Adjustable Reamer Question

[Joe_CNC]

Can anyone recommend a brand or source for decent adjustable reamers? Most of the ones I have tried in the past have yielded poor results compared to fixed diameter tools.

Thanks,
Joe

[HuFlungDung]

Joe,

Are you talking adjustable hand reamers, or expansion chucking reamers?
IMO, the adjustable hand reamer is only successful when used with a pilot or some other means of guiding the reamer straight into the hole. Otherwise, they often gouge, seize or generally ruin the start of the hole. Worse yet, they often set up a chatter pattern that is impossible to get rid of.

It can be a lot of trouble to make pilots of every conceivable size, but the results can be quite pleasing when this is done.

[caitolly]

Joe,
There are at least two, that I know of, expansion/adjustable reamers out there.
One style, usually with replaceable blades, are more suited to reaming bushings and the like, to a precise fit when size needs to be modified during assembly or out in the field. It's usually tough to get consistent results with a tool that has variables.
The other reamers are designed to expand the cutting diameter for "regrinding" to original diameter when it becomes dull and worn out, they are not designed for producing holes of larger or varied sizes.
caitolly

[caitolly]

P.S.
an excellent, but sometimes pricey source for all types of quality tooling is www.mcmaster.com
I have never recieved anything but top of the line quality from them.
caitolly

[Joe_CNC]

Originally Posted by HuFlungDung Joe, Are you talking adjustable hand reamers, or expansion chucking reamers? IMO, the adjustable hand reamer is only successful when used with a pilot or some other means of guiding the reamer straight into the hole. Otherwise, they often gouge, seize or generally ruin the start of the hole. Worse yet, they often set up a chatter pattern that is impossible to get rid of. It can be a lot of trouble to make pilots of every conceivable size, but the results can be quite pleasing when this is done.

I'm looking for an adjustable reamer that could be varied about +/- 0.005" to fit irregular bushings.

I was considering McMaster part number 2987A32 and the optional reamer pilot.

- Joe

[HuFlungDung]

There is one other type of adjustable hand reamer made. It does not have removable blades. It has a slotted body, a pilot diameter at the lead end, and a tapered expansion bolt that forces the cutting flutes to "belly outwards" when the bolt is tightened. These are excellent hand reamers, but only come in common nominal sizes. You can only get maybe .005" or so expansion in a 1" diameter reamer, because the slots in the reamer body are blind because they stop behind the pilot.

If you are working with standard sized holes, this would be worth getting hold of. See the MSC Industrial Supply catalogue, 2003/2004 edition, top of page 197.

[JFettig]

HuFlungDung, I have used one of these, they are quite nice, one thing is to make sure not to try to chuck them up in a machine, they will typically break into many peices. Or at least thats what I am told by a few machinists at work.

Jon