Compensator Build
 

Hey guys, my Kaos broke at the Glue Dobber's Dan Quinten Memorial contest in Tulsa, and I am working on building a Compensator from Eureka for the next contest.... which is June 16 at Thunderbird field in Fort Worth. That is not much time I know, but I think it is possible. As far as the Kaos... most of you have seen pics of it, but I'll attach another for those of you who have not. My desire was to retire that airframe and build something else, but up until now I have kept going back to it. Thankfully I noticed the failed vertical stab glue joint and lower hinge, and did not lose the plane. As far as reason for retiring the plane... First, there is an incredible sentimental value to it. Second, I have moved into expert and believe there must be better airframes for the more demanding sequences.

I have not done a build thread, nor read or followed one, so bare with me. I feel I can build a nice plane, and hope to share some of the experience with y'all.

Cheers,

Blake

RE: Compensator Build
 

I started on the Tuesday, May 22, by digging the short kit out of the attic and looking for some of my building tools. (I just moved to this house a month ago!.. and nothing is arranged for building) To this point I have trimmed all of the pieces and skinned the cores. I am not going to bother with retracts, as we are only flying SPA here, and put gear blocks and servo rails in the wing cores. The servo rails are set for JR 3301's, and I plan to use the DEPS and one JR3301 for the elevator. The rudder is getting a JR 8411sa. These I had laying around...

I typically like to build up wings, and it has been many years since I skinned a foam core. I did not like foam because they always seemed to be heavy, but this kit was given to me and I did not have much choice. One of my close friends whom also is now a neighbor, has recently set up a vacuum bagging system. He offered to let my try out his set up, and I was excited to give it a try. I choose to use Gorilla Glue, and it seemed to work out well. I weighed my cores and skins, and got a combo that was balanced. The pre glued weights were 170, 172 for the wing halves, and 21 for each stab half. (in grams with foam and skins combined) The post, pre trimmed weights are 240, 238, and 31, 31. Can anyone tell me from experience if gaining 70 grams per wing half and 10 for each stab is respectable or not?

My engine of choice is OS 61 SF abc, and am going to use a Jett bubble less on the cg in this application. Not sure on radio, I have been using a Futaba 9ZHP on 72mh for 11 years and still love it, but also have an Aurora and DX7 to choose from. I have not ever used the DX7, and only used the Aurora on an EPP foamy. I am also considering using a Lipo with regulator, any suggestions here? I typically use a NiMh 2000 Mah 5 cell.

RE: Compensator Build
 

Blake,

Looking forward to your build.

Your weight gain in the wings of 2.4 oz (70g) per panel is not bad. Some are able to do it with 1.5 oz of epoxy or 3/4 oz per skin. But you will likely offset these 2 additional oz with a light battery and no retracts.

Your skinned panels stand just shy of 17 oz total. You're aiming for a total unfinished wing weight of 24 oz or less. Your finished and equipped wing should be no more than 3 lbs with retracts or 2.5 lbs without. Carve out the right wing tip and hold off on permanently installing the left tip until you balance the model laterally. Then hollow out to balance. If you are able to build, finish and equip the fuse at a total of 5 lbs, you'll wind up with a 7.5 lb model which should result in a nice flying Compensator.

Are you planning on painting or covering the fuse?

David

RE: Compensator Build
 

Looking forward to following your build thread. There is a sticky on the main page that lists the links to a bunch of classic build threads that you can look at to get an idea how others have presented their build info.

Other than flying, I find building the most interesting part of the hobby and like many I find the building process provides the best flying experience and is then most rewarding.

RE: Compensator Build
 

I will be Monokoting the plane. Someday I would like to get set up to paint, but it will not be for this build. Last night after my post I started thinking that I have the numbers incorrect on the wing cores. I know the weight of the skins, and thought I remembered the weight of the cores. It seems like I added 40 to 130 and forgot the other skin... If 130 grams sounds right for one core, then the two skins were 32 and 40, and that puts the glue at roughly 40... either way I guess the result is the same... 240 and 238. But it would be nice to know, because the Gorilla glue was ultra easy to use, and the combat guys say it isn't any heavier than West Systems epoxy. Thank you for the tip on the wing tips.

RE: Compensator Build
 

Worked on the plane most of the day, and am feeling good about it. Thank you David for the guidelines to look for on weights, the wings seem inline at 260 grams each with leading and trailing edges bonded and sanded. Of coarse the rails and gear blocks were installed in the cores before I sheeted them. The horizontal stab is 70grams with le and te installed and halves joined. The vertical with rudder is 33. I should be able to join the wing and start building the fuse in the morning. I already prepared the fuse sides, though I plan on redesigning the upper for 1/16 sheeting instead of carved blocks...

Anyone played around with dihedral? Plans state 1" under each tip, which is essentially a flat upper surface... Let me know if it needs tweaking!!

I will try and post some pics in the morning... Right now it's not much to look at though.

RE: Compensator Build
 

I received a couple small boxes from USPS today. One was a 12 once tank from Jett. The other is a very special one though!! I have a Sequel short kit, and when reading a build thread by GlockGuy I noticed he had the ability to form the Compensator canopy. It is used on the Sequel in the AAM build article, though the plan shows a Birdy canopy and denotes "use canopy of choice" or something to that nature.

Anyhow, I was looking feverishly for a Compensator canopy, two in fact, because I haven't seen a Compensator that I think looks good with any othr canopy. It really is possible I would have not built either plane with out one... Vain huh?? Well, Leo (GlockGuy) PM'd me last week that he would soon be gearing up to produce these, and it could not have been better timing. I had just broken the Kaos, and was trying to decide on a Pheonix or Dirty Birdy... Not wanting either, just don't like arf's, I made up my mind when I got that pm what I would do.

I am not sure he was intending on gearing up this quick, but he sent me two of the nicest canopies I've ever seen!!! Thank you Leo!!!

RE: Compensator Build
 

Here are some of the pics I took last night, maybe today I will take some that look more like an airplane!!! Also here are a couple pics of the canopy!!!

RE: Compensator Build
 

I have built 2 and flown one more Compensator and 1 inch under each tip is good dihedral yes pull a string across top and its flat. Compensator maybe the most honest airplane SPA legal only mod to consider is maybe strech fuse a bit from wing saddle to tail 1.5 inches or so. Did you purchase the streched version of kit from Eureka? Please do post more pictures so we can enjoy the build.
Thanks

Tim

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RE: Compensator Build
 

Thank you for the input Tim. It is the stretched version from Eureka. I considered returning it to plan, but remembered adding a good bit of lead to the tail of the Kaos... A fellow competitor won it in Tulsa a couple years ago and gave it to me!! I will post more pic in a bit, it's coming together well.

RE: Compensator Build
 

Blake

If you will go to the Trenton rc flyers website and look at the Gator Flea article it shows formers and 1/8 sheet planking top round deck which should be great for the Compensator, sometimes little brother "Gator Flea" may have a better idea. After sanding to shape you will have between 1/16 and 3/32 which should hold up to everyday handling of the model around flight line. You could design a foam deck and sheet but the planking idea maybe easier. Did the kit come with orginal diamond stab or a symmetrical one like Zimpro did when Dennis had Compensators available?

Tim


http://www.trentonrcflyers.com/patte.../gatorflea.pdf

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RE: Compensator Build
 

I built some formers, and sheeted. The planking would have looked better. I'll post some more pics tomorrow morning. It has the diamond stab.

RE: Compensator Build
 

Well, it doesn't look much more like a plane today... lol, but I have a fuse now! Back to the shop!

RE: Compensator Build
 

Looking good! First pattern plane I can remember was my dad's Compensator!

RE: Compensator Build
 

The top deck looks great. Keep posting your progress

Tim

RE: Compensator Build
 

Thank you Tim! It looks better in the pics though. If I were to redo I would use more srtingers, and wet the sheeting before applying it...

I decided to do the cowl and bottom block while the fuse is still easy to handle, and it took a bit more time than I expected. I used Sig's yellow glue, hoping it will fill some small voids and sand well. I also joined the wing halves. I didn't remember to take a pic yet, but when I made the formers I cut the inside of the third one, which is near the cg, to cradle the Jett bubble less tank. The tank is right inline with the carb, so maybe that will all prove to work well. If not, I have a new OS SF-p I can put in it, and went ahead and cut holes in the firewall for the fuel lines to the pump.

RE: Compensator Build
 

More pics.

RE: Compensator Build
 

Well, I have done a little in the last week... but not much. I started pulling dead bushes as the milkweeds reached the the eves of the first floor, and that is still consuming most of my time. I still hope to somehow finish this bird by the contest on the 16th, but do have a nice Jensen Ugly Stik I can lean on if I have too. Here are a couple pics I took yesterday. The belly pan is complete now also.

Cheers,

Blake

RE: Compensator Build
 

You are fast builder, especially after moving into new house, with a ton of things to do. Looks good.

Crank

RE: Compensator Build
 

Blake

Have you installed the retract plates in wing or did you decide to go with fixed gear? The plan if memory serves me correct shows the tricycle gear rear mount at 1 inch behind cg, the plane will tip front to back on landing. Move the gear back about 1/16 of an inch. This will help keep the plane from having the rocking horse like effect of tipping on the tail skid after fuel is burned out of tank on landing. That usually happened when the landing was complete and plane stopped rolling.

Tim

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RE: Compensator Build
 

Thanks Crank!

Tim, thanks for the tip, but I installed the blocks before I sheeted the wing. IIRC I moved it back about 0.125", I hope that is enough. I usually like an aft CG location. The tank is on the CG, so at least it will not be a factor. If I need to , I can bend the gear to place the wheels further back... I am working on it now, and hope to start Monokoting tomorrow.

Cheers,

Blake

RE: Compensator Build
 

Pictures when u can

Tim<br type="_moz" />

RE: Compensator Build
 

Build has been moving along well. I set the incidence on the stab and glued it on. I have found that using a 0.070 carbon rod in a Teflon sheath (available from CST) is my favorite push rod method. I believe I first learned of this on this site from Troy Newman, but I might have that wrong. It is referred to as DEPS and I like to use it for the elevator and rudder. Installation is a pain, and having a solid ply former at the LE of the stab, and in my case F4, made it impossible to do the way I typically do it. (Build truss and wrap Teflon with thread, then install in fuse) Here are some pics of the install.

RE: Compensator Build
 

After completing that, and then attaching the verticle stab, square... preping for Monokote went pretty quick. I plan to start after I put the little Dude to bed! (I hope by 9:00 LOL)

RE: Compensator Build
 

Looks nice. That's probably why I always wanted to build either the Compensator or Gator Flea.

Jim