PC 21 Scratch Build

[Jackson T]

Time to extend the tail servo wires! For the rudder servo I soldered on the lead from a broken ESC, and for the elevator servo I used a plug'n'play servo extension. I glued a piece of balsa to the connection between the servo extension and the servo lead to make sure it doesn't undo inside the fuselage.

This is the goofy wing mount. I know it doesn't look very professional, but I'm pretty sure it'll hold up to the loads. Next time I'll do more research and make the wing/fuselage joint much better.

 

[Jackson T]

The wing is officially glued in! I glued some balsa from the top of the fuselage down to the main spar, and along the top surface of the wing. The balsa from the fuse to the wing spar is mainly for strength, and the balsa along the top surface of the wing is for the covering film to adhere to.

 

[Quinnyperks]

I am getting my turbo timber tomorrow, I can’t wait

 

[speedbirdted]

Is the wing not removable?

 

[Jackson T]

I am getting my turbo timber tomorrow, I can’t wait

That's good, I hope you enjoy it.

Is the wing not removable?

The wing is not removable. It's only a 65cm (26in.) wingspan, so it doesn't really need it.

 

[Jackson T]

I'm making the instrument panel thingy out of cardboard.

Next I made the actual instrument panel with cardboard, spray paint, and some random pictures of avionics displays printed off from google. The PC 21 has a "glass cockpit". It's not a very accurate re-creation, but it should give some sort of cockpit feel.

Then, I painted the whole cockpit area black with brush-on poster paint.

Next up will be the canopy, but I'll have to wait a little while until I can get to the shops and get a fizzy bottle. Does anyone have any tricks to share on heat forming canopies? I have a plan B, but if I can heat form it that would be ideal. l experimented with heat forming plastic canopies a little while ago, but it didn't really work properly.

 

[JeromeAu]

It's coming along quite nicely Jackson

 

[speedbirdted]

I'm making the instrument panel thingy out of cardboard. View attachment 169744
Next I made the actual instrument panel with cardboard, spray paint, and some random pictures of avionics displays printed off from google. The PC 21 has a "glass cockpit". It's not a very accurate re-creation, but it should give some sort of cockpit feel. View attachment 169745
Then, I painted the whole cockpit area black with brush-on poster paint. View attachment 169746
Next up will be the canopy, but I'll have to wait a little while until I can get to the shops and get a fizzy bottle. Does anyone have any tricks to share on heat forming canopies? I have a plan B, but if I can heat form it that would be ideal. l experimented with heat forming plastic canopies a little while ago, but it didn't really work properly.

If you have a shop vac, some spare wood, and an oven your parents don't mind you sticking plastic inside of, building a vacuum table isn't all that hard. This is pretty much the exact kind I built and it works great. You can use lighter plastic though; the video deals exclusively with RC car bodies which have to stand up to a lot of beating whereas planes shouldn't be subjected to such beatings in the first place. A lot of people use soft balsa to make plugs however this is pretty wasteful as huge balsa blocks aren't cost effective if you only ever plan to make one canopy. My technique has always been to build the shape out of 4" thick XPS board which sands very easily and then coat it in epoxy resin (resin doesn't eat through foam like a lot of other stuff does) which both allows you to get an incredibly smooth finish and protects it from deforming under the heat and pressure much less.

 

[Jackson T]

It's coming along quite nicely Jackson

Thanks!

If you have a shop vac, some spare wood, and an oven your parents don't mind you sticking plastic inside of, building a vacuum table isn't all that hard. This is pretty much the exact kind I built and it works great. You can use lighter plastic though; the video deals exclusively with RC car bodies which have to stand up to a lot of beating whereas planes shouldn't be subjected to such beatings in the first place. A lot of people use soft balsa to make plugs however this is pretty wasteful as huge balsa blocks aren't cost effective if you only ever plan to make one canopy. My technique has always been to build the shape out of 4" thick XPS board which sands very easily and then coat it in epoxy resin (resin doesn't eat through foam like a lot of other stuff does) which both allows you to get an incredibly smooth finish and protects it from deforming under the heat and pressure much less.

Great vac forming tutorial, thanks for sharing it. I'll do some more research and see what I have to work with.

 

[Jackson T]

So... I went to the supermarket and I couldn't find any fizzy bottles big enough for the canopy . Does anyone have any ideas for alternate sources of similar material?

 

[Quinnyperks]

Use a plastic sheet and bend it.

 

[Grifflyer]

So... I went to the supermarket and I couldn't find any fizzy bottles big enough for the canopy . Does anyone have any ideas for alternate sources of similar material?

https://www.flitetest.com/articles/how-to-make-clear-canopies-for-your-rc-planes

 

[Jackson T]

Use a plastic sheet and bend it.

The problem is I can't find any suitable plastic sheet. Any ideas where I could find some?

https://www.flitetest.com/articles/how-to-make-clear-canopies-for-your-rc-planes

Nice write up @Grifflyer, that's a great idea with the laminator! I'll give it a go. The canopy is pretty big on my PC 21 though, it may not be rigid enough. I guess we'll find out!

 

[Quinnyperks]

I found some at a paper store. But you could use a takeout container.

 

[Jackson T]

I found some at a paper store. But you could use a takeout container.

Some good ideas there, I'll look into them if the laminating film doesn't work.

 

[FPVAirCombat]

Nice work Jackson! Glad to see your PC-21 taking shape nicely.

 

[Jackson T]

Nice work Jackson! Glad to see your PC-21 taking shape nicely.

Thanks!

 

[Jackson T]

Yesterday I made the rear canopy using laminate film as per @Grifflyer's idea. I used a piece of paper first to get the right shape, then I used it as a template to cut it out of the plastic.

I probably won't get around to doing the front half for a little while, as I have an opportunity to do some work with my dad for the next few weeks to save up for my full scale flying lessons.

 

[speedbirdted]

Looks good! For what it's worth try using canopy glue. It's nicer than CA because it dries clear and doesn't leave that annoying white fogging everywhere on plastic surfaces.

 

[Jackson T]

Looks good! For what it's worth try using canopy glue. It's nicer than CA because it dries clear and doesn't leave that annoying white fogging everywhere on plastic surfaces.

Thanks for the tip! I may not need to use any glue if I do it right, but I will keep in mind that CA leaves white fogging just in case I do.