Small prop+big motor works? + servo help

[agupt108]

I was wondering if I could use a smaller propeller say a 7x5 on a big motor like a 2218 which can handle a 10x4.5 prop. Also, I was wondering if there was a way to install servoes in my scratch build without using hot glue because it rips off the paper if I try to remove it to use in another plane and then if I want to re install I have to hot glue it again. Maybe something like velcro? But I don't want it to move when the servo spins because velcro is not that strong...Thank you!

 

[Piotrsko]

Velcro comes in flavors like up to 100 lbs strength, but not at the mormal places it is available in stores. I use double sided stickies like those used in mounting glass tiles to walls, double sided gorilla tape in various flavors and finally (gasp) old style glued in wooden mounts with #2 wood screws. The double sided tape will peel with some effort if it hasn't been in place for 20 years.

 

[agupt108]

Velcro comes in flavors like up to 100 lbs strength, but not at the mormal places it is available in stores. I use double sided stickies like those used in mounting glass tiles to walls, double sided gorilla tape in various flavors and finally (gasp) old style glued in wooden mounts with #2 wood screws. The double sided tape will peel with some effort if it hasn't been in place for 20 years.

Is there any tutorial for the wooden mounts? I think that will be easy for quick removal/installation. Thank you!

 

[Bricks]

Can do it two ways take a piece of plywood cut out slot for servo or two pieces plywood glued to where you want the servos so the screws catch it when mounting servos.

 

[agupt108]

Can do it two ways take a piece of plywood cut out slot for servo or two pieces plywood glued to where you want the servos so the screws catch it when mounting servos.

I don't have a wood cutting machine so I think I will have to use the second way. Thank you!

 

[Bricks]

I don't have a wood cutting machine so I think I will have to use the second way. Thank you!

It is easier but if you use the thin 1/16 inch plywood it can be done with an exacto knife or similar, cutting the slot makes a much better mount., and if hot glued in can be reused. .

 

[Aireal Anarchist]

for your hot glue issues....I use a small artist size paint brush and paint "DENATURED" ALCOHOL on the hot glue....denatured alcohol softens the hot glue and releases it's grip......it evaporates fast so a few coats is required....and the older the glue joint the more you will need to work it

 

[mastermalpass]

To answer your prop question: a small prop on a motor built for much larger props is like asking a tractor to tow a sports car: it will handle the load no problem, but it might not go as fast as you want it to.

For easily removable servos, I think one other guy on here would put tape around his servo slots and then hot glue his servos to that tape. The hot glue can be pulled off a strong shiny tape without damaging it.

Note: a small glue gun aimed at art level crafts will have a lower melting point and generally have a weaker sticking strength, which would be desirable here.

For plywood, I find that the fine-toothed hacksaws, made really for cutting metal, will cut through 3mm ply quite well. The finer teeth reduces the chances of the outer layers getting snagged and snapped off rather than sawn through. I found my larger toothed coping saw used to pull plywood apart like that, weakening it near cuts and sometimes spoiling the shape.