Cat45 taper drive slot slop

Hi all

I acquired a number of cat45 toolholders, with the intention of modifying to fit a Weldon quick change holder. The modification would involve milling 2 angled slots in the taper to receive the Weldon set screws. The drive dog on the holder is also too wide for the cat45 holder's slots, so I have A choice of whether to narrow the drive dogs on the master holder or widen the drive slots on every cat45 holder.

I would prefer to narrow the single master holder's dogs rather than have to modify many holders. Would that be a reasonable thing to do? Or would it potentially lead to any problems? Seems like there needs to be a little slop in the fit anyway, and increasing it by 0.100" shouldn't make much of a difference.

Thanks in advance for any advice offered,

Lee

Sent from my SM-N960U using Tapatalk

I did exactly what you are doing, I narrrowed the dogs on the master holder. I also built the height of them up a little with TIG before I milled them to give a little more engagement in the drive slots.

Thanks Mud,

I could have sworn someone mentioned doing that before, but couldn't remember where I'd read it. That should save some time, thanks.

How did you hold the holders to mill the angled slots? I was thinking I might be best to build some sort of fixture, as I have a few to get through.

Thanks

Lee

Sent from my SM-N960U using Tapatalk

I made a fixture, a cat holder is hard to hold well other than holding the tool end. this one I leave in the vise and just remove the bolt to change tools.
If you cut just enough off the dogs of the master holder to clear the C45 flange it will still engage the Weldon holder by a little, which is probably enough.. I wasn't worried about the Weldon holders so I cut extra. Not sure the weld is necessary but I'm a belt and suspenders guy at times.

Mud,

Thanks very much for the pictures of your setup. That's along the same lines of what I was thinking, but it helps a bunch to see it done

Lee

Sent from my SM-N960U using Tapatalk

Ok, I finally got around to making the fixture and cutting the notches in my 45 taper tools

I've taken a little bit off the Weldon master holder's drive tangs with a carbide lathe tool held in the vise. It was pretty hard - somewhere between my rc60 and rc65 hardness tester files....

I was hoping it would be softer, so I could drill and tap for a couple of small SHCS to avoid welding on the tangs. But, no dice...

Welding isn't really my forte - how do you tig something like this without worrying about warping the holder?

Or would a better option (for the crappy welder) be to just heat the tang to red hot and let it cool/anneal? Then drill and tap?

Thanks again,

Lee

Sent from my SM-N960U using Tapatalk

Leeko - Don't worry about warpage, it's so far out on the end of the tang it won't affect any precision surfaces. I just TIGed it with mild steel rod - ER70S-2

Ok, sounds good

Thanks

Sent from my SM-N960U using Tapatalk

Leeko could you post a picture of your fixture for cutting the notches? Or does it look like Mud's? I picked up a chunk of aluminum to make one, I have been collecting some cat45 holders to do the same thing!


Sent from my iPhone using Tapatalk

Grant,

I took some pictures, but they're on my other computer and it'll be a while before I can get to them. Muds design is way better than mine, though - I bolted a 45 degree fixture together from scraps I had to hand, and turned the taper into a turret lathe toolholder. It worked, but it chattered like crazy and I broke a few inserts before I realized how shallow of a cut I needed.
If I had to do it again, I'd make something like Muds...

Lee

Sent from my SM-N960U using Tapatalk