upgrade my ultrawhite

[tx_swordguy]

Ok guys I am looking for input on a couple of ideas I am kicking around. I fly a 503 powered ultrawhite with a 60" 2 blade Warp prop and 23' DWs. I have a 10 gal tank and fly off 1000' grass strip in Texas at 600' MSL. Hi temps in Aug are high 90s- low 100s. My AUW is 585-590lbs. My DWs spin at 350-360 in straight level flight at 50-60 mph. In order to maintain that I am cruising at 90% power for 6k-6200 rpm. My prop is set to see 6750 in flight so I have 500-700 rpm in reserve for climb which is slow if under 500' AGL. I am contemplating several ideas and open to others. 1. new engine pros- more power-cons- co$t. If I go that route I am considering the 670 and 582. 670 obviously more power by 40 hp, but I would need to do a lot to make it work.( prob whole new prerotator, or make a prop hub extention to move it back 3-4 " to fit the current prerotator) and I still may have to get a longer flex cable. 4 bladed prop, possibly change my yard arm to the tail. battery and voltage reg to run a fuel pump. 582 I could keep my b-box add a rad and change props and go. the bad to that is I am adding prob 15 lbs to gain 15hp. I have recently been thinking about rotor blades and this is where I could really use some help. My disk loading is 1.42 now and if everything stayed the same but I went to 24' DWs it would drop to 1.3 and my thinking is I could maybe drop my cruise rpm just a tad and gain some climb from the decrease in disk loading providing more lift. my DWs came with a 12" +/- hub bar and I am wondering if I could make another hub bar 24" long out of 2024t3 to gain that extra foot? I would be gaining a foot on the disk while adding 12" to the area of the disk that is already stalled and not producing lift. I have not contacted Earnie to see if he could make one up, but I know the hub on the 2 places are extremely long compared to the shorter blade lengths. So, spend boocoos bucks on the engine/ prop, prerotator stuff?(like 8k) or spend little on 24" aluminum hub bar and maybe a 3 blade prop to gain some marginal lift and give me a maybe 80 % cruise and a little better climb?

 

[Penguin]

Engine upgrade for sure.
B box is ok w/582, probably need the C box with the 670. Note my ratio of 2.62:1 which I found to be ideal for the 582.
WD can sell you a different hub and a 3rd blade relatively inexpensively to upgrade your prop. Anything more than a 60" prop would be nice but will require a lot of work and $$$.
The 23' DWs should be fine.

 

[AirScooter]

What you need sir is a Rotax 618, and I happen to have one complete with the hard to find exhaust. (original exhaust)

 

[BEN S]

I have a like new in the box 582 and E box for sale if you decide to go with a tried and true platform.

 

[scottessex]

582 with 3 blade prop. Use the 23 blades. Just like mine was.

 

[helipaddy]

582 with b box, keep original prerotator. 3 blade prop. Penguin magic radiator mod. You're sorted.

 

[phantom]

a 503 is has enough power if you use a 3 to 1 gearbox and a 72 inch prop.

Norm

 

[scottessex]

The 503 with a lrger prop would be a good mod, BUT if you just want to change the engine, change over to a 582, keep the B box and prerotator assy, add the radiator, Yes just like penguin did have it mounted at an angle, keep the 23 ft blades, and go with a 3 blade warp drive, or a 4 blade IVO prop. As long as you keep it light you will be happy with it, and it will be a great performer.
Mine had a 582 same set up as we are talking about. I changed it to an arctic cat 530 and it has been happy ever since.
Electric or pull start is up to you. Pros and cons of both.

 

[Boots]

Don't do this ! (" I am wondering if I could make another hub bar 24" long out of 2024t3 ")

 

[scottessex]

I have, It worked fine, it was on the rivited Rotor Hawk blades, very smooth.
Are you going with shorter, or longer?

 

[Boots]

Scott,
Are you saying you made a hub bar out of 2024 T3 ? I wouldn't if I wanted a longer hub bar I would get R F D to make it .

 

[scottessex]

Yes! I had to make one to replace one that was corroded on my first gyro.

 

[Boots]

My DW hub bar isn't made from 2024T3 is the reason for pointing that out . If the bar fails
It won't be much of a savings on building his own.

 

[tx_swordguy]

I don't have a problem with having RFD making a new hub bar. IF Ernie would make one is the question. He likes his rotors complete as a set with the hub bar. I have not asked him yet, however according to Aircraft sruce 2024t3 is an aircraft grade structural, high strength, treated alloy with exceptional fatigue resistance. It is also the only type they sell in the .75"x2.5" that my original hub bar came in. If you know the exact type of aluminum I am needing I am completely open to suggestions. I am still interested in pursuing the additional foot of rotor, whether by having RFD make a hub bar or doing it myself. If nothing else it would be a fairly cheap way of trying a longer rotor . I have yet to hear a aerodynamic reason against gaining a foot of rotor diameter at the cost of adding a foot to the already stalled region of the disk. It obviously would not work if I put a 12' rotor hub on, but that is not what I am looking at doing.

 

[GaryMac]

Ernie made a longer hub bar for me when I needed to take my 23 footers up to 24. I haven't flown them yet, but I expect no issues.

 

[MikeBoyette]

As I have stated many times the reason dad won't just sell you a new longer hub bar is the rotor system is balanced as a unit. If you just put a longer hub on the blades you now have a whole new rotor system. This whole new unit needs to be balanced and tracked. Balancing Dragon Wings is not something that is easy to do. I have done many many sets with dad and I am still amazed at how easy he makes it look. In my humble opinion a 670 I too much power for an Ultra White stick with a 582.

 

[GaryMac]

Mike brings up a good point.

I should point out that I sent my blades back to Ernie so he could make the longer hub bar and balance everything.

 

[scottessex]

Boots, what is your hub bar made from?

Mikey is right, you need to have the blades balanced and tracked as a set.

 

[Boots]

Scott,
I don't think the material used for a hub bar is a trade secret. But i have seen some spec,s of the dominator shared on the forum before and Ernie did not appreciate it .
So I'd rather Mike or Ernie share that info here.
The ink is/was on the bar stock that was used to make my hub bar. They may be a reason why he uses that grade of aluminum .

 

[tx_swordguy]

I have essentially quit on the idea of the 670 it is cost prohibitive. I will go with a. 582. It goes with out saying that the blades and hub must be tracked and balanced as a unit. That isn't just a dw thing. You can't just slap any rotor together and throw it on a gyro and get butter smooth performance without having balanced and tracked the rotors. Whether the manufacter does it or the end use does it, it still has to be done. My current set of dw have always been one side heavy since I got them from Ernie. I balanced them with tape until I pulled them off balanced them upside down and had to drill out some of the tip plug to set them up right and now they fly much better. Am I an expert rotor balancer ? No. Am I afraid of some trial and error testing to set them up ? No. I will see if Ernie can set me up with a new hub bar. I appreciate the information and concern.