adjustable reamers

[ahidley]

How do you adjust aka set an adjustable reamer with an odd number of blades? How do you measure it?

[lakeside53]

Ream a hole with them, then plug gauges, then adjust then gauge... Urgh..

They are more useful for for "adjusting a fit" than setting them to an absolute value.

[randyjaco]

Lakeside got it. My suggestion would be to do a test hole on scap . If you get that right you can do the good piece. The downside is that the drilled hole will have to be very close to the final desired diameter.

Randy

[wierdscience]

Right on all counts,adjust to hole,ream,measure repeat as needed.And you can mark your calendar that if you're reaming a split bronze bushing,on the weekend with no chance of a spare,that on the last pass it will start to chatter it's arse off.

[becksmachine]

Agreed, with this addition.

Lets say you are reaming wrist pin holes in 4 connecting rods. You take the first one and with 3 or 4 iterations of adjusting the reamer, you cautiously sneak up on that perfect double grunt push fit of the pin in the small hole.

With your now perfectly adjusted reamer you proceed to ream the remaining 3 rods, and the pin falls through them all just with gravity.

What?? (Well, ok, maybe I cleaned that up a bit. )

It may or may not be obvious, (it wasn't to me the first time or three!!) the reamer cuts differently depending on how much material it/you are removing. When sneaking up on that perfect adjustment, do one hole to confirm either correct adjustment or that the hole is still undersize, then do all the holes before making the next adjustment.

This way you will be removing the same amount of material each time and results will be much more consistent.

Dave

[dave_r]

At the very least, it will wait until the last shop in the vicinity that sells that part will be closed for the day or will be closed by the time you get there.

[dalee100]

Agreed, with this addition.

Lets say you are reaming wrist pin holes in 4 connecting rods. You take the first one and with 3 or 4 iterations of adjusting the reamer, you cautiously sneak up on that perfect double grunt push fit of the pin in the small hole.

With your now perfectly adjusted reamer you proceed to ream the remaining 3 rods, and the pin falls through them all just with gravity.

What?? (Well, ok, maybe I cleaned that up a bit. )

It may or may not be obvious, (it wasn't to me the first time or three!!) the reamer cuts differently depending on how much material it/you are removing. When sneaking up on that perfect adjustment, do one hole to confirm either correct adjustment or that the hole is still undersize, then do all the holes before making the next adjustment.

This way you will be removing the same amount of material each time and results will be much more consistent.

Dave

Hi,

This!!!!! Having spent years setting such adjustable reamers for production use, consistent tool loading is critical for consistent results.

Dalee

[Doozer]

When sneaking up on something critical like that
maybe best to hone the last few thousandths.
A brake cylinder hone at worst, a Sunnen honing
machine being best.

-D

[old mart]

The more oil/cutting fluid you use the smaller the hole, wiping most off with a tissue, a little larger, and dry, largest.