phuffstatler

My Feedback: (20)

I run PowerMaster 30% heli fuel in everything. It's pretty messy to clean off, and darned expensive, but it sure works well... You have to be careful with some painted surfaces, or it'll eat it up when the raw fuel gets on it.

Bipe, I can't believe you ruined a perfectly good floppy disk for hinges! (Just kidding, I'm glad someone found a great use for those... I certainly have plenty of old ones laying around)


phil in georgetown

Bipe Flyer

The aileron servos are installed and hooked up. It should have a pretty good roll rate dontcha think?

Dukester

My Feedback: (31)

I use Witches brew 15%. It comes in a synth/castor mix and I pour in a little extra castor to bring the percentage up to about 10%. So maybe call it 13% nitro? I run it in all of my engines (even the 1/2a stuff) except for a few of the higher end 1/2a engines which I keep some 35% for.

Powerwise, here are a few tach readings for mine (tach readings are my best memory and may be +-1K rpm)
OS 26 on a Zinger 9x4 does about 11,500
Saito 40 on a APC 10x8 does about 11,000
Magnum 30 I tached it at abotu 11,000 but I don't remember what prop it had on it.

I swapped the Saito 40 into my Sportsman Waco30 for the OS 40LA and was actually pretty disappointed. The OS40LA would turn a 10x6 right at 14,000 and some change and the drop down to 11,000 on the Saito was significant. Especially when doing aerobatics as the lower revs didn't produce the same speed and tumbles as the 40LA. I switch to a 10x8 and that picked the speed up some, but still not the same. The sound however is perfect. I've only got about 2 1/2 hours on the Saito, so it may improve some.

You may try the 30 with a slightly higher pitch as I imagine the little Pitts will be something like my bigger one and like to carry some speed for best flying.

Looking very good by the way.

Duke

mainegold

My Feedback: (1)

I'm liking this bird way too much! Yeah, I think it might do a nice roll or two but will anyone see it when it happens? Just don't blink!

BipeFlyer, will you leave the bottom of the fuse open (no wood) then cover? If so, is this for weight savings?

Thanks,
Jack

Bipe Flyer

Thanks Duke, good info.

Jack,

I'll be sheeting the bottom with light 1/16" balsa. On a 1/2A plane I often leave the bottom rear of the fuselage unsheeted and just cover over it to save a little weight. I've left it open for now so that I can do a test fit of the control system for the tail. I'm leaning towards pull-pull on the rudder and a pushrod for the elevator.

Bipe Flyer

I think this little plane deserves wheel pants, but I can't find any paint that matches the grey Ultracote. Hangar 9 only makes a few colours of Ultracote paint. I guess I could paint them yellow or red. Suggestions?

mainegold

My Feedback: (1)

Try a marina, they have strange gray paints for yamaha, tohatsu, etc. I would think you could shoot them with any primer and 'clear' over to shine them. Auto body stores have all kinds of gray.

Jack

Bipe Flyer

I may have to buy some Tremclad (Rustoleum) white and grey and mix them to get the right shade.

Bipe Flyer

I guess if I'm going to do the wheel pants, I might as well give it the characteristic Pitts gear. I glued some 3/32" balsa onto the aluminum gear with 3M76, which is high tack spray cement that will bond to almost anything except foam, which it will eat through. I glued another piece behind the aluminum, onto the first piece of balsa to build up the gear and then sanded it to shape.

Dukester

My Feedback: (31)

[] When I see a scratch build like this, I'm almost embarassed when I go look out in my hangar. That's a seriously good looking aircraft. If it flies half as good as it looks, it'll be a keeper.


Duke

inSANe DIEGO

Hey Bipe,
It's a beauty! I wish I had HALF the time required to make as much progress as you have. It's really moving along. Keep up the good work. I'll be watching you...

Bipe Flyer

Thanks John. I'm enjoying this build. It's been a while since I've built anything in the .15 to .25 range. It's nice because it's a little more involved than a 1/2A model, but not as big a job as a .40, .60 or larger model.

I've been making the servo tray and doing a little painting. I picked up a can of "Dove Gray" Lusrekote which is very close to the Ultracote, so the wheel pants and struts will be painted.

Bipe Flyer

I've started on the wheel pants.

The first thing to do was make the plug for vacuum forming. I started with a piece of 3/4" pine and cut the outline. After much carving and sanding I had a plug, which I then hardened with thin CA.

Bipe Flyer

The next step was to get the vacuum forming materials together and preheat the oven to 350 F. The vacuum box is nothing more than a wooden box with a bunch of holes drilled in the top and one on the side for the vacuum. For the vacuum I just use our household electrolux.

Bipe Flyer

The next step was to prepare the plastic by stapling it to a plywood frame. I use high impact polystyrene because it is easier to form and not as brittle as PVC.

Bipe Flyer

Next I put the plug on the vacuum box and put the frame in the oven. I use a couple of coffee cups to hold it off the rack. Once the plastic is in the oven you have to keep a close eye on it. It will start to bubble upwards for 5 to 10 seconds and then start to sag. Once it has sagged about 1/2 an inch in the centre, turn on the vacuum and press the frame onto the vacuum box. The whole time from putting it into the oven to putting it on the box is about a minute.

You may be able to see that even though I hardened the surface of the plug with thin CA, it still shows the wood grain through the plastic. It's not a problem though because the pants will need to be sanded anyways before painting.

Bipe Flyer

Next was the canopy. I used the plug from my .40 size pitts and I will cut it down. I mentioned in the last post, the plastic will pick up every detail, even wood grain, so the plug has to be perfectly smooth. A canopy has to be flawless because it cannot be sanded, for obvious reasons. No Problem, just pull a piece of plastic down over the plug and leave it on there. Sand the plastic until it is perfect and then vacuum form over it. The result is a nice clear canopy. The heating and forming process is the same as with the styrene, but be careful not to let it heat too long as it will form bubbles in the plastic. The plastic used for the canopy is PETG (Vivak).

Bipe Flyer

That's it. Two nicely formed parts. I just need to make 3 more wheel pant halves and glue them together.

Bolio

Bipe this is really scratch building, I admire that on you.
When I hear so many people ranting about how hard is to build an airplane..........
Guys like you keep the hobby alive and running.
Beautiful thread and plane.
Congrats from Mexico and good luck with the maiden.
Saludos.

Bipe Flyer

Thanks Bolio,


The wheel pant halves are glued together and sanded.

Andrew

Andrew -

What thickness HIPS and PETG are you using for your pulls? The plane is starting to look superb, as usual.

Wazmo

How did you cut the molded halves to fit together so well?

Bipe Flyer

Andrew,

The pants are 40 mil and the canopy is 30 mil.

Wazmo,
I trim the pant halves with rc car "body scissors" and then I sand them flush on a sanding block. The parts are hard to hold on to, so I put a piece of double sided carpet tape on the pant half and tape it to my fingers. The halves are glued together with model airplane cement, which melts the plastic together, and then sand the seams smooth.

Edit: typo

Bipe Flyer

To open up the bottom of the wheel pants, I use my Dremel routing table. I cut a slot on each side of the pant, then cut out the centre section with a pair of scissors and go back to the routing table to even up the sides. Then it's just a bit of hand sanding with a piece of sandpaper wrapped around a 1/2" dowel.

Bipe Flyer

The pants and the cowl front are painted.