sideoftheroad

My Feedback: (2)

I bought a new prop for an OS .61 but the hole is too small for the engine. Do you guys just drill out a bigger hole?

maukaonyx

Try to use a prop reamer because it will create a centered and truer hole than using a drill. It's safer for your hands too. Jon

JollyPopper

My Feedback: (6)

Yes, and you want to get it as close to the size of the threads as you can get it without having to thread it on.

Jetdesign

My Feedback: (8)

Prop reamer.
http://www3.towerhobbies.com/cgi-bin...?&I=LXK248&P=7

tschuy

My Feedback: (1)

I find that the prop reamer in my field box gets use whenever I change props. I purchased the SAE and metric reamers from Tower and they work great.

Cheers,

sideoftheroad

My Feedback: (2)

How do I tell if I need a metric or standard prop reamer?

airbusdrvr

OS is SAE (standard). Just measure the OD of the threaded part part of your prop shaft. It is most likely 5/16 or 1/4 inch. Then use the prop reamer until you reach that diameter.

Charlie P.

Yes.

For 8mm I got fancy and bought a stepped "pilot"drill bit that I use ina drill press. Bennett Built has them down to 5/16" wit ha 1/4" pilot.

KW_Counter

Why don't I want to screw it on?

KW_Counter

Jetdesign

My Feedback: (8)

You'll have a tough time getting it off.

JohnBuckner

My Feedback: (1)

One additional reason to assure you do not screw a propellor on is if you do there will be a greater tendency spit the propellor nut, washer, propellor and prop drive bushing completely off the airplane when conditions are right. This occurs most often when starting and an over lean condition may exist with a hot engine. It also more rarely can occur in flight.

This seems counter intuitive and I am no engineer so will make no attempt to explain why but only suggest to never screw a prop on.

John

WhiteRook

My Feedback: (38)

where can i get A 7/16 Reamer ? cant find one.

Bozarth

My Feedback: (15)

I would also guess that screwing it on, and creating threads inside the prop, might prevent the prop from completely seating against the thrust washer - meaning your prop might be on crooked.

Kurt

frets24

My Feedback: (15)

A 7/16 prop shaft!! That's huge. Although my largest engine is a 2.20 glo so I may just not be up on some of the gasser stuff.

OK, so maybe not so huge.....I just checked my SAE reamer and it goes to 1/2"in random 16th and 32nd step increases startins at 3/16. Must be due to standard shaft size increments. I think it was from Tower, though I picked it up at the LHS.

winglift

My Feedback: (10)

I used to use the drill, however I discovered that often the hole is off centered. That's because of the flukes in the drill will often grab the material unevenly especially if you are using a hand drill. I had better results with the drill press, however would often have the same problem, especially with plastic or APC propellors. The reamer is the best way to go in my opinion. I have had good results from the step reamers available. I have both the SAE and METRIC step reamers. Look here: http://www3.towerhobbies.com/cgi-bin...opeller+reamer

WhiteRook

My Feedback: (38)

yep, its a quadra 100

KW_Counter

Keep in mind the prop hole on a new prop is usually 1/4"
and the shaft is 1/4 x 28. The difference is minimal.
Screwing the un-reamed prop on a 5/16" shaft would be a definite no no, if not impossible.

John,

Your explanation makes some sense.
I do occasionally take the prop nut off when starting.
Never considered that threading the prop on was the cause.

Bozarth,

My engines, OSs, the shaft is not threaded the full length, the bottom is smooth.
In addition, the metal shaft and prop nut will easily overcome the plastic threads.

gaRCfield,

Just unscrew it. I've never had a real problem taking the prop off.

Thanks all,
KW_Counter

Bozarth

My Feedback: (15)

KW - sounds like you can't screw the prop on since you don't have threads all along the prop shaft. Perfect. But don't dismiss the strength of threads.

Kurt

tacx

My Feedback: (1)

Buy a tapered reamer and quit wasting your time with SAE and Metric step reamers.

Get a tapered reamer and you always have the right size.

If you read APC Props recommendations you will see that they recommend a tapered reamer.

baronbrian

My Feedback: (13)

A tapered reamer may be convenient, but I have concerns about how to keep the reamer plumb to the face the prop without the step following the smaller hole. Also, my prop shafts are not tapered, I don't like that only a very small amount of the prop will acually be the right size when finished.

countilaw

Ii had a tapered reamer years ago. Someone borrowed it and I never got it back. Where did you get the tapered reamer?

Frank

baronbrian

My Feedback: (13)

Menards has one

countilaw

Found one here: http://www.jrhobbyhardware.com/shop/...ex&cPath=16_36

$6.00 plus $3.00 shipping.

Frank

raptureboy

I bought mine at Harbor freight. If you work it from one side and then the other the hole will be fairly consistant and once you balance it you can adjust for the hole being slightly off by weighting or shaving the hub