Prop. Sizing.12X6
 

I have a OS .61FX that i am fitting with a 12X6 APC prop. The hole on the prop is too small, what is the prefered way of opening the holes up? Should i just get a drill bit, i've seen people use a graduated reamer also. Thanks for all your help and advice.

RE: Prop. Sizing.12X6
 

That reamer is by far the simplest, most economical way to do it. There are good reasons the majority of flyers have one in their flight box.

There are a couple of brands, both work perfectly. Any LHS will have one or both brands. They come in SAE and metric. The SAE one is what you'll need for the OS.

Don't lock yourself into just one brand of props or just one dia/pitch. I'm using a couple of different props on the two OS61 models that're getting the most use right now. One's a Yak 54 and the other is an Extra 260, both about the same size. However, one is heavier than the other and flies better with a different pitch.

RE: Prop. Sizing.12X6
 

The 12X6 is just what i happened to have around the house. The manual says that it can handle a 13X6(so i figure bigger prop, more thrust). Next time i go to my lhs i plan on getting a wood 13X6 just because i think that i would look good with the custom cover job i just finished on my Tiger 60. Are there any brands of prop that i should look for? Any i should Avoid?

RE: Prop. Sizing.12X6
 

i just bought a reamer and I wish I had bought it earlier. Waaaaaay easier than drilling out the hole.

RE: Prop. Sizing.12X6
 

Use a prop reamer to enlarge the holes in a prop. The proplem with using a drill to enlarge the hole it's too easy for the bit to wander as the bit drills out the hole which will result in the hole being off center, which will throw the entire prop out of balance. By using the reamer to enlarge the hole it will stay centered and keep the prop balanced. You can possibly use a drill if you can use a drill press and firmly secure the prop so that it can't move as the hole is drilled out. But if you don't have a drill press use the reamer.

Ken

RE: Prop. Sizing.12X6
 

Sounds like Ken has used my drill press before!!:eek: Talk about junk!! I have a couple of reamers of both metric and sae, there is always one in my flight box. My prop box has a lot of different makes but APC has won out on my glow engines. In wood props I started using Xoars and don't even bother with any of the cheaper wood props.

RE: Prop. Sizing.12X6
 

Hint, when using a prop ream tool, hold the tool stationary and rotate the prop for a straighter and better centered hole. Start from the back/engine side to get the best start.

RE: Prop. Sizing.12X6
 

I know the OS manuals list some pretty big props but the engines do not always like them very much. My Thunder Tiger 61 could not handle a 13x6 TopFlite wood prop. It worked "ok" with a 13x5 TopFlite and very well with an APC 13x4W. You just have to experiment until you find what YOUR engine and plane like. Luckily these props are fairly inexpensive. I can't imagine experimenting a lot with big props.

RE: Prop. Sizing.12X6
 

For drilling out prop holes I use these bits that have a 1/4 inch pilot bit:

http://bennettbuilt.com/page9.htm

They work great with a drill press.

Bruce

RE: Prop. Sizing.12X6
 

Please balance the prop after opening out the mounting hole by either method. Your engine may not say so but it will love you for it. I speak for the legion of damaged crankshaft bearings.

A handheld prop balancer will do.

RE: Prop. Sizing.12X6
 

I've used a great planes $2.99 hand held balancer after my LHS convinced me to buy one. Amazingly, they were right. I've yet to own a stock prop that was acurately balanced from the manufacture.

RE: Prop. Sizing.12X6
 

:):):):):):) My old basic flight instructor though removing the price tag was the only thng needed to balance a prop. Today at the field I met one of the new guys and the sticky part of the tag was still there on his prop, just brought back some good memories. DJ, there is one size APC prop that I keep running into that is always in good balance, I just can't remember what one!! Always nice to run into it though. If you take that finger balancer you can cut a CD or disc in half and mount the two halfs in a flat piece of balsa and set it in the holes, shazam, it's even better then holding it with your hand. I made one years ago but my basic instructor got a nice GP balancer for Xmas, it ended up in my flight box, he still uses the remove the price tag way to balance.