New Winter project bristol Scout D

[Gerryy]

Attached is the beginnings of a CAD plan for the Bristol Scout D. I am using an Eppler 205 airfoil and basic balsa and liteply/ply construction. Power will be a brushelss outrunner of somesort as soon as I figure out what the power requirements will be.
Comments welcome
GY

[Gerryy]

Update to the WW1 Bristol Scout D project. I am finishing up the CAD plans and had some balsa laser cut and a cowl vacuum-formed. Still some fine tuning to do. Here are the new plans
GY

[Gerryy]

The fuselage parts fit like a laser-cut kit, which basically is how I designed the parts. I have already found a few flaws in my drawings as some of the notches and tabs did not fit together correctly. I also found a few parts I had forgotten to draw in. So I am building this Alpha prototype to work out all the bugs before the construction article is finalized.
GY

[Gerryy]

Here you see the front of the fuselage. It will be faced with a semi-round 1/32-inch ply firewall. I have a couple of different brushless motors to test and when I find the prop and motor combo that works best, I will draw in the locations of the mounting holes.
The holes cut in already are for power wire clearance so you don't have to drill holes to wire in the power system.
GY

[Gerryy]

The forward sheeting will go on this weekend and some stingers (1/8x1/4) will fill out the aft turtledeck section. I also plan to install the servos and work the locations out for the pushrods and the exit slots on the fuselage sides.
So far what you see, took about 30 minutes to assemble with thin CA. Self aligning and perfectly straight before the glue goes on!
GY

[Gerryy]

Here's one paint scheme that looks promising!
GY

[CalmAir]

Hi Gerryy,

Glad to see you posting your designs. I like reading your articles in the mags. I really like seeing build up posts like this. Keep posting the progress. I am anxious to see how it turns out and what color scheme and brushless system you end up with. Your sure built up the fuse quick, but don't you hate it when you left something outta the plans when you think everything is accounted for? I hope you make this plan available to purchase.

Dale

[NitroDad]

Question? Where do you go to have your parts laser cut? Anyone that has a laser, or do you have someone on the inside?

[Gerryy]

thanks for all the replies to the Bristol Build along! Right now I am still working out the "Alpha" build of the original design as I drew it and have fould missing parts, and a few slots cut in the wrong places. Once I work everything out, I do plan to publish the article with the new plans being laser cut. Right now my test cuts were done by good friends Dave Johnson (Hobbico manager) and by Jaime Johnson of Arizona Model Aircrafters. I am sure Jaime will offer basic flat kits of the cut parts. He also has other little laser kits for machine guns, spoked wheels and so on!
Also, Keith Sparks produced the plastic vacuum-formed parts I am using. Engine cowl, dummy engine and pilot bust, all to keep weight down.

I was away on vacation for the last week so will be getting back to the boards soon enough to show more of the building details!
Stay tuned!
GY

[Gerryy]

Here's the tail surfaces. Built over the plans, they are made of 3/16-inch thick stock. very easy and light weight!
GY

[Gerryy]

All the edges are straight so I sliced off the sticks from a sheet of medium hard balsa to the sizes I needed. The corner gussets are also cut from 3/16-inch thick stock. The elevators are made with a single LE stick then after installing the wire joiner, the section between the two halves will be removed so both halves will remain in straight alignment

[Gerryy]

The rudder is one piece. It has a 1/2 inch wide center vertical that will be hinged to the fuselage tailpost.
To make the rudder blend into the sides of the aft fuselage, I cut the end of fuselage short by about 1/4 inch and glued on a block of 1/4-inch balsa, then sanded it into a wedge shape to match the rudder width.
I will be adjusting the top and bottom view of the plans so the rudder will blend into the fuselage without adding work.
GY

[Gerryy]

moving onto the wing, you can see the bottom wing panel is straight forward and not very complicate. 3/16" sqare spars, 1/16-inch top and bottom trailing edge sheeting. 3/16" inch wing tip structure.

[Gerryy]

the root ribs are stacked to produce the space between the fuselage and the wing panel as is on the full-size. The holes will have dowels installed for alignment with the attachment holes in the fuse side. A 4-40 blind nut will be installed near the main spars so the panels can be attached to the fuselage.

[Gerryy]

The ailerons are built in place while the wing panel is assembled, it will be cut free later and hinged back into place after forming the leading edge bevel.

[Gerryy]

The leading edge sheeting is 1/16-inch and goes from the main spar forward. there is no cap stripping for the ribs.

[Gerryy]

To save some weight and to make construction easier, there is no leading edge sheeting on the bottom of the wing panel. The triangle gussets are for reinforcing the areas where the interplane struts and their hard points will be attached

[Gerryy]

The wing tip is formed out with the addition of this spar extension piece that angles down to the outer tip edge. Everything is sanded to blend smoothly when covered.

[Gerryy]

Here's what a week's worth of lunch hours gets ya! All 4 wing panels completed. Ready to sand in Dihedral angle into the root ribs and start assembling the one-piece top wing.
GY

[Gerryy]

The wingtips come out real nice if you take the time to sand everything smooth and remove excess material from the corner gussets with a sanding drum and moto-tool
GY

[Xrossbow]

Hi Gerryy, it's looking good.

Have you given thought to the power requirements and weight yet?

[Gerryy]

I am pretty sure the model will come in between 16 and 18 oz. ready to fly. For power, I am going to use a Electrifly Rim fire brushless outrunner 22M-1000. This motor has a Max. Constant Current limit of 11A and a Max. Surge Current of 15A. I have a Castle Creations Thunderbird 18 for an ESC and I will be using an ElectriFly 1500mAh 2-cell 7.4V LiPo pack. I am using two cells so I can turn a large 10x4 prop at lower rpm for a larger prop disc area. I am not looking for speed, but rather duration and slow easy performance.
GY

[Xrossbow]

Sounds great Gerryy. Looling forward to the end product.

[Gerryy]

started soldering the landing gear today with 1/16-inch diameter mustic wire. All I did was print out an alignment jig on paper and used thumbtacks to hold the wire in alignment

[Gerryy]

to keep the legs in proper alignment, I used a scrap of balsa and some clamps (clothpins) to hold the wire steady. I then stripped some wire strands out of an old power cord and bound the solder joint area with the thin copper wire.

[Gerryy]

Using high silver content Stay brite solder and liguid flux, I soldered the two axle joints as well as the brass the attachment tabs to the upper cross members.

[Gerryy]

typically you'd have an attachment tab with two ends and two screws holding the gear in place. But since the little Bristol is so lightweight, I figure a single end tab is good enough! Next I will be assemblying some very lightweight, laser-cut spoke wheels from a Pat's Custom Models kit, Stay tuned!

[Gerryy]

I built a pair of plywood and balsa WW1 wheels from a Pat's Custom Models kit to use with the bristol. The have foam cord tires that glue up nicely with Bob Smith Industries, rubber reinforced CA glue called IC-2000. Plus the glue is black in color!
Takes about an hour to build each 3-inch diameter wheel/tire. The hub/spokes will be covered later with either the paper pattern covers included in Pat's kit or with Iron-on fabric/film covering.
GY

[Gerryy]

Today I installed the 3/32 inch plywood cabane struts and started the forward fuselage sheeting.

[Gerryy]

Each cabane strut slides into place and is positioned by the internal doublers that have slots cut into them. The trick is making 4 struts that are all the same length.

[Gerryy]

The forward sheeting is 1/16" thick and is glued in place in two pieces left and right. Make the first side and fit it into place than use it to make a mirror image for the other side. The cockpit opening isn't cut out until after the sheeting has been glued into place. Notice the small wedges I glued to the aft stringers to blend the sheeting into into the tops of the stringers.

[Gerryy]

I rethought the shock absorbing tailskid, and installed a simple 1/16" music wire skid. It is sandwiched between three 1/16" sheets and glued to the last former in the fuselage.

All that's left is to final sand the wings and tail surfaces, install the radio and power systems and screw the main landing gear into place. I am going to bring the model to the WRAM show in a few days to show off a little for those who have been following the build on RCZone.

I'll be removing and hinging the ailerons tonight then work out the pushrod exits.
more to come!
GY

[PipesCS]

I have been wanting to do a small electric biplane next. I look forward to seeing how you mount the upper wing to the struts.

[Gerryy]

Actually it's very easy. Since I designed the cabane struts to align with the attachment ribs in the top wing center section, I use short pieces of 3/32x3/16" plywood (about 1/2" long,) with holes drilled into them as attachment tabs. When the time comes, the bottom wing panels will bolted into place against the fuselage sides, then I'll bolt the attachment tabs to the tops of the cabane struts with 2-56 bolts and locknuts. I can then move the top wing center section around until the top wing aligns with the bottom panels and I use alligator clips to secure the tabs in place. I then epoxy the tabs into place one by one against the ribs. After the glue has cured, I unbolt the wing from the struts and add the sheeting around the tabs so I can seal the covering around them.
Another way is to simply add 1/8-inch plywood hardpoints and then bolt the panels to the wing with small 90-degree brackets. But i find this way too time consuming and heavier than the plywood tab arrangement.
GY

[Gerryy]

Finally, up on its gear! The PCM wheels are really nice and easy to build! very lightweight compared to 3 inch Williams Bros. wheels

[Gerryy]

The tail surfaces fit easily into place. The struts under the leading edge are simple bamboo skewers.

[Gerryy]

The aileron servos are simply installed in front of the ailerons. The base is 1/16-inch balsa. I used foam sticky tape to install the servo. I coated the balsa base with CA to give a hard smooth surface for the tape to stick to. I used GWS micro servos with standard arms.

[Gerryy]

Cutting the ailerons free of the wing is easy. When I built the wing, I left a 1/32-inch wide gap between the aileron end rib and the next wing rib. This gives enough room to slip a sharp razor saw in to cut through the trailing edge sheeting. Then running a hobby knife through the leading and trailing edges pops the aileron free!

[Gerryy]

Here the top wing panel aileron has been cut free. Notice the triangular gussets added for strength. (So the covering won't warp the ribs) I added these to the laser cut sheet, and they are the greatest thing I ever did! Just pop them out and slide into place and hit with thin CA. Better than cutting them out and having to sand the proper angle in them!

[Gerryy]

I got the bottom wing panels installed tonight. I added a 2-56 blind nut and bolt to the root rib and the bolt is screwed in from the battery hatch opening in the belly of the fuselage. I added a thin plywood hard pad to take up the tightening stress. I will also add a washer under the bolt head. Sanding the root rib adjusts the dihedral angle of the wing panel.

[Gerryy]

All done for the night. here's the Bristol so far. Actually not a whole lot of time has been needed to get to this stage, unfortunately I won't have enough time to cover the model before the WRAM show as I had planned to enter it in the WW1 or the Electric catagory for static competiton! Oh well maybe next year!

[Gerryy]

I received my graphics tonight and have to say Callie Graphics are amazing! These are super thin stick-on mylar and boy are they nice! And very reasonably priced! I got the 4 six-inch wing roundels, two 2 3/8" roundels and the fuselage A/C numbers all for only $23, and that included shipping! You can see the photo of the full-size Bristol elsewhere in this build-along and that's all I sent to Callie for the decals, that and the dimensions I wanted the markings... Took about a week to get them once she received my check!

[PipesCS]

I have a friend doing the artwork for the Panther on the Gee Bee

I will also need to do the N numbers and tail logo.

I am not sure what I would need to send to them. Do you have and address?

[Gerryy]

If you would like to contact Callie Graphics you can do so at the website: www.callie-graphics.com, or email at info@callie-graphics.com or by phone at: 505 293 2922

[tandemairbike]

Nice job Gerry.

About your landing gear building methods, the old techniques still apply
big time.
Looking forward to the article.

Tandy :)

[Gerryy]

Oh yes, soldering music wire is a very useful skill for scale modellers. I have had much success with Stay-Brite silver bearing solder. I have used both glavinized wire and good old copper wire to bind the joints but the stay-brite liquid flux is great stuff! It flows easily and is easy to remove from the finished solder joints so corrosion is not an issue. I have a really big landing gear project coming up with my 1/3-scale Howard Ike racer team effort with Henry Haffke!

It uses 1/4-inch and 3/16" wire. My trusty old high wattage soldering iron broke last weekend so I will be doing this one with my propane torch!

[Gerryy]

here's a shot with the top wing in place. I started to install the radio gear last night. All that's left is to finish the attachment tabs for the wings and make the interplane struts then I will take the model apart and begin covering.

[tandemairbike]

Looking Good!

[PipesCS]

I am working up a JPEG to send for the Panther Logo for the Gee Bee.

I won't be able to do the numbering on the wings as the samples on the website are way off from the lite blue I am using

The panther is in the process of being colored in using microsoft word.

Thanks for the info on the graphics site

[Gerryy]

no problem, just tell Callie, Gerry sent ya! You'll love her work!
GY

[PipesCS]

Could you upload a photo of how you did the strut attachment?

[Gerryy]

Will do soon. my daughter has my digital camera right now and when I get it back I will indeed upload more images.

[Gerryy]

Here are some details from the plans for the cabane attachment. Basically I use a 3/32-inch ply tabs with holes drilled in them that match up to the tops of the cabane struts.
Attaching and aligning the top wing is easy. First bolt the tabs loosely to the tops of the cabanes. Then use cloths pins (or long allagator clips,) to clamp the tabs to the ribs. Adjust the wing until it is properly aligned and then one at a time unclamp the tabs and glue them in place with thick CA and kicker. When the tab is secured, go on to the next one until all 4 are secured in place. Then add the bottom wing sheeting around the tabs.
GY

[Gerryy]

Here the front view shows the cabane and tab orientation. I use 2-56 screws and locknuts. The plywood tabs are about 1/4 inch wide and 3/4 inch long.
GY

[Gerryy]

After the tabs are glued to the ribs, I added sheeting to the bottom of the wing center section to give support and to allow covering around the protruding tabs. here's a top view of the wing center section
GY

[PipesCS]

Have you considered adding the tabs to the ribs in the CAD drawing?

[Gerryy]

No, that would require making two of the center section ribs out of 3/32 inch plywood. The structure does not need that much weight. Spreading the load with seperate tabs is sufficient and more than strong enough. The same is done for the interplane struts. For me it is more important to have the ease of alignment that the seperate tabs provide.
GY

[PipesCS]

Morning Gerryy.

In looking to a future project for may growing pile of speed 400 out runner subjects I am looking at a set of old drawings from a 1938 M.A.N. on the Heinkel HE 51.

They were for a rubber model and as your biplane has perked my interest I am thinking about doing a set of plans on it for an out runner 450. I have not been following the magazines over the last few years. Has anyone done the Heinkel in a 36 inch span lately?

[Gerryy]

The He-51 is an interesting stick and tissue job. No one has done one in a long time as for MAN. I am not sure of the other magazines however. My best guess would be Flying Models. You can check their plans library from their website however.
GY

PS: as for the Bristol, I have been pretty busy lately so I will have to get back to the project and finish it up.

[tandemairbike]

Isn't it great how, after all the new stuff comes along, the old stuff is still viable and satisfying?
.02
Tandy

[tandemairbike]

Gerry;
In your Staudacher Cowl article, what gloss clear coat did you use?

Tandy

[Gerryy]

The best clear coat I have found so far is the stuff from great Planes, the LusterCote brand. But make sure it is compatible with your base color coats!
GY

[tandemairbike]

Thanks Gerry;
Is it compatible with acrylic latex?
A couple weeks ago I puchased a pint of Sig Supercoat clear dope. It cost me $7.15 plus tax. K&S silk goes for 17.00 a yard.
I really don't like iron on covering that much.
I remember when a pint of dope was $1.45 and a yard of silk was 3 bucks. At the same time a roll of Monokote was $7.95.

The only reason I quit using silk and dope was the smell. Didn't bother me, but my wife couldn't hack it.

The latex stuff don't stink but it's not fuel proof. Thought of using Krylon clear acrylic but it's not really gloss and I don't know if it is fuelproofWhat are your thoughts?

Tandy

[Gerryy]

I've only used it over other model airplane paints. not over Latex, but make a small test panel and check it out. Ne sure to apply light coats, as the carrier/solvent, can be harsh on some paints. I usually fill a pot of hot water from the tap, and place my spray can in the water for a few minutes to heat it up and increase internal pressure. The difference this makes in the finish is amazing! Never have had a problem with this method. I put about 4 inches of water in the pot.
GY

[tandemairbike]

Thanks for the input. I'll give it a try.

Tandy