Lil Monster

Ron, I need to figure out how to do that. We had a club member who would video a lot of our days out flying but has since been a bit dormant after suffering some health problems. I certainly wanted a beam mounted engine on this but I figured I needed to get a engine or two off of the shelf. I have a bunch of Scientific models to get to. I'm looking forward to those.

I hate to threadjack, but...
Did I read that right? Scientific? Whatcha got Mr. Cook?
I dig the kits with plastic cowls and/or turtledecks.

Hi Ken,
That's a really nice plane! I took a look at the poet-side shot to try to glean the answer to my next question (the one I should have asked first):

How do you build a sheeted trailing edge? Can you provide some helpful hints?

I have a Black Hawk Models Hurricane that uses the same type trailing edge. The lazy side of me wants to cut the rib ends off and use a 1/4"x5/8" slab. However, I can see the V-shaped trailing edge being stronger.

All I can think is to plane a taper into the "common edge" or glued edges. I guess sanding could do the same thing, and leave the wood with texture for glue to saturate and adhere to.

Then the trailing edge assembly gets slid onto the rib ends.

Whatever hints you can provide would be much appreciated!
The Hurricane has been on hold just because of the trailing edges.

Thanks in advance.

Jim, I have plans for a few of the Scientific kits. I know there's a few but from memory I have the Zig Zag, Atomic, 3 types of P-51 Mustangs excluding the F-82, Lil Stinker, Stuntmaster, Bullet, and a few others. The Bullet is probably getting completed first as I have the decals and canopy for it. The Mustangs would be next. My Lil Stinker is already built but needs to be rebuilt. The main problem with Scientific kits are mounted a Cox engine on them directly on the firewall. Hollow out the body and put a tank internally and then use a product engine which pulls the CG back to the rear. This is my plans with the Stinker and the others. The Atomic uses a Mccoy .098 for power.

As for built up trailing edges, first thing you do is to get a straight rule and cut one edge of the sheeting straight. Using a ball point place small xxx's on the cut side as this is the side you will be gluing together. Do this with the opposing side and don't worry about the widths.

Hopefully they were straight enough that you only needed to remove very little material. Make small balsa jigs of the tail end of the ribs by stacking a pile of scrap balsa together and sanding them at one time to the shape of your ribs. They can be slightly smaller as this will help create a friction fit once the assembly is installed. Place small pieces of scotch tape or masking tape on one half as your going to use these to hold the mating piece directly on the tail end . Place a small continuous bead of yellow glue down the mating area of the two pieces. Don't flood this piece just make it a thin continuous bead and lay the mating piece on top of it making sure it's now trued up edges are in line. Once inline, pull the loose ends of tape around snugly to secure it. Open the trailing edge up and evenly space the jigs you made in between to hold the proper angle and then wrap some more tape around it.

Insuring that everything is lined up and your tape is holding the assembly together correctly just set it aside until it dries checking it now and then for fishmouthing. Yellow glues with their water content will buckle the thin balsa. It's imperative to stick it and forget it as adding more glue will ultimately cause the wood to warp. If you get it right on the first try, it usually stays and this is the tricky part. If one decides to build directly over the ribs and do one side at a time sheeting the top and then the bottom, the outcome is usually a pretzled trailing edge which can't be easily corrected. Once dried, slip the assembly onto the tail end of your ribs cutting and sanding any overhang off at the ends as needed. All in all, it's a simple process but over the years I ruined many wings just trying to do one side at a time. This is done easier with larger wings of course with less tendency of warping. It's just that this sheeting is very thin and susceptible to cupping and warping. As far as strength, I would have to say that while a solid piece is strong, it's only as strong as the dadoes placed within it to receive the ribs and this is the failure point at every rib. You don't have that with a sheeted trailing edge. However, both will break so don't crash the model.

Nice job on the sewn hinges and the poly has a nice shine to it , have you used the system 3 water base before ? I am sure you checked it for fuel resistant. Glad you got your camera fixed I have done that build up TE before and found it to be a pain!

Eric, I've been using this water based poly for 15 years. When the crosslinker is added, it's fuel proof to over 40% nitro. No paint aside from epoxy like K&B or Klass Kote has the durability that this stuff has. It's not easy to use and it takes a lot of practice to use it. Spraying it is in order and this is what I need to do. This was painted with a 2" spongebrush and I did this in one week from covering to this. There's 4 coats of nitrate dope as a base.

          While this is not on topic, here's a picture of my recently finished Vector .40 which is done in polyspan covering using System 3 poly. Systems 3 is non toxic water based finish.

Thanks for the lesson Ken , i had been doing it the way the plans say and your way of building the TE right (straight) and then putting it on the wing ribs sounds more better and easier! I will remember when the next one comes around . (( Nice !!)) The stuff is not cheap But neither is Dopes

Ken,
I have the Super Mustang. This one looks like very similar construction to the P-40 profile with built-up symmetrical wing and engine cowl.

If one if yours is the same kit, maybe we could build at the same time. It would be several months before I could start another kit...I have three in just-barely-started mode. It might be fun to compare notes during a simultaneous build.

Jim, I have plans only. Well I stand corrected, the Bullet is more than just plans. That being said, I took my plans over my flying partners house today with my son. Over lunch, we discussed how we would like to proceed here. My buddy Dan is a well known stunt flyer and we talked about these. The problem with the wing on the built up version is that the wing is not symmetrical. In fact only one model has a stunt wing which is the Stunt Master. This is a easy enough fix and I will proceed by using purchased leading edges and trailing edge and just utilize rib length. Having a symmetrical wing will offer better stunt and inverted characteristics. In addition, Dan was a key pilot in the Musciano events in Virginia in the 90's.

At lunch, he suggested using 3/4" pieces tacked together shaped and then split apart and hollowed out. This makes hollowing easier and more accurate rather than working through the bottom of the fuse. Dan has the plans to the F-82 twin and this is certainly one I would like to do. I currently fly a F-82 twin which I use 2 Fox .35's. It has a 67" wingspan and is a really cool plane. I would love to do a small version of it.

Hi Ken,
The Super Mustang came from Jimmy Dodson in SC. The P-40 came from a fellow in Wisconsin. Both have symmetrical wings.
Both are larger than the flat-bottomed built-up wing/profile fuselage planes like the Typhoon and FW-190 (smaller wingspans around 18"-19"). My favorite feature on these Scientifics (large and small) are the vac-formed engine cowls!

As I studied the Super Mustang, I noted similarities to Brodak's 1/2A Mustang. In particular they both share the same wingspan,fuselage length, and both have a trapezoidal balsa patch where the elevator pushrod exits the wing. They both have the same ribcount too! Similar construction methods are employed on the P-40 kit, although it has a slightly smaller 21-plus inch wingspan. All of these kits share the firewalls you mentioned (for integral fuel-tank engines). Where the Brodak Mustang kit (and I suspect the Zero and Wildcat) differs is the default beam mounts and no cowl. My "P-40 (not the Red Tiger)" thread showcased this very P-40. I hope the Super Mustang turns out as good as the P-40, in finish and flight.

All parts were traced onto cardboard, and all assembly instructions were scanned and landscaped with stitching software in order to print full size copies later.

I see that once again someone likes to play games with the positive and negative reputation that the forum uses. If something I noted was incorrect, I'd personally like to know about it rather than use the negative reputation feature. I think that's what needs to happen here .  

        Jim, revisiting the plans after reading your post I discovered I have "Sizzlin Liz". This wing is not symmetrical.

Ken,

You should be fixed up. Not sure why as I read the post in question and didn’t see anything that would warrant a negative point. I used to think it was accidental when that happened, but see it more frequently and I start to wonder.

That said, I will post something separate that explains how the reputation system should work after I run it by Jacob.

Ken Cook wrote:I see that once again someone likes to play games with the positive and negative reputation that the forum uses. If something I noted was incorrect, I'd personally like to know about it rather than use the negative reputation feature. I think that's what needs to happen here.

I hope I didn't trigger anything...my old phone is so slow I need to create a post, submit it, and then edit it to include pictures. This isn't causing what was mentioned above is it?

Cribbs74 wrote:
You should be fixed up. Not sure why as I read the post in question and didn’t see anything that would warrant a negative point. I used to think it was accidental when that happened, but see it more frequently and I start to wonder.

Nothing in there that troubles me! Like Ron, I really don't see how it seems so easy to "mistakenly" hit the negative button. Are people really that careless? If it's intentional there must be an undisclosed reason. Sad that there are possibly those in our "friendly" forum who might do it just to be nasty. Don't see how it could be one of our regular contributors. Must be a "lurker". An extra Greenie from me Ken.

Hey, I don't always agree with everyone here, but I certainly wouldn't get nasty and take revenge. Each to their own.

If one surfs using a touchscreen device, especially a phone with a small screen, it is very easy to accidentally hit and "click" things that are close to the edge of the screen. I have accidentally "liked" a lot of stuff on Facebook with my iPad, using my fumbly fingers to scroll down near the left edge. I could imagine one could hit the + / - area accidentally with the edge of a thumb while just holding the phone.

I hope it was an accident and nothing else. It would be nice if there were a "confirm" screen for the up/down votes.

I think it'd be a great idea (if possible) to just delete the 'down vote' feature. If you particularly like a post, you can say so, if not, then the old saw "If you can't say something good, don't say any thing at all" could come into play.

The moderators here do an excellent job of quickly sifting the very few ding-dongs that show up with stupid posts/attitudes.

As Kari pointed out...even on my computer, I take careful aim when sending greenies for fear of missing the mark and sending a negative. I do like the ability to applaud the tech efforts and humor that show up here on a regular basis.

Anyway, that's the view from out in these sticks !!!

I am sure Jacob cab turn off the feature (extension) or he can set it so only moderators can vote

This feature is not needed and usually causes some frustration

I have fat fingered a few Reds unintentionally...I ONLY ever intend to give green or nothing

KariFS wrote:If one surfs using a touchscreen device, especially a phone with a small screen, it is very easy to accidentally hit and "click" things that are close to the edge of the screen. I have accidentally "liked" a lot of stuff on Facebook with my iPad, using my fumbly fingers to scroll down near the left edge. I could imagine one could hit the + / - area accidentally with the edge of a thumb while just holding the phone.

I hope it was an accident and nothing else. It would be nice if there were a "confirm" screen for the up/down votes.

Yes, it is too easy when using a portable device, to accidentally swoosh your thumb over the (-) or (+) while attempting to just scroll thru a post. I know I have done it a handful of times. I usually sent the offended member a note of apology, explaining my unintended action and give them a (+) greenie to help off set the negative.  
As a side note, I don’t think I’ve ever read anything here on CEF that would cause me to give someone a negative mark. This is a very friendly forum, full of informative people who share their knowledge and experience in a positive and polite manor that deserve only greenies (+).

Ron, thanks for that