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RATA
08-25-2005, 05:40 PM
Scratch Built Foamy

This is what I call my R.A.T. It is a Completely scratch built foamy. Based on a friend of mine, Rory Greenwell’s Kablooie. What started out as an attempt at a modified Kablooie, (Rory’s Scratch built foamy, see last picture), has turned into a completely different plane. All the moments are different, Also, CG, Length, Width ECT… After many-failed design attempts I finally managed to get the R.A.T. structurally sound. Rory, being an expert flyer and instructor has test flew it for me during the whole development process, and has finally given her a WOW “that fly just like a something extra” I would encourage everyone, at least once, to go through the process of scratch building; there is no greater reward then flying something of your own design.

Cost to build, including wings $25.00

Powered by: AXI 2208
Prop Master Airscrew: 8x6
Battery Kokam: 1500

margotcopeland
08-26-2005, 12:03 AM
Plans??? Video???

Looks VERY cool! Would it work with a less expensive brushed setup...like an IPS 100 (or smaller?) It seems like it would be great for someone wanting to do aileron training.

LOVE the paint!

RATA
08-26-2005, 01:30 AM
I do have Video, and may be viewed at: (not the greatest and a bit corny)
http://www3.telus.net/junkyarddesigns/Rat.wmv (http://www3.telus.net/junkyarddesigns/Rat.wmv)

In it's original configuration the wings were 5 inches longer, and she would fly just fine on a GWS 300 motor and was somewhat docile, but even then I would think she would be a bit advanced to be used as an aileron trainer. Once I cut back the wings 2 ½ inches on each side and went Brushless it became a very fast plane that tracks and axel rolls as good or better than an extra 300 (in my opinion) I would not recommend this as a trainer. I went from flying a GWS Beaver right into my R.A.T. and believe me I wish I had transitioned though an aileron trainer first, for I wrecked RAT after RAT.

I do not have plans prepared or set up for the R.A.T. yet, but if your interested I will pass on your request to my friend Rory Greenwell who sells his Kablooie all over Canada and the USA (his Kablooie is the last photo I posted)

Terry

qban_flyer
08-26-2005, 03:09 PM
Scratch Built Foamy

This is what I call my R.A.T. It is a Completely scratch built foamy. Based on a friend of mine, Rory Greenwell’s Kablooie. What started out as an attempt at a modified Kablooie, (Rory’s Scratch built foamy, see last picture), has turned into a completely different plane. All the moments are different, Also, CG, Length, Width ECT… After many-failed design attempts I finally managed to get the R.A.T. structurally sound. Rory, being an expert flyer and instructor has test flew it for me during the whole development process, and has finally given her a WOW “that fly just like a something extra” I would encourage everyone, at least once, to go through the process of scratch building; there is no greater reward then flying something of your own design.

Cost to build, including wings $25.00

Powered by: AXI 2208
Prop Master Airscrew: 8x6
Battery Kokam: 1570

Cool looking "paint job" on second one. Love it! :D

RATA
08-27-2005, 01:23 AM
Thanks man. It was my son's idea to splash different colors of paint on it, and then he outlined each color with a black marker. It realy stands out in the air.

RATA
08-28-2005, 05:09 AM
I just put the RAT on floats. I will be trying it at the lake in the next few days. I am hopping that this will be a great alternative come wintertime. Having 2 wings ready to go, one on floats and one on wheels, seems to be the best solution to having two planes.

qban_flyer
08-28-2005, 05:34 AM
I just put the RAT on floats. I will be trying it at the lake in the next few days. I am hopping that this will be a great alternative come wintertime. Having 2 wings ready to go, one on floats and one on wheels, seems to be the best solution to having two planes.

That's a mighty cool looking "floated RAT". Did you cut the pontoons yourself or are those ready made foam floats?

I used to fly nitro powered amphibians back in the '80s. Quite a thrill to see those models get "on the step" and climb out of the lake and into the wild blue yonder.

You'll love it.
:p

RATA
08-28-2005, 05:53 AM
That's a mighty cool looking "floated RAT". Did you cut the pontoons yourself or are those ready made foam floats?

:p


The floats are GWS. I find them to be ok on the water, but in the snow they tend to crack. I do not have much experience on the water, for my last attempt (earlier this summer) started out with 4 or 5 fantastic touch and go’s, and ended with one drowned RAT. I am still concerned about getting my electronics wet, but eager to keep trying until I get it right.

qban_flyer
08-28-2005, 03:33 PM
The floats are GWS. I find them to be ok on the water, but in the snow they tend to crack. I do not have much experience on the water, for my last attempt (earlier this summer) started out with 4 or 5 fantastic touch and go’s, and ended with one drowned RAT. I am still concerned about getting my electronics wet, but eager to keep trying until I get it right.
Yeah! A drowned rat is not a pretty sight.

I used to wrap my receiver and batteries in plastic bags in those days. Since the servos were high up in the fuselage there was no water problem with them unless the plane flipped over. I never had that problem.

I had the power switch in the center of the fuselage mounted in the servo tray with a piece of pushrod wire going through a hole in the switch and held in place with a wheel collar. This rod exited on the left side of the planes through a 1/16" hole and had another wheel collar on its end for leverage to be turned on and off. Epoxy was used to reinforce and waterproof the hole, then I added a dab of vaseline in the hole to prevent water from entering the fuse.

With electrics is basically the same set up except that our servos are on the outside. I've heard that the servos we are using these days are somewhat waterproof, but it is something I am not quite sure of how they have managed to achieve that feat. I have no clue as to how to protect brushless outrunners and ball bearing brushed motors from the water unless we encase them in a rather tight cowl with no other openings than the prop shaft's.

I would use vaseline in the area where the arm attaches to the servo spline but I have no clue how it may affect the servo or its case. I definitely wouldn't want vaseline migrating inside the servo mechanism and electronics though I wouldn't want water in there either.

I'll just have to get me a set of GWS or Wingo floats and experiment with some of my more used (abused) planes and radios and see what I can come up with. I love flying from water, it's so classy to watch it struggle for a while to get on the step and ROW like a full sized plane.

The mistake most people make when ROW is they fail to hold up elevator when they apply throttle to the motor so it takes them a while to get on the step if it manages to do so at all. Holding up elevator forces the float onto step, then the plane moves on the water rather gingerly and it's ready to take off in no time.

BTW, it took me a while to learn how to ROW properly. I began by just applying power just like I did on land. More often than not the plane refused to get on the step, much less take off. Same thing with taxiing on water, up elevator is a must if we want the model to steer in the direction we want the to. Float rudder(s) do help in ths respect also, though they are a bit complicated to install properly so the linkage would not bind the sevo.

Have fun and keep me posted of how your RAT does on water.

L8R:D

RATA
08-29-2005, 05:01 AM
Well, I never got the RAT on the water, but I did fly it this morning. The AXI 2208 I am using has enough power to very quickly pull me along the grass and in to the air with very little effort. She was a completely different plane with floats on. After trimming it out I found it to be a very stable and pleasantly flying plane.


The next step for myself is to take my RAT and make a transition from a foam-based plane to a balsa plane.


Re-creating the RAT in balsa should not be very difficult (I think) and as a balsa plane I am hopping that it will fly even truer then it does now. The fuselage will be the easiest, but I am still thinking about the wings.

berryulson
08-29-2005, 10:58 AM
Nice project! What exactly are the specs and did you buy or make the wings? I also made my first (and only, so far) scratch-built after flying the Beaver. I cut my wing out of a Hobbyzone ABX wing so the undercamber aided in airleron training. I'm currently working on a 50" balsa/depron idea with wings from Nasty Toes Aviation. Your RAT seems to to fly very well.

berryulson
08-29-2005, 11:10 AM
The fuselage will be the easiest, but I am still thinking about the wings.

Couldn't you just chop the foam up in sections for your templates?

RATA
08-29-2005, 03:31 PM
A friend of mine Rory Greenwell cuts all my wings. During the design process I tried a number of different airfoils. For example, my float wings are a flat bottom airfoil, while my standard wings are almost a fully symmetrical airfoil.

I am having Rory cut me a fully symmetrical pair just for test. However it would be this pair, depending on how they perform, chopped up in to pieces for my balsa wings templates.

I started out on a GWS Beaver, and after about one month I had Rory cut me a set of Beaver wings to which I added ailerons. The beaver, once I added Lipo’s to my setup, flew fantastic, Loops, Roles, Spins, and limited inverted flight all became part of the Beavers routine.


I would like to see some pictures of your scratch built, if you have any.

qban_flyer
08-29-2005, 04:56 PM
Well, I never got the RAT on the water, but I did fly it this morning. The AXI 2208 I am using has enough power to very quickly pull me along the grass and in to the air with very little effort. She was a completely different plane with floats on. After trimming it out I found it to be a very stable and pleasantly flying plane.

The next step for myself is to take my RAT and make a transition from a foam-based plane to a balsa plane.

Re-creating the RAT in balsa should not be very difficult (I think) and as a balsa plane I am hopping that it will fly even truer then it does now. The fuselage will be the easiest, but I am still thinking about the wings.

A balsa wing may be a little lighter, but not by much. As where rigidity is concerned, it will be more rigid but won't tolerate many accidents. A foam wing like the one you are now using will do just fine with a balsa fuselage and if you've already cut one, cutting another one should not be a problem.

Want to make the foam wing more rigid? Use strapping tape to reinforce it (a la Zagi), then either cover it with Colored packing tape or "Solarfilm". Solarfilm is a foam friendly low temp shrinking covering material similar to and applied to foam like MonoKote is to balsa but at a much lower temperature. I have used it regularly on plain old ACE white styrofoam wings since the '80s with no problems.

RATA
08-30-2005, 05:04 AM
A foam wing like the one you are now using will do just fine with a balsa fuselage and if you've already cut one, cutting another one should not be a problem.

That’s a great idea, and it will save me from making too many changes at one time. I am assuming that my fuselage templates will do just fine for my Balsa pieces. I am thinking that I should drill quite a few holes in to the Balsa fuselage just to lighten it up a bit.

Hopefully this week I will be able to get a good start on it. Keeping my foam wing will allow me to eliminate the wing as a problem, if I have any changes to the flight characteristics while testing the new fuselage. http://www.wattflyer.com/forums/images/icons/icon14.gif

qban_flyer
08-30-2005, 12:26 PM
That’s a great idea, and it will save me from making too many changes at one time. I am assuming that my fuselage templates will do just fine for my Balsa pieces. I am thinking that I should drill quite a few holes in to the Balsa fuselage just to lighten it up a bit.



Hopefully this week I will be able to get a good start on it. Keeping my foam wing will allow me to eliminate the wing as a problem, if I have any changes to the flight characteristics while testing the new fuselage. http://www.wattflyer.com/forums/images/icons/icon14.gif

Great idea to have lightening holes in the fuselage. It will save you a bit of weight while keeping it rigid and in true alighment.

Keep us posted on your progress.

berryulson
08-31-2005, 11:32 AM
This was my first. Set it up so I could experiement with high wing or low but just used as a high wing. http://img.photobucket.com/albums/v297/berryulson/904-4.jpg
I carved the fuse out of styro GWS style. This actually flew pretty well. http://img.photobucket.com/albums/v297/berryulson/904-7.bmp

The Commander wing is in place just to get the idea. Doesn't look too flyable.
http://img.photobucket.com/albums/v297/berryulson/904-5.jpg
(Don't know why those 2 shots reduced so much.)

berryulson
08-31-2005, 11:50 AM
Here are a few shots of my new one under construction. The tail has changed since the one pictured and is now more of a pattern style and the sides are now white with basswood reinforcing. Am going to sheet the foam wing and use a canopy cut from a Quiet Storm canopy instead of a MFuntana. Will start a thread when I get my new scanner hooked up.
http://img.photobucket.com/albums/v297/berryulson/3-05.bmp
http://img.photobucket.com/albums/v297/berryulson/305sideview1.jpg
http://img.photobucket.com/albums/v297/berryulson/305fuse1.jpg
(I'm just not having any luck reducing these properly from Photobucket.)

RATA
09-02-2005, 02:58 PM
Very nice job, are you covering you new design, for it looks like the rudder is made form a few pieces. It looks like it would be a very fast plane. What type of motor are you going to be using?

RATA
09-02-2005, 03:18 PM
I have started to re-build the RAT in Balsa. Piece for piece I used my original templates.

The only difference to the balsa RAT when compared to the foam RAT is with the balsa RAT I removed some of the negative incidence from the elevator, and some of the positive incidence from the wing; this allowed me to remove most all of the down thrust that was need in the foam version.

I am using 1/8”x 4”x36” sheets for my fuselage. I was going to go with 3/32”, but at the time it seemed a bit light. The only problem I have encountered is with the height of my fuselage, its widest point being 5”; I had to add a piece balsa to the top of my canopy on both sides. I will post the rest of the build as I work my way through it. :D

qban_flyer
09-02-2005, 03:41 PM
I have started to re-build the RAT in Balsa. Piece for piece I used my original templates.

The only difference to the balsa RAT when compared to the foam RAT is with the balsa RAT I removed some of the negative incidence from the elevator, and some of the positive incidence from the wing; this allowed me to remove most all of the down thrust that was need in the foam version.

I am using 1/8”x 4”x36” sheets for my fuselage. I was going to go with 3/32”, but at the time it seemed a bit light. The only problem I have encountered is with the height of my fuselage, its widest point being 5”; I had to add a piece balsa to the top of my canopy on both sides. I will post the rest of the build as I work my way through it. :D

Looking good!

RATA
09-04-2005, 04:57 PM
Almost done. I should be ready to start covering the RAT by Monday, and by the middle of this week I might have to move the Balsa version out of the Foamies Thread. :eek:

qban_flyer
09-04-2005, 05:17 PM
Almost done. I should be ready to start covering the RAT by Monday, and by the middle of this week I might have to move the Balsa version out of the Foamies Thread. :eek:
Holy Molly!

This RAT may turn out to be lighter than your original foam one. It has so many holes as to look like swiss cheese, heck I'd call it "The Swiss Rat".

Good looking job. Keep us abreast of how it turns out and where you move it to once it goes away from us our foamy's thread.

RATA
09-05-2005, 10:52 PM
The Swiss Rat. I like that idea. Too bad I could not turn it in to an ARF and market it. With a name like "The Swiss Rat" it would probably be a huge seller...

RATA
09-07-2005, 03:36 PM
Almost done. The conversion from Foam to Balsa has so far been painless. The recreation of both my wing and my fuselage, for myself, was a simple matter of numbers. However, covering the plane at first looked a bit difficult My friend Rory Greenwell (first posted photo) has been there, instructing, guiding, and helping. I went with a bright color scheme, figuring it would be easer too see. Now that it's almost done I can say it was worth the effort. Hopefully today I will have all the electronics in and by this weekend, or sooner :rolleyes: have it in the air. Once the new RAT is all done I will post a comparative side by side picture of both the Foam version and the Balsa version.

RATA
09-09-2005, 03:32 PM
Test flight…

Pictures one and two are of the completed RAT waiting for a chance to go up. The Balsa RAT in comparison to the Foam turned out to be very tail heavy, I believe this to be from the size and amount of lightening holes removed which resulted in more mass being removed from the front portion of the RAT then the back. After what tuned out to be a frail attempt to re-balance at the field we took it up.

Wahoo, the Rat flew, poorly but it flew. After a few close calls due to being tail heavy, It was decided that to continue I would have to make a few modification to get it balanced where it should be.

The color scheme bombed using Nelson SoLIGHT. With Nelson so thin the yellow was partly transparent, and the red was a transparent; with this color arrangement once the plane was anywhere near the sun the colors would have the appearance of bleeding together making it impossible to distinguish top from bottom.

Back to the drawing board…

The first thing to do was to add a third color to the wings; this made it stand way out, and hopefully I will no longer become discombobulated.

The modifications to the Balsa Rat when compared to the Foam Rat are as follows.

The Wing servos had to come 1 ½” forward.
The Rudder and Elevator servos were moved 6 1/8” forward.
The Battery compartment moved 3 3/8” forward

This brought it right on the edge of being balanced. Wanting to error on the side of being a bit nose heavy I decided to remove the Balsa canopy and it’s trailing edge as far down as the tail; this worked, and by removing the extra wood off the back end the Rat came right in to balance.

Pictures three and four show the current modifications. It does not look like the original Rat anymore, so I think that the qban flyer’s suggestion will stick, and I will call it “The Swiss Rat” I will post the new test flight later.

RATA
09-10-2005, 05:43 PM
What started out as a scratch built FOAMY Rat has really taken a twist and gone off the foamy topic by evolving in to a Balsa design. I really should have moved this thread in to another section, but oh well.

After all the modifications, as indicated in my previous post, were done I headed up to a large field on the Old Army Base. (Now a Cadet summer camp here in Vernon, BC)

I met my friend Rory there for what was anticipated to be a spectacular calamity, given the way it flew the day before. The day started off with myself forgetting to screw the wing servo horns on; thankfully we caught it before any flying was done, for at that point I was already thinking about calling it a day.

I set the Rat on the ground with anticipation, fully expecting to be fighting a dog all the way down and I just kind of stood there almost not wanting to try it.

Anyways, I at about ½ throttle the Rat lifted off the grass, straight as an arrow; the Rat seemed to remain in ground effect effortlessly. So, I applied a little backpressure and it climbed out perfectly straight. At this point my anticipation went from hopping to find all the pieces when it went down to wanting to hand off my transmitter so I could do a little jumping for joy. After enhancing my calm I few the Rat around effortlessly needing little to no trim.

This is by far was the best plane I have ever flown. Axel rolls were almost dead on, inverted flight required an immeasurable amount of down. I found this version when compared to my Foam Rat to be straighter, faster, and 100% more stable. Slowing it down for landings will take some getting used to, for with the Foam Rat I can come in and setup a short field landing by cutting back on the throttle and trimming the nose up a bit and instantly the Rat slows down and settles in to a nice landing. Not so the Balsa Rat, when I attempted the same setup it was almost like it was on rails and it just glided right by. Having said that, if I set it up earlier I am able to bring it in at a little better the walking speed, Very cool.

:p

RATA
09-29-2005, 04:56 AM
Test Flight Number Three…

This flight was to be more of an aerobatic demonstration of my Rat; here is where she started to show it’s greatest flaw. As mentioned in TF #2 while balancing the Rat the battery had to be moved quite far ahead of the CG, and although this balanced the plane it changed the way she would pivot around it’s CG; in Hammer Head for example.
Look at it this way. If you were to take to sticks each being 3 feet long, and lets say the CG will be one foot from the end. Now, balance stick one by distributing all the weight at both ends of the stick. Stick two we will place our weight not at the ends, but as close to either side of the CG as we can.

Although both sticks will now be balance at the one foot mark the have totally different tendencies when forces are applied.

Stick one when thrown will have a tendency to want to pitch back and forth and wobble out of control this is because of the distance of the weight for and aft of the CG.

Stick two one the other hand will have far less wobble, and be far less pitchy this is because our weigh need to balance the stick has been placed as close to the CG as possible.

I discovered that the fuselage on my Balsa Rat was more like stick one. So, not being able to modify it any more I decided to build a new one.

I went from 1/8 to 1/16 Balsa
Lengthened the fuselage by 1 1/4 “
I increased the surface area of both the Rudder and the Elevator.
Battery placement was also moved back over the first third of the wing
Pictures One Two, and Three


This time when balancing the Now (Super Rat) I was able to configure it in such a way that the component placement was as close to the CG as possible.

Attached Thumbnails

Test Flight Number Four, Five ECT…

After the above modifications I was not surprised to see that the Rat flew even better then before. Pivots around the CG were perfect Hammer Heads were bang on as it rolled over almost flawlessly My Test pilot Rory Greenwell said” I nailed it this time and not to change a thing” when I asked just how it was, he said “it’s as good as any ARF”

This brings to a close the journey of just how my Scratch built Foam RAT made the evolutionary journey to a Scratch built Balsa RAT. I still fly my Foam Rat, but I will admit will the addition of the Super Rat my foamy is starting to collect a little dust.