R8 & 3/4” Shank Tooling Holder

[erikmannie]

I still need to:

(1) Make 2 more legs,

(2) Weld it up. I’m going to weld it (stitch TIG with so much skipping around) because that was the original plan. The steel frames caused a *lot* of extra work (!) with regard to drilling & face milling the bottom side.

(3) Make the feet. I don’t have an idea yet for the feet. I would like them to be cylindrical and heavy. Maybe press fit or weld the bottoms of the muffler tubing into some steel round stock. I think that I should do all the work on the feet on the lathe before I weld the shelves on the unit! That way everything would be perfectly cylindrical, and I could control the overall length of the legs + feet.

 

[erikmannie]

One idea for the feet would be to make thick steel bushings (e.g. .750” wall, 3” length) on the lathe. I could weld the .050”wall muffler tubing to this bushing, and then machine down the weld bead.

If I wanted solid bottomed-feet (as opposed to hollow), I could then weld in a circular plug, or weld on a 1/4” thick steel circle. In all cases, these weld beads get machined down to flush.

Plan for press fitting into a machined foot: the foot would be in the shape of a very thick walled, thick based pencil holder. See the photo below of thin walled, thin based pencil holders.



Doesn’t the press fit seem like a cleaner plan? I could even use red Loc-Tite.

 

[erikmannie]

I made the 4 feet for the legs today. They are just bushings made out of 1018 steel.




I am making leg #3 out of 4 now. It is 36” long, & I am using the follow rest for the first time.

I could not get the follow rest to work for 31” of turning (I still experienced deflection). Now I am doing 21” of turning, and everything is working fine.

Here are the pictures of me trying to turn 31”. Even at 380 RPM (I wanted to use 620 RPM), the tubing was bouncing.

 

[erikmannie]

Here is a picture of what is working.

I have a HSS turning bit, 620 RPM, .005”/rev power feed, CF, DOCs are between .0005” and .0075”. I do a lot of spring passes. The tubing wall is only .050”.

 

[erikmannie]

I will do about 3 more spring passes after these photos, but here is the surface finish on this muffler tubing at the chuck,



in the middle,



and at the tailstock:



It is difficult to get a good surface finish on 1018. In the photos, the tubing has a film of Mobilmet 766 (the CF that I use) on it.

 

[erikmannie]

I am working on the last leg now. This photo is a spring pass over 22” of .050” steel muffler tubing. I turned it down .012” with HSS. The spindle RPM for the spring pass is 1200 RPM. The power feed is .005”/rev.

The CF on to the follow rest & then on to the work is intentional. I have the tool bit rotated a lot, and the follow rest is blocking direct application of CF.



Here is the resulting surface finish:





I will do this to the other side of this 36” long leg, & then it is on to files, emery cloth & Scotch Brite.

The follow rest sure gets in the way when you try to chamfer something, or at least it did for 1-1/4” tubing.

 

[erikmannie]

I was working on this leg for a good 4 hours, but when I was sanding it this happened.

I started with .050” tubing, and turned that down to .035”. There was a high point on the tubing where I had it chucked it too hard. A 12” bastard file got into that, & that caused a 2” laceration in the tubing near the end of the tubing.

I knocked down the high points of the laceration. I figured I would shorten all the legs & hide the laceration in the foot. I continued filing & sanding. The pressure that I was putting on it with 80 grit Emery cloth overwhelmed the thin wall, & it collapsed at 620 RPM. My hand went into the work, but I got out of there really quickly.

I’m actually OK with this, because I would have had to shorten the whole rack by almost 3” in order to hide the aforementioned laceration in the foot.

My plan is to just make another one. I’ve already done so successfully 3 out of 5 times, so I figure I have a 60% chance of successfully fabricating the last leg.




Edit: the clean area on my hand is a very mild burn. There is a bruise halfway across my hand, behind the knuckles. I am going to go wash my hands.

 

[mattthemuppet2]

I'm very glad you got away with just that. Just like working on cars, you always have to consider where your hands are going to go when something lets go. Hope you heal up fast!

 

[Just for fun]

Erik, Glad you didn't get hurt worse. As Matt said, heal up fast.

 

[Aukai]

You need to use a lot of ice for 48 hrs