Flybarless Caliber 5 ???

[MarKFK]

I would like to know, could you put a flybarless conversion from a Thunder Tiger Raptor, or a TRex 500-600, on a Caliber 5 ?

[Ah Clem]

I installed a Compass 6HV head on my Calibur 700 a couple of years ago.

It did require cutting the main rotor shaft down and drilling a new bolt hole in it.





It flew quite nicely with the stock rotor head, but this made it even nicer.

I don't fly it much anymore because of the question of availability of spare parts.

Very nice, very different machine!

[2Doggs]

I was wondering about doing an FBL conversion on my Caliber 5.

I've been flying electric helis for the past few years, but recently found a N.I.B. Caliber 5 on eBay for $100 that I found too hard to pass up!

When I bought my first Caliber a few years back, I recall their being an FBL conversion kit, which included parts to lock the moving servo mount in position, and different bellcranks.

I've not been able to find that kit anywhere, however, presumably due to the Caliber 5 being sadly out of production. It's a real shame, since I've always loved the simplicity of the Caliber main frames, and the quiet running and durability of the two-stage transmission, and I regard the dual-point tail mechanism as the benchmark heli tail linkage.

It looks like it wouldn't be too difficult to lock the servo mount, however. It might even be feasible to use multiple layers of 3M double-sided foam tape to stick the moving servo mount to the fixed part, and the existing brackets will hold the whole assembly together.

Instead of the collective servo being mounted as per the FB, you could to mount it with the servo arm on the right side of the heli, with the output shaft to the rear, and connect it to the longer of the two aileron linkage rods.

The elevator servo would need to connect to only one of the two elevator linkage rods. For FBL, you'll need to use longer servo arms, perhaps 21mm or more, depending on the head, so the upper elevator link looks like it may be the only option, since the lower link will foul the fan housing.

It would be important to look for an FBL head that has short blade grip arms - ideally 30mm, otherwise there won't be enough swash travel using the existing FB bellcranks. The mainshaft will need to be shortened.

Although the resulting linkage geometry won't be perfect, I think it would be possible to compensate by judicious use of servo arm offset and ATV or EPA in the FBL controller. It looks like you could use the ZYX, although a V-Bar would give you swash levelling at full low and full high collective as well as at zero pitch, which might also be useful for correcting the imperfect geometry.

If I can find the right FBL head, with short enough grip arms, I might give it a go.

[Bigbobby]

Hi 2Doggs
Quest now produce the Caliber range and have a FBL head for the Caliber 50(nitro 50)/Caliber 550 (electric 550). RCJapan sell bits if you need them and the part numbers are available from the Quest website http://quest-co.jp/.