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Old Sep 07, 2012, 07:23 PM
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USA, TX, Houston
Joined Nov 2003
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Build Log
Bridi RCM Trainer 40 - A trip down memory lane

A build log of an old Bridi Hobby RCM Trainer 40

Story: When my father taught me how to fly radio control planes, he started with gliders. After I could launch, fly, and land "dead stick" with those, we upgraded to power flight. The first plane we built together was the Bridi Hobby RCM Trainer 40. On its maiden flight, it flew great for the 5+ minutes in the air, but when my father was landing, he found the only hole in the field and it busted into pieces before our eyes. The wing was ejected and the only piece recoverable. We kept the wing and hung it on the wall, in a closet, then the garage, and finally my son's room. It hasn't flown for nearly 30 years.

...but that will soon change.

A local RC Group member was given a partially built Bridi Trainer 40 from his uncle a few weeks ago. He wasn't sure that he wanted it so he posted it for sale on RCG. We got in touch and met this morning to work out a trade. For his uncle's kit, I'm building him one of my "Funder & Lightings".

So we begin the "resurrection" of my old Trainer 40 wing with this partly built fuselage. The plan is to sand, seal, and paint the fuselage (no covering). This will be an electric conversion of a 32-46 sized brushless outrunner, a 4S-4000mAh LiPo, Spektrum radio equipment, and possibly the addition of a dedicated front gear MG steering servo. By no means is this sucker going to be light. It'll fly and hopefully look nice. That's about it. Besides, after 30 years, it's about time I had a chance to fly it!

Enjoy the ride.

-Lee / YarSmytheJr

** Specifications of Aircraft / Updated January 2014 **

- Motor: Gen Ace BL3749-770KV
- ESC: Gen Ace 60A
- Battery: 4S - 5000 mAh (changing to 4S 4000 mAh to save weight)
- Prop: APC 11x7
- Servos: Futaba S148 (elevator/rudder), JR MN48 (ailerons)
- TX/RX: Spektrum DX8 with Orange DSM2
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Last edited by YarSmythe; Jan 12, 2014 at 09:03 AM. Reason: Updates
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Old Sep 07, 2012, 07:27 PM
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Not my first e-conversion rodeo.

Here are pics of a Hobbico Flightstar Trainer 40 I converted back in 2004.
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Old Sep 07, 2012, 08:19 PM
Terry Dunn
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United States, TX, Lubbock
Joined Jan 2001
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Cant wait to see the finished product. I know you'll do it right.
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Old Sep 07, 2012, 09:04 PM
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Bridi Trainer

Dear Yar,

I have a Bridi 0.60 sized trainer, started in 1985. The fuselage and wing are assembled, no engine or controls were ever installed. It sits in my basement. In 2005 I unwrapped it from when I moved to NC, and vowed to finish and fly it.
Well,... I haven't. I am looking forward to your progress, and would welcome any suggestions for me
Incidentally, the plans for this say "Great Planes", however if you remove the glued-on label it says Bridi underneath.

Sincerely,
Nelson
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Old Sep 07, 2012, 09:25 PM
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Quote:
Originally Posted by CAMaker View Post
Incidentally, the plans for this say "Great Planes", however if you remove the glued-on label it says Bridi underneath.Sincerely,
Nelson
Nelson, same here. Our original kit was marked Bridi Hobbies. When Great Planes bought them out, they took their inventory and put stickers on them until they developed their new version of the kit. The one I got today also had the glued-on sticker! Made me laugh.

I'll pass along whatever I can to help you out. Feel free to upload your pics to this thread too! Happy to see the .60 sized version.

-Lee
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Old Sep 08, 2012, 09:14 AM
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BEFORE photos

I have a little bit up of an uphill battle. The plane has been sitting in an attic for 20-something years. I haven't seen any signs of termite or bug damage (ie - pieces chewed) but there is some heat related damage and what appears to be water stains.

I'm no Bridi expert...but my first "scratch of the head" is that there is NO reference to "RCM" anywhere on the box or instructions. The space where it should be...is blank. Overall, the plane is starting to come back to me but I have noticed that my wing doesn't quite fit as tight as it should. Almost as if my wing chord is too long. Will have to do some more checking.

Anyway...a few pics to share.
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Old Sep 09, 2012, 04:42 PM
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Houston, we have a problem. A "Jr" problem.

Remember when I was scratching my head and wondering why the wing doesn't fit in the saddle properly? Well, I know why.

From what I've read online, there are three versions of the Bridi Hobby Trainer 40. The Jr., RCM, and Advanced. The kit my father and I built was the RCM which supported a .40-.60 sized engine and a wingspan of 58.5". The box that came with the plane I picked up does not say JR, RCM or ADVANCED on the front. Simply, TRAINER 40. However, I found the instruction manual and right on the front it says "JR.". A quick glance back at the wingspan on the box confirmed my suspicion: 52"

Soooooo, I'm still scratching my head at this point. Do I continue with a wing that is heavier and 6.5" wider? Gotta think about this for a day or two. My gut says it isn't going to be an issue and that I can easily modify the wing saddle to support my old wing.

Stay tuned.
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Old Oct 22, 2013, 09:18 PM
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Sorry for the long delay. Life got in the way. Back on track now.

Today I cleaned up the fuselage and tail surfaces. Going for the same yellow/gold them from the wing via Monokote (decided not to paint). Tail control surfaces are done. Working on the fin right now. Should have the tail done tomorrow.

The wing is to big for the saddle but not by much. As for the aileron torque rods, I have two choices: 1) Drill out notches in the root saddle or 2) Remove the torque rods and put servos in the wing. Drilling out notches is the easiest step but I like the idea of having independent aileron servos. We'll come back to that.

Found a nice electric conversion of a Bridi Trainer 40 online. I hope mine will look as good.
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Old Oct 23, 2013, 02:22 PM
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Quote:
Originally Posted by yarsmythejr View Post
Sorry for the long delay. Life got in the way. Back on track now.

Today I cleaned up the fuselage and tail surfaces. Going for the same yellow/gold them from the wing via Monokote (decided not to paint). Tail control surfaces are done. Working on the fin right now. Should have the tail done tomorrow.

The wing is to big for the saddle but not by much. As for the aileron torque rods, I have two choices: 1) Drill out notches in the root saddle or 2) Remove the torque rods and put servos in the wing. Drilling out notches is the easiest step but I like the idea of having independent aileron servos. We'll come back to that.

Found a nice electric conversion of a Bridi Trainer 40 online. I hope mine will look as good.
Good article. I used wing saddle tape to get a good fit to the fuselage. The fit is snug and the tape gives the wing to fuselage some cushion.

I Dremeled relief notches in the root saddle to allow adequate movement of the aileron torque rods. I also considered servos in the wing but decided to keep it as original as possible.

Keep up the great work on yours!
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Last edited by swimmer; Oct 23, 2013 at 02:27 PM.
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Old Oct 23, 2013, 08:50 PM
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Well here's another weird twist! I found our original manual for the Trainer 40! Can you believe that it actually says: "RCM Trainer 40 JR" ??? I know for a fact ours was NOT the "JR" version due to our wingspan. I wonder if Bridi used the same instruction manual for the "JR" and the standard Trainer 40.

One side of the fin is covered. Will finish the other side tomorrow...maybe even the horizontal stab.
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Old Oct 24, 2013, 11:45 AM
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Finished the rudder & elevator. Starting to cover the fuselage in the matching yellow from the wing.
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Old Oct 25, 2013, 11:28 AM
Sailaire brethren
United States, KY, Bowling Green
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i may be wrong but I thought there was a .60 sized version of the Bridi trainer and then the .40 version
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Old Oct 25, 2013, 12:35 PM
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There is a .60 version but there are multiple versions of the .40: a standard (58" wingspan) and JR. (52" wingspan). Seems like Bridi, RCM, and Great Planes made a mess with the design and several versions came out. All I know is that my wing is 58" and I believe the .60 version was at least 60". Personally, I don't think I'll notice any difference flying this wing on a ".Jr" fuselage. We'll see!
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Old Oct 25, 2013, 02:16 PM
Sailaire brethren
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The .60 version flew with a lot of power. For a trainer it really moved out. Cranked way back it would fly like a Sunday flyer but seemed to like moving fast and getting folks into almost pattern performance

With that k&b engine for power and no muffler ( back in ancient times) it literally and figuratively screamed.

Hope your "RCM Advanced Jr" flies well
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Old Oct 26, 2013, 02:12 PM
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Good luck with it, it should fly great! And yes, I also started with a Bridi Trainer 40 for my first RC plane back in 1979......I think! Michael
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