Willja67

When i grow up i want to be Mike Patey.
 
Here are a couple videos on his Wilga Turbine conversion that could be part of a master class in working with composites and particularly of interest to me in building my cowl. I wouldn't ever want him to see this he'd just shake his head, but hopefully it'll do for my poor little 
 
 
I couldn't really separate my cowl like he did his because i couldn't get it off in one piece and i used duct tape instead of the thinner foil tape he used, but the exterior of his cowl was much more finished than mine, so i can add a little height with the micro slurry when i finish it. 
But here is a pic of laying up the joining strip on the left side of the cowl:
I wetted out 5 plies of fiberglass on plastic cut it out and peeled 1 side of plastic off and used the other to keep the whole mess from becoming a unusable mess until i had put it in place inside the cowl. As per the video i cleaned the surface then "basted" epoxy onto it to get in the pores then after it was all in place i covered it with more plastic and worked the squeegee to get the resin to bridge between the joiner strip and the cowl so hopefully the edge of the strip won't peel up like some of the plies on the cowling. 

 
This is the video. At about 4:40 he starts talking about fairing design and about 8:00 he shows how he bent the sheet metal to make his mold. I thought he layed up the fiberglass on the inside ( female mold) making the exterior surface of the part smooth but he used a male mold. A guy in my EAA chapter showed me how to use plastic sheet over the surface of the layup to make it nice and smooth. These techniques ought to reduce the amount of work considerably. 

I'm looking for it in the Mike Arnold videos but he made his landing gear strut fairings by bending sheet metal into roughly the right shape but open enough he could lay the fiberglass up inside it and then he just riveted the trailing edge together. The smooth surface of the sheet metal meant he didn't have to do any surface finishing.

I finally split the cowling again. not shown was making fastener locations and using 3/4" lathe screws to hold the top to the bottom. Ive stripped out most of the mold and marked the flange for trimming. My prep and cleaning must not have been enough because about 6" of the flange peeled off with moderate pull. I'll have to re epoxy thathere you can see all the lathe screws holding the top and bottom together. I was smart enough to mark the camloc locations in the lower cowling so reattaching was fairly painless although at least one on the other side is in the wrong place, you can tell as the cowling wants to bulge out until the fastener is released then it sits down nice and flat. I made amistake making the mold. You can see the cowling drops below the bottom of the fuselage a couple inches. The stock cowling doesn't. I'm wondering if I'm going to blank my radiator and have to lower it. I was hoping to reduce drag with this cowling not increase it.you can see the cowling is definitely peaked on top, kinda like me. The flat parts either side of the peak are very flimsy so i think i'll build it up with dry micro for a better contour and then lay another layer of glass over that to stiffen it up.Not sure how visible it is but there's about 3/8" between the cowling and the top of the firewall. This happened because the white foam used to make the mold was 3/16" thick, so the camlocs are pulling the cowling tight to the side of the plane and so the middle is being pushed up aggravating the fact that the 3/16" foam that wrapped around the firewall also isn't there.Again not sure how easy this is to see but I pulled out all the lathe screws except the front one and let the cowling settle at the back end and it hangs down about 3/8" below the original parting line, so I'll trim it tapering from that 3/8" at the back to nothing at the front.  Probably still have to do something to seal the firewall but at least it'll be a much smaller gap to seal paying more attention to little details while prepping and laying up the fiberglass would have saved me a lot of work right now fixing all the bubbles and other imperfections but all in all I guess it's not too bad for my first real foray into composites. 

The problem is i have a KF1 and most 4 bangers are flat out too heavy as is the yamaha. I'm not interested in 200 horses I'd be happy with a more reliable 80 hp if i didn't have to worry as much about seizing the engine.  The only reason I'm looking at the 100+ hp options is that's what a huge percentage of the sled market is.

Like i said quick and dirty, but yeah any idea to cut weight down is welcome.
I know I started the thread talking about high power engines but since i have a KF1 and winning the stol drags is just a fun little exercise but not something I'm serious about, finding a good engine is. And it would be nice to have a lightweight alternative to the rotax 582  with maybe a little more power, that could use an adapter like the above to mount a rotax c gearbox. 
If i were to decide to convert a sled engine these are things i would look for:
1. Obviously lightweight
2. Large production run with good parts support
3. Known reliable engine that makes 100-120 hp, Hopefully doesn't have the seizing issues rotax has. 
4. Not alot of electrical work to do on it, ie minimal sensor and ecu/ wire harness problems to deal with. 
I don't know much at all about snowmobiles so can any of you suggest a make/ model/ year sled that would fill the bill? Any other requirements to go on that list?
It would be nice to come up with a package that some enterprising individual could sell in kit form or even create a conversion manual that could be bought.  If i had the machining skills it would be tempting but i don't. 

okay here's a quick and dirty concept. The red thing is the engine the grey thing is the bed mount plate and the purple thing is Psru mount plate. 
Ok guys shoot it full of holes, any reason this couldn't work?

Well maybe we could take a page out of the rotary engine guys book. The above pic doesn't precisely show what I'm talking about because i couldn't find the pic i wanted but, you can see the thick aluminum plate that the engine is bolted to that is then mounted to engine mount(very much like the plate my 532 is bolted to on my bird). You can also see the big plate with the standoffs to the engine that the PSRU and starter are bolted to.  One design I've seen has the bed mount plate extended forward with the psru mount plate bolted perpendicular to the front edge.
Why couldn't we do something like that? Might have to get a little creative to design the standoffs for the top of the mount plate but as I've mentioned most of the 2 stroke engine mounts are already designed for a bed mount. That should make things maybe a little easier since we won't have to come up with an entirely new mount. 

Well that electric motorcycle looks pretty cool. If you can find a 4:1 psru and if the fuselage of the model 1 is strong enough that all that power doesn't twist the front end right off the plane that might be a pretty fun ride.

This thread is about beating a 915 equipped kitfox with a model 1 which is I think in the realm of possibility though maybe not probability. 
If you want to talk about beating Draco then perhaps start another thread called "Dragon Slayer". 

Well you got me looking at the etec engines and wondering what it would take to hang one on the front of a kitfox. Given Rotax's exit from the 2 stroke aircraft engine market it would surprise me if they didn't make bolting a redrive onto the pto side of their current engines a difficult chore, just to keep us guys from committing aviation with their engines. Obviously there's the issue of fitting all the tuned parts ie intake manifold,  exhaust etc under the cowl and dealing with the computer issues ie limp modes etc. I haven't heard of anyone even trying to do this so I'm guessing the above is a pretty daunting task?

right side joiner strip layed up.

Ok i understand now what you're talking about. Thanks for the explanation. Although i have an expert welder lined up to weld the brackets to my fuselage he's graciously offered to do it for free and i don't want to take advantage of the situation, so i'll probably spring for new wheels, unless someone wants to trade. 
 
I will probably be selling probably the whole gear minus the tires and maybe the axels if anyone is interested. 

Just from what i can see looking at my current setup and the new gear leg and the matco brakes that the new leg is designed for the current brakes at least don't look compatible with the new gear.  And I'm not sure what you mean by welding lugs on.

I don't know if my axels are what you need or if the matco ones that you have are what i need but if it works out that way it would be convenient.

Ok guys since the topic came up, I'm going to have to buy new wheels brakes and maybe new axels as well since the gear i bought was built to take matco stuff. My big question mark is the axels. Have any of you seen a setup like this before? Does that cap that says hadco on it get pried off with a screw driver? I'm hoping that my axels will fit the matco wheels otherwise that's another $140 i'll have to spend

I've been thinking about something like this for my -1 (should i call it silver fox?). I guess you'll show your progress as you go but how are you going to form the lexan?
a few of my ideas have been
1: build a frame to clamp the lexan in and put it over a heat box until it sagged to where i wanted it and use a frame just like you're doing with the middle tube bowed out. 
2.  same as above but make the bubble oversize  so the aft end of the door touches the fuselage 5 or 6"s aft of the opening. Might look a little goofy and haven't thought about how I'd build a frame for it yet.

I really need to learn the lesson to not overthink things too much and just go ahead and do something. I spent a week and a half wondering what the best way to temporarily join the 2 halves back together so i could lay up the joiner strip and originally was going to use popsicle sticks with dabs of bondo but that stuff takes too long to set and i finally realized that hot glue and foam had worked well since i started the project and it worked just fine again.
I'm going with the 2 piece cowl. Right now the slight inconvenience of very slightly limited access is far outweighed by ease of construction and however many ounces of weight i'll save. 

Ok guys I'm looking for opinions here on 3 subjects:
1. Right now the cowling is in 2 pieces, top and bottom. I'm considering cutting the top piece in 2. So one piece goes from windscreen to firewall and the other just covers firewall forward.  Right now I'm leaning towards not just for simplicities sake. 
2. Is somewhat related, how many access doors do i need? I figure i'll need to check rotary valve oil and coolant level, but do i even need that? With the wingnut style camlock fastener i can have the top of the cowl off in 2 minutes or less, so again for simplicity I'm leaning towards not. 
3. Should i install some windows in the lower cowl between the door and firewall?
In one of Trent Palmer's videos he had a prop strike and in the aftermath added windows in this location  (about the 6 minute mark). Do you guys think that's worth it? Does it give any appreciable added visibility? I'm a bigger guy and my legs are fairly thick and i wonder if I'd even be able to see out the window if it were there. 99% of my flying will be solo so having the window in the other side might be worth it. His other mod of a forward looking backup camera does seem like it's a really great idea. 
 
Anyways you guys that have experience operating these planes I'd like to be your thoughts. 

Thanks, but it's a long way from done. But I'm more and more convinced that it's not going to end up in the dumpster.
tonight's progress was getting the rest of the cowl off the plane and into my basement shop, so I'm finally not freezing my hands off working on it:
doing the preliminary trimming:
There are an awful lot of bubbles in this thing. Glad it's not structural or it would be in the dumpster. 
And started getting ready to install the joiner strip between the 2 halves
I'm using duct tape again as a mold release. 
 
I managed to get the lower half of the mold to come with the cowling when i pulled it off the plane. Some of it will get cut away but it helps the part hold its shape and not deform under its own weight.  I'll need to post cure it at some point.
And you'll notice that i managed to save the circular area around the hub which will help when i join it back together to lay up the joiner strip between the 2 halves. 
 
And we all know the job isn't official until you've shed some blood on it:yes that's really my blood. 
 

Well for better or for worse i cut the cowling in half and removed the top part from the mold.  Couple reasons, first off i only recently found out how dangerous it is to leave the air filter uncovered so that moisture can get in the engine. I reached in the intake and wrapped some plastic around the filter but not very well. Now i can secure it better. Hopefully the last couple months hasn't destroyed my engine. Fortunately utah is pretty dry usually but we've had 2 or 3 periods of damp weather during those 3 months it was uncovered. Second reason is that i hope to take it to get the new gear brackets welded on soon and a 60 mph wind might have ripped the whole cowling mold off.
I never added the last 2 plies that i previously mentioned that i was planning on. I'm going to see if adding some stiffeners will be adequate. Maybe a little more work and might be a little on the flimsy side but less weight. It feels really light which I'm happy about. 

Check your gas lines! I was up there a couple years ago when a similar magnitude quake hit and it was almost a non event except a gas line in at least once house broke and a spark blew said house up with a couple of fatalities. 

ok i didn't realize what you meant by spinning before just thought you were talking about being able to make a larger diameter plug. I have seen a video of someone doing stuff like that and wrote it off as something i wasn't going to try but now i'll give it some thought. 

Some of the adjustment locking parts are missing. Plus I'm ignorant enough of what should be there that i just don't know what i don't know. 
The Shop Smith is a nice tool, too bad the company has gone downhill. My dad says that it often takes 6 months for parts to come, if they come at all. 
Fortunately I was able to get the spinner to the point where i can finish it by hand.