I figured I should put together a list of what the development tests I want to do before setting out to actually build a prototype of a VP quad. The temptation is high to just build something, but I know I will learn a lot more by doing some testing ahead of time in a controlled environment.
Would like to build 2 test stands. One based on Trex450 heli parts and another based on Trex500 heli parts. Both are available in belt drive or torque tube, both are available from HobbyKing and hence are quite inexpensive.
The rigs need to be modular enough to test both belt and torque tube designs.
What I would like to test:
– How much power can be handeled by either torque tube and belt drive
– Failure mechanism at high power. (what fails first?)
– How much does the boom flex (carbon vs aluminum) as this may impact the effectiveness of the torque tube?
– Ability to test out different blades (length, profiles) at different angles of attack, and record thrust vs RPM vs angle of attack.
What I will need:
– some sort of I/O card for data acquisition so I can record in real time things like RPM, blade angle, voltage, current, thrust, displacement/bending of booms,… (add more)
Preferably a USB solution so I can use a laptop to do the data recording on Labview?
– a test rig that can accommodate the data acquisition parameters. Also needs to be inside a lexan or mesh enclosure so failure testing doesn’t hurt me.
I will start with a heli body, since i will be using all the gearing inside the heli body and stick a motor in sideFigure out the gearing first.
I got searching the other night for ideas on bulding a VP quad again.
One of the issues i had last time was finding a decent pitch slider mechanism. Well I found a few reasonably priced:
It seems the align trex500 heli pitch slider p/n is either h50189 or H50190. Should find out what the difference between them is.
Crashed and broken
The current incarnation of my mini quad.
This quad started off as a Turnigy Micro quad V2 from HobbyKing. Being my first quad, I crashed that frame more times then I can count and fixing it became increasingly more difficult. The original frame has many weak spots in the frame design, and breaking it is just a matter of time (if you crash a lot). I never had a chance to properly tune the KK2 controller board, hence the ample crashing in my back yard. 🙂 Continue reading
A post on RCGroups got updated last night. A new variable pitch multi-rotor craft got posted, and it looks very slick. This got me motivated again in continuing my work in this field.
While looking for the heli parts that were used in the above post, I came across this RC helicopter manuals collection of helis I never heard before. It’s good to know about it and see how other helis are designed and put together, for future ideas.
TREX 450 bible
HobbyHobby (Mississauga location)
Hobby-USA (carries CopterX Black Angel parts)
Value Hobby (in USA)
Airy Harden Blade II : Highly cambered blades that come in 238mm, 210mm, 185mm and 160mm.
The HoneyBee CP2 (that uses the 238mm blades) has a rotor speed of 17oorpm. So keep things under 2000prm. (Reference)
Supposedly, more surface area and more camber on these smaller blades for a Blade CX2/Lama V4.
Heli-Direct Pinions selection: well organized