TopModel Bidule 170 ~ build thread by JimD

[Stew2]

I hope they work well, but I think you are going to need aluminum where they interface with the hub hex. I think just carbon there really only uses the strength of the resin. Turn down the aluminum discs and rivet the carbon to the side of that. When installing I would pay close attention for the disc to ride in the middle of the gap between the pads in the caliper. I deal with this by shimming the caliper mount away from the face of the gear as necessary. I have found the careful alignment there helps greatly in pad life. I typically have to shim the caliper pads after every tow session or at least after every aerotow. I think this maintenance schedule could be extended with a master cylinder that had a larger volume stroke. I have been eyeing the master cylinders that are used on bicycle hydraulic brakes..... Haven't found one I like yet, but that is a mod that I am thinking of.

[JimD]

Scot, I like those ideas!...We continue to move on toward perfection! 😎👍

[MarnochS]

The calipers are not self-adjusting like bicycle brakes are so shim's are necessary to take up the wear. I think the carbon rotors wear and don't gall like the aluminum rotors ( making sandpaper ) the old carbon rotors I started with were the standard 2 mm thickness and have worn down to about 1.9mm in 3 yrs of service. I did order some new carbon rotors and they have a initial thickness of 2.6mm ( different manufacture than the original )

[JimD]

The carbon discs worked extremely well, but we only got to use them for one event before the Bidule 170 engine had a catastrophic failure at the New England Aerotow in Salem, CT in May 2019. The crankshaft failed at the back of the woodruff key slot and the prop/hub/spinner departed on tow. Luckily, we were able to land with no problem to either tow plane or sailplane, but the Bidule 170 was out of service at that point.

Upon closer inspection, the sudden massive vibration caused by this event did considerable damage to the fuselage firewall structure. At this point in time, we had just gotten our Cmelak tow plane in service, so the Bidule 170 was stored for repair at a later time.

With the pandemic lockdown, a lot of projects that were on the back burner were brought to the front of the line. the Bidule 170 fuselage was stripped of everything and the wooden structure was repaired. Various other accumulated areas of wear and tear (like the landing gear plate) were also fixed. Once the fuselage was back to full-strength, recovering was completed.

This was the first of two Bidule 170's we had and it did the bulk of our aerotowing work from Spring of 2016 to the Spring of 2019. Our second Bidule 170 was sold to finance the Cmelak build.

This Bidule 170 has been well traveled and has accumulated several hundred hours of flight time (probably the most of any airplane that I have ever owned). Looking forward to having it back in service.

[stevekremer]

Looks good Jim!

[horsefeetky]

stronger than before im sure.. the work horse will be back in the air soon i see...

[JimD]

Finally got the right weather to get the repaired cowling painted...here it is, all ready to go again!

Thanks to Gunny (Aviation Concepts) for doing the fiberglass repair work on the cowling, and to Jeremy Hartmann (aka Swiss1) of the Model Box for getting the matching orange spray paint.

[horsefeetky]

hey jim do you have a spare set of brakes for the bidule laying around you might part with..

[JimD]

Sorry, but I do not...just have sets of worn pads and rotors. They are a testament to the many hours of aerotow time this plane has done.

[JimD]

Yesterday was a beautiful day to be socially distancing on the mountain...sad knowing that it would have been a perfect aerotowing day. Really miss seeing everyone!!!

Anyway, Bidule 170 #1 is officially back in service and performing perfectly after the fuselage refurbishing. Was cool getting to use the Aviation Concepts brakes again!

Thanks again to Gunny for doing the cowling repair and to the Model Box (aka Swiss1) for getting the color matching orange paint for me, you guys are the best!

[gunny11]

Nice pictures!

[jgallacher]

Beautiful pic's Jim. What is the color in the trees? I finally got out of the house and flew my Pegasus at the Torrey Pines Gulls field in Poway CA the other day, felt good to just go sit outside in a field.

[JimD]

The amazing color is eastern redbud trees. Absolutely love this time of year because of them.

https://www.arborday.org/trees/treeguide/treedetail.cfm?itemID=912

[JimD]

There is also some dogwood (white) mixed in.