pass then it had to be repeated which could make the whole process a bit time consuming.

King Way Tool 03.jpg King Way Tool 04.jpg

I decided it was time to build myself a King Way aligning tool but with somewhat of a twist. I didn’t want to drop a heap of coin buying precision vials for a tool I might use once every six months or so, rather I decided to come up with a method that facilitates the use of the precision level I already have. Here’s my solution:

King Way Tool 05.jpg

The frame itself is just a joe basic King Way setup to which I added a tilting rest which supports the level itself.
The rods are 16mm 1045 which is what I had to hand and I milled flats on them which makes lining everything up quicker but the flats are not necessary.
The cross shape of the tilting level rest means the V base of the level is supported at three points making it very stable which allows me to complete a check of my lathe in a couple of minutes with the level readings being much more consistent than when using V blocks.

King Way Tool 11.jpg King Way Tool 14.jpg

The slide is made from 1” 1045 BMS and is drilled and tapped at 180⁰ and 150⁰ to allow use on both V and flat lathe beds or dovetail ways.

King Way Tool 13.jpg

The level tilt can be adjusted by either the M6 X 1.0 cap screw or by using feeler or slip gauges under the embedded ball bearing.

King Way Tool 12.jpg

Now I know that a King Way tool has two levels perpendicular to each other but for my purposes the single level is good enough for now.
The tilting rest does allow me to use the level along the bed if I use a couple of V blocks. Again my lathe is far from level so the tilting rest allows me to make this check with minimal fuss.

King Way Tool 10.jpg

Something I found interesting is that a greater deviation of the level occurred with the ball foot resting on the flat of the bed than when it rested on the opposite V way which actually supports the saddle. I suspect this may be caused by the level movement being larger as the effective pivot length becomes shorter.
When I get a chance I will do a check with the ball foot on the flat way and an indicator on the V way to see if there is any actual variation.

King Way Tool 06.jpg

Deviation with ball foot on flat way.
King Way Tool 07.jpg

King Way Tool 08.jpg

Deviation with ball foot on V way.
King Way Tool 09.jpg

Given that on a Hercus the distance between the rear V way and the opposite flat is only 100mm and between the V ways themselves is only 130mm then the deviation as per the level is within 0.02mm over the 600mm measured.
I know the lathe turns true as I just made up a 400mm crank shaft rod which was within half a thou end to end and I’m happy with that as long as nobody tells Schlesinger
Cheers,
Greg.

Very nice kwijibo, did you make brass plugs to go under those adjustment bolts ?
I reckon that you have

Thanks shed, I've got to confess that I was too lazy to bother with brass feet for the screws, they don’t need to be done up super tight so there is only minimal marking to the rods.

I performed a more complete survey of my lathe yesterday and got it all pretty good with a couple of minor tweaks, of course the proof will be in the using the next time I turn something with a bit of length.

First check was rear V way to front flat way which indicates the alignment of these ways is pretty good from the head stock to around half way but starts to go pear shaped between there and the tailstock end. Note the slab mill is just there as a counterweight to keep everything balanced on the narrow ways.

V Way To Flat Way Check 01.jpg
V Way To Flat Way Check 02a.jpg

If I’m reading things correctly:
The level indicates that the flat way falls from the middle to be lower than the rear V way by 0.03mm give or take.
The DTI indicates the front V is either higher than the flat way by 0.03mm (0.09 – 0.06) or out of parallel to the rear V way by something similar or a combination of both.

Next check was rear V way to front V way which indicates the alignment of these ways is pretty consistent end to end.

V Way To V Way Check 01.jpg
V Way To V Way Check 02a.jpg

Both level and DTI indicate a deviation of a bees dick less than 0.01mm.
Because the ball foot of the frame is riding on the angled surface of the V way it is impossible to say if this deviation is due to a difference in height or parallelism.

Last check was for parallelism between the rear V way and the tailstock V way which indicates they evenly converge by around 0.04mm over the measured length.

Tailstock Way Check 01.jpg
Tailstock Way Check 02a.jpg

The level deviates within 0.01mm give or take.
The DTI moves out by just short of 0.04mm which if I read things correctly indicates a deviation in parallelism.

Next step from here would be to get a test bar and take more measurements against that but to be honest I’ve never really had any problems producing accurate work on this lathe and can’t see any point in spending money going down that particular rabbit hole.
Doing these tests has definitely been worthwhile though because I'm now fully aware of what problems are there and will know when I need to work around them.

By the way, thanks to Anorak Bob for the little combination DTI which he very kindly sent over, this is the first time I’ve had a chance to use it in anger and it’s a little ripper.
Cheers,
Greg.

Inspirational work Greg.

And I'm glad the little Mitutoyo has proven useful.

BT