RE: Hotser
 

Oh man, this thing is so not suitable for fun fly events! My Hots #6 is reserved for those events. This one couldn't possibly deal with the the nonsense. It's built for one thing and that is to go fast.

The ABS stock before the pull measured at .064. After the pull it mesaures at .029. I've played with several different types of plastic and many different thicknesses but I think this is the answer. The cowl feels plenty strong and plenty light.

I can't wait for the fibreglass to cure on the plug and to pull another one. But now I realize that I should have soaked thin CA into that end grain before glassing. I think that would have helped prevent the vacuum crushing the balsa. Next time, next time...

It's a learning process.

Dave

RE: Hotser
 

I didn't realize how much thinner the plastic gets.
Amazing how factories can stamp out pretty deep sheet steel body parts..I imagine the metal gets stretched thin.
The manuever I'd like to see you try with this thing is get up to high speed then try to do a knife edge loop.
If the plane will do it, then go for consecutive KE loops....[X(]

RE: Hotser
 

....papapa...omm mau mau papa omm mau mau....

I don't think so! Not even close! A knife edge loop with this thing? Much less consecutive KE loops? Not even in my wildest dreams did I expect this plane to do that. I just wanted to go fast.

I'll put it on the checklist. Just don't hold your breath.

Dave

RE: Hotser
 

Time still marches on. And so does the Hotser...

Plus I've finally bought a new camera. So no more cell phone photos!

MonoKote is finished, next is painting the cowl. Then the engine still needs to be run in. It's close. It's really close!

Unfortunately I didn't realize that the tail numbers I printed were the wrong size until after I'd already cut them out. Oh well, it'll do.

Dave

RE: Hotser
 

Nice work, looks great!

RE: Hotser
 

Excellent Dave..!
The cowl turned out looking real good.
Definitely worth the effort....[just like I said it would be]....:D
Now the real interesting part comes to see how fast and how aerobatic it turns out to be.
Every time you build a model, [especially a high performance model] and get it all ready to go it's like being a kid waiting for Xmas morning..huh..?

RE: Hotser
 

Wouldn't this be number 7?

RE: Hotser
 

Every single one of my Hots' have been in this iidentical color scheme and they've all had the "6" on them. It's just coincidence that the number finally matched how many I had built. So now, on my seventh Hots, the number will again be just a number.

It drove the guys at the club crazy that the first few had the same color scheme so I stuck with it just for laughs. I can't wait to bring the pair of them to the meeting, that'll be fun!

Dave

RE: Hotser
 

Hey CP,

Yes, I love the cowl. I have to admit I've never liked Hots' with cowls before but this is cool. I've made vacuum formed cowls for 2 planes and one canopy before (all were Sykosis', one was yours!) I think I'm finally getting to where it is predictable and reliable. The 1/16" ABS is the cat's meow. After pulling, it's about half that thickness and feels just about right. Much stronger than the styrene that I used at first.

Aerobatics isn't what I planned for this bad boy. I've got pattern planes for that and my trusty #6 Hots for the wild stuff. This is built strictly because I feel the need ... the need for speed. The aileron size is drastically reduced but I'll bet it still has a decent roll rate. The current one rolls so fast you can't predict where you'll come out of a full throw roll. Just do 'em high:)

With the construction of a Hots, I'm concerned about wing integrity at these speeds. All of the wing sheeting inside the fuselage is removed to make room for radio and servos. No fiberglass reinforcement on the joint, you'd only cut it away anyhow. The only strength is the spars. I did upgrade it from 1/4" balsa spars to one piece 1/4" spruce spars and added ply shear webs in the first 2 or 3 bays, double webs inside the fuselage where the sheeting is cut away. So no, there will be no 150 mph snaps.

Buy yes, you're right. This is the point in a project where it gets so exciting that you can't stand it. All the planning. All the wild hair ideas. All the thumb your nose at the status quo. This is going to be one fast Hots!

Matter of fact, it's going to be Hotser than Hots!

Dave

RE: Hotser
 

What’s hotter than a Hots? A Hotser of course!

And here it is!

Everything is there. There are still a few changes inside to be done. I need to move the aileron servo as the arm hits the next servo. I need to do some Locktite work on some of the clevises. But all in all, it’s there. The engine needs to be run in as well.

It’s a hair lighter than my previous Hots. 3 lbs. 14 oz. compared to 3 lbs. 15.3 oz. And that is with cowl, header and tuned pipe, plus the repairs from the building disaster.

The view from the front is the one that explains the project. Oh man, look at the difference in wing thickness! Add to that the pizza cutter racing wheels, the cowl and the Jett Q500 racing engine. Wow, this thing is going to move!

As I’m getting ready to hit the road to Louisiana for my niece’s wedding and our club meeting is Thursday, I probably won’t have time next week to disassemble, break in the engine and reassemble in time to get it to our club meeting on Thursday. So I predict about 2 weeks to first flight.

Is it a Hots? Well… Is it Hotser than a Hots? Definitely!


Well, rats! We're back to the 500 Internal Server Error! I guess you guys will have to dream about it for a while. I'll upload the pictures when the server works.

Dave

RE: Hotser
 

Wow, still server errors. I've been trying for hours to load pictures but no joy. I'm giving up. I'm heading to Louisiana early tomorrow morning for my niece's wedding. Have you ever heard about parties in Louisiana? They do live up to their reputation!!! And my family doubles the standard.

Sorry guys, y'all are going to have to wait a couple of days for the pictures. Time to crash out. I'll try again Sunday night when I'm back with the living. It's going to be a heck of a weekend! It'll be a heck of a maiden too.

Dave

RE: Hotser
 

My old Midwest Super Hots could manage a knife edge loop. It did have slightly enlarged control surfaces though, and the loop was HUGE...the downline was always a thriller: "will I make it???"
Never tried consecutive loops though.

RE: Hotser
 

Back from Louisiana and the file upload still won't work. Half the time I can't even get to the server in the first place. We're back to this?

The good news is we got my niece hitched and had the obligatory South Louisiana blow out! 3 parties in 2 days. Saturday's party at an 1898 mansion on the private Avery Island (McIlhenny, Tabasco, etc.) started at 1:30, wedding at 3:30, more party until 8:30, back to the hotel for the after party for friends and family. And that doesn't even include the party the night before.

A good time was had by all and I couldn't be happier that my dear niece has hooked up with such a wonderful man. He just doesn't realize what a crazy Cajun family he's married into yet. But I did try to give him a preview!

Next few days, a few final touches on the Hotser to get it ready for Model Of the Month at our club meeting, then pull the engine and break it in. Maiden, maybe late next week, following week at the latest.

Oh, CP, I think I told you that the Yours, Mine and Ours Sykosis finally bit the big one. It led a storied life bit it's pretty well gone (although the wing and tail section are still in one piece). My brother pulled the remains off the wall, complete with rubber bands holding the fuse together, and was talking about what it would take to rebuild it. I told him that they're not that hard to build from scratch and he'd have to remember the weight penalties of repairs. He pardoned himself and went into his bedroom. Came back to the model room and he already had another built! He enlarged it by I think 20%, is running it on the .074, did all the keep it light tricks, all the lightening holes, all contest balsa, everything on the plans. He says it flys like a dream! Unfortunately we had to go clean up the wedding site or he would have taken me to fly it. Did I really say I needed to help my sister instead of go flying?????? Next time ... next time.

A good time was had by all.

Now if only uploads will start working again I'll show you guys The Hotser!

Dave

RE: Hotser
 

Dave..I always figured the Sykosis could be built slightly larger at basically the same weight for a .074.
The .074 is just a naturally better all around choice to design a little pattern plane around....if you are after "do it all" performance.

Rudeboy did a KE loop with his Hots.....so there you go...!
Hanging on to complete the last 1/4th of the loop...I think having the plane as tail heavy as you can stand it, plus managing your speed helps.
I wonder if any full scale planes can do them..?

RE: Hotser
 

I saw Rick Volker almost do a compete KE loop at Geneseo 3-4 years ago (in a Su-26 IIRC). It's that last pullout that'll make or break ya I guess. In a quick internet search I could not find evidence anyone does one in their routine, but..?

RE: Hotser
 

I got the original Hots to knife edge loop but had
to move the CG back where it belonged, it was
near impossible to manage with my level of skill.
Ralph

RE: Hotser
 

If I had to venture a guess, I would put my money on this thing: [link=http://www.youtube.com/watch?v=sID5JVlzxXA]Skip Stewart - Prometheus[/link]

That thing is just insane.

RE: Hotser
 

That's the one! I was trying to think of the name - yes indeed this would be the other likely candidate for a full scale KE loop.

RE: Hotser
 

Wahoo! RCU is finally going to upload?

So here it is, here is The Hotser! Alongside with my Hots #6. Yeah, they're both #6, they're all #6, but this is my 6th and 7th Hots and Hots variants. 1 through 7 have all had the number 6 on them and if I ever reach Hots #37, it will also have the number 6 on the side.

I'm just back from the Johnson Space Center RC Club meeting where I did a presentation on both planes. Here's an original Hots. Here's the changes I've made through the years. Here's how I fly this one and what I've done to fix various problems. Now, let's go faster.

I discussed changing to carbon fiber pushrods. Monster size elevator joiner wire. Plywood insets on the elevator halves for the monster size joiner to fit into. Reduced aileron span to move the aileron away from the fuselage and away from the wingtip. The original has a big nasty gap between the aileron and the fuselage. Lots of turbulence there. Aileron all the way to the wing tip, that puts the aileron right in the wing tip vortex leading to flutter and drag. Plus, this is a speed plane, not a fun fly plane so I don't need the crazy aerobatics. Note the fixed TE at the wing root as well as at the wing tip. This does several things. It reduces flutter induced by the wing tip vortex. It reduces drag from the wing tip aileron. It reduces drag from the aileron gap at the fuselage. It reduces drag from the aileron deflection at short moment arms near the fuselage where it doesn't do any good. Did I say it did good things?

Control setups are very different. The carbon pushrods are ultra light and ultra stiff. The HD elevator joiner will let me do away with the dual elevator pushrods and the drag of an additional pushrod and control horn. With the reduced aileron size and increased torque rod size, there was torque rod twist problems. So the torque rods are sized for .60 - 1.20 airplanes.

Carbon fiber racing LG. Streamlined, ball bearing racing wheels, custom vacuum formed cowl to reduce drag from the standard flat firewall. Jett Q-500 racing engine with tuned pipe.

Final speed is up for debate. It's been a popular topic around JSCRCC. But I know the answer, it'll be FAST!

I still have to break in the engine since Dub repaired it after I threw the rod. He says it's running strong. I have replaced the air valve carburetor body with the red Jett carb for sport flying capabilities at the cost of a few hundred RPM. I'm not racing, I'm just having fun. And ease of use is a big part of having fun.

So there it is. What was expected to be a quick project that was interrupted more times than I can count. But I never give up.

We'll have some fun soon. I do have structural concerns. This design was never meant for this kind of speed or stress. I'll be gentle for a while. Eventually I'll blow it to pieces in flight and I'll enjoy every shard.

I've got a couple of pattern planes to build after this one but the next speed plane will be a Screamin' Demon. Hopefully I'll be ready for it then. Thank's to Mike's kind offer of plans. I'll fly this one for a while, when I get used to it I'll finally build the SD.

Thanks Mike. Thanks CP. Thanks to everyone who has helped through this and previous projects.

Dave

RE: Hotser
 

Dave, does Jett subscribe to the "under-propped" break in regimen at high rpm with 25% oil..?
The idea is to not let the engine get hot, but to give the moving parts a chance to spin at high speed and develope the micro-fine wear patterns like that.
For example, I'd break that engine in with a 8x6 cut down to 7 inches and run it at the highest rpm that still exhibits a nice spray of oil but in a 2 cycle scream. The prop on these runs is basically there to cool the engine and to provide it with negligible load.

RE: Hotser
 

Yes, Dub does talk of breaking in by cutting a full inch off of the flight prop so you can run it at 19,500 RPM while still running very rich.

I like your description of the prop being nothing more than a cooling fan! I will be doing that next week.

And I'm glad the pictures finally came through! I was beginning to worry.

I should post some pictures of the broken rod now that I've got a real camera. It's one for the books! Dub said that this particular failure was extremely rare. I guess I'm a lucky guy? I'm definitely lucky that he could rebuild it for a reasonable price!. Thanks Dub!!!

Dave

RE: Hotser
 

It has happened. The planets aligned, other priorities have been settled, the last little bits have been arranged and this morning the Hotser was maidened!

Man, that's FAST!!!

With an 8.8 x 8.5 and 15% Cool Power with a bit of added castor, the Jett Q500 tached out at 18,980 while still running a little rich.. And I’m running the red carburetor instead of the Throttle Body Air Valve. I can live without those last few hundred RPM in return for the nice idle.

I topped off the tank, fired it up and taxied out. No problem, no trepidation, no worries. Then I hit the throttle, not even full throttle. It was way out of trim and it was way fast! That first flight was 3 minutes of sheer terror. It had lots of up trim as well as quite a bit of roll. I started working aileron trim and before I knew it the plane was nearly out of sight. My hands were trembling and I could hardly hold the sticks. I was cranking in down, down, down. Very quickly the plane was so high that I couldn’t tell if it was right side up or upside down. I chopped the throttle and put it in a vertical dive. The dive was the most relaxing part of the flight. When I pulled out I finally got my orientation back and it was close to being trimmed. With shaking hands and less than half throttle, I zoomed it around the field and worked on the trims. I did throttle up for just a few seconds to see how consistent the trim is at speed but the timer started beeping so I chopped throttle and landed.

I knew landing would be interesting on those rock hard pizza cutter wheels and no give carbon fiber LG. About 5 or 6 good bounces later it finally settled down. But it took me about an hour to settle down. I did make a second flight but the engine didn't seem to want to run right so I landed it pretty quickly and I found a loose bolt on the engine mount. Enough adrenaline for one day, I packed it up and brought it home for inspection, cleanup and more Locktite.

Wow, this thing is fast! 3 hours later I was finally starting to calm down. I absolutely can’t wait to fly it again!

Dave

RE: Hotser
 

Nice report.!
It sounds like you got your aerobic workout done for the day too..!

RE: Hotser
 

Yes, my pluse rate was through the roof so I guess you're right, I can claim it as cardio. Here it is a day and a half later and I'm still smiling.

I pulled the cowl and engine. Cleaned the bolts and blind nuts with carb cleaner and replaced everything with fresh Locktite. I went through the internals and double checked everything. I mechanically reduced the elevator throw so that high rate has as much throw as the low rate setting where I flew it. The plane is ready to rock again.

Lots more trimming and flight testing to be done. Hope to get a speed reading soon too. Oh man, the sound of 19k rpm stood people's hair on end!

Next session is planned for July 4th. It should be an entertaining morning.

Dave

RE: Hotser
 

For a plane like yours'.......I'd guess that 1/8" up, 1/8" down on ailerons would be plenty and no more than 1/4" up, 1/4" down for elevator. Assuming a 25-28% CG range with an empty tank. It's possible to set up speed planes conservative enough to be almost boring..that's when you are ready to do some laps.
Don't be shy about adding oil to that Cool Power fuel.