Smithy Milling Problem

[spirit20]

Greetings all long time reader, first time caller. LOL I have a 1340I Smithy. When I go to do milling I will set the depth of the cut, & loch the spindle and have a problem. When I lock the spindle depth it changes the setting to a shallower cut. Any thought?

Help
Just a tinkerer in Michigan

[Harold_V]

I'm not familiar with your machine, but one of the causes of a drifting setting when clamping is a loose gib. It might be helpful to know how much movement you get. Is the change predictable? Does it change during the cut, or just when you apply the lock?

Harold

[Jose Rivera]

Spindle lock not tight enough?

If using a collet to hold the end-mill cutter maybe not tight enough and the tool is moving up the collet ?

[spirit20]

Than you both for your help. I think you got the answer Jose the 2 setscrews on the fine feed meconisms were loose. I did tighten them up but have not had the time to see if this corrects the problem. My wife has been very ill & sometimes the trip out to the sanctuary is limited, but I will try to check it out this week.

[ScaleModeler1974]

I had a problem with my CB1220XL many years ago.......the mill head would shift towards the back of the machine by about 10 to 15 degrees.......I fixed the problem a few years later by removing the mill head altogether.

[steamin10]

WHAaaat! Fifteen degrees, or fiteen thousnaths?

coment reserved on Chinee 3-1.

[ScaleModeler1974]

You read it right........every time I went to mill something.....anything the mill head would kick back about 10 to 15 degrees.........only had 1 bolt to hold it in place.

[steamin10]

EEeewwww, IIccchhh!

(no further comment necessary)

[spirit20]

I also get the milling head to start to rotate when milling. I am fearful that if I crank down the 2 locks very hard it will crack the mill housing.

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Mid Michigans only true Spirit

[warmstrong1955]

I own a Smithy 1340, and had the same problem.

Here's a pic of the wrench I used when I was still milling with my 1340. Not my idea... I copied it from here: http://www.home-machine-shop.com/projects/Mill_Wrench/

You might look around that website.....he's pretty sharp on all things Smithy, and other things as well. Ned also has a Yahoo group
http://groups.yahoo.com/group/smithy-machines/

I cut the handle off the wrench that came with it, and welded an old broken 1/2" drive socket on the end. The ratchet is 15" long, and took care of the movement problem. I never used excessive force to tighten the head up, just a one hand pull was plenty. The stock Smithy wrench just isn't long enough.

Bill

[steamin10]

Ya, I overdo the handle length on most things. That allows me to be lazy in my grip and not have to pull my shoulders out locking things down.

I made a hammer -wrench with a plastic head for bonkin the bolt down to drop the R-8 loose, and then spin the bolt out by hand. Handy to have one tool that doesnt walk away for another use.