7x16 Lathe tapered gib question...COMPLETED MOD !!

[V 45]

This is where I'm at today with my tapered Gib mod to my 7x16 lathe. I have the Gib bracket on a sine bar with a .070 space block on top of a parallel. Sine bar is 4". I didn't want to make a tapered jig and waste what little metal I have. I made the actual Gib out of a piece of bronze since that's what my buddy gave me and said would last longer than brass. I made them to .250"x.300"x 5". I haven't cut the taper on them yet. My question is how deep do you make the angle on the Gib bracket?? Right now if I lay the bronze on the bracket I have .015" left sticking up above the bracket. Then how deep a cut into the bronze? Or did I cut tooo deep already ? I can make more brackets...just don't have any more bronze !!
Thanx again...V 45

[V 45]

I decided just to go ahead and machine the gib down to the bracket. Heres a pic. I'm now having to mill the taper deeper on the bracket since there was about a .032 gap left. I took it down .034 and now it fits very nice. Back to the dungen to finish the back one.

[steamer]

Generally speaking, a tapered gib has a 1 in 40 taper.....hope that was the question...?

Dave

[V 45]

I was going by the plans of Rick Kruger, pictures from Bogs (John), and Chuck. I made the gib brackets out of steel. I just went by trial and error on my lathe to get the depth needed. Thanx Steamer.



Here are the tapered gibs installed on my lathe...just a fit check. They look like they work. I have to find a 6-32 screw long enough for it now and mill the groove for the adjustment in the gib.

[Bogstandard]

Sorry I couldn't have jumped in earlier, major mods to my house are having to be organised.

I can't remember exactly how I did things, but the pictures I sent to you with the text you should have shows exactly how I did things.

Before you go any further, you should contact Chuck Fellows, as he did the same sort of mod, and worked out how to do the adjusting screws much better than I did. Just ask him where his post about it is.

Another thing I did do, was to put two pins in each slide on the saddle and a groove on the gibs, basically to stop them slipping sidewards. I don't know if Chuck did the same, but to my mind, it could stop problems appearing later.

I hope this helps.

John

[V 45]

 Thank you again John...I did see the slot down the gib, that makes sense to use guide pins. Did you just press them into the carriage ? Or in the gib bracket ? It will be a few days before I get back to it. With work and all !!
  Thanx again... Dave

[Bogstandard]

Dave,

They were just loctited in. They can't come out with the gib strip slot sitting on top of them.


John

[V 45]

Here is my completed tapered gib mod to my 7x16 mini lathe. Wow what a difference !! I like it a lot !! I made my adjustment screw different than most. I don't have a 20 ton press !! So I used a 1 inch 6-32 cap screw...turned down O.D. .025" to give the bracket some clearance or it would hit. I then drilled and tapped a piece of .375" drill rod to 6-32.....then parted off 2 pieces to .078" and silver soldered to the cap screw. Works great !!
Thanx to all that have helped me with this modification !!   

[steamer]

Thats the classic way to adjust a tapered gib!   PERFECT!
Bet thats a good bit stouter now!

Dave

[V 45]

Thank you Steamer !!!  It's much more rigid than ever before. No more loose carriage !!!!!

[Bogstandard]

Nice one Dave, once it gets bedded in properly, you should find the saddle moves like silk.

John

[V 45]

Thank you John,
 I made a few cuts last night and I already love the way it feels !!
V 45... Dave