~My Motor Dyno & Du-Bro Prop Balancer~ - RC Groups
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Dec 12, 2012, 07:32 PM
"Auntie Samantha"
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~My Motor Dyno & Du-Bro Prop Balancer~

My Motor Dyno in Conjunction with the Du-Bro Prop Balancer!

I've had quite a few inquiries about my Motor Dyno that I had posted in the Servo Testers section, so I've put together the following vid to show how I use the dyno for various functions......eg: motor/prop combinations, changes in blades-pitch adjustments (VarioProp), amp/watt/kv readings, ESC timing, prop/spinner balancing, etc.

Motor Dyno (10 min 41 sec)

As I stated in the vid, I run all my full run-up tests outdoors in a safe environment! I have a big fan out there, so I can run at WOT without fear of something overheating. So far (knock on wood) I have never had any serious incidents resulting in loss of limb or equipment!

Here are the links to the testing equipment"

Turnigy Plush 80A ESC
FrSky FLVS-01 - Lipo Voltage Sensor and Display
K1 KV/RPM meter
Watt's UP meter
GWS MT-1 Multi-Function servo tester
Overlander/Neodym Multi-Function DC meter

My Modified Du-Bro Prop Balancer.

I added four 2 1/2" risers to my Du-Bro balancer so I would have clearance for props up to 20". I know, the balancer can be located on the edge of a table to balance larger props, but I preferred this method.

I didn't want to get into the process of how I balance my blades as there are several good tutorials online for that purpose.

3 Bladed Prop Balancing for RC Aircraft

HOW TO/DIY: Balancing a 4 Blade Prop on Du•Bro Balancer

The same idea can be applied to 2-4 blade 1-piece props as well. Find the un-equal side with the balancer and make the appropriate adjustments.

There are numerous methods for balancing prop blades. Some like to remove material (sand, dremel, grind) on the heavy side, others like to add material (glue, tape etc.) to the lighter side.

The first thing I do is weight each blade (individual blade props) with a scale, and then make the appropriate adjustments to achieve equality. I then mount the blades on either a backing plate or hub depending on the application, and check balance with the Du-Bro. At this point I start applying the paint to the prop tips, usually a couple of coats. If I do have a slightly un-balanced assembly, I will apply additional coats of paint to the lighter sided blades, thus reducing the amount of material I have to remove on the heavy side. So far this method has worked great for me.

As you could see in the vid, those prop set-ups with a coned spinner (P-51...etc.) can cause a whole different scenario. Once I'm satisfied with the prop/backing plate balance, I'll install the coned spinner and see where things balance at that point? If there is an issue, then I'll make the appropriate adjustments in either the cone itself or the backing plate.

Speaking of those coned spinners with either alum. plastic or even CF backing plates, they usually come with 2 prop reliefs cut out, or in most cases, no prop reliefs at all. I found this very informative DIY: How to cut a spinner for props, so check it out!

Once I'm satisfied with the balance of my prop/hub assemblies, I mount them on the motor I plan to use. I then install everything on the Dyno for a full speed run-up. If everything goes well, Amp draw, Watt output, Prop balance, then it's time to install in to the plane!
Last edited by Sandancer; May 04, 2013 at 12:15 PM.
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