Made a new 3/8" floating reamer holder using parts from the junk box, 3/8" TTS holder, old 3/8" drill chuck and self-lubricating 2" diameter Turcite-A round sandwiched in between.
DonAttachment 415224
Made a new 3/8" floating reamer holder using parts from the junk box, 3/8" TTS holder, old 3/8" drill chuck and self-lubricating 2" diameter Turcite-A round sandwiched in between.
DonAttachment 415224
Interesting! I always thought reamers were for precision holes, where the possible runout of a chuck would get in the way?
A reamer will follow an existing hole, and you want it to float to be able to do that.
Jim Dawson
Sandy, Oregon, USA
The idea is for the reamer to float with about +-0.010" of X-Y movement so the reamer follows the hole. I first drill a hole with an undersized drill then using a single point tool in a boring head open the hole to about -0.010" and finish to size with the floating reamer. These holes are then used to locate my part in a fixture held with 3/8" internally expanding XYZ pins. https://www.miteebite.com/products/m...xpansion-pins/
Don
Attachment 415246.
Again, interesting! Learn something new. I've always been using reamers right after drill without re-clamping the part, so they are as coaxial as possible. This is an interesting other possibility, especially if I somehow need to re-clamp the part between hole making and reaming!
Yes, why wouldn't you? :-D
The floating reamer holder on my 1100. Why the Kurt D688 was mounted on a subplate with no Y-axis overhang. Used all 10.5" of Y-axis travel and 8.75" of the 8.8" opening of the D688 vise.
Don
Attachment 415388
Nice. Looks very stretchy :-)
How much of the Z did you have left?
Sketchy really. Sounds like trolling. Enough Z -axis travel to run the program, change tools, and make the holes. Do you need more?
Don
"Clearance is clearance." All you need is a few thou :-)Do you need more?
My point is that it looks like a nice way to get right up at the limits of the machine. Just curious about how close, exactly, you managed to get!
I guess it's true that "Great Minds Think Alike." I use a very similar set up to ream the chambers on the rifle re-barreling projects I do on my own rifles. I found that the Tormach 3/8" tool holder fits the bore of my lathe tail-stock just loose enough to be able to use it as a "Floating Chamber Reamer Holder." As luck would have it, my home made barrel nut wrench fits right onto the outside diameter of the same Tormach tool holders so it give me a secure handle to guide my chamber reamer right down the center of my barrel-blank's bore.
I'd be interested to see exactly how the front section and the rear section of your setup fits together. My set up just floats inside the bore of my tail stock. Yours seems to be more ridged with the floating part being in the junction between the front and back parts. Is there any chance of getting you to show exactly how much movement it has in any direction? It would be nice to have a slightly more rigid setup like yours with just enough "Float" to allow for my reamer to self-center.
MetalShavings
I milled two slots with just enough radial play for +- 0.010" of float for the 1/4" SHCSs
Don
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Just out of curiosity, what is the reason to bore then ream as opposed to just one or the other?
I bore first to be sure that I have a straight hole located in the right position. I you just ream a drilled hole, the reamer will likely follow the axis of the drilled hole which may or may not be straight or true. The reaming after boring is done to size the hole on the axis of the bored hole. The floating reamer holder is used to compensated for any runout in the system. This includes spindle bearing runout, spindle taper runout, toolholder runout and even the runout between the shank and the cutting end of the reamer.
If you ever get into chambering rifles, you will find that the difference in a good chamber (accurate rifle) and a poor chamber is a floating reamer holder.
gary
So the sizing is that much better with the reamer? Naive me figured if you could bore to within .010" you could just dial it right to size and be done with it, but then I'm rarely trying to hit a hole within +/- .0005", so I wouldn't know!