# Recent content by HeliDev

1. ### Epoxy and Acetone

Hi Guys, I was doing some reading around, and I found reference in another thread on a different site stating that using acetone with epoxy can increase the likely hood of becoming epoxy sensitive. The theory is that the acetone removes the oils from your skin, and make the chemicals able to...
2. ### The best theoretical gyro rotor blade shape? Can a gyro rotor blade be bend in 2?

Just to add a couple of points to what has been said already. While a 4 or 6 bladed rotor may seem like a good idea, you add a large amount of complexity to the rotor head. Without going into the details of rotor head dyinamics to deeply, a 2 bladed heas offers the simplest solution from a head...
3. ### Landing gear drop test

Off the top of my head. (I have used metric, I dont do imperial) v= final velocity, v_0= initial velocity, a= acceleration, s= distance, t=time v^2=v_0^2+2as =0+2*9.81*.4572 =sqt(8.971) =3m/s Assume the deceleration is over a small time interval if t=0.1 v=v_0+at 0=3+a*.1 -a=3/0.1 =...
4. ### COSMOSXpress FEA tool

Hey guys, Havent used cosmos, but have used ansys and femap. For what its worth, I dont like femap much. Dont get me wrong, its a powerful tool, but the setup is painful compared with ansys workbench. I havent had the chance to try either with composites though. although have done non linear...
5. ### lift equations

A good starter is "Helicopter Aerodynamics" by Prouty, Helo Books, 2004 "HelicoperTheory" by Johnstone, Dover "Principles of Helicopter Aerodynamics" by Leisham, Cainbridege Press Dont by anythingwritten by Hollman, its junk, inaccurate, and will be of absolutely no help. Ive got a few, and...
6. ### lift equations

Hey mate, Heli aero s a pretty tricky business, akin to the black arts. Im not sure how much experience you have got in this area, but considering that this is a very similar question to the one that I asked when i first got into heli areo, Im guessing that you are just starting out. Before...

Theres a program addon for excell called solver. That will solve for 2 variables. You should be able to find it with a search.
8. ### Anyone fly in Aces High II?

Dude I hate you!!!!!!!! Last thing I needed with my full time study and full time work was another distraction!!!!!!!!!!! Cant get it to work properly yet, spent most of last night trying though:D
9. ### Blew a Apex seal

Depends on how much damage you do!!!! After the strip it turned out that the apex seal had slit and then done a neat little 90deg turn, completely screwing the housing, and the rotor. The other housing had the chrome worn down, so it too was stuffed. So the rebuild was 1 rotor, 2 housings...
10. ### Aerobatic Configurations

Hey all, just tooling around with a few ideas, thinking about aerobatics plane. Nearly all aerobatics planes are biplanes, what about other planforms? What about a delta, or canard delta planform. You would be able to build a strong light structure with a relatively low wing loading. Another...
11. ### Building Update

Hey Mate, that looks awsome!!!! How long did it take to get to that stage of the build?
12. ### Glass Rotors?

Without checking the only blade failures that I can think of in Aus are the Robonson failures we had. I would need to check though to be sure. Pretty sure the robbie blades are honeycomb sandwich, with an aluminium spar. The older blades were an aluminium skin, the newer ones are a stainless...
13. ### Glass Rotors?

You will need to be pretty careful here mate, blade failure is pretty unrecoverable. Could be worth you while to check out some aluminium rotors. Rotors experience some pretty high forces, and bend in some pretty funky ways. If they arent laminated properly, or designed correctly they will...
14. ### Jet Black BP100

CATIA is certainly one program I would like to have a go on. Unfortunately they dont offer a demo version, and the student version is only open to those who use CATIA at their university.
15. ### Jet Black BP100

Hey Guys, Thanx for the replies. Over the past couple of years Ive used a few programs, Rhino, autocad (yuck!!!), solid works, and I have a seat on alibre. I have mainly started using proe because thats what they use at work and Im trainig my self in mechanica, so Ive been doing some extra...