Which material to use to make a firewall ?

Started by knvshrm, April 18, 2018, 03:58:53 PM

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knvshrm

Hi guys ... Was making the ft old fogey but was tuck here. What material should I use to make the firewall ?? Will 5mm depron do the job or would have to make it out of wood ? I am using the emax cf2822 motor with a 9 *5 prop.
Regards.

girishsarwal

Plywood! 5mm depron wont last a few minutes before breaking/bending/splitting to pieces.
gs

girishsarwal

UPDATE: I checked your other post as well, take back my plywood suggestions. I guess you are good with the depron firewall given that motor.. you will need to specify your targeted AUW as well. I'd make it thicker than 5mm though
gs

knvshrm

See the weight of the whole plane with electronics will be around 600 gms

knvshrm

I do have a peice of balsa but it is a bit small than the power pod front.

knvshrm


girishsarwal

Why do t you post some photos of your build, that will help us better with the decision making process
gs

knvshrm


knvshrm

Can you plz PM. me your phone no. So I can send you the photos.

prabal276

Please use plywood!
A depron firewall won't last!

K K Iyer

@knvshrm,
Mr Sarwal was actually right in his first reply!

That Emax CF2822 will easily pull well over 600gms.
The 4 mounting screws need something to hold on to, so that they don't pull out.
Hence plywood.
The Flitetest plan of the power pod shows a 50x45x1.5mm ply firewall.
Often when I don't feel like cutting ply into a nice round shape, I use 1/4" balsa.
If you have neither, use 1-2mm plastic from a jar lid or tiffin box.

K K Iyer

Quote from: knvshrm on April 18, 2018, 04:13:43 PM
I do have a peice of balsa but it is a bit small than the power pod front.

Can be used if at least 3.5x3.5cm (or 3.5-4cm dia).
Just needs to be a bit larger than the mount (3cm dia)

knvshrm

The balsa peice broke...will be using the plastic lid.thanks sir .

prabal276

Yes, that plastic jar lid is a great idea!

knvshrm

And sir how do I attach the power pod into the frame? FT people have just used some skewers and inserted the power pod there.how do I do it . I don't have those skewers.
Regards

knvshrm


prabal276

Skewers are easily available on online websites cheaply.
I can't think of any other options.....
Maybe if you have some thin cheapo ball pens? You could empty then out and use them?
Or some thing aluminium tubing.
I suggest you get those skewers.

knvshrm


K K Iyer

Skewers, ballpen refills
Toothpicks. Pencils.
And my favourite, mentioned many times on this forum - PHOOL JHADU KI TEELI (handle end)

knvshrm


knvshrm

But will phool jhadu ki will be sufficient to hold the power pod. Will it not break ?and can we leave the power pod on these skewers or the tilis will they be enough?

K K Iyer

The best proof is obtained by personal experimentation.
I typed a msg that was a lecture on shearing and bending loads etc, so I deleted it.
You are an engineer.
You have two adjacent surfaces to be prevented from sliding by pins.
One pin is a rod of 1.5mm
The other is a tube of 3mm dia, thin skin, weak core.
What you are asking is 'which will break first?'

Need to consider the material the pins are anchored in. Depron.
Which will give way first? Skewer? Jhadoo? Depron?

The Jhadoo I mentioned was a Phool Jhadu, not a Seekh Wali Jhadu.

To give you a hint, why not anchor with Drawing pins?

taksh

Quote from: knvshrm on April 18, 2018, 03:58:53 PM
Hi guys ... Was making the ft old fogey but was tuck here. What material should I use to make the firewall ?? Will 5mm depron do the job or would have to make it out of wood ? I am using the emax cf2822 motor with a 9 *5 prop.
Regards.
you are using 2200mah Lipo or any other?

knvshrm