[PROJECT] X Power Feed

[f350ca]

For a .002 interference, you'd probably want to expand it .004 to make sure you got it on. You only get one chance.
steel fas a coefficient of expansion of 6.7 x 10 to the -6, or .0000067 in/in deg f

So for initial bore of .666 in circumference is .666 x pi = 2.0923 (that size is the devil to machine)
For expanded di of .670, circumference is .670 x pi = 2.1049

delta cir =2.1049 - 2.0923 = 0.0126

for expansion, delta L /L = coef of expansion x delta temp

0.0126 / 2.0923 = .0000067 x delta T

or delta T = 900 degree farenhiet over room temperature

Should be doable with a propane torch.

Cooling the lead screw wouldn't do much, you might drop it from say 70 to freezer temp say 20 f or delta t of 50 It would help but would only shrink 0.00022 in dia.


Check the math but it should work.

This was a smaller bore so less expansion but only a 1 thou interference, I was afraid of breaking the gear when it cooled. At blue temperature on the gear it literally fell on to the shaft.

[Highpower]

(01-11-2015, 02:58 PM)EdK Wrote: Willie,

What's that thing sitting on the lathe ways in the second picture?  

Ed

Ed, that is the extension shaft that came with my Z power feed unit. But it was made to fit a full sized Bridgeport which has a larger diameter shaft on the feed screw than my clone has.

   

Because of that it flexed on my lead screw and was the reason I made the sleeve to go into it. I pushed  the sleeve into the extension shaft with some Loctite 609 sleeve retainer compound, and when it had cured I finished bored the sleeve ID on the lathe.

[PixMan]

Ed,

I think you should go ahead with the 3" deep bore. I don't have a 17mm reamer to send you but you can get one for $12.00 (shipped) on eBay. It looks to be a carbide tipped one, maybe used but probably OK on the size.

http://www.ebay.com/itm/17MM-Carbide-Tip...1e97c440ba

I would do it as follows:

Make a blank to overall length that is a little oversize on the O.D.
Center drill one end, turn it around
Drill with a 21/64" drill
Bore an inch deep to cleanup & true it
Ream with that tool to full depth
Turn a 3" long plug that the part just barely slides onto it
Finish turn the O.D. and thread it

Done.

[EdK]

Thanks for all of the suggestions guys. I've got a lot to think about. I probably won't get to it until the weekend though since the company is moving this week and I'll be working long hours to get everything ready to go to the new location.

Ed

[Highpower]

(01-12-2015, 12:45 PM)EdK Wrote: I probably won't get to it until the weekend though since the company is moving this week and I'll be working long hours to get everything ready to go to the new location.

Ed

You mean from the dumpster to your home shop?



I'm sure you will come up with the perfect solution for your mill Ed. Your projects always turn out very nicely.... and shiny!

[EdK]

You have more faith in me than I do Willie.

Ed

[the penguin]

This reminds me of the knee feed I did on the Jet JVM836 mill I have. Jet didn't offer a knee feed, but they had one for the similar Wilton (no longer sold) mill. The Jet/Wilton tech said it was a direct bolt on, so I ordered it, of course, it wasn't a direct bolt on. So I called the Jet/Wilton tech and explained the issues, his response was classic, "you own machine tools, make it fit", he then hung up. As I had no recourse, thats what I did, its worked great after I got it on and got the bugs worked out.

[Highpower]

(01-12-2015, 08:10 PM)the penguin Wrote: This reminds me of the knee feed I did on the Jet JVM836 mill I have. Jet didn't offer a knee feed, but they had one for the similar Wilton (no longer sold) mill. The Jet/Wilton tech said it was a direct bolt on, so I ordered it, of course, it wasn't a direct bolt on. So I called the Jet/Wilton tech and explained the issues, his response was classic, "you own machine tools, make it fit", he then hung up. As I had no recourse, thats what I did, its worked great after I got it on and got the bugs worked out.

Jack, we have the same basic mill but mine wears an Enco badge. They didn't offer a knee feed for mine either, and when I called their techs I was told "it can't be done".

They obviously don't know about the determination of the people that make up this forum. 

[the penguin]

yep, looks familiar, BTW white is a terrible color for a milling machine or a lathe (I have a Jet GHB-1440A)

[EdK]

Finally getting back to this project. I'm working on the spacer ring. I've got it faced on both sides and it's still chucked up in the 3-jaw chuck. I'll bore a 3/4" hole in it before I remove it from the chuck. Then I need to locate it on a mandrel or arbor of some sort to turn the OD concentric with the ID. I have a set of expanding arbors but have never used them. Will one of those work for me to hold the ring for turning the OD? I'll chuck the arbor in an ER-40 collet. I know I'll probably need to take light cuts. I'm not turning to a specific diameter. I just want to get the OD cleaned up and concentric to the ID. I'll make the part it mates to fit whatever the diameter ends up being.

Ed