The airbrake is definitely neccessary unless you have a 1000 ft runway. It makes all the difference in the world in slowing the Hot Spot down. Beleive me, I had a failure on the air brake system and it was a bear landing it without it even with a strong headwind. I would not build a HOT SPOT without an AIRBRAKE Steve

Steve,
I just started flying my HS, wonderful to fly, but soon we discovered some nasty habits, flying it off an airbase concrete RWY.
But first:
Throw away the Eurokit gear, I had to make countless mods before it even worked. F.i., no way the spring air based system could pop the gear if it was lying on its back on my bench. Even upright it got stuck if only the lightest of obstructions came in the mechanism. It must be able to overcome the air resistance when flying, so it should have some extra capacity cranking the gear down. Up was no problem.

The first mod, even before the maiden flight, consisted of replacing the wheels/brakes with Intairco units. At least I could brake now with assurance.

We made the first (very successful) flights with the Eurokit but after a few flights we made twice landings while passing over small rubber ridges in the concrete. Sickening to see if after a nice landing, the HS suddenly starts to bounce, and You can't do a thing at it! The last one I had considerable damage done to my wingtips, my whole nice paint job ruined! Of course the landing speed must have been a tad too high, but we (my son and I) are new on the jet scene...need some time to get lower speeds on final.

So after my last mishap I got the Eurokit gear out and now I have the absolutely gorgeous BEHOTEC units installed, terrific workmanship these are! These are of the air/air type, iso of the spring/air type of Eurokit.
Currently I am awaiting the Jet A-1 struts, which have a trailing link type of dampening. I figure they will take the Intairco units. I hope these expensive mods will stop this crazy HotSpot Dance!

A few weeks ago at the Apollo 11 Field near Van Nuys in LA, I witnessed an HotSpot owner who had shortened his HS's nose leg a little bit, in order to get the nose lower after landing thus preventing bouncing.
From a friend in the UK I got the advise to add canards to the nose...
As a short term remedy I will have to learn to push firm down elevator, right after touchdown, which is a bit unnatural to me. Plus then we also get my brakes on, which run in sequence with down elevator.

Some tech details about mine:
Power is JetCat P80
Futaba R129 DP receiver
Emcotec RV6 power unit
2 X 5cell 2200NiMh batteries
One 2500NiMh Bat for the engine (all batteries stowed as far as possible aft in the fuse for balance)
4 X 8411 for aileron/elevons
2 X Multiplex FL BB for the rudders, a perfect match for this model!
To get all stuff programmed on my Futaba FC28, which has only 8 programmable channels I had to make use of THREE Stephan Merz (SM) electronic programmable Y-cables: for the twin rudders/nose steering, the parallel running wheel brake with elevator, and two servo's that control the separate gear and door sequencers.
Airbrake (be SURE to fit one! I like the ventral type also, shown in the previous pics....too late to install it in mine.
Sequencing doors (they close again after gear down.....at first it looked overkill to me, but at least they do not get damaged with a bad landing..)
Fuel tank 2 liter Coke bottle, PET quality, which is very sturdy)
UAT hopper
Ultra Precision UP8 gear valve
Ultra Precision door sequencer
Ultra Precision Wheel brake valve
Ultra Precision tubing (very resistant against kinks with tight bends)
Jet-tronics air brake electronic valve
All couplings and filters FESTO
Separate wheelbrake airtank
Weight empty 10,5 kg, some 22 lbs

Hi Flying Arrow- What paint scheme did you finally decide on? Would love to see it. Scott

HI all, I read Wolfshound post about the Hotspot flying slow and asked him, what"s your CG at, but he replyed that the secret to slow flight was adding 3mm spacers under the turbine. I don"t know as of yet if he raised the turbine on all 4 points or just changed the angle of the turbine. I hope to get a answer from him shortly.
Might make sence to put the spacers at the rear, that I think would reduce all that up elevater for level fight.
Rcpete

The trick to landing the Hot Spot is the speed. You have to get it slow. Get the nose up on final, and just bleed off the speed, be ready on the gas just in case you need to drive it in. When done right, it just looks cool.
I did have one really nasty one awhile back and got the bounce. It was horrible. Bounced so bad, it came down on it's ***** end. Broke a wing tip and my pride.
There are some tricks to try- dial in a little brake on gear down, as soon as you touch down, you stick. Works with any plane. I know some scale guys that do it. Not too much, or you slide.

Make sure it sits a couple of degrees positive AOA on the gear. Mine nose gear spring was weak and the airplane wouldn't rotate even though it was blasting down the runway. You don't have many good options when that happens.[:@]

Here are the latest pictures of my Hotspot. I will begin electronics install soon along with all the rest of the stuff. Glassing will come after she is ballanced and all components are functioning. The gear doors function excellent and will make this just even harder to land I've been told. Figure about a few more weeks and I will be starting my JetCat P-120! . Enjoy!

Darn!
Just received my new legs, high quality Jet A-1 Trailing link legs, but alas....WAY too short! Some 40mm off....
Already have word from the dealer he is willing to take them back, good service. Have to look for other solutions.

ledd4du:
I guess the P120 is a bit overkill, a friend of mine had the same setup initially. Max speed was not that much higher as with his P80 which he installed later, but of course fuel flow and weight were.
The biggest drawback was the higher idle thrust output, which made landing even more difficult to bleed off speed.
Compliments with the work on Yr HS, looks like good craftmanship!
Again: the retracting doors(after the gear is down) of course mean less drag on final, drag that is much needed on this slick plane, but sure keeps damage away from at least these in bad landings.
Covering up these big holes will give lots of more max speed, I have been told. Some HS's have been crashed by literally blowing themselves apart because of airflow ramming into the fuse, plus others have reported the speedbrake coming UP during high speed flight as ramair was seeking its way out of the fuse.

Randy M,
My last bounce was exacly the same, after two bounces it just fell down vertical, tail first, from 5 feet. That noise of the fall made me sick, but damage was not too bad after all, bent legs, damaged tips (same, plus a buised ego...), trailing side of fuse cracked open. Good the twin rudders that stick out far behind the fuse protect the engine, otherwise damage would have been quite considerable to the engine!

RCpete347
I guess from a thrustline point of view, adding spacers under the backside will lower the thrustline, thus pushing the tail lower with power on, same as UP elevator. To a certain extent, it will always need some up trim, to get that S-type of profile, needed with flying wings. I might consider it trying too, but not all mods at he same time, just carefully one by one..

In the beginning I had also trouble with my landings (on a grassfield). There was always one bend leg after each landing. Than I installed these



(www.digitech-turbines.com)

Now I can even smash the plane to the ground without any damage.

I'm using Eurokit...

Koenieboy

These are the legs richard is talking off!
But you are right they are perfect under a trainer!

Koenieboy
Indeed, as Henk says, these are the ones I have now.
I decided to keep them now, already made long pianowire 6mm extensions, and a friend of mine is machining alu leg extensions to go in between the mechanism and the Jet for extra support. I need some 50mm extensions on the mains and 65mm on the nose. I kept the total nose strut about 10mm shorter, to have less angle of attack during landing. Cannot go negative as this brings the danger of not being able to rotate for take off, as has been said before.
Will post pictures in a week or two when they are finished.
The legs plus wheels now fit very precise into the fuselage holes, only I had to make the rectangualr hole for the gear leg some 4mm wider to accomodate the wider legs, so I have to make new gear leg cover plates to close the holes when the gear is retracted. No big deal.

I trust these legs will solve the bouncing problems, in the 1/1 world planes like some Cessna Citation models have them also and they are very easy to land.

Justinh,
Here is some info for making doors on the HS
The wheel well is covered by doors that swing open, actuated by a small type air cylinder. Be sure to make the door sturdy, I covered it with carbon plus made a frame under it. If not they will deform in the breeze and might be wrung off. The area around the hole in the fuse should be beefed up with some plywood framework, otherwise it will deform.

The struts have long slender cover plates, you will need to make some mountings that You can glue thes covers onto.

The mechanism is covered with a small CFK plate which has a small flap that covers the moving part. The small flap is hinged with small robart hinges and fitted with some flat elastic band (the one type that is sometimes used in old fashined underwear!) so that the flap is always pressed against the leg, whether up or down.

For the nose gear the long rectangular geardoor is hinged and also actuated by a small air cylinder, the front small cover is again fitted with an electic band.
Here are some pics to make it more clear, I hope this will clarify a lot. Cannot answer more questions, will be gone for a good week.

believe me when i say it is all a bit overated
i have build lots of kangaroos and harpoons for customers (12+)
i also used the absolute standard servo 5077 50N (5kg) to prove that it is more then enouhg to fly around for ailerons and rudders and nose leg and thrust pipe
we flew them full throttle with a 85N engine koen saw them fly or bounce at the pampas years ago before we had the jet1a.

I have decided to stick with the Jet A1 gears, they look anyhow terrific.
Had a friend make alu tubes and used longer 6mm piano wire to lenghten the legs. Thereby I shortened the nosegear a bit to get a lower angle of attack after landing, so hopefully it will glue itself better to the ground.
In all it looks very sturdy now, the Behotec gear mechanism just slipped in the old Eurokit mountings, only I bought a UP valve because it is now an Air/Air system, unlike the spring/air of Eurokit.

The longer legs fit exactly in the recesses, only the area around the leg itself had to be opened a bit more, and I have to make wider cover plates that will be attached to the gear legs.

Hi Scott,

Thank you for asking. I got it to paint ready stage, but i did not paint it. I was busy building my rookie II, Lightning and other jets. I will have to finish it but will try after the summer.

Best regards,
Eid

Dear Friends,
I have a hotspot unfinished kit that came from an old Turkish modelbuilder.But, he lost all instruction pages, I find from graupner download pages but no illustration and pictures for building tips, only written instruction.
can you send to me , If, anybody has orginal illustration pages.
thanks,
www.gjet.net
[email protected]

Cumhur, please check your email. I just sent you a copy.

Kelly

Kelly,
Thanks for your mail, but , this is not what I looks for illustration pages. Actually, I need orginal one, from graupner. Because, there are many small hardwhere,playwood and stuff whic is not marked on it. And , I could not find it anywhere , strange!!!!!
gtba no 1995 ( I was member, but not now)
cumhur
www.gjet.net
[email protected]

Just finished this Hotspot for a customer in Texas. It is built stock with Eurokit gears, wheels and brakes. Has a Ram 500 for power and all flying surfaces covered with Ultrakote. Speed brake is actuated with an air cylinder. Standard servos are fitted in the rear of fuselage with carbon fiber push rods for the rudders. Booms are bolted to the fuselage. The jet group at Markam Park in Ft Lauderdale has a few of them flying. Here are some pictures

Hello can you still buy the hotspot, if so were ?

I don't think they are available any more. You may be able to find one in old stock somewhere. Check with Graupner or someone who supplies from Graupner.

A few months ago, I tried to find a HotSpot kit. Graupner does not make them anymore.
I contacted a lot of dealers in the US and Europe and found nobody had them.
The only place I am aware of to get one is from
Peter Liebetrau at http://www.jet-team-liebetrau.de/index2.php.

He is the original HotSpot maunfacture. I talked to him and he has a new wing design for the HS which is now part of his kits. The price is very good...the problem is the shipping costs are astronomical.

Finally its ready to go. I'm just not sure of this Elevon setup.

Mitchell

Hi friends:


My new paint of my HotSpot. Flying ago 3 weeks in Bragança, Portugal.

Hitec servos, Eurokit gears, JR radio, 2L Coca + UAT, Simjet 2300 GS.


Regards from Spain.


Carlos.

I'm starting assembly of mine, can anyone tell me what size of hard balsa should be used to cap the elevons and wing elevon hinges? should the cap be added on top of the existing wing opening and remove twice the cap width from the elevon or should I remove the cap width once to both wing and elevon? It's important to know because surface area will change with which way I go and the throws would not match.

Thanks