Another Spring Tool Holder

[Hawkeye]

After John (Doubleboost) posted pictures of his spring tool holder, and all the mention of them recently, I had a productive weekend making my own.

The first video I saw on the topic mentioned that they are often used for holding form cutters, such as could be used to make the shaped handles for lathe feed screws. With this in mind, I made mine to take either a standard 3/8" HSS tool or a wider form tool.

I saved a lot of machining by using the portable bandsaw to slab out large sections. This also leaves a few pieces that can be used for other projects.
   

In looking at examples of factory-made spring tool holder, I saw that some had an insert in the bottom, bridging the spring gap to provide some sideways rigidity. Easy to do, so why not? Note that the spring slot is cut last, since its purpose is to take out some of the natural rigidity of the holder.
   

The finished tool holder. You can see the side tool slot, which could be used for a threading bit or a small form tool. The third setscrew at the far corner is used with the corner one to hold a wide form tool across the front of the holder.
   

I haven't cut anything with it yet, so I can't give you a report on how (or whether) it works.

[f350ca]

Looks good Mike, I'd like to try and make one for the shaper. Think it would help when cutting dovetails.

[DaveH]

Very nice Mike

DaveH

[stevec]

With all this interest in "spring toolholders" I decided to dig up the old one I have (lately anything to do with "Spring" catches my interest).

       

       

It's 1", so never fit in any turrets or lantern toolholders until I got my 16X60 lathe, so it lay untried in "inventory".

Now that I have QCTPs on both lathes I'd have to make a special toolholder to try it out.

It has the inset on the bottom like Hawkeyes but also has the insert in the opening and a screw that can be adjusted so as the limit the "spring travel" or even totally eliminate any "spring".

[EdK]

(02-19-2014, 08:15 AM)stevec Wrote: ... (lately anything to do with "Spring" catches my interest).
...

same here. They are saying -20F next Tuesday morning. I thought we might be done with that shite for this winter. Sorry, I'm a bit off topic here.

Ed

[Hawkeye]

Yeah, Ed. Snow in the air a couple of times today. Almost motorcycle season.

Steve, I'm keeping in mind that I can add one or both of the additional spring features if mine needs something more.

Actually, after I got home from work today, I figured I'd better take the holder for a test run. I poked through the big box of shaped 3/8" cutters that came with the lathe and picked one to try.

It has quite a bit of top rake. A simple round-nose 1/4" wide. I set the speed at 195 RPM, to suit the 1 1/4" HRS stock.
   

I got pretty aggressive cranking the crossfeed in. It's kind of scary to see your toolholder suddenly bend down and back up again when the tool digs in. I went in about 3/16".

It doesn't eliminate chatter as promised in some writeups and videos, but maybe a neutral top rake would change that. I did manage to clean up some of the chatter by feeding it in to make contact, then let it spin for a while. The flex allows it to feed the edge in gently until it's nearly clean.
   

While it doesn't eliminate chatter, I think it will be useful when I need to do some deep or heavy form cutting. I may not use it as much as the tangential toolholder, but it will be a welcome addition to the setup.

[arvidj]

Ok, resurrecting an old thread because John [Doubleboost] used a spring tool in a recent video.

Mike,

After a years of use ... or non-use as the case may be ... how would you rate your spring tool over the tangential and regular tools holders?

Thanks,
Arvid

[ieezitin]

Im interested too... been thinking about making one...

Anthony..

[Hawkeye]

As it happens, I've been using it a fair bit in the last couple of weeks. Mostly with a convex or concave form tool. Same tool - opposite function on each end. It seems to do a pretty good job when it's fed lightly for the finish cut.

I wouldn't compare it with other tooling like the tangential. It comes in handy when a cutter digging in could cause problems. The spring tool tends to release it's bite when it bends down under load. Two ways to look at it. It gives you a tool that serves a purpose. It's also a good project if you need something to make.

[Roadracer_Al]

I made one for my shaper. I clearly used the wrong material... it took a permanent bend after the first use.

I was entertaining the idea of squirting some silicone caulk into the spring gap in order to offer some damping and get the chatter down.