How to balance a new Prop?

[Levahj]

Fairly new to the RC boating thing. Have been using a carbon fiber 45mm prop on a stock ESC with standard, run of the mill, twin 6cell 5000M Nimh's . Great price, fantastic hole shots, good top end from my perspective and cheap if I break it and need a new one. Also no need to balance. Kind of wondering if there really is a better prop to be honest for just recreational use.

Now for whatever reason I am feeling the need to try a metal prop now. Going with the Grim Racer 42-55 which so many folks seem to like from what I can gather. Everyone says in the forums to balance the metal props. Kintec where I purchased it, however, describes the Grim racer props as "If you don't know how to balance a prop these are as close as you can get".

So now the questions:
1. How in the world do you balance one of these tiny props?
2. If I dont balance it, what kind of performance degradation can I expect? Does the boat wobble or something or is it just a few MPH slower?
3. Is Kintec pretty much right on for saying the Grim Racer props come as close as you can get to balanced? Should I even mess around with balancing a Grim Racer prop?

Thx,
Marc

[m4a1usr]

1. How in the world do you balance one of these tiny props?
Purchase a decent or better quality balancer and read up on the how to. You only need basic tools and a very good mask for protection. From there its all about experimenting.

2. If I dont balance it, what kind of performance degradation can I expect? Does the boat wobble or something or is it just a few MPH slower?
One of the problems with anything that rotates and is not balanced is it will have a section of travel in its 360 deg travel where it wants to leave or push away from the center axis outwards. Like wise in another section it will want to be forced inwards towards the center. Both of those areas of imbalance will cause friction. These are called parasitic forces or wasted energy regions of travel. They cause heat, wear on bearing surfaces and reduce available power.

3. Is Kintec pretty much right on for saying the Grim Racer props come as close as you can get to balanced? Should I even mess around with balancing a Grim Racer prop?Jan is right on the money. Out of the package they do seem to be of much better quality then the same from Octura. But they still should be balanced. Something to always remember is most of us use a gravity or static balancing method. That is about as primative method there is to balance anything. A dynamic balance is one step better but that system is relatively expensive to setup. And for the bulk of us static will suffice as its adequate

Thx,
Marc

Now some comments from my own experience with Grim props is that they all seem to have extremely thick blades. I mean thick when I say thick. To maximize performance out of any prop you need the blades to be thin or as thin as possible. That requires you to feather them out. You can leave them thick at the hub but not at the tip. ABC or Grim props are very nice but to make them great you will need to cut them a bit. So for the sport boater and novice the Grim makes sense to buy for a "out of the package" bolt on prop.

John

[ms71171]

Few more tips since I just started sharpening and balancing props myself.

1. The prop balancers are 20 bucks or so. All hobby shops will have them since they are multi use for rc plane props too.
2. As you spin the prop on the balancer you will see an obvious heavy side since it will always stop lower then the other blade. Mark the heavy blade with a marker. Then, take a small file or sandpaper, or even an Emory board to take material off the back part of the blade only! The back is the side of the prop that faces the boat. The pushing part of the prop faces the water and I've read that you don't want to file this side ever.
3.to sharpen the blade use consistent angled filing from the back of the blade following the curve of the blade around, but don't file any off the flat back edge of the blade - forgot the name, but it's the opposite side of the blade edge the hits the water.
4. To polish, just get some jewelers clay or Dremal makes a polishing compound and either hand polish or use a dremel tool until it has a satin, but not shiny surface.

I've had good results on the 3 props I've done so far. It's definitely a learning experience.

[bwells]

The Kintec balancer is what I have and seems great, 30 bucks I think. I did 3 props and it took a long time. My next load of 3 Octura props I sent to Egneg, ( I know cheating) but it seems to be the way to go. I still fine tune them now and again but it is deffinatley an art. Not familiar with Grim or ABC but with a good file, balancer, and sand paper you should be able to get it balanced,oh and TIME. As far as running a prop that is not balanced, I would assume it would ruin your strut, outdrive or the attachments to the hull. My 2 cents