Scale Build Off - 1/4 scale (55") Pitts Challenger III
- Thread starter wilmracer
- Start date
The next forum building contest starts the week after this one closes, right? You're in a perfect position for that one!
Lol... seems I need about 8 months to finish a project. Maybe one of these years I'll actually finish one in time for the contest.
Lol... seems I need about 8 months to finish a project. Maybe one of these years I'll actually finish one in time for the contest.
That's just cause you (and a few other crazies on the forums) take on some insanely ambitious and awesome projects. Which we all appreciate watching and learning from.
She LIVES!
Power is inline with what I was expecting on 4S, particularly with a low pack. I have a suspicion that I'll end up running her on 5S but I'll wait until I've had a chance to test her out with a fully charged setup.
Specs and expected power:
Motor Specs:
Max Amps: 95
Max Watts (Burst): 1750
Max Watts (continuous): 1500
Max Cells: 6S
w/ 15x7x3
on 4S:
Amps: ~75
Watts: ~1120
Pitch Speed: ~50mph
Thrust: ~171oz (10.6lbs)
on 5S
Amps: ~92
Watts: ~1700
Pitch Speed: ~55mph
Thrust: ~220oz (13.75lb)
Power is inline with what I was expecting on 4S, particularly with a low pack. I have a suspicion that I'll end up running her on 5S but I'll wait until I've had a chance to test her out with a fully charged setup.
Specs and expected power:
Motor Specs:
Max Amps: 95
Max Watts (Burst): 1750
Max Watts (continuous): 1500
Max Cells: 6S
w/ 15x7x3
on 4S:
Amps: ~75
Watts: ~1120
Pitch Speed: ~50mph
Thrust: ~171oz (10.6lbs)
on 5S
Amps: ~92
Watts: ~1700
Pitch Speed: ~55mph
Thrust: ~220oz (13.75lb)
Just peaked that 4S pack and ran her up again. 1220W @ 80.6 Amps. Respectable on 4S, particularly if I can keep her around 9lbs. After tweaking the tailwheel she is steerable. On a paved surface and attempting to make sharp turns she has some problems with low speed handling, but in the turf or with some speed she should be fine.
In laws are in town so no major construction underway over the weekend. I did spend a bit of time back and forth from the shop cleaning up the front of the cowling to the point I'm happy enough with it. There might be a bit of tweaking, and the exhaust fairing needs to be added, but at least now the front and profile look right.
I ended up cutting off the chin intake that was from the original mold. I don't think I would have been able to get it to look right. I filled the area with a piece of 64th ply, skimmed in bondo, and then sanded so the cowl looked right W/O the scoop. Then I took a small piece of heavy cardboard tubing as a base and added the intake, covering it in bondo and shaping carefully.
I'm happy with how it came out and it should allow for excellent airflow in. Exhaust flow also shouldn't be a problem.
Plan is to start on the upper wing tonight or tomorrow night. Hoping that goes fast now that all the decisions have been made.
I ended up cutting off the chin intake that was from the original mold. I don't think I would have been able to get it to look right. I filled the area with a piece of 64th ply, skimmed in bondo, and then sanded so the cowl looked right W/O the scoop. Then I took a small piece of heavy cardboard tubing as a base and added the intake, covering it in bondo and shaping carefully.
I'm happy with how it came out and it should allow for excellent airflow in. Exhaust flow also shouldn't be a problem.
Plan is to start on the upper wing tonight or tomorrow night. Hoping that goes fast now that all the decisions have been made.
Attachments
Well, that cleaned up NICE! I really like it a LOT!
There are several air exits in the cowling aft of the motor, ESC, and likely aft of the battery. This internal shot shows the side and top air exits. There will also be an air exit on the underside of the cowl back toward the landing gear. That exit will replicate the fairing for the exhaust and the exhaust tube itself.
I think there should be plenty of air movement to keep things cool, and I'll have a temperature probe on the ESC to be certain of it. The telemetry system includes one and I might as well use it
I think there should be plenty of air movement to keep things cool, and I'll have a temperature probe on the ESC to be certain of it. The telemetry system includes one and I might as well use it
Attachments
Really sad news this morning... One of these Wolf Pitts went in at an airshow yesterday. Details are sparse but there is video of the incident online and lots of speculation already.
I wasn't familiar with Greg Connell but I had seen images of his Pitts while researching. It was absolutely beautiful. Thinking of him and his family today.
http://www.ajc.com/news/news/local/plane-crashes-during-air-show-at-dekalb-peachtree-/nrM4z/
I wasn't familiar with Greg Connell but I had seen images of his Pitts while researching. It was absolutely beautiful. Thinking of him and his family today.
http://www.ajc.com/news/news/local/plane-crashes-during-air-show-at-dekalb-peachtree-/nrM4z/
Attachments
Conjecturing may be in poor tastes, but it looks like, from the motion of the plane after rolling upright out of the cuban 8, a control surface let go. It sure looks like something broke.
So... grinding away. I had hoped to have this flyable by Joshua's event this weekend. It might be close, but I don't think I'll be able to wrap up the glass work and get the final testing done in time. Our club spring contest is the following week and FF is coming up rapidly so no time to waste.
Top wing has been laid out and positions for everything have been determined. I need to grab some balsa stock from Hobby Hangar today so I can keep rolling. I did cut loose the ailerons and line the aileron bay with balsa stock. Next up is finishing wingtip shaping and then get the CF tow laid in for strength. I have my process down... now it is just a matter of knocking it out in a messy shop. I'd love to stop and clean but until I'm done with sanding/shaping/glassing I don't feel like doing a deep cleaning. Getting close though.
Also decided I was going to have to have a better battery hatch option. Decided on a removable panel from the underside of the cowling. I need to grab updated pictures but I've got it lined and magnetic now. I will probably add a pin latch as well just for 100% confidence but the magnets feel strong enough to hold her shut.
Lots left to do but the end is in sight.
Goal is to have ALL work on the Pitts done (perhaps minus the cockpit, although that will go quick) by mid June. Have the mods made to the P-40 by July 1 and the rest of the time to finish packing and planning.
Top wing has been laid out and positions for everything have been determined. I need to grab some balsa stock from Hobby Hangar today so I can keep rolling. I did cut loose the ailerons and line the aileron bay with balsa stock. Next up is finishing wingtip shaping and then get the CF tow laid in for strength. I have my process down... now it is just a matter of knocking it out in a messy shop. I'd love to stop and clean but until I'm done with sanding/shaping/glassing I don't feel like doing a deep cleaning. Getting close though.
Also decided I was going to have to have a better battery hatch option. Decided on a removable panel from the underside of the cowling. I need to grab updated pictures but I've got it lined and magnetic now. I will probably add a pin latch as well just for 100% confidence but the magnets feel strong enough to hold her shut.
Lots left to do but the end is in sight.
Goal is to have ALL work on the Pitts done (perhaps minus the cockpit, although that will go quick) by mid June. Have the mods made to the P-40 by July 1 and the rest of the time to finish packing and planning.
Attachments
Looking excellent.
Nothing here that anyone can't learn to do. Just time and patience (and a VERY understanding spouse)
So very true. The first time I used epoxy my wife thought that something had gone horribly wrong at the local military base.
"Honey... is there a gas leak?... are we all going to die?"
My shop always smells of primer and resin. It is a good thing it is pretty well separated from the house
bhursey
The Geeky Pilot
Thats exactly what I got from the video also seems he had it under control at the end but was to low to pull out.
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