Plans for a smallish Hotliner (~50" span) - RC Groups
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Sep 26, 2001, 09:19 AM
Battery Pyrotechnics Guru
OzMax's Avatar

Plans for a smallish Hotliner (~50" span)

HI all,

I am looking for plans or ideas to assist me making a rather small hotliner (or a slowliner if you let me choose the power package).


+ Wingspan - 40" to 50" (ok so we are getting close to the size of a speed 400 pylon racer.. it is for slope, field and strong thermal flying.. if that's possible)
+ Aileron & Elevator only (and esc) (only 2 servos at this stage, not 3.. will use a cable rod to get the servo action out to the wing tip ailerons. I know it would be better with 3 (micro)servos, 2 for the wing, but I am not a millionare at the moment (and they are really expensive here in Oz $55AUD a hit.. ouch, they used to be $37, 6 months ago)
+ Speed 400 (6v), 480 or 600 direct drive (wingspan dependant) or is this unrealistic. (6-8 x 600AE to start with until I get some 1500's and above)
+ Probably a T Tail. V might be ok.
+ Uses a carbon rod for the tail and a very, VERY easily builtup balsa front (or plastic, or even foam)
+ Any type of wing tapering (i.e. untapered, single, double, tripple)
+ Wing with just small amount of Dihedral. Not after a polyhedral wing.
+ Easily built foam core wing. (either EPP front/EPS rear/packing tape covered, or all white foam balsa covered. I can't build rib wings properly just yet - not setup for it. You know gear, patience, sanity, etc )
+ Thinking a RG14 airfoil, but there are probably others better suited. (unknown thickness, 6%??? just a guess)
+ trying to get that sleek f5b/pylon racer look. (Many kits here in Oz look like flying bricks, IMHO.) (Something like a smaller poor mans version of the F5B Avionik-B-99/2000 from ICARE) [ 99]

Will be used for aerobatic training and fun fly. (or Sanity Retention if talking to my superiors)

I have some basic concepts and ideas but I don't want to attempt making anything unless I have some solid details of how to do it. (hence looking for plans).

If you have anything even remotely like this, by all means let me know..


Last edited by OzMax; Sep 26, 2001 at 10:01 AM.
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Sep 26, 2001, 12:12 PM
Swedes don't grow on trees
Jonas Leander's Avatar
Check my web page and click "Speedster 400 Mutataions". The Hotster 400 is sort of what you want. It climbs very well on 7 cells, 8 would be a blast. If this looks interesting, let me know. I have a few things that you should alter if you build it. (You'll find plans as well on the page)

I forgot: Span is 1m, S400/6,0V / 6x3 folder / 7x600AE / AUW 430 grams.

/ Jonas
Last edited by Jonas Leander; Sep 26, 2001 at 12:15 PM.
Sep 26, 2001, 09:24 PM
Battery Pyrotechnics Guru
OzMax's Avatar
Yes that is getting closer. In fact the single design may do for all. I was going to make the fuse out of some cardboard tube and just have the wing slide into a slot on the top of the tube.

I take it all I do is hack the Speedster 400 plans to bump up the wing span and aileron sizes? (or do you actually have the Hotster plans somewhere?)



(Just out of interest,
+ how did you make the VCT pod/tail assembly? Do you have plans for it yet? Interested to see how you joined the two together
+ What is the lost foam method. Is this glass over foam, then disolve the foam?
+ I was considering making two plugs to make glass fuses for this sort of plane, one for a pylon racer size, the other for a hotliner size. or at least a plug so I can connect a carbon rod to a cardboard/glass tube)
Last edited by OzMax; Sep 26, 2001 at 09:33 PM.
Sep 26, 2001, 09:30 PM
Battery Pyrotechnics Guru
OzMax's Avatar
Hmm wouldn't you know it, I just downloaded the plans and guess what, I already have one of your planes. I built a Speedster 400 a while ago, but it got demolished during a room change. I think I even have a half sanded wing somewhere.

In my original post when talking about ideas, most of them came from your design... I have also made a corflute racer based on your design and it flies well (bit slow for me, but the wing thickness is way up).

There you go..

Last edited by OzMax; Sep 26, 2001 at 10:39 PM.
Sep 27, 2001, 04:13 AM
Swedes don't grow on trees
Jonas Leander's Avatar
I'm getting famous

For tube fuses, check Pierre Audette's page.

I have CAD sketches for the 1m wing and the fuse for the CVT.

The mods: What is least pleasing with the design is now is low speed turns. It tends do drop the tail. I'd suggest that you increase fin area a bit and make sure you have some differential set up on your ailerons (I ended up with reverse diff - no good I guess.) Adding a rudder would be nice - but I wouldn'd bother.

When I get round to it I am going to try it with an 8 cell pack of 1000 3US (AA-NiCads). The fuse won't accept them as it is configured now so it'll have to wait. I think the extra power will compensate for the added weight and I know that the extra weight will be nice when you are "Hotlining"

Lost foam: You're right: Make foam plug , sand to shape. Cover with packing tape, shrink tape with hot air gun. Cover with glass / epoxy, dissolve foam. Very quick for one-off fuses. I might make a mould for the CVT, but it is still being developed so i haven't set on the final fuse shape yet - it will be slimmer!

/ Jonas
Sep 27, 2001, 08:40 AM
Battery Pyrotechnics Guru
OzMax's Avatar
I too found the low speed turn characteristics a bit of a handfull on my corflute version (but that's not a fair comparison now is it), which is based on the design. I think when I do it properly, it will be V tail and be substantially larger..

here is the game plan so far.

+ Take your wing design (100cm)
+ Take your boom and CVT design (however toying with T tail design)
+ Take Pierre Audette's Pod assembly

Get this working first.

Then I will make a Glass fuse based on the same tube and CVT dimensions.

I have so far designed a plug to convert from a Carbon Boom to a tube so that will work well. It makes it easier than having to glass or glue the boom into the fuze as it (the plug and tail) can now be slid in and taped in place.

I only intend to use 600AE's at this stage, but once I get the hang of this, will go to the same concept for a speed 600 with a larger pack. Would a solid balsa wing still work for that size however? Might have to go to a foam/composite wing... ouch...

Last edited by OzMax; Sep 27, 2001 at 09:30 AM.
Sep 27, 2001, 09:39 AM
Battery Pyrotechnics Guru
OzMax's Avatar

Well I now have all the radio gear ready.

Schultze 24BE
JR R610M receiver
2 x JR 371
Graupner 6V Speed 400 Motor
6x3 folding prop (need to check this)
8x600AE pack

I have just..

+ Made and marked up the Pod
+ Made the Boom with supports for the Pod

Yet to do

+ Make T tail
+Glue boom into Pod
+ Elevator servo goes to the far back. May need a support or two as all my servos have their lugs removed so I can fit them in foamies.
+ Receiver goes under glied boom assembly in the pod. Receiver wire out the back and up to the T tail.
+ Make up wing (put elevator into the wing, not just tacked onto, to save room). Have ailerons on the outboard areas with a control rod cable run going along the bottom out to them then using dubro connectors, etc,etc.
+ Wing will have 2 forward dowels to go into the pod, rear will be either bolt on or tape on. Yet to see how much room there is
Wing will sit IN the pod, not on top as is the case with other designs. (Hence must have the aileron servo in the wing. )
+ Motor held in with masking tape wrapped arround it. and two extra pieces of fibre tape arround the front to stop any unexpected slippage.

I will include some diagrams and photos as soon as possible.

Oct 02, 2001, 10:19 AM
Battery Pyrotechnics Guru
OzMax's Avatar
Well it's finished.

Somehow I managed to cram all the gear into a really small fuse.

The C/G is a little out so I will change the speedcontroller so the battery can move forward. Apart from that it's ready to go.

I even managed to get a wingbolt system in there.

(the pic is from a video stream, hence the low quality)
Oct 04, 2001, 05:48 AM
Battery Pyrotechnics Guru
OzMax's Avatar
It flies!. It seemed well behaved, turns were stable. Stalls were gentle, and would glide very well. Haven't done any speed tests yet as it's been a bit windy.

Future upgrades.
+ Cover Fuse
+ Maybe rebuild wing - thinner

Other than that... it's pretty good (in my opion but then again I am biased)
Oct 04, 2001, 07:05 AM
Registered User
cool, how is the wing mounted, i see the bolt at TE, but th front?
Oct 04, 2001, 09:47 AM
Battery Pyrotechnics Guru
OzMax's Avatar
Ahh.. they are held together using the magic of modern technology.

The front has two dowels which lock into the front of the tube. The single bolt at the back holds everything down.

The wing is not actually sitting directly on the tube, but is instead raised on some balsa square. This is necessary to increase the compartment bay space. Also if you didn't do this, the access hole would not be wide enough to get the battery in.

I intend to get some close up shots and put together may a plan or two.

It's not HIGH Tech, but it certainly works well (considering how much gear is actually packed into it)..

Oct 04, 2001, 09:55 AM
Battery Pyrotechnics Guru
OzMax's Avatar
An image of the wing retension system.
Last edited by OzMax; Oct 04, 2001 at 09:57 AM.

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