Sharkface build, Big bandit

[Big Bandit]

And now for something completely different, for me anyway. It all started with Lee Damms leaving his Eric Clutton designed singe channel Sharkface on view. As I already had a plan that I had copied a few times I thought that it would be a nice little build for a bit of fun. It's designed for anything from .8cc to 1.5cc so I hooked out 3 motors that fit the bill. An early version OS Pet, 1.5cc, a DC Wasp .8cc, and a Cox 049 with a diesel conversion, I've settled on the Cox because I do not need to bother fitting a tank in the model.

 

 

As has already got a sort of silencer fitted, I think Cox called it a quiet zone.

 

 

All the bits were transferred to the balsa using the original Typewriter carbon paper. using a ruler and a french curve.

 

 

Fuselage copied

Two sides can be cut from 1 36" x 4" sheet with enough left for the tailplane.

 

Cheers,

 

Chris.

[Big Bandit]

Since it has been designed to use 1/4 sheet doublers and 1/16 sheet sides, I can see no sense in that so I've decided to use the basic sides with 1/8 square balsa edges and 1/32 ply doublers. First hold both sides together and sand the edges.

 

 

All of the formers are from 1/4 balsa from the scrap box, and the fin is from 3/32 scrap sheet. Also the wing rib template is from a scrap of 1/16 ply with sand paper stuck to one side, and the nose former from 1/8 ply.

So all of the bit's together, 2 9g servo's a 4 channel Multiplex RX and a 250 ma/H nim.

Trim up the sides in 1/8 sq balsa and stick the ply doublers with contact adhesive, I used UHU Por which works well, and my favorite Ambroid balsa cement for all other joints. The small bottle is Ambroid thinned 50% with Acetone for pre gluing all joints.

 

While the fus sides dry I've cut the wing ribs, 12 off 1/16 and 3 off 3/32.

 

 

When the fuselage sides are dry pin together and trim around the edges.

Back in a bit, Chris.

[Big Bandit]

To carry on, Mark the position of the formers on the inside face of the fus sides, and glue the formers to one side using an engineers square to ensure every thing is square.

 

While these were drying I cut the servo tray from 1/8 lite ply, and glued 1/4 square spruce runners to the fus sides for the tray to sit on. Glue the sides together with formers F2 and F3 using the servo tray to hold the formers square, I weighted this assembly down with an old battery and allowed to dry.

 

 

Pin the bottom main spar to the plan. I've cut the centre for the dihedral joint and chamfered the end of the spars to suit.

I built the wing off the spar adding the 1 x 1/4 trailing edge after slotting for the ends of the ribs, adding a 1/4 x 1/2 false leading edge, and the obligatory gussets to the rib LE joint.

 

The front ends was then pulled together using rubber bands to hold in place whilst the glue dries, ditto the tail end using a paper clip.

The 1/8 ply nose former added

 

Usfull tools nicked from Chris Bott's idea is sticking emery paper to hardwood strips very handy for cutting spar slots and the emery nail sanders are good for slotting out 1/16" for the rib ends to the trailing edge.

 

I'll see if I can do some more tomorrow before getting back onto the Super 60.

 

Cheers

 

Chris.

 

[Big Bandit]

Hi All,

 

Quite a productive day on the little Sharkface down the shed, the plan I have was a freebee in Aeromodeler Magazine in July 1965. Originally for single Chanel using a rubber powered escapement for rudder only. I've just added elevator. On with the build.

 

First off, sheet the fus top and bottom, although the plan calls for 1/16 balsa I've used 3/32 with some 1/8 at the nose end back to the former F3, which will be blended in with the rest of the sheeting. I've purposely left the top sheeting behind the wing off in order to get at the linkages. Glue and pin it all on and leave to dry.

 

In the mean time trim the ends of the top spars for the wing to accommodate the wing tips, and fit the spars.

 

 

While the spars and fus sheeting drie cutting a few gussets passes the time

 

 

As does cutting an offcut of nylon to 1/4 strips for the rudder and elevator hinges.

About 5 will do for this one, and it's easy to cut more if required.

 

 

Next job is to cut the dihedral braces for the spars and LE, I've glued these straight on and held in place with paper clips to dry.

 

More to follow when I've had me caffeine fix .

 

Chris.

[Big Bandit]

To follow on, while the braces dry I've cut some wing tips.

 

And doped the tailplane fin and rudder, these are just cut from 3/32 sheet so NONE shrinking dope should be used for these to avoid warping. I also pin them down to be sure.

 

While they dry, I've glued the wing tips in place and trimmed spars, trailing and leading edge for the other wing for the dihedral and joined them with one wing raised by 2 1/4". It doesn't say on the plan but that looks about right.

 

I've also made up the elevator joiner, cut the elevators from the tailplane, and grooved out for the joiner.

And hinged the rudder to the fin with the tape strips I cut earlier, these make a good hinge. The last time I used this type of hinge was back in the late 60's on control liners and they never let me down. Simple cheap and reliable.

 

 

So this where we are today, the fus has had it's first coats of dope, when the glue has had time to dry on the wings, they can be sanded to final shape, and the elevator needs hinging. Then it's time to cover it all, I'll use lightweight tissue on the fus and heavyweight on the wings.

 

And with the fin pinned to the fus, I can get an idea of what it will look like. Not bad for a quicky with a fivers worth of balsa plus some bits from the scrap box, in fact I went over board when I brought the wood at £17, just less than £12 will build 3 models plus a bit of tissue dope and glue.

 

 

I doubt if I will get any done tomorrow as I'm off the see the outlaws, but Monday should see it about done, then it's back on the Super 60.

 

A happy new year to you all.

 

Cheers ,

 

Chris.

 

Edited By Big Bandit on 31/12/2011 18:51:52

[Danny Fenton]

looks great Chris, you have been busy!

cheers

Danny

 

[Bob Cotsford]

Gawd, I can remember that as a free plan, it must have been one of the first Aeromudellers I bought out of pocket money!

Nice to see the old control line hinges being used, as you say they never seemed to fail no matter what abuse they were subject to.

[Big Bandit]

Hi Danny, Bob,

 

It's just for a bit of fun, and I've had the plan for years so it's a bit tatty now and I've had a few copies made. They haven't turned out to good though as some of the creases have been copied as well so things don't quite line up in places so I may re-draw it at some time.

 

Happy new year both,

 

Cheers,

 

Chris.

[Danny Fenton]

Happy New Year Chris, and thanks for your help with the diesels and vintage builds. Much appreciated

Cheers

Danny

[Bob Cotsford]

and a Happy New Year to you too Chris

[Lee Damms]

Glad you've started Sharkey, Im sure you'll enjoy flying her, minimum outlay maximum fun. Can't wait to hear what she's like, you'll have the first New Year Sharkey to enter the Sharkey squadron.

Lee

[Big Bandit]

Hi Lee,

 

I'm sure I will enjoy flying it, and really looking forward to getting it finished, as you've already said it's a quick build and cheap as chips. That Surestart you've got fitted, I have about 3 of those and was wondering what back plate you use (the black one) it looks a very tidy mounting.

 

These things remind me of the matchstick back in the early 80's, which was a free plan in RCM&E back in 1981. I had the plan blown up to A3 format for both A4 sheets and stuck them together. The then, mini servo's were 16gram Futabas with a standard RX and 500ma/H nicad. The first one was powered with a Cox QZ, then a Black Widow, after building about 5 of them the final version had a Tee Dee 051 which was mental. The wing was fully symmetrical at about 30" span on aileron and elevator. I'm expecting great things of the Sharkface.

 

I've since tried the electric version without the same level of success, maybe time to revisit it.

 

A happy new year to you,

 

Cheers,

 

Chris.

[Lee Damms]

Hi Chris a Happy New year to you. The fitting is a Sure Start firewall mount DMS X56 from Dens Models £3 he has loads of other goodies including an backplate with R/C throttle. sure start firewall link

[Big Bandit]

Hi Lee, Thanks for that and I'll get a couple ordered, I might even get an RC carb for one of them as I have a couple of other 1/2A lazer cut kits. A Das not so ugly stick and a small pattern ship, both worth a punt for some relaxing building sometime.

 

My mate John Walton has brought the business off of John D Haytree, so he has an abundance of spares, he's also looking at doing the diesel conversions like the one on my motor along with his already massive range of vintage motor spares, Goes under the name of Motorvation, worth a look if you want any engine parts or a renovation job doing.

 

Cheers,

 

Chris.

 

[Big Bandit]

 

 

Any road up I did manage a bit of shed time yesterday, and down loaded the pici's, it's not far off now.

 

First off I wanted some wider strips of nylon for the elevator hinges so cut these first.

 

 

Then stick some to one side of the tailplane, leaving enough gap to stick some on the other side. Balsa cement rules for this job just like the old control liner days.

 

 

Then stick some on the other side.

 

Just out of interest I found one of my old galloping ghost (servo's / actuators) made by Fred rising and shows how things have changed.

Fred Rising actuator compared with a 9 gram servo

 

 

This is the clutch end. It used a split supply of 3 volts each side from a 2 pole two way relay. 4 pen cells in total.

 

 

And the connection end, straight push rod to the rudder, just just pulse the push switch on the tranny with your thumb, more off than on for left, more on than off for right, and equal off and on for neutral, usually takes a few models to get the hang of it and it does work in the end.

 

then pull up the tapes fairly tight from the underside of the tailplane and pin to the top.

offer up the elevators.

Then pull the pins and glue the tape to the upper side of the elevator, turn over and do the other side the same. Nice free hinges for next to nowt.

 

 

Glue the tailplane to the under side of the fus, I use the freeby tapes from A well known Scandinavian furniture warehouse to measure when the tailplane is spot on square. Just stick a pin somewhere in the centre near the front and measure to one side of the tailplane.

 

Do the same to the other side. When the measurements the same the tailplane is square to the centre line of the fus.

 

 

Back in a mo.

 

Edited By Big Bandit on 03/01/2012 17:38:49

[Big Bandit]

Aaaaaaahh that's better. I always need a caffeine fix. I've mounted the servo's direct to the servo tray then mounted the tray to the two 1/4 square spruce runners previously glued to the fus sides with rubber grommets and brass spacers to give an amount of vibration resistance. Notice the intentional gap with the fus sides, as this one's IC powered it's important that any vibration is isolated from the electronics so far as is reasonably practical. A couple of plastic sleeves and wire push rods is more appropriate for this model. An 800 ma/H Nim provides the RX power.

 

Then finish the gussets already cut for the wings, one side.

 

Then the other. A bit of extra glue at each tip as appropriate to ensure the wings balance at the centre rib, and the jobs a goodun.

 

Overall weights, Wings, 30 Grams.

 

Fuselage ready to cover, fin, rudder, tailplane, and, elevator, with all radio, linkages and 800 ma/H Nim installed, 182 grams.

 

Motor, 67 Grams, to me that's 279 grams in total uncovered, tissue, dope, and a bit of trim, the thick end of nowt or 9.84 oz's in English uncovered,12 oz's at most ready to fly with the CG about where it's supposed to be. Sweet.

 

And it's a diesel . More after work tomorrow

 

Cheers,

 

Chris.

Edited By Big Bandit on 03/01/2012 18:56:20

[Big Bandit]

Manage a bit more today, first off to cover the fuselage with light weight tissue, give the area to be covered a coat of None shrinking dope.

 

Apply the tissue dry brushing more 50 /50 thinned dope through while wiping away the excess with some clean kitchen towel, to get rid of any wrinkles.

 

 

Allow a few minutes to dry then, using some fine grit paper or worn sand paper just go around the edges lightly, and peel away the excess tissue.

 

Finish the rest of the fuselage in the same way.

 

And the end result will be a covered fus with clean edges and a smooth covering. Repeat for the tailplane and elevators, Fin and rudder.

 

Then using shrinking dope, give the LE and TE of the wing a coat, and Apply Heavy weight tissue, pulling tight and without wrinkles. A small water spray helps. I try to cover the bottom of small wings in one go.

 

 

The small water spray I use.

 

 

Complete the under side of the wing, spraying with water and doping around the edges as you go. Keep the tissue tight and wrinkle free as you go.

 

Allow to dry, and trim off the excess with the old sand paper. Then cover the upper surface of the wing.Use two pieces for this and the same method as for the under side.

 

 

Complete both upper surfaces and allow to dry, the tissue should pull drum tight

 

Give both surfaces of the wing two or three coats of 50 / 50 thinned shrinking dope, and the fuselage, tailplane, fin, rudder, and elevator two coats of none shrinking dope thinned 50 / 50.

 

Drill for the motor mounting screws, and fix the motor in place. Add the wing pegs ( I use bamboo Barby skewers) for these on small models.

 

 

Ready for trim and fuel proofing.

 

Cheers,

 

Chris.

Edited By Big Bandit on 05/01/2012 21:15:33

[Big Bandit]

As for completed weights, 316 Grams or.

 

 

11 oz's in proper money.

 

Ready for a bit of coloured trim, again using tissue, a quick spray of fuel proofer and the weekend weathers looking good for a maiden.

 

 

It balances spot on the main spar at 11 ounces RTF.

Cheers,

Chris.

[Lee Damms]

Nice bit of covering that Chris think I'll pinch your idea of spliting the elevator for my MK2, just ordered some scales I should imagine mine will be a few ounces more with the solatex wing and painted fuselage. Looking forward to hearing what the performance is like I've never seen a dieselised cox before, I'm going to try and get my DC Merlin going for the MK2

Regards

Lee

[Steve Hargreaves - Moderator]

I'm depressed.......!!!

 

I don't think I could have found my scalpel & read the plan in the time its taken Chris to build the model......

 

Fantastic work there Chris.....looks really good.....

[Big Bandit]

Hi Lee,

 

The Merlin would be a good choice to power one of these, I have about 3 of them.

 

In saying that dependent on age the Merlin does tend to suffer from Contra piston problems with them locking so that they can't be adjusted. I just take the cylinder off and tap the piston back, after doing this a couple of times the thing loosens up and they run sweet. On the other hand if the contra piston is too loose it makes starting quite hard so I drift the thing out of the top of the cylinder and put it on a piece of hard wood on the anvil of my vice, then use a suitable sized ball bearing to "ping it". Just put the bearing in the open end and one tap with a four oz hammer, not to hard usually does the job. Squeeze it back into the bore gently in the vice with a piece of hardwood at each end. I do this with any diesel I own that has a loose contra piston, it works every time.

 

Once sorted they are a delight to operate compared to some other motors.

 

Hopefully my Sharkface will be trimmed up and fuel proofed today and the motor run up in the garage, just a couple of tank fulls while the fuel proofer dries.

 

Can't wait to get my Matador started now, I've been following you blog with interest and forming up my idea's, the motors going to be a Mk2 ED Bee if that doesn't provide enough urge I'll change it to a PAW 149 both good motors. What I'm trying not to do is over power it at the same time I don't wont the motor to be screaming to maintain height.

 

Cheers,

 

Chris.

[Big Bandit]

Thanks Steve,

 

They are so easy to put together, and quite enjoyable in a simple sort of way, and what with the balsa cement, dope thinners, tissue, diesel, acetone it's like going back to basics again.

 

Looking forward to seeing your Sharky taking shape.

 

Cheers,

 

Chris.

[Lee Damms]

Hi Chris, now thats a good dodge with the contra piston I thought I'd have to make a new one. Just for info there's a note I came across on the modelenginenews.org site which says

A note for Merlin owners, there is a red fiber gasket that fits under the exhaust port band of the liner. This gasket not only seals the crankcase for primary compression, it also sets the "deck" height of the cylinder and thus, the transfer/exhaust ports. If it's missing, or too thin, transfer does not occur and you've no chance of ever starting the engine. With the correct gasket in place, the Merlin is a docile, easy starting engine of modest power, able to be "throttled back" by slackening off the compression to spin a 8x4 wood prop comfortably--doubtless, a reason it gained popularity with the FF scale community.

Lee

[Lee Damms]

Hi Chris forgot to say thought about putting my PAW 1.5 in but its an old non throttle job and I did'nt fancy an un throttled PAW the ED Bee should be much more sedate and with the standard rigging angles should be fine unless you're doing a full solartex covering.

 

Lee

[GONZO]

You could 'enjoy' the full single channel experience with the Sharkface if you get one of PhilG's single channel emulation encoders. Put it in a plastic case, feeding a FrSky (or other make) 2.4gHz module, with a push button on the front. The encoder is configurable for sequentual or compound opperation. It can even be configured to give kick up elevator and quick blip throttle. The Rx and servos are as used for propo. The big plus is its reliable using a 2.4gHz RF link .

Single channel - its the way foward in RC!

Check out the link to his site and go to the '2.4gHz Conversions' and 'Archive' pages:

Phil and Shaun's Single channel and Vintage R/C page

 

 

Edited By GONZO on 06/01/2012 14:09:33