Thread: tramming a lathe...chicken or the egg...which came first

Tram the head first with a test bar in the taper of the spindle.(but this is something you shouldnt have to do)
This assumes you have a proper test bar.
Or are you talking about using rollie's dad's method of aligning the bed?
Is this is your old/"new" lathe?

Originally Posted by Stustoys

Is this is your old/"new" lathe?

yeah...thats the one (the toy one)...the one out of the box....she said to me over the weekend..dont you think you've got too much crap in here, .. but I think she was refering to the 2nd hand bandsaw I just got hahaha.....should have got the lathe out a long long time ago...she was standing next to it talking to me and didnt even notice how bright and shiny it was......

I was thinking of Rollie's method unless there is something easier for me

The face plate is <0.01mm when rotating it ...a bright mild steel bar when measured about 75mm away from the jaws is 0.09mm.....tried roating the chuck on the face plate and hitting it with soaft face hammer etc but stays the same...do I need a better chuck.?

lol well I'm glad you are still with us

Ok so your leveling the lathe then? Do you have a good level?

pictures eskimo

You're mounting a 3 jaw chuck to the face plate?
You can mount the chuck on the face plate 3 positions right?
When you move the chuck from one position to the next, does the high spot stay in the same place v the spindle or move around as you move the chuck? This should tell you if it is the chuck mounting or the chuck itself that is the problem.

Stuart

Hi Eskimo,
So your didn't get caught out with the lathe.lol

It wont matter if you take a light skim off the face plate. If the lathe spindle is out (which wont be much), it will turn it a slight concave or convex, but will still be true enough to bolt the chuck on to take measurements of the spindle.

Dave

Originally Posted by Stustoys

You're mounting a 3 jaw chuck to the face plate?
You can mount the chuck on the face plate 3 positions right?
When you move the chuck from one position to the next, does the high spot stay in the same place v the spindle or move around as you move the chuck? This should tell you if it is the chuck mounting or the chuck itself that is the problem.

Stuart

Ta Stuart

yes its a 3 jaw
the high spot follows the chuck...not the faceplate
moved the steel bar 180 degrees and the high spot still in same place with the chuck..

this says the chuck is at fault...?

are the cheapies at H&F anygood?

Originally Posted by Dave J

(which wont be much),

this is not an AL960 Dave,...going by the some of the other stuff I have bought I wouldnt be suprised if it was worse than what one should expect
You have a Fuerda from H&F dont you Dave...is it the cheapie or one of the dear ones
How do you find it?

Before doing anything take the chuck apart and give it a good clean out. If nothing changes you could follow the idea below to true it up.

If the lathe came with a 4 jaw you could machine a bar (the larger the better) in it so it runs true, then clamp your 3 jaw onto the bar backwards and take a skim off the back of it.
If you don't have a 4 jaw you could weld a bar to a piece plate that is big enough to bolt to the back plate or face plate, bolt it on the face plate and machine it true to mount the chuck as above.
I have trued up a few chucks and the cast iron cuts like butter as their usually pretty good cast.

Dave

What's the run out as close as you can get to the jaws?
What was your lathe again? AL54B? I cant seem to find it.

Like dave says clean it. If its anything like mine it will need it. Careful of the burrs though.
Then you could try tightening the jaws with one socket check run out, then loosen and tight with the next socket, check run out, repeat for the third socket. That may change the run out.
You could also try shifting the jaws around to the other slots. I've never bothered to do this with mine, but I've read that some chucks like there jaws in a certain slot and the chuck tightened with a certain socket.

Stuart

Ok...i'll strip and clean it
just noticed that it is a Fuerda...

Dave...you want me to do what....weld.......hahahahaha
you've never seen me weld have you...lol
but I will try.... if cleaning doesnt help...I'll keep my fingers crossed

Its a BB25-1 Stuart...a toy!!!

The test indicator says .04 at about 10mm out from chuck

Stuart.isnt the Chuck in question a 3 jaw chuck,standard self centreing.

If this is the case the Jaws will only be able to go into there correct pocket for the Chuck to run "true".

Unless this is not a Scroll type chuck.

Maybe it has bolt-on jaws,in this case you probably could interchange the Jaws,but not advised as these type of Jaws are usually numbered,as should be the Jaws for a Self Centreing chuck.

Never really heard of or viewed somebody checking Jaw runout by tightening the Jaws from 1 key hole then moving to the next and so on.

Not saying that there might be some slight change, though doubtfull as the key hole turns the Scroll.


Eskimo if its only a Standard 3 Jaw Self Centreing Chuck give it a pull apart if it has a back plate check for burs or rubbish,check the Thread if its a Screw on type.

If its a Bolt-on type check the holes for burs.

If you clean it and check it put it back together and its still running out just live with it,even if you purchase another similar 3 Jaw chuck it will still run out just maybe not as much.

If you do pull it apart mark the Back Plate ,body and anything else that you pull apart so that it goes back together the same way.

Originally Posted by pipeclay

Stuart.isnt the Chuck in question a 3 jaw chuck,standard self centreing.

Hi pipeclay Yes I believe it is.

Originally Posted by pipeclay

If this is the case the Jaws will only be able to go into there correct pocket for the Chuck to run "true".

No, the jaws can go in any pocket(slot), the order of the jaws has to be right but you can start at any pocket.

Originally Posted by pipeclay

Unless this is not a Scroll type chuck.

Maybe it has bolt-on jaws,in this case you probably could interchange the Jaws,but not advised as these type of Jaws are usually numbered,as should be the Jaws for a Self Centreing chuck.

Never really heard of or viewed somebody checking Jaw runout by tightening the Jaws from 1 key hole then moving to the next and so on.

Not saying that there might be some slight change, though doubtfull as the key hole turns the Scroll.

The scroll will have some clearance and in theory this will mean that one keyhole should be better than the other two......... as I said I've never tried this but if I remember I'll measure it tomorrow just out of interest.



Eskimo The 0.04 reading, did you take that before cleaning or after?
What have you mounted the lathe on?

Stuart

did you all know that Fuerda make chucks to 2 standards....with the best one being DIN and the second one Chinese Accuracy Standard.....i think i was robbed cos i reckon i got less than that

FUERDA-Workholding Solutions


so its the DK type I want.....?...lol...no one told me!!!

Stuart the error was before .....cleaned the chuck and no difference...same as before...
its as rough as guts inside......I'd be there for a year polishing it to get the rough machining marks...hold on ...was it machined...lol...

Hi eskimo
Do you have a 4 jaw? You could try putting that on, centering the bar, then check the run out 75mm from it. Not sure I would be worried about 0.04 run out, in fact I've never checked the run out on my 3 jaw.
Stuart

Originally Posted by Stustoys

Hi eskimo
Do you have a 4 jaw? You could try putting that on, centering the bar, then check the run out 75mm from it. Not sure I would be worried about 0.04 run out, in fact I've never checked the run out on my 3 jaw.
Stuart

Nope...dont have a 4 jaw

But cant be sure the 1inch barstock I have is not bent so I am going to make a test bar which now poses this question....

My chuck backing plate is not removable..the spindle incorporates the plate

the spindle taper runout was <.005mm.... could hardly see the needle move..if I did it right..lol

so how do I machine between centres with out an adaptable face plate?
the chuck wont accept the passing thru of a 4MT so that means the chuck has to come off...do I need to make a plate, one that bolts to the chuck backing plate or is there another method I could consider

its a standard looking backing plate with 3 bolt holes for the chuck and 1 hole to get at the bolts for cover plate of the front bearing