Is there any guys out there with a 503 single ignition who can do the following test to which i can compare.
Find a solid pole or beam (corner off hanger) and put your normal bathroom scale (the one your sofness is using to constantly monitor if she can still flies with you) upright against it. Now, push against the scale with the front wheel at full revs and take the highest reading from the scale.
Make sure there's enougth ventilation in front of the trike.
Will be interesting to know what Kg you get?
Thrust Test 503
Good morning all,
We perform static run tests every time we service an engine and here are some interesting values:
Please, just don't even think of the old comments about not relevant because of cavitation....prop eff is not good at static...and so on. We do this to load the engine and compare THE SAME systems over time.
503, typical 2 blade wood prop : 96 - 105 kg
582, 2-blade wood : 150 - 167 kg
Jabiru 4-cylinder, 2-blade wood : 96 - 116 kg
Rotax 914, 3-blade comp ( DUC and Arplast are so close ) 215 - 225 kg
Trust me, you learn a lot by measuring thrust before and after. By just balancing a prop Dynamically to below 0.1 IPS gives about 5 kg more thrust within about 10 - 20 minutes..
Regards
Wagtail
We perform static run tests every time we service an engine and here are some interesting values:
Please, just don't even think of the old comments about not relevant because of cavitation....prop eff is not good at static...and so on. We do this to load the engine and compare THE SAME systems over time.
503, typical 2 blade wood prop : 96 - 105 kg
582, 2-blade wood : 150 - 167 kg
Jabiru 4-cylinder, 2-blade wood : 96 - 116 kg
Rotax 914, 3-blade comp ( DUC and Arplast are so close ) 215 - 225 kg
Trust me, you learn a lot by measuring thrust before and after. By just balancing a prop Dynamically to below 0.1 IPS gives about 5 kg more thrust within about 10 - 20 minutes..
Regards
Wagtail
Hey Tower....this "113Kg beast", do I make him hang on the prop before starting or does he grab it at 6000RPM. 
Wagtail, the first test I’ve got 85Kg, then a few days later after fitting a new air filter and main jets (150's) could only get 55Kg. Now where do I start? (Got a 2blade Geo Kelly) Does someone perhaps have another spare prop that I can borrow to test? If it lifts me I'll buy it!
Made 2 failed take-off attempts on Friday
(one up, zero wind, QNH 1021)
Wagtail, the first test I’ve got 85Kg, then a few days later after fitting a new air filter and main jets (150's) could only get 55Kg. Now where do I start? (Got a 2blade Geo Kelly) Does someone perhaps have another spare prop that I can borrow to test? If it lifts me I'll buy it!
Made 2 failed take-off attempts on Friday
(one up, zero wind, QNH 1021)
Good morning,
While I am in the country and the e-mail is working, I will answer a few questions.
We are located between Sasolburg and Parys on a Private airfield. Coordinates : S 26 53.585 E 027 41.337
Gravel strip of 1400 meters CAUTION there is a "road" crossing the runway and from time to time the fence is pulled up to allow the cattle to pass. Please do a proper low level pass to inspect. The fence is at the 700 meter mark and the road is very clear.
Next, relationship between Hp and thrust. This is a potential can of worms. There is a basic formula calculating kg thrust in relation to Hp, blade diameter, rotational speed, air density and a few constants. The relationship between Static thrust and Hp is even more difficult because of the effect of the Prop constants. Bottom line, the pitch of a prop has a significant effect on Static thrust and remember we are not flying on Static thrust, so a lot of people have negative comments about the value of performing static thrust comparisons.
Dynamic Balancing of a typical 2-blade prop can be performed for R 400 and it can take anything from 30 minutes to 2 hours. Prior planning is required to make sure Strobe and the optical equipment is available
Regards
Wagtail
Regards
Wagtail
While I am in the country and the e-mail is working, I will answer a few questions.
We are located between Sasolburg and Parys on a Private airfield. Coordinates : S 26 53.585 E 027 41.337
Gravel strip of 1400 meters CAUTION there is a "road" crossing the runway and from time to time the fence is pulled up to allow the cattle to pass. Please do a proper low level pass to inspect. The fence is at the 700 meter mark and the road is very clear.
Next, relationship between Hp and thrust. This is a potential can of worms. There is a basic formula calculating kg thrust in relation to Hp, blade diameter, rotational speed, air density and a few constants. The relationship between Static thrust and Hp is even more difficult because of the effect of the Prop constants. Bottom line, the pitch of a prop has a significant effect on Static thrust and remember we are not flying on Static thrust, so a lot of people have negative comments about the value of performing static thrust comparisons.
Dynamic Balancing of a typical 2-blade prop can be performed for R 400 and it can take anything from 30 minutes to 2 hours. Prior planning is required to make sure Strobe and the optical equipment is available
Regards
Wagtail
Regards
Wagtail
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