Hatz Biplane Association

Doug and Wojtek,
Many thanks for your comments and info.
Wojtek love your plane,
Thanks Fraser

Hi,
I use wheels 600x180mm (bigger than from plans). Thrust line: 9". Prop: 84". Landing gear shortened to 26". Estimated prop clearance approx 12" (final measurement soon).
Wojtek

I have a lot of the drawings, but certainly not all. I haven't gone through the Smithsonian and I understand they have a limit per "transaction" of how many drawings they'll copy for you due to the volume of requests so it could take a while to get everything. I actually purchased some of the drawings from someone in Florida who advertised then on Barnstormers. The rest came a from a CD. I'm a member of the National Waco Club and there is a member who sells CDs of many, many Waco drawings. I don't know if every single QCF or UBF part is accounted for on the CD, but I certainly have most everything I need to evolve the Hatz to the F2. Actually, the Hatz is already so close to a Waco that it doesn't take much... Radial engine (already on the plans), changes to the empennage (cross checking Hatz & Waco drawings), wheel pants, some cosmetic landing gear changes, some cockpit changes, fuselage stringers and general lines...

Sounds like a lot, but not really.

Thanks for your comments Doug.
I will probably go for the longer length landing gear (its easier to cut a bit off than add a bit).
Even though I won't need all for some time, Its easier to get all three kits at once when they have to be shipped to the other side of the world.

From some of your comments on other threads I gather that you have some or all of the Waco F2 drawings. Was this a relatively straight forward exercise obtaining them from the Smithsonian?

Once again thanks for your comments.
Fraser

Ed's right about the thrust line. Not sure where mine will end up yet, but it probably won't be the 9" specified on the plans.

As for wheels & landing gear, my F2 Hatz will wind up somewhere in between the two plans options. I wanted larger wheels, but not as large as Hans & Sam since I'm putting wheel pants on. I have a set of F2 wheel pants (fiberglass) so I wanted/needed wheels larger than the 7.00x6 on the plans. I went with 6.50x8. Heavier, but not too much so, and scales nicely for the F2. This means my length of landing gear will be correspondingly adjusted to account for the wheels, thrust line, and prop. Like Ed, I plan on using the full 84" prop called out by both the plans and Rotec.

I did the math a while back and I think you could get away with the standard gear and the full size prop if the thrust line was 6" below the longeron. There was clearance... not a lot, maybe 9" I think? Anyway, point being that you can play with tire size and gear length and not necessarily have to build the "Rotec gear" from the plans.

Thanks Ed,
I hadn't thought a lot about the thrust line, will probably go the longer gear legs anyway.
Cheers

The length of the gear legs will also be influenced by where you locate the center of thrust. Hans and Sam located it 6 inches below the top longeron, being about 3 inches above the plans location. I located mine at 7 inches, went with the longer gear and Grove 7.00 x 6 wheels and tires. I suspect that I did not need the longer gear since my thrust line is a couple of inches above the plans but I would rather have more clearance than less and I would like to turn the recommended prop which is quite large.

Doug or anyone else what wheels do you intend to use on your Rotec powered Hatz Classic. Similar to Hans & Sam or more conventional. The reason I am asking is that I am about to order the Tubing kits from VR3 engineering and have to decide on the standard length or longer length landing gear tubing.
Thanks Fraser