Bidule 170

[BobM]

I recently did some repair work on my main landing gear.

My Bidule is not outfitted with the brakes as many others are. The brake installation seems to provide some extra support on the composite main gear where the axles and wheels attach.

I built my Bidule with the axles and wheels installed as per the directions with the original kit and found the stress of the landings would eventually cause a failure of the composite main gear where the axles are installed. This portion of the gear cracked and shattered on my last landing about a month or so ago.

I removed the main gear for the fuselage, the axles, and wheels...the original main wheels needed to be replaced as they were starting to crack and it would only be a matter of time before they came off the hubs.

After the wheels and axles were removed I took the composite gear and sanded off the outer finish on both sides of the lower 4"-5" on the legs down to the axle attachment points.

I used denatured alcohol and soaked the legs each for a bit as well as wiping everything down. I wanted to be sure to wash any oil and residue off the areas that were going to be reconstructed and reinforced.

I made a simple form from some scrap 1 x 2 pine and covered it in saran wrap. Then the main gear was set vertically on one side. I used West Systems resin and hardener without any fill at first and coated all the areas of the main gear where I put the pieces back together, making sure to brush in all the areas that needed to be reconstructed. After the resin was put on to coat I added fiber filler to the remaining resin to slightly thicken it and add some strength to the mix. This was then used with the form on one leg at a time. I did one leg one day and then turned the form around to do the same process to the other leg the next night.

The result was very good. After some initial sanding and shaping the main gear looked like it was back to its original dimensions and shape. I did some more sanding with some 120 paper and cleaned everything with denatured alcohol and let it dry.

The next step was to add fiberglas cloth to both legs. Setting the main gear upside down I was able to take some heavier cloth and cut a length that would go from the inside of the leg down and around then back up the leg on the outside. The cloth was then attached with West Systems resin and a pair of small wood black with saran wrap were used on the end of each leg to apply pressure to the cloth and resin wrap.

This was left to set overnight and then the next day I was able to remove the wood blacks and clamps and take a look at the cloth that was applied. I little quick sanding with some 120 and 220 paper to smooth everything out and then cleaned with alcohol again. After this was prepped I then brushed on resin without any filler over the cloth and edges. I wanted to make sure to fill in the weave of the cloth and also allow for the transition from the repaired and reinforced areas to the upper section of the gear. This set over night and the next day I used 220 paper to clean everything up and prep for painting.

After getting all of the landing gear sanded smooth with 220 and 320 paper it was cleaned with alcohol again. I then used Monokote white primer for the base coats on the landing gear, the whole gear was primed and it set overnight. The next day I sanded the primer smooth and then applied another light coat to make sure everything was primed. This was allowed to dry over night and then the next day I applied the Monokote Jet White paint. I did the top and sides of the gear first and then after it was dry I completed the underside of the gear.

Once everything had dried well I took the gear and marked the position of where the new axles would be installed. I drilled 3/8" holes in the gear legs and then used 3/8" cap bolts for the axles. They seem to work just about right as the bolts have a smooth shoulder before the threaded section that is almost perfect in length for the 8" Dubro wheels I planned on installing. The wheel his were drilled out to 3/8" and the bolts were then put into the wheels with washers on each side of the hub. A nut was threaded onto the bolt to lock the wheel into correct position and then the assembly was installed on the main gear through the new axle holes. Nylon lock nuts were used for holding the axle assembly to the main gear.

I used a pair of washers on each side of the gear where the axles are installed. A standard washer and also a larger fender washer. My hope is the washers will distribute the stress of the loads onto the gear over a larger area and reduce the chance of the composite gear failing again.

I'll be giving the new installation a try this weekend and hope the reinforced gear will work well.

Here are a couple pictures of the finished gear and wheels.

[lenb]

Dean,
I immediately tapped the wing blind nuts to 1/4-20 and use a wing bolt to attach them. Scot's slick setup for the front bolts work pretty well so far.
With over 103 hrs on the air frame at this point, I can attest its will last a good long time with standard care and average skill. Try to always land on the mains and keep the nose wheel up, its very easy to make soft landings with a couple extra clicks of power right at the point of touchdown.

Love the plane, love the ZDZ 180 power and the brakes are awesome.

Len

[Helijet]

Lol...nice to know we are all experiencing similar issues / resolutions. Don't get me wrong. This airframe with the 170 and brakes is a true aerotowing workhorse.
It just needs some improvements in order to keep up the pace of busy weekends. I understand that.
Thanks again for all that have posted. I have employed many if not all the recommendations noted on this site! Will keep you posted as I log more time.

Dean

[Stew2]

I used Dubro control horns on the flaps, ailerons and rudders and used 2 of the "gold" ones supplied in the kit on the elevators. I only received 2 with the kit. I swapped the wing bolts to steel from day one and use them on the rear bolts only. The forward ones have the latch catches that Asher found from McMaster Carr. They are convenient for not having to move the fuel tank to get the wings on and off. Everything is loc-tited when assembled, so I haven't had to go back on anything yet. The brakes are the total bomb on the Bidule and I use them not only for safety, but also to bump the idle up and get some vibration off the airframe when waiting for the sailplane to hook up. I have had the Bidule out for 3 aero-towing sessions/events so far and my total time is on the order of 20 hours so far. I am going to see what I can get for vibration reduction with some mixture adjustments, but past that I am working ways to stiffen up the fuselage to see if I can get the shaking to decrease. Right now I have hinges and servos getting hammered at idle that I need to change somehow to make sure this thing has the best chances for a long life. Keep posting your experience, it helps all of us!! Thanks,

Scot

[Helijet]

Thank you for the info Scot. I will do the same. As for vibration issues, I had some chaffing and foaming of the fuel tanks which was resolved with some extra support plates front and back of the tanks. My engine mount bolts loosened a little after each run but with some extra blue locktite they are holding now. A couple of loose nose steering bolts needed locktite and retightening. The cockpit bolts needed a silicon washer to add a little vibration dampening. mostly stuff around the engine compartment. OH I DID FIND ONE SERIOUS PROBLEM. PLEASE CHECK YOUR NYLON WING BOLTS. I had one that would seem to snug up well against the wing but with vibration would loosen up. The last time I tightened it, the bolt would not bite into the threads. It appears the blind nut's thread is just a bit too wide for the nylon bolt. I substituted a 6 mm metal bolt which worked perfectly. Clearly poor Chinese quality control. I thought I would try the machined aluminum rudder post that was supplied with the kit. DONT BOTHER..IT SNAPPED ON THE 6TH FLIGHT. So, a Dubro one will be substituted ( as others have done ) The DLE is becoming smoother with each run but it does shake more than I am used too ( btw the Falcon CF prop is perfectly balanced -not using a spinner ).

Despite all the above noted little snags the plane is an amazingly easy one to fly and will perform much heavier duty than my Hangar 9 33% Pawnee did. I must say that I am disappointed with the quality of the hardware that was supplied given the cost but I suspect at least $300 of that is built in shipping costs to Etienne. I have also found that having the disc brakes makes for much safer field operations of such a big bird.

​Dean

[Stew2]

Dean,

I did what Len is describing. A 1/4" aircraft ply plate that is laminated to the fuse side and keys over the top of the gear plate. 3/4" triangle stock cut from rock hard maple, glued in with West Systems epoxy. And Jim Dolly and Len can both attest to my testing the gear strength this past weekend as I bounced a couple of landings pretty hard off the mains. There is a hum at the end of the field, but at least I did not put it down in the corn!! Easy to do and strengthens the gear mounting immensely. What are your vibration challenges? I am working a very shaky airframe now and am curious to what you are addressing. Congrats on the Bidule time, it is addictive, and while there is no known cure, it is at least treatable!!

Scot

[Helijet]

Fantastic...I can see that working and its a simply retrofit.
​Appreciate the help!

Thx
Dean

[lenb]

Hi Dean,

I cant find a picture, however I did a similar mod as Scot did. I made a saddle which mounted to the sidewall and stepped up over the plywood gear mount. Tri stock anything you can.

Len

[MarnochS]

Hi Dean,

I added a Vertical shear brace( 1/4" ply ) along the front and back of the landing gear plate to tie it to the sidewall and stiffen it up a bit. My AMR Payload Master 100 had a similar configuration........



Scott

[Helijet]

So...I have about 3 hours of run time on the Bidule now with about 6 or so landings and lots of taxing. The DLE 170 is running well and most little vibration related issues have been sorted out. After today's flying session I was cleaning her up and checking things over. While looking at the main landing gear I noticed some rippled covering. On inspection I noted that I could rock the gear for and aft a little. The main plate is still intact and I could not find any breaks in the fuse. I had placed the for and aft brace but it seems I forgot to add triangle stock to the sides of the main gear plate. Before I go and start tearing out the main plate could anyone give me some words of wisdom as to how to properly beef up this area. BTW all landings were gentle so I suspect its the powerful disc brakes that is causing the stresses on the plate??

​She is an awesome flyer as everyone says!

Dean W.

[kd4jaz]

That link at the front of this thread doesn't work anymore.......at least not for me!

[lenb]

Yah Dan,

Congratulations......

[Helijet]

Soooo...I am happy to report that another Bidule 170 is ready for tow duty. The maiden went well with just a few vibration related issues to sort out. I would like to thank all those that pioneered the path before me ( steering arm, servo saver and disc brakes, CG ) as I used all the recommendations. She will see some light duty this weekend at the High Country Aerotow in B.C. Canada and then should be at a number of future events in the Pacific NorthWest.


​pics to follow
Cheers
Dean

[lenb]

Hi Bob,
Happy to see you were able to get the steering system together for the aerotow. God job!

Len

[BobM]

Like many others I have had difficulties with the steering on the Bidule 170. I decided to use the design that Stew put together on his Bidule as well as Len's. The design is excellent and I know it seems to be working very well on the Bidules that have it installed currently.

I went through the basic making of the parts and had an assembly about ready for final work and installation a few weeks back now, but I realized when I was about to install it the control rods for the throttle and the choke on my Bidule go right through where part of the new steering assembly sits. I am using the DA 170 for power on mine instead of the ZDZ 180 as on Len's and Stew's.

I did a quick rethinking and reversed the upper and lower brackets and all seems to fit well. Steering is in place and linked now and everything seems to work and also go in the right direction.

I used the same materials that Stew did......the Losi 1/5 scale car steering, 2" x 1/8" angle aluminum and some thicker aluminum stock for the servo mounts.....plus a variety of various screws, nuts, washers etc that Stew listed with his design. I also picked up some 5mm threaded rod as I found the linkage lengths were slightly longer once I had made my steering system. I wanted to be sure the rod is threaded very deep into the ball links so there will be less likely chance of failure.

I also used a JR DS8911 HV high torque servo instead of the one that Stew is using. Have to see how it works.......it seems to be very good as I was using the same servo before I made the new modifications.

Here are a couple pictures of the assembly and the installation. I removed some of the ply plate at the front of the firewall, but not the sides. It would make it easier to have access to everything if I took out some of the side plywood as well.........have to decide if I will put in a removable plate similar to the setup before the modifications.

Next week will be the real test at the New England Aerotow. Hopefully I will be able to tow on demand and not have to pull things apart as I did in the past to deal with the steering issues.