Avispad Build Log (Without Dihedral)

Started by vishalrao, August 17, 2012, 05:53:24 PM

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umeshk

I think the landing gear needs to be flexible rather than rigid, so that it absorbs shock and prevent it from transferring to the fuse.. using iron or steel is not a good idea.. aluminium is a better choice as it is light and flexible..

umeshk

@ vishal can you please post the link to the plans .. thanks

S_K


S_K

Btw, its a very nice build, Vishal!!:) Absolutely clean finish..!

vishalrao

#54
Quote from: kamaraj74 on August 24, 2012, 11:19:36 AM
when i give throttle motor does not spin

Does the motor doesn't respond at all or it stops after some time? Does the ESC keeps on beeping after you connect the power?

Try initializing the throttle range first. Before connecting the power to the ESC, move the throttle to the full open position. Now connect the power to the ESC. You might hear 2-3 beeps and then nothing. Then move the throttle to full down position. You will then hear a beep sequence indicating that the initialization is over. Your motor should then respond to the throttle.

BTW Kamaraj, the motor is just fine for your model. I do hope that you are using 3S and 7x3 prop.

vishalrao

Quote from: umeshk on August 24, 2012, 12:37:40 PM
I think the landing gear needs to be flexible rather than rigid, so that it absorbs shock and prevent it from transferring to the fuse.. using iron or steel is not a good idea.. aluminium is a better choice as it is light and flexible..

Agree! That's the reason my landing gear snapped. Looking at Aluminium option now.

Quote from: S_K on August 24, 2012, 01:07:24 PM
Btw, its a very nice build, Vishal!!:) Absolutely clean finish..!

Thank you S_K!

kamaraj74

Thanks friend
as per your instruction i did now it is working thanks a lot

kamaraj74


vishalrao


vishalrao

New Landing Gear

Made from stainless cycle spokes. Appears to be springy, but strong enough. Only landing will tell :) Won't crack the fuse for sure in case of hard landing.


Mjet

Hi Vishal,

Nice design , pl tell me the thickness of spoke. have you tested it ? i will use it in my blue baby.

Regards
Mohan

vishalrao

It's 2mm Mohan. The design is same as in the original Avispad build thread by BEX. The only thing is that instead of inserting the gear into the fuse sidewall, I have inserted it into blocks made out of foam board.

I'm yet to test it!

VC

One way to test it would be to pick up the plane on full load and drop it on a carpeted floor from a height of 3 feet or so. The u/c should not buckle.
Growing old is mandatory, growing up is optional!

vishalrao

#63
 :-\ Scared to do that VC sir! Will wait for the skies to clear and do the landing test  ;D The best part of this design is that (I think) the fuse won't be damaged. At the most the landing gear will bend in case of hard landing.

A cross member can also be added to strengthen the gear but then it'll lose the spring action, transferring all the impact to the fuse.

samlikespad

Nicely done vishal! since you have the ply piece (epoxied or bolted I hope) on both sides, it should hold. But I dont think the extended portion with foam support is going to help much ;)

And hey, thats one mean looking prop!!! is that a sport prop?

vishalrao

Thank you Sameer! Since it's very difficult to make exact hole on the ply same as the spoke dimension, there will be some movement in the landing gear, if they rest only on the ply. The foam board support helps a lot. What I did was drop a few drops of cyano into the landing gear holes (in the foam board) and now they are rock solid. Since the ends are threaded, one can also bolt them on top of the foam board by adding a washer.

The prop is a normal 9x6 electric one Sameer!

samlikespad


Mjet

Thanks vishal. Is foam board ( Means Laminated foam ) is available in India   (:|~ ?pl share the Manufacture name and availability.

thanks and Regards

vishalrao

I don't think it's called laminated foam as there is no lamination. It's a homogeneous mass ranging from 2mm to 10mm I think. It's used for making advertisements/standees etc. It's available at many places over here. I think it's called foam board or sun board. Try going to a sticker shop or CNC cutting unit and inquire over there.

girishsarwal

Vishal, I think that's a wonderful job, esp the springy foam. I think the washer should really be added, perhaps a rubber one as there will be considerable play during landings, CA probably wouldn't hold metal to foam long

Do you think double sided tape can be used a replacement for the foam, are they the same material? How about using natraj erasers as a substitute, ofcourse keeping a tab on the weight

Also, god forbid, in case of a hard landing and the gear twisting about; since there is quite some play, would it be easy to straighten it out without unmounting?
gs

vishalrao

#70
Thank you girishsarwal! Regarding spring action from foam board, it's not that way. The foam board, unlike it's name is very hard and doesn't offer any movement. The shock absorbing action comes from the vertical movement of the spokes as there is no horizontal strut or member restricting movement of the spokes. Unlike GI/Brass wire, stainless steel cycle spokes have lot of temper and retains the original shape when stressed to some extent.

I hope the attached illustration will explain better.

manu

even crashing requires a flight......

kamaraj74

you will get laminated foam at aero engineering work chennai  web site: aeroworks.co.in

vishalrao


rastsaurabh

Is it aerofoiled shaped ??? if not then lamination is of no use ???