Warpdrive Prop Setting

[SkySteve]

I guess I've lost it. I'm doing some prop adjustment on my Warpdrive prop using the Warpdrive protractor. There are so many numbers on the protractor and it's been a long time since I used it I can't remember for certain if I'm doing it right. Here are two photos. The first photo is of the blade that has the protractor on it. That blade has been leveled. The other photo is a close up of how I have the protractor set. Mickey's little white hand is on the "0". Mickey's big grey hand is on the "20", if that helps. I am wanting to set the prop blade at 20 degrees. So the question is: Am I good to go, or am I all screwed up?

http://i237.photobucket.com/albums/ff12/KitfoxSteve/DCC570F9-6121-4703-8471-39C69D1C0873-10976-000011B363F3D80E.jpg

http://i237.photobucket.com/albums/ff12/KitfoxSteve/52A91046-1DF0-4AF4-B674-E281A1DA7ACC-10976-000011B36F522A24.jpg

[GT280flyer]

That reading will work if your prop hub is 0 degrees vertical. If not 0 degrees vertical you must first place the back of the degree gage on the front of the hub and zero the gage, eg. level the bubble, then add your 20 degrees to the outer grey scale reading taken from the hub surface.

[t j]

Steve,
If you held the protractor against the hub with the white bar in your hand and the opposite side against prop hub, then rotated the white ring to set the bubble to level first, then rotated the white ring the number of degrees you want, then placed the protractor on the blade and rotated the blade to level the bubble, and read the same side of the protractor each time, you are good to go.

If your starting point (protractor against the hub) was zero, you have 20 degrees of pitch.

[SkySteve]

GT & Tom,
Thanks. I think I'm good to go. The prop hub was leveled vertically first, i.e. the bottom of the plane sits horizontally level. Next I leveled one blade horizontally. Then set the protractor to the 20 degrees and attached to the outside edge of the horizontally leveled prop blade, as in the photo. Then rotated the blade to level the protractor bubble. This was done with each of the three blades. Each of the 4 blade bolts were torqued to 120 in lbs, re-checked and adjusted 'till each blade was correct and all three sets of 4 blade bolts were equal. Finally torqued the six hub bolts to 175 in lbs.

[GT280flyer]

Steve, sounds like your in good shape. It is best to set your protractor inner scale to 0 degrees with 0 on the outer scale, lock the scales together, then again set the back side of your protractor on your prop hub to be sure the hub is in deed at 0 degrees, eg. level bubble on protractor.

[SkySteve]

GT, Thanks for the explaination. Yes, that's what I did. I'll finish my annual inspection, then go fly the thing and adjust ... adjust ... adjust to fine tune to the sweet spot!!! Sure wish us Sport Pilots could use an IFA system.

[avidflyer]

Don't know if I ever posted these pics here, but I built a tool that helps to adjust the prop blades to a very accurate setting. It uses a lazer and I usually shoot it accross the hangar and make a mark on the wall with the first blade, and then line the other blades with that mark. If you want to be at a certain setting in degrees, you can set the first blade with the protractor, and then match the other blades to it. I also built a tool to twist the blades easier, don't have a pic handy of it. I'll try to get one tomorrow. Take care, Jim Chuk

[SkySteve]

AvidFlyer,
Now that looks like a pretty interesting set up.

[avidflyer]

Here are a few pics of that prop wrench that I mentioned in an earlier post. It really helps to turn the blade with out haveing to have every thing so loose it doesn't want to stay in place. Take care, Jim Chuk

[SkySteve]

Thanks, Jim!

[chefwarthog]

I really like the lazer set-up, it's much more precis then a bubble level, and by projeting the beam of lazer on a long distance you divide you error by the lenght to the wall...... way much pricise then the direct bubble!! but if the lazer could has 2 beam... one on the floor to set the verticality of the blade and the other for the pich angle..... how do you set the vertivality of the blade with your rig Jim?

[avidflyer]

That pretty well takes care of it's self. The lazer line will move horizontally on the wall with twisting the blade. That same line will move vertically by turning the blade. If you look at the first picture I posted of the lazer attachment, you can see the lazer line on the far wall. Look just a bit lower and to the left of the lazer and you will see a red line on the wall. If a lazer shot just a point, it would probably be better. (some do) This one trys to put a line on the wall. I just use the bright end at the start of the line to hit the target. Take care, Jim Chuk

[chefwarthog]

Ok by swing the blade clock or unclock the beam travel up and down... by rotating the blade on his axe, it's monving the edge of the beam front and back.... I understend!;)

I remark that your rig sit on the surface of the blade in contact on the tree head screws to prevent warble... :D

And what give you the degree you are at?

[avidflyer]

If I wanted to start as a certain degree of pitch, I would use the protractor on the first blade and then set the other blades to it with the lazer. If I just wanted to dial in a little more or less pitch, I might just guess at how much to twist the first blade using the lazer. (LIke I did last week) I wanted a bit better climb, so I just gave it a guess and went for it. If I had used the protractor, that would have been a guess also. I'm not sure how much one degree difference would make on the RPM. And in the end, that's all that matters anyway. What RPM are you wanting the prop to turn. (Usuallly static RPM with the plane tied off) Hope I answered your question. Jim Chuk

[chefwarthog]

Yes Jim, I had received it, loud and clear!!! :D

It's been few years that I follow discussion on this Forum, putting posts, asking questions, before 2008 I did not know much about aviation.... And there are a lot to learn and assimilate, but thank's too you guys, to have the patience and enthusiasme, to answer my question!!!;)

[styree]

I realize this is a very old thread, but seemed like a good starting point. I have a 912ULS w Warp Drive 70" 3 blade. What is a good starting point twist and what is your typical final to use? I have seen/read anywhere from 11.5 to 15. Just looking for some addl feedback before I go out there and start changing everything. I am currently setup at 12.

Thanks

[patrick.hvac]

I realize this is a very old thread, but seemed like a good starting point. I have a 912ULS w Warp Drive 70" 3 blade. What is a good starting point twist and what is your typical final to use? I have seen/read anywhere from 11.5 to 15. Just looking for some addl feedback before I go out there and start changing everything. I am currently setup at 12.

Thanks


I have the same combo.
When I started with 12 I was capable of overshooting max rpm, static.
You will need to test yours and find the spot you want without exceeding limits.
I landed at 14.

[avidflyer]

As I understand it, a static RPM of 5300 is a good place to be with the 912. More RPM will be better climb, and less RPM will be better for cruise speed. What is your static RPM now? JImChuk

[styree]

As I understand it, a static RPM of 5300 is a good place to be with the 912. More RPM will be better climb, and less RPM will be better for cruise speed. What is your static RPM now? JImChuk

I'd love to share my RPM, but the really super awesome and inexpensive JPI EDM-350 I bought is "having trouble" figuring out what the RPM actually is.

[avidflyer]

Unless you have a readable tach, every thing is a guess, I would say. JImChuk

[styree]

Unless you have a readable tach, every thing is a guess, I would say. JImChuk


LOL, I should have clarified. I am "on hold" until I get the tach issue resolved. Should be this weekend, I hope.