Anyone have the answer to my question above about the elevon wood caps?

thanks

Where can I buy or get a Hotspot?? I know they don't make them any more..

The speed brake mod is essential to good landings and works very well it cures the bounce problem. The plane is stable at slow speeds and will out maneuver any BobCat or
King Cat...

P. Richards aka Swat Team

Can be bought in germany:

http://www.jet-team-liebetrau.de/pro...spot/index.htm

PLease excuse my stubborness, but I need an answer to my question below:

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

Measure the elevons and I will tell you what you want to know, but if the existing gap is 1/2" you simply cap the edges with 1/4 hard balsa which should be fine.

You need to cap both- trailing edge of the wing and leading edge of elevon. 1/2 inch balsa should be plenty. Just lay it out on the wing and cut them out. I capped the ends as well with 1/8 if I remember correctly. If you add the rudders, do them the same way. But you can use 3/8.

So Randy you are saying that then the elevon size will remain the same, right?

Thanks a lot for your help, I assumed what you suggest as correct, but wanted to confirm, I will use 1/2" hard balsa

Yes, the elevon should end up the same. You have to cut away the areas where you will add the wood. I used 1/2 I think. You could use smaller but you have less to hinge to. I used the hinges provided in the kit, glued in with aeropoxy. Haven't budged in over 1000 flights. Robart hinges work great too.

Hi HS Flyers,

I picked up one of these jets unbilt couple of month ago and will start building in a few weeks. Did you guys split the elevator/aileron and put individual servos (qty 4)? Pros and cons of using a single servo on each or spliting would be appreciated.

Thanks,

I've seen it done both ways. Splitting them sure adds some redundency but more expence and complexity. Mine are single w/ one 8411. I'd go with 8611 now. Either way is ok, mine has been working fine for over 4 yrs- propbably 1200 flights.

Randy,

Thanks for the info, I have a few 8411's and I was thinking about using one on each side. I read in one of the posts where due to a servo failure on one side the plane went down. I am contemplating to use 4 8411's and not splitting the elevons.... may be that is an overkill.... But then again redundancy is a piece of mind.[sm=wink_smile.gif]

Hard to say which one is safer. They both have up and down sides... The single servo per side would increase the likelihood of trouble due to a servo being overloaded, which won’t be a problem with adequately specified servos. The dual servo per side would increased the likelihood of trouble associated with manufacturing quality, and there's no guarantee that a servo failing in flight would allow you to 'limp home' on the remaining 3...

Personally, I run 1 per side (a Hitec 5945MG on 6V) and its more than adequate for high speed flight with ~28lb of push behind it. Of the other Hotspot pilots at the rallies I attend, each of them also has their jet set up on 1 servo per wing (usually 8411's). I know a number of others have theirs jets set up on 2 servos per wing, but I don't know any 1st hand.

Kelly

Kelly,

Thanks for the info. Got another question, have you seen anybody modifying the hotspot with a Canard? I think flight characteristics would improve...any thoughts?

Thanks,

how is this plane on a p-80?

It'll fly fine on a P-80, normal length takeoff roll and decent top speed. I think that's the turbine it was originally intended to fly with. You can probably save some weight in construction by not having to beef things up quite as much... It goes without saying though, you won't have the same top speed or vertical vs that of a P-120 or similar engine.

USSCAT, never noticed your question... (sorry) Canards have been done on this jet, but I don't really know how many variations have been done or how well they tend to work. The plane as I see it flies just fine already so I'd have a hard time deviating from the design.

Kelly

One more question guys, I am trying to set up the speed brake. I planed to use a futaba 136g which has about 90 oz/in of torque. it travels 180 degs, but I am not getting a full deployment even with longer arms so I was trying to use a aircylinder. I have seen several posts from years ago about servo vs air cylinders, any comments would be appreciated.

If you were to use the air cylinder, which way would you install it, a) the tail end of air cylinder toward the speed brake hinge or b) tail end toward the fuse end

Thanks,

Mine runs of a Hitec 645 MG. Its got adequate torque to deploy while on final. The speed brake won't go all the way to 90 degrees. I think mine goes somewhere around 70 or so. If you use the linkage to its limit, you'll have trouble getting the brake to lay flat without binding the servo arm. I'd run out and check for you, but I've got it packed up and ready to roll off to the High River jet rally tomorrow. [8D]

Kelly

Kelly,

Would you use cylinders in place of servo? I am thinking that would be less weight and less power usage.

Thanks

Not really any lighter but it was pretty easy to set up.

In order to be safe, it should not be chained up to any of the critical air systems... (Gear or brakes) This kinda demands an entire new set of pneumatics, and driven by a servo... If that's the case, you're likely to gain weight, and certainly complexity with the pneumatic version. The servo option is variable and only pulls significant levels of current when applied, if its not set up to bind when retracted. I haven't noticed any specific Rx voltage drop when I apply the air brake brake. I use an eagle tree data logger that records data in 1/8 second increments...

Personally, I'd stick with the servo. I actuate mine about 1/2 way as I'm coming off the down wind leg, then full once I'm in line with the runway and want to start bleeding off speed more aggressively. Its a functional brake when the nose is level or down, nose up, the drag induced by the delta wing is going to be WAY more than your air brake.

Kelly

My old HotSpot (rest its soul) used a MPX Mc/V2 programmable digital servo on the speed brake programmed for 180 degrees of throw. Worked perfectly. Never an issue with plenty of power. I would use one of those or a modern Hitec digital and program for more throw.

P.S. I had it set up so that the servo arm was in-line with the pushrod at full brake deployment so there was effectively zero servo load. It was easy to do. I'd skip the air cylinder and use a servo.

Woketman/Kelly/Randy,

Thankyou for all inputs. I was fooling with the ~3/4 " diameter cylinder that I planned to use, I may have to change to a slimer one if I go the numatic route. I may just end up using the Futaba 136G retract servo. I think I can get about 60 degree lift off of it.

I am sure I will have more issues as I go along. It is nice to have a support team here.

Thanks again guys.......

Hi Guys,

Does anyone know where I can get couple of the phenolic tubes for the wing? My kit was missing one and the guy that I bought it from got some 20 mm carbon tubes that fits the aluminum tubes perfectly but the wall thickness is thinner than the phenolic material. it is a bit loose inside the wing.

I finally resolved the speed brake problem that I had. I dropped the box frame floor where the cylinder was mounted to by 1/8" and machined a aluminum adaptor to fit the horn that was installed. It is operating like a dream, it sounds pretty coooooollllllll. I guess I will hook it up to the brake line air supply....any comments or suggestions would be appreciated.


Thanks,