Mejzlik prop balancing...
12-07-2005, 03:53 PM
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Mejzlik prop balancing...
Okay, so I watch the prop balancing video and take a few notes and go out and try to balance a Zinger 24x12 for practice. Using the GP Magnetic balancer, I start by balancing the prop blades to where it sits horzontally no problem. Then, I go to balance the hub. I start by placing the blades in the 11/5 or 1/7 position to determine which side of the hub is the heavy side. I figure it out and place some velcro on the hub and it works out perfectly.
Now, I try and do the same process on a Mejzlik 22x8 and 22x10 CF prop drilled for a DA50. I balance the blades so the prop remains horizontal (didn't take much) and now move on to balance the hub.
So I place the blades in the 11/7 position and the high blade falls towards the ground and seems to pick up acceleration in doing so and I figure, bingo, the heavy side of the hub. Just for giggles, I take the "light" blade and put it in the 1/7 position and let go and now that blade falls towards the ground and seems to be accelerating as it does so. I try it again turning the prop around, using different surfaces, and the outcome is still the same. There's no wind in my garage.
So, I try the other CF prop and bingo, same thing happens. How come I can balance a wood prop and not the CF prop?
Jon
Now, I try and do the same process on a Mejzlik 22x8 and 22x10 CF prop drilled for a DA50. I balance the blades so the prop remains horizontal (didn't take much) and now move on to balance the hub.
So I place the blades in the 11/7 position and the high blade falls towards the ground and seems to pick up acceleration in doing so and I figure, bingo, the heavy side of the hub. Just for giggles, I take the "light" blade and put it in the 1/7 position and let go and now that blade falls towards the ground and seems to be accelerating as it does so. I try it again turning the prop around, using different surfaces, and the outcome is still the same. There's no wind in my garage.
So, I try the other CF prop and bingo, same thing happens. How come I can balance a wood prop and not the CF prop?
Jon
12-07-2005, 06:47 PM
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RE: Mejzlik prop balancing...
you have to balance the prop at the 9 and 3 o'clock postion first, once the prop balances there...your halfway done. Now the prop is balanced horizontally...now to check for Hub balance, Put the prop at 12 and 6 o'oclock position and see what happens...switch the bottom blade to the top now and watch what happens.
It should have gone one direction..to the heavy sided Hub. Now at this point I take a strip of sticky back velcro(fuzzy side) and put it on the light sided Hub...start to add thin and thick CA to the velcro until the prop balances vertically...no matter which blade is at the 12 o'clock position. Once that is perfect..re-check the horizontal balance and spray Laquer thinner to the light blade.
should take about 20 minutes to get the prop perfect.
It should have gone one direction..to the heavy sided Hub. Now at this point I take a strip of sticky back velcro(fuzzy side) and put it on the light sided Hub...start to add thin and thick CA to the velcro until the prop balances vertically...no matter which blade is at the 12 o'clock position. Once that is perfect..re-check the horizontal balance and spray Laquer thinner to the light blade.
should take about 20 minutes to get the prop perfect.
12-07-2005, 08:55 PM
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RE: Mejzlik prop balancing...
xtra330, Do you mean laquer clear? Laquer thinner will just evaporate. BTW Polyurathane clear will do the same.
Albert Santiago
Albert Santiago
12-21-2005, 08:09 AM
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RE: Mejzlik prop balancing...
ORIGINAL: EMB145CA
So I place the blades in the 11/7 position and the high blade falls towards the ground and seems to pick up acceleration in doing so and I figure, bingo, the heavy side of the hub. Just for giggles, I take the "light" blade and put it in the 1/7 position and let go and now that blade falls towards the ground and seems to be accelerating as it does so. I try it again turning the prop around, using different surfaces, and the outcome is still the same. There's no wind in my garage.
So, I try the other CF prop and bingo, same thing happens. How come I can balance a wood prop and not the CF prop?
Jon
So I place the blades in the 11/7 position and the high blade falls towards the ground and seems to pick up acceleration in doing so and I figure, bingo, the heavy side of the hub. Just for giggles, I take the "light" blade and put it in the 1/7 position and let go and now that blade falls towards the ground and seems to be accelerating as it does so. I try it again turning the prop around, using different surfaces, and the outcome is still the same. There's no wind in my garage.
So, I try the other CF prop and bingo, same thing happens. How come I can balance a wood prop and not the CF prop?
Jon
I've done well over a dozen CF props and I only had "one" that was what I'd call prebalanced. Surprisingly the hubs were usually the worst part. I've done two where I almost ran out of room on the velcro to wick the CA into. It takes time Jon, but you'll get it.
...........Mark
01-22-2006, 05:53 PM
#7
RE: Mejzlik prop balancing...
I think I figured out what's happening. You had the prop at 11/5 (you said 11/7). As you're facing the prop, the high blade on your left fell to the ground indicating that "your" left side of the hub was heavy (you are standing in front of the prop). So you then took the "light" tip as you called it and put it at 1:00. When you did this you put the heavy side of the hub on your right. So the prop tip at 1:00 fell to the right with the heavy side of the hub as it should. Does that make sense? Your hub's heavy side switched sides so that's why the high tip always fell.
Another thing I'd like to add is that I usually first "temporarily" balance the hub by adding duct tape to the light side. I keep adding little pieces on top of one another until it balances (or a washer taped to the hub if that's what it takes). Then when it balances like that and there's no weird things happening, I balance it permanently with the velcro and glue. Also I like to rotate the prop on the cones to make sure I'm not getting false readings from the prop not sitting properly on the axle.
Joe
Another thing I'd like to add is that I usually first "temporarily" balance the hub by adding duct tape to the light side. I keep adding little pieces on top of one another until it balances (or a washer taped to the hub if that's what it takes). Then when it balances like that and there's no weird things happening, I balance it permanently with the velcro and glue. Also I like to rotate the prop on the cones to make sure I'm not getting false readings from the prop not sitting properly on the axle.
Joe
ORIGINAL: EMB145CA
Okay, so I watch the prop balancing video and take a few notes and go out and try to balance a Zinger 24x12 for practice. Using the GP Magnetic balancer, I start by balancing the prop blades to where it sits horzontally no problem. Then, I go to balance the hub. I start by placing the blades in the 11/5 or 1/7 position to determine which side of the hub is the heavy side. I figure it out and place some velcro on the hub and it works out perfectly.
Now, I try and do the same process on a Mejzlik 22x8 and 22x10 CF prop drilled for a DA50. I balance the blades so the prop remains horizontal (didn't take much) and now move on to balance the hub.
So I place the blades in the 11/7 position and the high blade falls towards the ground and seems to pick up acceleration in doing so and I figure, bingo, the heavy side of the hub. Just for giggles, I take the "light" blade and put it in the 1/7 position and let go and now that blade falls towards the ground and seems to be accelerating as it does so. I try it again turning the prop around, using different surfaces, and the outcome is still the same. There's no wind in my garage.
So, I try the other CF prop and bingo, same thing happens. How come I can balance a wood prop and not the CF prop?
Jon
Okay, so I watch the prop balancing video and take a few notes and go out and try to balance a Zinger 24x12 for practice. Using the GP Magnetic balancer, I start by balancing the prop blades to where it sits horzontally no problem. Then, I go to balance the hub. I start by placing the blades in the 11/5 or 1/7 position to determine which side of the hub is the heavy side. I figure it out and place some velcro on the hub and it works out perfectly.
Now, I try and do the same process on a Mejzlik 22x8 and 22x10 CF prop drilled for a DA50. I balance the blades so the prop remains horizontal (didn't take much) and now move on to balance the hub.
So I place the blades in the 11/7 position and the high blade falls towards the ground and seems to pick up acceleration in doing so and I figure, bingo, the heavy side of the hub. Just for giggles, I take the "light" blade and put it in the 1/7 position and let go and now that blade falls towards the ground and seems to be accelerating as it does so. I try it again turning the prop around, using different surfaces, and the outcome is still the same. There's no wind in my garage.
So, I try the other CF prop and bingo, same thing happens. How come I can balance a wood prop and not the CF prop?
Jon
02-05-2006, 10:22 AM
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RE: Mejzlik prop balancing...
ORIGINAL: Tor
Link?
ORIGINAL: EMB145CA
Okay, so I watch the prop balancing video
Okay, so I watch the prop balancing video
Here you go >
http://downonthedeck.com/videos_instruction.htm
Look for Prop Balancing 101
HTH
05-24-2006, 01:36 PM
#10
RE: Mejzlik prop balancing...
Just wanted to mention... I also used to use velcro and CA for balance. I have a DA50 and found that using AN style thick and thin flat washers under on the prop bolts is a great way to balance the blades and the hub. You must have your prop drilled so that two of the holes are inline with the blades. Otherwise it won't work. This method is also how we balance full scale airplanes when the prop is mounted to the engine. Not to be confused with off the engine zero balancing.
01-23-2009, 09:56 PM
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RE: Mejzlik prop balancing...
I stumbled on this old thread and I am now starting to balance my props mostly APC... Question? when I find the heavy blade I spray the light side with clear laquer, now the blades stay put in any position... Like 3-5, 1-7, 12-6 2-8 anywhere, does this mean I'm done If I place the blabe at 12-6 nothing happens it stays put.. The balancer I'm using is a GP magnetic and it moves freely
Greg
Greg
01-23-2009, 10:18 PM
#15
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RE: Mejzlik prop balancing...
If it stays put in all those positions, you're done! What size APC are you balancing? If it's under 20" or so, I wouldn't bother to hub balance it (Velcro method mentioned above). Tip balancing yes, but not really the hub with smaller props. Also on plastic composite hubs, you can balance them by sanding the back of the heavy blade although there's no reason not to do the clear lacquer.
