CF Prop drilling

[David Shad]

Ok...sitting here looking at my first 50 dollar CF prop...and need to open the mount hole some to fit my PA 75...if it were wood or nylon...no problem for my
reamer or drill in the press...what's my best option for this one...really don't want to screw this one up...as you guys can imagine.

[Lynn Weedman]

hey David,
I use a six inch long .250 x .3125 step reamer setup in a drill press @500rpm.
Lynn  Weedman

[jim ivey]

I was thinkin A C.N.C szip jig borer ooops overkill !! Use the reamer and sneak up on it. dont get in a hurry. Ya might wanna hold it in a small vise on the  hub as well. jim

[Garf]

I had a CF prop eat up a reamer. It's as unforgiving as Kevlar.

[Bill Little]

Well, being super cautious (and CHEAP! LOL!!) I use a hand held reamer like the one from Fox..........

Big Bear

[John Leidle]

  Hi David,
   I will probably be concidered wreckless but I've drilled out several Carbon Props with my cordless motor. I start W/.260", .275", .280",.290" , .301"
 .307",  .312".    Afterwords I put it on the balancer to make sure blades are of equal length  ..working slow.
  John

[Will Hinton]

I do the same as coach Bill.  I've done several over the years, no problems.

[Rafael Gonzalez]

I wrapped the reamer (like Bill, not cheap but cautious) in sandpaper and and slowly bore to the size that fits the crank from both sides. A few years ago, I Had a MOKI 2.10 on a hanger 9 Edge. Bought a 3 bladed Boly 19-10 (~$120) the prop was gorgeous. Used a reamer to fit the MOKI crank and ended up ruining the prop! It cracked and tore fibers from the inside of the hub...Would not want to use a prop like that... the next one I sanded and it worked beautifully.  A week later on a long landing over-run in a short farm field, broke the prop on cow manure for an arresting area... No more C.F. props for me...

[Steve Helmick]

I use a step-reamer from a machine shop cutter supply store. Used in a drillpress, like Lynn Weedman. I tried a Fox-type hand reamer and got absolutely nowhere. The "Magic" (Mejzlick) props are a whole different experience than a Bolly, at least my first one.  Not really sure why, but it was almost like the hub was granite. Steve

[Randy Powell]

Hmm, I just use a drill press and a drill bit.

[PJ Rowland]

Hmm, I just use a drill press and a drill bit.

So do I.  - its just a hole.

[Ward Van Duzer]

I'm too cheep to gamble! I gave mine to Randy and let him worry about it!

W.

[Bill Little]

So do I.  - its just a hole.

Right, but in a piece of property that costs about half as much to replace as many of the "engines" I use (PAs included!!)! LOL!!  Doesn't cost me anything but time to hand ream a CF prop.............

Big Bear

[Eric Viglione]

Big Bear - I know you out-gun most of us in the "he's got big guns" department, but I'm guessing you haven't hand reamed the new Mejlik prop's yet... I'm no lightweight, and my hand is hamburger after doing one that way, and my reamer is dulled out after doing just one prop. They are tough stuff! They make Bolly's look like play-dough!

If I remember correctly, Randy suggested what he uses is a automotive .310 valve guide reamer, he can correct me here if I've miss-quoted.

(You might actually find a partially used up one in your pit crew's trash there Bill!  or at least get a heck of a deal from the tool guy)


The good news is that at least the Mejlik's are partially pre-drilled from one side, so all you have to do is complete the drilling and don't change direction.

EricV

Right, but in a piece of property that costs about half as much to replace as many of the "engines" I use (PAs included!!)! LOL!!  Doesn't cost me anything but time to hand ream a CF prop.............

Big Bear

[Will Hinton]

Not to minimize any of these posts, but I just did my Mejlik I got from Randy at last years nats with my hand reamer, and coach Bill makes me look like a pantywaist!  Patience and resolve plus CHEAP helps.

[Steve Fitton]

Wow, that's pretty studly to do a Mejlizk by hand! I tried to one at KOI two years ago, and wiped out two reamers and chewed up my hand, left hardly a mark on the prop.  I drill mine now...

[RandySmith]

Wow, that's pretty studly to do a Mejlizk by hand! I tried to one at KOI two years ago, and wiped out two reamers and chewed up my hand, left hardly a mark on the prop.  I drill mine now...

Weinnie !!   

[Bill Little]

Big Bear (snip)
If I remember correctly, Randy suggested what he uses is a automotive .310 valve guide reamer, he can correct me here if I've miss-quoted.

(You might actually find a partially used up one in your pit crew's trash there Bill!  or at least get a heck of a deal from the tool guy)


The good news is that at least the Mejlik's are partially pre-drilled from one side, so all you have to do is complete the drilling and don't change direction.

EricV

Thanks, Eric, I *think* I can come up with one of the valve guide reamers.  I *might* even put it in a drill press instead of a hand held t-bar.    You are correct, I don't think I have reamed a Mejlik prop yet, I still have a large supply of Bollys.   I can tell how I got the nick name "Mongo" from our crew chief at some other time.

As an aside, John Brookfield who was listed in Guiness as having the "World's Strongest Grip" (he has held a bunch of "World Records") is a very good and old friend of mine.  He has lots of "training tips" for developing "grip".  He gave me a copy of his book "Mastery of Hand Strength" when it was first published and it has a lot of things to do which are simple but extremely effective.  He is actually a good bit smaller than I am but his hand strength is literally "not of this world".  The things he can do with his hands are not "tricks" but are really unbelievable.

Bill

[Wayne J. Buran]

I would suggest using the proper size reamer to open the prop hole. Standard drills will not open a hole to a larger size without causing the tool to grab or drill oversize. That said if you can find the proper size 3 or 4 flute core drill you may have better luck. Spend the money on a reamer, why rip up a $50.00 prop.
Thanks
Wayne