Measuring run-out on Delta Midi

[redfishsc]

I have an ongoing battle with my Delta Midi-lathe.

I just cannot seem to get the thing to run truly round. My problem tends to be worse at the tailstock-- I can feel more eccentric turning at the tailstock end than at the headstock end.

I have checked everything I can imagine---- clean MT2's, straight mandrel, good live center. I also use a "rotating jacobs chuck" instead of the live center often times, but the problem doesn't change by switching to the live center. The mandrel still turns out of round, especially toward the tailstock.

Nothing is overtightened. The headstock bearing is new as is the headstock spindle.



I have access to one of those dial indicators that checks the runout of machinery. How do I use it to check the runout on the lathe? My typcial setup is the Beall Collet holding the mandrel and either a live center or the rotating jacobs holding the end.


Lastly, my tailstock has a bit of slop in it- it wiggles more than I believe it should. It seems to have a few degrees of slop side-to-side, meaning that it can "point" to the right or left of the center of the headstock. How can I solve this?


Thanks for those helping me solve this 6-month problem. This is the LAST DELTA lathe I will ever buy. It barely had 20 pens worth of time on it when I bought it used, I should not be having these kinds of problems.

 

[Mikey]

First thing you need to do is put the dead center in the headstock and then put the live center in the tailstock and see how they (the points) line up when you lock down the tailstock. Rotate the headstock and make sure the point doesn't move around which would mean a bad spindle or bearings. Sometime the tailstock seems to wiggle, but as soon as you lock it down, it will always go to one position. I have learned with my Grizz that if I pull the tailstock toward me when locking down that it always lines up.

 

[Paul in OKC]

Directly in line is not the issue, especially if the bearings and spindle are new, though if you haven't checked the alignment it might be something to do. I feel that if both ends are solid, the mis-alignment won't cause runnout. I still sounds like someing at the tail stock end is not running true. If you use the indicator, put the tip on the mandrel close to the tailstock end and rotate the spindle and see how much the needle moves. The rotating chucks will have some runnout, but sould be livable.
On the tailstock 'pointing' issue, pull it or push it then tighten the lock, also tighten the little lock on the quill. that will keep everything steady.

 

[woodbutcher]

I have a Delta midi and had similar issues. I replaced the Delta live center with a Oneway and carefully filed the removeable tip to allow the shoulder of the mandrel to solidly seat itself on the live center cone. For what it's worth I had the same problem with my PM 3520 and the above fix worked on that too. Also as Paul suggests.

 

[redfishsc]

Thanks for the tips. I will have to check the runout of the live center and the rotating chuck. If I find anything on them I may have found the problem. If not, and I can't locate the problem, I guess I just continue balding prematurely.

 

[TAld]

Redfish, Read my post from Dec. 11 titled "lathe help please".
You did not say if the lathe is still under warranty. If so, call Delta for warranty service.
I have battled w/Delta since Dec. on this issue. Long story made simple.
1. Called Delta- they gave me a number to call locally for warranty
2. Tech came to house and measured run-out at 0.017"
3. Parts ordered.
4. Jan. 5, 2007 I called company doing the warranty work. NOW they tell me Delta won't pay for a tech to come to house to do the work I have to carry it in for service.
5. Informed them I am 62 yrs old and disabled-waiting for back and neck surgery and can't carry it in. Told the company to call Delta and inform them I want a total refund!!! And my attorney would contact them immediately.
6. Company called back 12 mins later and said Tech will be here Tuesday and he already has the spindle and bearings.
Will let you know how it goes!

 

[TellicoTurning]

See Tom, sometimes age does count for something.