General Propellers:

Break-in propellers will lightly load the engine. During the first few hours of running a new engine there is more friction between the piston, piston ring, and cylinder wall as well as all other moving components like bearings. During this time it is important to keep the heat down in the engine due to other factors such as running a large prop and flying at low airspeeds or hovering. If you don't break in the engine properly, it will never perform well. Using a small prop and keeping the plane moving is best. For gas engines, do not break-in the engine on the ground. Make sure the engine runs reliably first! This can take as long as is required, but don't run the engine on the ground in an effort to break it in. There is not enough air to cool the engine. Glow engines have 20% oil in the fuel which cools the engine tremendously. Gas engines don't use a lot of oil, so they need really big cooling fins. That's the main reason gas engines are so heavy, they need much bigger cooling fins than glow engines do. Use a petroleum based oil for break in, then switch to the more slippery synthetic oils later. Synthetics are too slippery and don't allow the parts to wear in quickly so compression will be low which causes poor idle, transition and top end power.


Keep in mind the following!

Balance the prop. Yes, they should be factory balanced, but are you going to take their word for it? Remember balancing the hub is not a big concern. Put the heavy side of the prop down when the piston is at the top so that it acts like a counterweight. Many engine manufacturers use too small of a counterweight to keep the overall weight of the engine down. The prop can help. Don't tighten the prop so much that you crush it. Neither wood nor CF can hold up to over tightening. When the prop starts to crush, you are tightening it too much. Check the prop after the first flight, and if it is loose, check it after every flight until it needs no further tightening. All that vibration will seat the prop. If the prop is loose, it is not good!

Drilling holes in the prop for the 2, 4, 5 or whatever screws can weaken the prop. The prop can fly apart, so don't let anyone stand in front or to the side of the prop when running the engine. If you run the engine in a garage, it might go right through your Ferrari, so it's best to run in out of doors. Don't throw anything into the engine (like a rag) to kill it. You could do serious damage.

If the prop has tip damage, you can sand the damage off and make it even in some cases. Balance the prop when you are finished. If the prop is wood, and it is split, discard the prop. Don't let the spinner cone contact the prop. It will gouge it.

When installing your prop, special techniques must be employed. Just tightening up the prop bolts one time won't do it! You will lose your prop on the second or third flight otherwise! When you lose your prop, you lose your spinner too!! Check out the video of a prop coming off in flight. Go to the video page.

Proper procedure for tightening prop bolts:
1) Obtain thin steel washers and place them under the heads of the socket head screws. The heads of the socket head screws without the washers will gall the aluminum thrust washer and will prevent full tightening of the socket head screws.

2) Tighten the screws a little at a time. Tightening one screw as much as possible without the others being tight will cause uneven pressure on the thrust washer hub. Tighten one screw some, then go to the screw 180 degrees from it and tighten that screw. Go around and around several times. Don't overtighten so that you crush the prop.

3) Fly the plane for 5 minutes. You can leave off the spinner cone (of course have the backplate in place).

4) Land the plane and retighten all the prop bolts. (Not too tight!)

5) Fly a standard length flight.

6) Retighten all the prop bolts

7) Fly one more time

8) Retighten all the prop bolts. If they don't move this time (they should not). Then you have two options: a) leave it alone or b) remove one screw at a time, put on some very light thread locking compound (not too strong!), and reinstall the screws one at a time. It is not necessary to use thread locking compound, but if you lost a prop before and now you are jaded, this is your extra insurance.

9) Check the bolts every once in awhile, though the prop should never loosen if you followed the above procedure.

TBM offers the following propeller types. Following is a comparison of them in general terms.

• Wood
  • TBM
  • Xoar
  • Bambula
  • MSC
  • ZDZ

Xoar, Bambula and ZDZ props look fairly similar in shape and the performance is similar as well. Whichever has the best price may be the best choice. Xoar is the largest manufacturer in the world and they offer hundreds if not thousands of unique props so if you need something exotic, try Xoar. TBM props are slightly wider so the rpm’s and noise are reduced slightly. MSC are wider still, so the rpm’s and noise are very much reduced, so much in fact, that the next size smaller prop is required in some cases and even with the smaller diameter, the noise is significantly less. Laminated props are built up from several layers of wood which makes them much harder, stiffer and stronger as well as being very beautiful looking. Laminated props are a little more expensive but a very nice option.

• Composite
  • APC

APC and a few other manufacturers offer composite props of various shapes. Many of the composite props offer similar performance. APC offers good quality at competitive prices.

• Carbon Fiber
  • Mejzlik
  • PT-Models
  • Biela
  • ZM

Most CF props are made in Europe. CF props are so highly engineered that China does not currently have the capability to manufacture them in large sizes. All our CF offerings are very high quality. Mejzlik offers narrower blades which offer more rpm and noise. Biela offers beautifully painted props which are great for a scale look. These 4 and most of their competitors offer fairly similar performance at fairly similar prices. The prices for CF props are significantly more than prices for wooden props, but the extra price is worth it for many people. CF props offer less noise, higher efficiency, longer life and better looks than wooden props.