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Hello:
really is a good thing that every body tell his problems. But... One question ! Do you fit the fins with screws to the fuselage ? I always fit it, because the system of fit the wing not is enough for fit the fins. Carlos. |
Kelly,
Here are the pictures of the wing root, i know they don't tell you much without a proper reference point. But if you want i can trace the outline of the root airfoil on some paper, scan and send it to you. If you need any more measurements just let me know. http://imagizer.imageshack.us/v2/800...0/691/6pgs.jpg http://imagizer.imageshack.us/v2/800...0/850/hwyr.jpg http://imagizer.imageshack.us/v2/800...0/138/ijdt.jpg http://imagizer.imageshack.us/v2/800x600q90/35/d5u0.jpg @Carlos; I'm not using any extra screws on the fins, they are just wedged between the fuse and wings. Maybe the flutter just becomes an issue once you add rudders? Or maybe i'm still too slow to have problems with it. Regarding rudder servo's, you might want to look into the MKS DS6125 servo, full alluminum servo case with titanium gear train, absolutely zero slop and almost double the torque of similar servo's. Regards, Bart. |
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Not sure if the pic is clear but I put my rudder servos in rear fuze. I mounted them on a board and dropped them in using nylon line through the arm slot in fuze attached to servo horn to fish them through.
Then screwed them down through fuze bottom. Fins was bare wood with film covering. Not too rigid but I never had flutter at 400kph+. used plain old 504's Also the rudders are only halfway to top of fin. Andre http://www.rcuniverse.com/forum/atta...mentid=1976284 |
Hey Bart :
That profile look cool, please, send me it to me too. Not has washout ? True ? [email protected] Many thanks in advance. Carlos. |
Hey Kelly
The statment regarding the air brake in turns on finals, I do have some info on this: I use the pneumatic system on my speed brake so I have no choice in how far it comes out when deployed, but to reduce air speed for a nice light landing I do deploy it on the start of the downward leg before finals! The rule of thumb is the throttle is kept at 25% all the way round the turn on to finals giving you a kind of thrust over drag situation! This puts the airframe in a +Alpha position with no loss of control. The throttle then controls the height and the elervater controls the speed, I just pick where I want to touch down and just kill the power! It works for me and I must point out that I am using an AMT Mercury which has an outstanding throttle control, I love the Hot Spot and will always hopefully own one! ;) Regards John |
John,
My statement on the use of the HS speed brake/air brake in turns stems from Steve Elias' suggestion several years ago. As per his advice I plaqn to actuate the brake from a servo linked to the left slider on the tranny. Steve recommendation was NOT to deploy it during turns. Anyone's direct experience on this would be appreciated. Thanks. Rgds, Art ARRO |
Originally Posted by Art ARRO
(Post 11755338)
John,
My statement on the use of the HS speed brake/air brake in turns stems from Steve Elias' suggestion several years ago. As per his advice I plaqn to actuate the brake from a servo linked to the left slider on the tranny. Steve recommendation was NOT to deploy it during turns. Anyone's direct experience on this would be appreciated. Thanks. Rgds, Art ARRO Once you have the brake out you need to keep the plane up by raising the throttle a little, or it will fall out of the sky pretty quickly |
Originally Posted by Kelly W
(Post 11755058)
No problem Art, its good to see this site can still work for guys to offer help to each other. Ya, Al W is a good friend, and it took a while to convince him to let me have the jet when I lost mine... It was either this kit from Al, or a used jet with some (fixable) nose damage hanging in a hobby shop near Toronto. I think that one's still there if anyone in the East is on the prowl for a jet, but it has the Euro gear and I think Du-bro wheels... Not traditional hardware.
Hey, on the speed brake... Are you going air or servo operated? If servo, can you post a pic or 2? My speed brake frame survived my crash but isn't worth using in the new fuse. Kinda feel like a scratch build at times, and I could use some inspiration... Interesting note on the turbulence at high alpha, makes sense. I heard there is a similar theory on F-16, having the nose blank the fin, which is apparently the reason for the relatively large fin + ventral fins. Don't know for sure, just what I was told. On the HS, I only extend the brake full on final but half extension and gear down sure makes it feel mushy... No idea what it would turn like on full brake. The biggest HotSpot instability issue I've witnessed was from my buddy Jon. He's on to his 2nd hotspot, with a homebuilt UT-160 for power. The jet can get into a Roo-like chicken flop if the airspeed comes down too far, while flying on a rearward CofG. His 1st one crashed twice because of this, both times rebuildable though. At least, if it does crash, it goes in at low speed. Forward CG doesn't seem to have the same problem. If it happens - pilots say the way out is to just cut the throttle and wait for the nose to fall - then fly out if it still has altitude to recover. Jon tried to power our of a spin the 2nd time, and it didn't work out well... I once saw a guy at Superman do this on purpose. He floored it in the spin and the jet went ballistic flopping all over like a bouncy ball. Guessing that is a gyroscopic effect from the turbine. Looked cool, but probably beat the hell out of the bearings! Man, this thread is making me want to go out into the garage and get on with finishing it. winter - please go away...:( K It's not winter that's in your way for finishing that jet, it's the piles of other stuff in your ????...... Oh, ya, I guess it is a garage. :p Don't worry about the boneheads on this site. There's lots that appreciate the insight - just learn to ignore. There's even a feature where you can ignore individuals in your settings. I have a few in mine..... PaulD |
Originally Posted by Art ARRO
(Post 11755338)
John,
My statement on the use of the HS speed brake/air brake in turns stems from Steve Elias' suggestion several years ago. As per his advice I plaqn to actuate the brake from a servo linked to the left slider on the tranny. Steve recommendation was NOT to deploy it during turns. Anyone's direct experience on this would be appreciated. Thanks. Rgds, Art ARRO I deployed it to the 1/2 way click on the slider on the down wind leg, turned on final, went to full. The odd time I did a go around or full circuit with the brake 1/2 up, the plane really flew different. This plane is kinda neat in how smooth it flies when clean, almost like its flying itself for you. Gear down and brakes up, and its not particularly difficult but the pilot definitely needs to 'fly' it with the throttle stick and be conscious of energy management. Flying at 1/2 deployed speed brake, I never noticed any issues relating to yaw stability though. With throttle, I think it needed a bit more nose up elevator but it might have been just my imagination... Suppose my preference using a 1/2 way point is based on trying to make the transition of flight characteristics a little less dramatic, not critical though... K |
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Thought about posting this long ago but forgot. To the hotspot owners here, anything stand out about the design of this spanish UAV? ;)
http://www.uasvision.com/2011/07/29/...ish-coastline/ http://www.rcuniverse.com/forum/atta...mentid=1976398 |
Originally Posted by cmjets
(Post 11755132)
Hello:
really is a good thing that every body tell his problems. But... One question ! Do you fit the fins with screws to the fuselage ? I always fit it, because the system of fit the wing not is enough for fit the fins. Carlos. Some feel the need to do a bulkhead in the fuselage to sink in fasteners and so on, and some fly without. Out of the build process, its probably the obstacle that I look forward to the least! If you were to build in a few features to give a more secure wing + fin fastening (saving the builder time, scraped knuckles, and head-scratching) it might go a long way to differentiating your jet from the other manufacturer in Europe. Are you using traditional built up fins and wings, or are yours composite as well? One product idea for you... Several years ago someone (I think it was in Brazil, the Dominican, or some other South American location) flew a hotspot in a speed competition. They made a composite low-profile canopy insert. It matched the fuselage really nice, but cut the height of the canopy down to what looked like 1/2 or 1/3 of stock. If you were to offer such a product, I'm pretty sure a few of us would show interest in them...:) Just a thought to share. Bart, The reflex in those wings is very subtle...! I also have a Yellow Aircraft Stingray, and their reflex is much more obvious. On top of the built in reflex, the stingray still needs the elevons offset to fly level though... Anyhow, I'll PM you my email address. I'm curious to compare the profiles to my older wings. Thx, Kelly |
Originally Posted by Kelly W
(Post 11755424)
Thought about posting this long ago but forgot. To the hotspot owners here, anything stand out about the design of this spanish UAV? ;)
http://www.uasvision.com/2011/07/29/...ish-coastline/ http://www.rcuniverse.com/forum/atta...mentid=1976398 PaulD |
Hi Art
I fly with Steve quite a lot he's a good friend of mine, I will send him your regards! You Guys are going to have to come over for one of our Jet meetings? Regards John |
Found the link to the speed event in South America. It was in Brazil, back in 2005.
http://www.rcuniverse.com/forum/rc-j...nt-videos.html Here's the smooth canopy. The jet may be a really good copy and not a production hotspot, difficult to tell. The 2 aluminum tube spars look a little out of place... Either way - Carlos, think about making us some low profile canopy inserts... :) http://www.rcuniverse.com/forum/atta...2&d=1375335371 Here's another with the fins chopped, and a single fin over the engine... http://www.rcuniverse.com/forum/atta...0&d=1375335165 And another scaled up and scratch built. Its got a big AMT it... http://www.rcuniverse.com/forum/atta...7&d=1375335233 |
Hello Kelly: my model will be all mold, fin and wing composite too. I will install nuts into the fuselage rib for fit the fins.
but I think until the summer I not will work in this project. now I am very busy in another projects. You can see my Blog... Carlos. |
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[ATTACH]1977350[/IMG]
Here's the wing root profile. Keep in mind that this is traced at an angle, if you want to use this as a template to make wings you need to have it at the original angle of the wing root. Should work if you print this on A3 size paper. Carlos, i measured the washout on my wing, it's 3 degrees! Regards, Bart. |
Thanks Bart ��
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I have one for sale in the classifieds...http://www.rcuniverse.com/forum/atta...mentid=1978382
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The 2 aluminum tube spars look a little out of place... What is out of place is that left eurokit landing gear.! Stiil flying that set in my old Roo... And the SHS is still around, and it is not a kit... it was purposely built for the jet speed event..with a very strong custom fuse, fins and wings... this thing is tank solid and very lightweight. I once borrowed it for a friend of mine for a speed flight. He is a good pilot, but he landed it as it shouldnīt and kangarooed it for more than 100 meters... last jump went of the runway and plane disapeared in the vegetation. To his surprise, the plane wasnīt damaged or have a single crack even if the landing gear legs where bent almost flat (!) |
LOL, not a criticism, just a note that its clearly had some plastic surgery done! ;) I'm impressed - that must have been some work... Do you still have the tooling used to create the low profile canopy insert?
Ha, i didn't notice the euro gear till you mentioned it. I have Robarts, and thumped it in real hard once, (ran out gas landed off strip...~7 years ago.) All the robostruts were buckled and folded back, the retract units and fuselage structure could not have cared less about the mistreatment! She's a tough bird! So did you modify and beef up a kit, or was this bird a total scratch build? Can you share any info / photos on what enhancements you made for flat out speed and durability? Very curious, starting my build soon! ;) (bathroom renovation is almost done, gotta keep wife happy!!!!!) Kelly |
Thatīs the proper way to keep flying jets without feeling guilt with your better half... :)
About the mods the airplane was completely scratch built. The wings where built with highest density foam,we found, with two wing tubes and skinned with veneer wood and fiberglassed. The fins are sandwiched balsa and fiberglass, The fuselage was layed up more or less like the graupner original, but with some veneer glued on it on the straight "soft" parts. Later, a carbon fiber rib cage was glued on it, and carbon fiber strips where glued in the leading edge seams and CF roving at the fuselage / former seams . The cabin is solid balsa sanded to match the fuselage curves. This single mod is the most important one.. the airplane feels and sounds completely different with it,.. you can hear the air being ripped if you dare to make a low pass in the runway at full power (!) The elevons are actuated by two servos each, but they arenīt split. as I think that they are more rigid this way.. Unfortunately we didnīt took pictures of the build, as we where in a hurry to build the airplane in time for the race, and at that time my cellphone didnīt have a camera.. p.s. forgot to mention that is a good idea to reinforce the fuselage underside glue joints behind the main landing gears.. some original HSīs had this part completely ripped of the fuse at speeds as little as 250mph. |
Now that's a really good idea! I happen to have an extra canopy insert without the window cover. I was tempted to throw it out after I lost my last Hotspot...
I hear you on the rear fuse. I smear a huge fillet of Hysol over every seam in the rear fuse. This one's getting gear doors, which should help some as well. Can't wait to hear what a low pass sounds like wide open with a smooth canopy and a smooth underside. This one is going to get a 180RX...... (de tuned a little of course) :) Kelly PS: LOL... Spot the speed freak! :cool:
Originally Posted by erbroens
(Post 11762114)
some original HSīs had this part completely ripped of the fuse at speeds as little as 250mph.
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Hello friends:
Here you have the new tank suitable for Hotspot, Kangaroo, Harpoon, Rookie... 3L of capacity. I hope you like. Carlos. |
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Carlos what are the dimensions of the 3l tank, and does it fit in the same space within the Hotspot.
Darren |
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