Comment by Vladimir "Lazy" Khudyakov on June 17, 2012 at 9:48am

Why you not use rubber band instead of pneumo?

Moderator Comment by Gary Mortimer on June 17, 2012 at 12:04pm

Yep, bungee would be much simpler. Get rid of the wheels, they are drag. I give that airframe 50 launches to distruction.

Comment by Michael Pursifull on June 17, 2012 at 1:08pm

Nice. What is the launch angle?

Comment by Michael Pursifull on June 17, 2012 at 1:09pm

@Gary: how do you recommend that he land?

Comment by Richard Unwin on June 17, 2012 at 2:22pm

I will be happy with 50 launches the plane costs 135 so thats less than $3 a launch, given the other risks to the airframe during flight I am not planning on handing the airframe down to the next generation:)

Ramp angle is 11 deg.

As for using a bungee, they are alot hard to get consistent launches and can have issues with degrading over time and also were going to cost more than what I spent on the ram.

Richie

Comment by Michael Pursifull on June 17, 2012 at 7:25pm

Thanks Richie. Do you know how much, if any, the AoI is for the wing (relative to the landing gear?)

Comment by Richard Unwin on June 17, 2012 at 9:32pm

Mike, its a flat bottom wing and I havent measured it but it looks to be inline with the wheels, it would be easy enough to change the angle of attack by moving the brackets on the trolley frame, I have tried to keep it as simple as possible and allow changes for different planes to fit on the trolley frame, my other two planes have similar UC but of course not quite the same dimensions so each wheel platform is well oversized to cater for the differences, if i progress to another style of plane or one with a UC i can quickly make another trolley, i might also remake this trolley lighter to get it moving faster with the same energy levels.

richie

Comment by Kim Skatun on June 17, 2012 at 10:40pm

Where did you get the parts for the ramp?
Kim

Comment by Michael Pursifull on June 18, 2012 at 2:01am

Look at his last blog post. He explains it.

Comment by Jason on June 19, 2012 at 7:48am

Looks way safer than the one I built with high start rubber.  Too much energy stored up just before launch.  I estimated 40 lbs of force.  I think your idea is great, I'm going to have to build one of these.

Comment

• ‹ Previous
• 1
• 2
• Next ›
• Page