RickP

My Feedback: (2)

Okay Gang,
Rough sanding complete. I am on to final sanding tonight and then I guess it's time for covering. I'll keep you all in suspense untill it's done I guess (let's see if you all are still reading LOL).

I balanced the airplane and unfortnatly it is looking like it is coming out a bit too tail heavy. I really hope not, the last thing I want to do is add weight as it is a tank already. Well, no stopping now. Lets see what happens...
RP

GallopingGhostler

Now I'm starting to see an F-16. Great job, RickP.

RickP

My Feedback: (2)

Thanks! It's only been 2 years LOL...
RP

GallopingGhostler

You can look to the positive. I started a Sterling 54" span Piper Cub RC lightweight rudder only kit back in 1994. I plan to finish it this year as a 3 channel 19 years later. So 2 years is a drop in the bucket.

MJD

My Feedback: (1)

At least you can bungee launch a DF.

Looking forward to the test flight report!

combatpigg

My Feedback: (3)

Rick, you have put so much work into this project that it would be worth moving the wing aft if it comes down to obtaining a 25% MAC CG without adding any useless weight.
I look at 25% as the most nose heavy CG....28% is where I usually fly conventional layouts.
The higher the wing loading, the more critical the CG becomes...so adding weight [just to obtain a flyable CG] at this point isn't an option in my book.
Bear in mind that covering a plane like this will move the CG aft slightly from where it sits now.

RickP

My Feedback: (2)

Combatpigg,
You are speaking what I was thinking and trying not to. The wing is not removable in this design and is well epoxied on at this point. I'm afraid to remove it would destroy it. To do this I would have to build a new wing - which is not the end of the world. That said I still don't have the battery pack yet so I am only guessing. It may balance with 4 AA's up front, but I was considering one of those really light 250mah packs and that might not do it. What I should do is get a weight now although I deathly afraid of doing so. I don't think I did a great job of keeping it light. Before we consider butchery, let me do that....
RP

RickP

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This project has been described to me as watching a Glacier move. That may be, I'm sorry guys! Anyway - finally got the prop nut adapter modifed... I started covering, but I hit a brick wall. Nothing much done in the past week or so.
RP

Tee Bee

I'm still watching this glacier. I'm not criticizing since I've got a couple of blobs of slow moving ice in my garage as well. Keep at it. We are rooting for you no matter the outcome of this project.

GallopingGhostler

RickP, you're doing fine. I'd just ignore the background noises and finish it in your timing. You're almost there, and the last 5% is perhaps the hardest. You've got a great looking airplane so far, and I'm sure it will be a fine flier. Will be neat to see piece of history take flight again. [8D]

SnApRoLl-

Very cool build!! Can't wait to see it finished.

Shawn

RickP

My Feedback: (2)

I've been holding out on you guys. Was going to keep you waiting on the edge of your seats, but I'll give in Here are some pics.
Whats left:
Paint hatch / cover
Instal Decals
Install tank
Instal servos / batt and RX

That's pretty much it!!

GallopingGhostler

Sharp looking model, kudos for the fine work.

SnApRoLl-

Sweet looking jet you have there. Will you be posting a maiden video?
Also, do you know where I can find any fan units that will work for a Cox Black Widow .049?

Shawn

combatpigg

My Feedback: (3)

Very nice..!
This has been one of the most interesting projects I've ever seen.

RickP

My Feedback: (2)

Hello All!

Well not much more to do. Here is the short list:
Install flight RX and Batt
Nose weight
Make hole for NV access
Add anti rotation pins for motor to keep it from spinning

I just got my decal proof sheet today. I'm going to try them on for size tonight and then pull the trigger for the vinyl. Enjoy the pics!!!!

Oh - to answer the questions the only 1/2A sized fans that have been used have used the Tee Dee's. I have not found anything for the black widow engines - not to say you can't try but the big back plate would be a big wind resistance I think.

I'll be posting a review video soon to facebook and I'll link it here. Maiden???? I am not convinced this thing will really fly. It's much heavier then I planned and the thrust output just isn't there. It may be a wall hanger for a while. Who knows - with some tweaking there might be something there, but I'm feeling pretty satisfied with this journey and just enjoy tinkering with it. We will see....

RP

combatpigg

My Feedback: (3)

She Looks fantastic..!
Congratulations for seeing this project through from end to end as a faithful reproduction of the original design.
I'll bet you will enjoy just admiring the plane for awhile as you critique the design and reflect on how the weight budget got spent.
It really is difficult to build a plane with complex curves, a beautiful skin and keep it really light......without resorting to doing a molded fiberglass job. At that rate, molded fiberglass is very easy to go overboard with, especially with a fuel proof paint job.

RickP

My Feedback: (2)

Okay Gang,
You stuck around this long. I guess we can call this project complete. Here are the pictures!

I've consulted with my best friend at the field and we chatted seriously about this. There is no reason not to give this a try - the trick will be successfully launching it. A bungee launch would guarantee that so long as the motor doesn't flame out. Then we can see how long I can stay aloft with all the thrust I can muster. Maybe in two weeks I'll give it a try. Stay posted.

RP

Mr Cox

It sure looks great, well done!

What is the total weight?

RickP

My Feedback: (2)

Wow, you really know how to hurt a guy LOL. I don't know. I've been too embarrassed to put it on the scale. Okay, I'll do it tomorrow....
RP

combatpigg

My Feedback: (3)

Running the engine with backplate pressure will allow for aggressive launches and the most aggressive, consistant needle settings.
You need a fine thread needle for the best results though.
If a aftermarket fine thread needle isn't available, then a OS .10-.15 needle can be adapted...and it can be mounted basically anywhere on the plane you like since there is enough pressure to overcome the most convoluted plumbing jobs.

RickP

My Feedback: (2)

Combatpigg,
I would love to run back plate pressure, but I can't find a TeeDee .090 pressure back plate. They are all over for .049's though. So I had drilled the crankshaft port on the nose and am using that. Do you think I am better off with backplate pressure? If so do you know how I can outfit it?
RP

combatpigg

My Feedback: (3)

You can angle drill into the case through either side mounting lug and press fit a 1/16" - 3/32" brass tube into a slightly undersized hole. I don't recall the drill size, but you need a "numbered" drill index to find a bit that is just a very slight press fit.
I've tried installing a brass tube in a puddle of JB Weld in the center of the backplate..but the bond eventually failed between the glue and the backplate. I thought I had done a pretty good job of prepping the backplate, too.

The fitting up front...I've never had any luck using it but there was a Cox engineer who used to chime into this forum who claimed that it worked for him. Obviously, Cox wouldn't go to the trouble of placing a tap there if it didn't work.....but none of the guys I ever raced with [and who taught me how to run TDs] liked the forward tap. IIRC the Cox rep spoke about some details involved with keeping the pressure line from slipping off the plastic nipple.

There is also no need to restrict the orifice inside the pressure tap, you just need to control the passage of fuel into the engine at start up with a pair of surgical clamps ["hemostats"]. The pressure builds fast, so you can dry crank the engine with your starter and just release the hemostats to see how the engine responds. Most likely it will be way too rich unless the needle is practically closed. Floods are a pain, so start a pressurized system from the lean side just to get it running but be quick to richen it up or else pinch the line off and open the needle 1/4 turn for the next attempt. People tend to get spastic, herky-jerky, impulsive, etc. while starting pressurized set ups [and make hamburger out of their fingers]....so always remind yourself to be calm and methodical. All hand movements around the engine should be well rehearsed ahead of time.
The worst that can happen if you try to "power start" a pressurized engine against a flood is that you will break the engine or sling the prop spinner and bolt off into never-never land. So, I can't emphasize enough that you need to be cautious and methodical when working with a pressurized fuel system. Having the engine inside a fan tunnel means that you will really need to be on your toes to control flooding.
Orienting the cylinder sideways [as you hold the model] helps to avoid floods.
Real cautious 1/2A diesel conversion flyers will power crank the engines with the needle closed and the compression set to a minimal "pop" setting. Then the needle is gradually opened until the engine shows signs of life while it is being cranked. The same idea applies to pressurized glow engines to avoid hydraulic locks. Having a nice firm NVA really helps on these high revving engines that tend to vibrate the needle out of position.

Mr Cox

Oops, sorry about that. I was just curious that's all...

GallopingGhostler

Sharp looking plane, RickP. You're bringing back a piece of history when the old gal flies.