Reaming Holes

[louckswayne]

Hey Guys
At what stage is best to ream the holes in aluminum changer finger, and how much
undersize do we drill to allow for reaming? Also, would the procedure be different
for doing the steel wraparound fingers?
Any help here would be great!
Thanks
Wayne

[mac639]

Why would you want to ream the holes? Shouldn't a 1/2" axle fit in a 1/2" hole? Or a 3/8" axle in a 3/8" hole? If the hole is a smidgen small just spin the axle with a drill etc. and sand it down a tiny bit.
Cheers,
Mac

[louckswayne]

Thanks Mac
I quess i thought that you would ream but if it isnt required then thats great!
I plan to use 1/2" drll rod for my axle.
Wayne

[azureskys]

A ream is to clean up the hole you drilled of any burs , sometimes a dril bit will leave a rough finish , a ream will clean that up . Russ

[louckswayne]

Ok Russ
Thank you!
Wayne

[Bent]

Wayne, my experience seems to be that any drill makes a slightly undersized hole. I just made 3 sets of changer fingers in brass with 1/2" holes They all fit too tight on a 1/2" shaft. So I had to go and buy a 1/2" reamer for $27.- an dream out the holes. It worked wonders. Now the fingers rotate freely on the shaft without any detectable play. Also, like Russ says, it will deburr the holes too.
Another thing I found reamers a valuable tool for: I fitted my pedals with 3/8"OD, 1/4"ID oilite bushings. I wanted these to go in with a tight fit to avoid them slipping out later. So I pressed them in with the vise. This made the 1/4" hole too tight for the shaft. I reamed out the hole and presto, now they fit perfectly.
I recommend a guy has a set of good quality reamers. Good investment

[louckswayne]

Bent
Yes i agree and they are costly, but they do a great job, and that is
what we need! As i plan to make changer parts soon i will probably
get one. I have a drill press and a belt/disc sander but i am currently
looking for a band saw before i can get started.
Thanks for giving your advice.
Wayne

[Bent]

Wayne, yes, you will find the bandsaw so valuable to your steel building. It will cut all your aluminum for you. All I have is a cheap old Busy Bee but it gets me through.
Also, you'll find the disk/belt sander invaluable. I have a neat little jig here that I used to shape the rounds on the fingers. Now I use that same jig in the mill and do the job there.

[louckswayne]

Bent
I plan to use a jig like yours for sanding the radius on the fingers. What do you find is
the best sandpaper grit for this? Would you sugest to drill and ream the axle hole
first and then saw out and sand the pc. to shape? Also, when reaming holes, i would
only ream down thru the pc. and then stop the drill press from turning and remove
the reamer! Would this be correct?
Thanks
Wayne

[Bent]

Wayne, What I did was cut out the round as best I could on the bandsaw with a 3/16" with a 10 tpi blade then put it in the jig on the disc sander table and start sanding. I believe I used 220 and 350 grit. Note that you don't really have any accurate cutting guide on the sander so you have to check with your calipers a lot. When all done with that, put all the fingers on a drill bit or something that is a perfect 1/2". then you clamp the fingers in a vise and using a long strip of sandpaper, with a shoeshine motion, you sand them all even.
As for the reamer, I use them the same way as a drill bit...plunge it down thru the hole, and back up thru and bob's your uncle