making a bigger mill drawbar hammer/wrench

[Clark]

I bought this, but it is too wimpy
http://www.use-enco.com/1/1/34975-in...-drawbars.html

So I drilled and tapped for 3/8-16, instead of metric, and attached a 2 pound brass head.

Now it knocks loose the heavy R8 Tools.

[PaulG67]

I think you need to clean your spindle, Or do not make them so tight. It should not take a two pound hammer to knock out your collets, certainly doesn't with mine, I tap it with the wrench I loosen it with.

[Clark]

The collets with end mills come right out, but not the heavy tool holders or chucks. I thought it might be my R8 Glacern chuck that had the same problem with my Rockwell mill. But this is a Bridgeport and I just got an Albright keyless with integral R8 this week and is it stuck to a light hammer but comes out with a very light tap from the heavy hammer. I weighted the draw bar and chuck at 4.5 pounds, but the threshold of easy removal seems to be two pounds. It might be like a momentum ball toy. That is the two pound hammer hits the two pound draw bar that hits the two pound R8 integral chuck.

[tim338]

It is also hard on the spindle bearings to have to pound out the collets or tooling.

[Clark]

Would it not be harder on the spindle bearings to hit the draw bar without enough mass to move the chuck?

I know if one hits a boat trailer wheel hub with seized bearings with a hammer that weighs less than the wheel hub, the hub will peen over and not come off.

When I was a kid in the 50s and my father was chief engineer of a gun designing operation, he said to me about collisions, "Calculate momentum. Energy will take care of itself"

[44man]

I use a HUSKY plastic hammer to knock my R8 loose. One tap does it. Do not tighten the draw bar too tight.

[danski26]

Huh....a tap with the wrench works on my Bridgeport and my mill/drill.

[country gent]

we had this problem at work with some "Soft" after market collets. Tapers can lock together with proper fit and be hard to release if drawn together to tight. Solid forms on drill chucks, boring heads, and other tooling can be worse for locking up tight. We had air powered draw bars on a few of our mills but mostly used quick change tooling. Check the pin protrusion in the spindle to long can cause binding. I also loosenned the drawbar about 2 turns and a quick tap with the wrench released it. Even the bigger cincinattis and milwalkees with the 40-and 50 taper tooling released quick and easily with a light tap, given some room to move.