combatpigg

My Feedback: (3)

I'm going to try a 5.5 x 6 prop on a ZALP .15 and see what that looks like.

MJD

My Feedback: (1)

Too funny - looking through the Cyclon website, I went to the bottom of their price list to look at something other than expensive .15's.. and just about bust a gut when I figured out their English translation of the Russian for glow plug is "suppository". I better get some Nelson HD, there's a cold damp winter coming.

Mmmmmmm... the F2A .15 TOP. Nice RC sport speed motor. I have one of these or the Profi on my bucket list as well.

combatpigg

My Feedback: (3)

Yes, you really need to loosen up your mind when navigating through those translations. I've seen the glow plug referred to as a candle before. Russians are very interesting to me because I grew up with some elders who fled the Zionist led revolution of the early 1900's as children. There are so many brilliant ones who are extremely inventive and skilled in the arts [including the technical arts].
Quite a few made it over here in the 1990s with engineering degrees, then took the tests to become licensed in what ever their technical discipline was in a completely foreign language. They needed the ability to decipher electrical code lingo, analyze foreign schematics, our legalese, and all the other hoops you have to jump through to get the professional credential.

iron eagel

Sorry to hear about the overpass being erected as an obstacle to your flying field.
I think it would be very interesting to see just what you could do with a .15 speed plane. Any idea of what the airframe would be like?

combatpigg

My Feedback: (3)

I'm thinking about building a "sidewinder" type plane with the cowl blended into the starboard wing panel.
The engine is really light, so what ever gets built doesn't need to be much bigger or stronger than what I normally do for .061 power.
I ended up getting a ZALP .15 FAI Combat engine. It comes with a restrictive intake and muffler, so obviously those are the first 2 things that must go.

iron eagel

Sounds like something that's going to be real entertaining!

As far as blending the cowl...
How about a parabolic curve (symmetrical) that blends into the LE of the wing? The more I get into this, the more I am beginning to think, that the entire airframe need to be lifting surface. I am working on the MkII version of the Stingray and it looks something like a snowboard with a pair of saber wings stuck onto it (sort of).

combatpigg

My Feedback: (3)

Laying the engine flat reduces vertical side area up front and I can't think of anything negative about that...unless your pipe plumbing is headed straight at the wing's structure. That's a big deal, but if the center section can encompass the plumbing and maintain strength then it's not such a big deal. This is where resorting to carbon fiber strands makes sense, but you could also go with steamed bamboo to make a rear exhaust sidewinder idea feasable. At any rate this idea keeps boiling down to a flying wing in my mind.
This engine would need a special header to adapt a tuned pipe, so for now all it needs is a rearward exit for the exhaust.
I don't know what the potential RPM difference is, but a tuned exhaust would add much weight and complexity, narrow down possible prop choices to custom carbon only and basically turn this into a federal project. For the first attempt with this engine I'm leaning towards making a 120% version of my "BATOUTTAHELL" model that is powered by the .061 Cyclon Combat engine.
It would be a good excuse to try heat forming plastic coke bottle cowl over a wood mold. Fiberglass is a lot of work, expensive and not real healthy to work with plus it generates a lot of trash.

MJD

My Feedback: (1)

I think a light model of 150-175 sq in is perfectly feasible for a light .15. You'll come in around 20 oz/sq ft or so which isn't too painful.

If you ask me the tuned exhaust would be more trouble and weight than it is worth for these combat engines, the whole idea here is light and compact and trouble-free ain't it? And those engines are no slouch open exhaust.

iron eagel

Yep, flying wing is pretty much the only choice as far as I can figure it. Building the center section to carry the plumbing and gear isn't all that big of a deal. Using formers like I did for the center section seems to work pretty well. Twelve foot radius turns doing a buck with the Stingray it didn't fold and that was all balsa.
The "BATOUTAHELL" is perfect approach for this one. If you look at the cowl as only being access panels as opposed to structure formed plastic sounds like the way to go.
The way you trick out engines with that type of airframe ought to yield some interesting results.

By the way...
A more appropriate description of the StingRay MKII would be, sort of like what you would get if a SR71 and a Raptor mated.

combatpigg

My Feedback: (3)

After reading your replies it sounds unanimous...flying wing sidewinder it is.
I wish I could just snap my fingers and pull out a nice 1/2" thick board of 5-6 pound density balsa to carve the wing out of.
Time to go shopping.

CafeenMan

Is it done yet?

iron eagel

MJD

My Feedback: (1)

Hey CP - remember me talking about electric airframes with hotsy .15's.. this was the picture I remembered. Just found it again..



Did 169 mph on a .21.. looks like a Novarossi. But with no top cowling, all out in the breeze like this. Clean it up and things would improve.

iron eagel

Any progress on this one yet?

combatpigg

My Feedback: (3)

I've got the wing "slab" glued together.
The engine mounts need to be cut out of 1/4" thick aluminum next. The shape of the fuselage is dependent on getting the firewall situated.
I've got to get an automotive project finished before I can dedicate much time to this thing yet.

That 169 MPH plane looks terrific. I would be leery of any ARF or RTF at that speed unless the company had a real good track record. [In other words, not built by Lanier].

MJD

My Feedback: (1)

The electric shown there is an F5B model and regularly powered into the high 100's. The comment at the time was that the glow powered version was 20mph slower than the electric.

iron eagel

At the rate you do things I figured it would be about ready to fly.
1/4 inch AL mount, your serious about this one, that ought to damp out the vibrations pretty good,
Are you going run the vent and exhaust back through the firewall?

Hope your automotive project is progressing well. Can't wait to see a picture of that show up in the email!

combatpigg

My Feedback: (3)

Yes, the firewall needs a 3/4" hole directly behind the exhaust exit and the model will need a tunnel to lead the exhaust out of the wing.
The car work goes very slow because to get the panels absolutely straight I've needed to make four foot long [hand powered] sanding tools. If you lay a straight edge across the panels you can see that they have some sag...even though they feel smooth to your hand. They even look good in primer if the sag is allowed to remain. I suppose the sandblaster could have caused some of it, or possibly just age.
So, there is no power sanding equipment that I'm skillful enough to run that will ensure absolute flatness on all the surfaces. It is all getting knocked down by my arthritic hands and shoulders. It's Hell. I ought to keep my eyes peeled for better body parts t start out with, but a 50 year old Ranchero doesn't have the same amount of after market support as the Camaros, Mustangs, etc.
This is the time of year to make hay on these panels before the flies come out.
I've also had what I think is a parasitic coccid attack on some of my animals and that has really cut into my time this winter nursing the sick ones. I expanded the amount of penned area, but tried to "carry" too many animals through the winter and there just isn't enough land to support their poop out put. You can feed and water them the most sanitary ways possible but if the coccid [protozoa] count gets too high it can be a killer.
I'm going to start spiking all of the water with apple cider vinegar to see if that old time wisdom can make a difference long term.

iron eagel

Hopefully the pain will be worth the results.
IS there any way you can adapt your hand powered sanders to a powered base? My neighbor who did body work adapted a air powered one (back and forth motion not orbital) so he could have a 3 ft long sanding surface, or would a powered sander just take too much off too quickly?

The problems with the animals health must have been a real pain. Good luck with the vinegar. sometimes the old farmers tricks are far more effective than you would think.

combatpigg

My Feedback: (3)

By the time I rig up a pneumatic sanding tool that is 4 feet long.......I just need to keep plugging away by hand. I use a 4 foot length of 2 inch ABS drain pipe with 50 and 80 grit glued to it to straighten out the concave areas and a 4 foot long "T-Bar" sander for the flatter areas. Once the surfaces are straight, then 180 grit is used to eliminate deep scratches. Primer surfacer is used to fill the hair-line scratches. 320 and 400 are then used to prep the surfacer for the primer / sealer. The sealer allows the painter to catch any last minute flaws before comiting to the actual [expensive] top coat.
If you were to follow all of these steps with a small model airplane...it would weigh a ton by the time you got done. It takes more skill [or intelligence] than what I've got to produce a 100% fuel proof and nicely painted model that also comes out as light as one that was done with iron on plastic film.

iron eagel

I hear what your saying, I like the PVC sanding bar idea, still sounds like a ton of work. That car is going to look pretty darn nice by the time your done.

With a wood model the only way to get it that nice is to use thinned tinted dope and sand, dope and sand, repeat as necessary upwards of ten or twenty times. Or at least that's how it works out for me, then you have watch out for the times you sand through the sheathing. Doing an old time finish on wood is a pain you go through a lot of sandpaper and time but it is possible. It's a lot easier when you use tissue over the wood ,but that adds a bit of weight but it is a lot less sanding.
I have yet to do a plastic film plane and have it come out the way I want it to look.

combatpigg

My Feedback: (3)

I bought the "Mr Monokote" video and Mr Stilly makes it look so easy. The finer you can get the wood finish, the better chance for total adhesion. You can only expect so much from shrinkable film for concave contours. Convex contours and open areas are what iron on film was designed for. At any rate, the planes with iron on film that hold up the best are the ones that the owner spends more time cleaning than he does flying.

MJD

My Feedback: (1)

I think tissue over wood, applied and sealed with nitrate then primed and painted comes out quite nicely with only a few coats.. at least by my finish standards which may be a bit on the functional side. Plus the potential to add some skin strength and torsional stiffness. You can topcoat the tissue/nitrate with a variety of color finishes too, not just butyrate dope. Lustrekote for example.

One of the only heat shrink jobs I did that I was really happy with was a .40 size Sweet and Low Stik I covered in 21st Century Fabric. I must have done a rare thing and paid attention to iron temperature and all that mumbo jumbo about sandpaper and stuff. Patience is another challenge. Anyhow it just came out clean and sharp and no wrinkles or booboos, not to mention the stuff is darn tough. It met its maker when I sliced the left wing off turning to final over some hydro lines. Forgot about that skinny wee wire up top.

Oops I digress, back to the BatZalp.

iron eagel

I am not a big fan of plastic film covering, besides not being that good at it. Sanding, and using balsarite or you name it I tried just about everything, and never have done one in plastic that I liked how it looked. Silk, tissue or balsa sheathed is typical of what you will see for finishes on my planes. For a knock about fun fly I sometimes will use plastic films but generally shy away from it. I did a trainer for my wife with plastic film and am getting tired of having to touch it up over and over again. Put it out in the sun for a day a the field and by that night it looks like total junk, and it electric. With glow planes I have sealed the seams and trim and within a few weeks I find something coming loose.
Someday I might do one in plastic that I like how it looks and holds up, but that day still hasn't arrived.

MJD

My Feedback: (1)

I hate getting the first drops of oil on a film covered fuselage. It's like ants and cockroaches, always gets in somewhere. Sometimes I like painted fuselage + film flying surfaces as a compromise.