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BalanceMaster testing

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Danny (Dan3111) bought a BalanceMaster for the Rotax 912 and we drilled it to suit and did some tests today. The unit does actually work and quite well. We used my Dynavibe balancer to check his prop balance then we fitted the BalanceMaster and redid the tests. The video shows the differences. It is quite substantial. It was showering today and after fitting the Balancemaster a car was parked in the way of where we were and the sun was affecting the readings at 5000 rpm. But there is well enough data to show a huge improvement. We will do some more testing again when I get one in for my engine as well and will refine the method and also the video

 

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V interesting, Mark.

 

Why does the tester not show the true rpm?

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Hi Bob

 

The RPM shown is the propellor RPM not the engine RPM as the balancer uses a reflective strip which all it wants to know is where in the 360 deg the prop is so it can determine where to add the weight to offset the imbalance. You usually place the reflective strip on the back side of the spinner

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Guest nicephotog

When you balance it, how will you attach a counter weight?

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To use the balancemaster itself you just bolt it on. If you are using the Dnyavibe to do a normal balance I use stick on lead weight on the outer lip of the spinner back. If you dont have this most people use washers under the spinner cap holding screws

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Great work Mark , Danny sent me a couple of youtube clips about 'balance beads', used in tyres , to understand how it all works . Amazingly simple once one understands the process.

 

I don't think it can ever be perfect though, because of the ' hunting ' gearset used in the gearbox . That means any imbalance in the engine will be in a different place at the prop shaft every engine revolution .

 

I suppose an extra Balancemaster mounted to the engine flywheel may take care of that .

 

cheers

 

Jim G

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Mark:

 

Thanks for posting that video. I had been considering buying one of these for a while, but had never seen anything like what you posted here with actual measurements.

 

Were you able to notice the difference before and after through the feel of the airframe?

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Scott it will only be noticeable when you fly it as the aircraft bounces around on the ground a fair bit at cruise power. Danny hasnt had a chance to fly it yet as you know the weather has been crap

 

Bones thats the general idea of course. The amount of mercury in the balancemaster is not a lot so can only do so much of course.

 

Jim I think one of the flywheel would be good as well. I think Danny is considering it.

 

When we get another in I will fit it to the girlfriend and do a far better video with proper camera and do a far better job on the video. It at this stage seems a worthwhile investment

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There maybe a deal being done with the Balancemaster guy :) so stay tuned but of course you can get them direct from BalancMaster in the USA but freight will probably be expensive...

 

The one we have tested is apparently for a 2 stroke its a bit too small for the 912 engines. The one with the slots is for the 912 it is larger and of course will have more force . Interestingly the guy tells us that you actually should remove all the weights from your dynamic balancing and just use the ring. The reason is actually making sense to me as well. When you do a dynamic balance like when using the dynavibe it is ACTUALLY only for the RPM you do it at. When the engine is doing a different RPM through the ranges the actual balance is different and I know this is true with other types of balancing I have done like on my balancer for turbine engines we use. So when these larger ones come Danny and I will do some more testing and also make a much better video as well with a proper camera and try to document it lot more. Danny flew his Savannah this morning with the Balancemaster fitted and it definately has made a difference he thinks. Certainly at the 4500 to 4800 rpm where he had vibration and a lot of Rotax seem to have it. So in a few weeks we will egt back into it and have a lot more definative results including looking at fitting one to the flywheel side as well

 

Mark

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Mark:Thanks for posting that video. I had been considering buying one of these for a while, but had never seen anything like what you posted here with actual measurements.

 

Were you able to notice the difference before and after through the feel of the airframe?

I've been using one on my Drifter for a while. Yes, I noticed a big difference. I borrowed Marks Dynavibe and and dynamically balanced it , which made an improvement, but the BalanceMaster improved it further and throughout the range.

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Mick....Old mate in the USA says not to balance it dynamically just use the ring. So when we get the bigger ones in we will do tests both ways and see. Of course when actually flying its a subjective a little bit. Danny said he really felt the difference at full power on climb out today. The Balancemaster guy said also and its pretty obvious that the faster you can turn it the better it will work. But even with the original dynamic balance being in different spots at different RPM then in theory the BalanceMaster should be counteracting that I suppose it just depends on the lag time to get the mercury to the different spots. Anyway we will see in a few weeks:)

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Mick....Old mate in the USA says not to balance it dynamically just use the ring. So when we get the bigger ones in we will do tests both ways and see. Of course when actually flying its a subjective a little bit. Danny said he really felt the difference at full power on climb out today. The Balancemaster guy said also and its pretty obvious that the faster you can turn it the better it will work. But even with the original dynamic balance being in different spots at different RPM then in theory the BalanceMaster should be counteracting that I suppose it just depends on the lag time to get the mercury to the different spots. Anyway we will see in a few weeks:)

I did read that, but I'm working on the principle that it can't completely negate vibration, just reduce it, the less it starts with, the less I should end up with.

 

I will be interested in your further testing.

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I thought Bob Keen at Dalby was an agent. See Balance Masters Australia on FB.

 

Wayne

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Great work Mark , Danny sent me a couple of youtube clips about 'balance beads', used in tyres , to understand how it all works . Amazingly simple once one understands the process.I don't think it can ever be perfect though, because of the ' hunting ' gearset used in the gearbox . That means any imbalance in the engine will be in a different place at the prop shaft every engine revolution .

 

I suppose an extra Balancemaster mounted to the engine flywheel may take care of that .

 

Jim....you said it right. I had a Balance Master on my prop shaft, didn't notice much difference, then installed one on the mag side (as recommended) much smoother!

 

cheers

 

Jim G

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Is Balance Masters Australia still selling these, saw something on the Australian Securities ASIC site about Balance Masters Australia deregistering the business name in 2017?

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I have no idea Alf. Possibly not with the de-registration. My mate is dealing with the guy in the USA and he is bringing them in at the moment. So I would say that the guy doing it before probably is not the agent/importer anymore. I have the 180mm one I am going to fit this weekend hopefully and do another video. The one I drilled and we tested on Danny's plane was the 170mm one mainly for 2 strokes. This new one has the slots in it. I had to make up a spigot to align it on my bolly hub

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I have no idea Alf. Possibly not with the de-registration. My mate is dealing with the guy in the USA and he is bringing them in at the moment. So I would say that the guy doing it before probably is not the agent/importer anymore. I have the 180mm one I am going to fit this weekend hopefully and do another video. The one I drilled and we tested on Danny's plane was the 170mm one mainly for 2 strokes. This new one has the slots in it. I had to make up a spigot to align it on my bolly hub

 

Thanks Mark

 

is your mate bringing them in currently as I’m after a couple for 912’s myself 

 

I have emailed them in the states also

 

is your mate bringing them in for buyers here and if so what cost in country

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I cant seem to message you on this new system....email me   [email protected]  and I will send you his number

 

I just clicked on your avatar and it gave me the option of sending a message. Don't know whether this helps, Don

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