As you may have seen in my other post, today was the first day I used my new Grizzly mill the way it was supposed to be used. But I have a few questions about the R8 drawbar.
First questionHow do you tighten it securely?
When I use my 3/4" wrench to tighten the drawbar down, the spindle moves. There are some flats on the end of the quill that I could use to hold it steady, but they are wider than any wrench I own – its like 1 1/2" across flats or something. (more than 1 1/4" for sure).
Do you NEED to use something to hold the quill end steady while you tighten? Or is just snugging it up as best you can with the quill wiggling around good enough?
I used a pair of channel locks today, since that's all I had that would reach between those flats. But I don't want to mark up the quill, so I think I need to find something better. Do you guys use anything here?
Second questionI have been able to use several different R8 collets and holders in the mill, but when I went to try and use my new R8 drill chuck, it didn’t work. I tightened the drawbar as far as it would go, but the chuck still wiggles up and down about 1/8”. That doesn’t seem right.
So, I took the drawbar out and did some investigation with the R8 holders that would tighten up, comparing it to the R8 drill chuck that won’t, and here’s what I see.
It looks like the R8 Drill Chuck doesn’t let the draw bar screw in far enough to draw up tight – it bottoms out for some reason. In most of the R8 holders the drawbar hole goes all the way through, even though it is only threaded part of the way. So you can tighten the draw bar as far as is required. But the Chuck only lets the drawbar go so far, then it bottoms-out.
Here’s a look at one of the working R8 holders with the drawbar screwed in as far as it will go. Note that there is about 14.5” between the edge of the holder and bearing surface of the drawbar at the top.
And here’s the drill chuck screwed into the drawbar as far as it will go till it bottoms out. You can see that 14.5” doesn’t get you to the same place on the R8 holder.
This is a close up – you can see there’s still 1/4” to 3/8” of threads to go, but the drawbar has bottomed out.
So, it seems I need to shorten my drawbar, or I need to figure out how to make the drawbar hole in the drill chuck deeper. The second one seems hard, and I don't want to screw up the nice new keyless chuck, so I’m focusing on the first one. My first thought was to make a 1/8” wide spacer, or use a stack of washers, to move the bearing face of the drawbar down some.
But looking at the top end of the drawbar, it looks like there’s a roll-pin holding the top in place so it won’t turn. I was wondering if I could push that out and screw the hext nut on the drawbar another 1/8”or so. Then I could make a new hold for the roll pin.
Do those sound like reasonable options? Are there better ones? Any other suggestions?
Thanks for the help!
Kim
PS Are R8 collets that variable? Why don't they all fit without me having to make changes like this? Seems like they would be standard or something...