with my extended boom (.71" stretch) on rchelitech's beltmod, i'm noticing i get a lot of vertical movement at the tail; about one inch total--1/2" up, 1/2" down. so, i decided to see if i couldn't make the boom struts functional rather than just ornamental.

note: this particular mod takes advantage of the rchelitech struts rather than the stock ones, though the stock struts may work. i dont have any to test, as i tossed them when they snapped.

parts list:
2 x 2-56 bolt-on ball links $3.10 ($1.55/ea)
2 x 2-56 swivel ball links $3.10 ($1.55/ea)
1 x 2-56 x 3/4" socket head screws 90˘
note: if you can find 2-56 x 1" the mod is simpler; they're just hard to find.

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the mod:

1) if you can find 2-56 x 1" cap screws, skip the first part of this step.
however, the 3/4" screw isnt long enough to go through all the pieces without filing down the horizontal fin clamp. i took a dremel sanding drum and nibbled away the thicker side of the clamp until the sides are equal.

you'll still want to clip off the old support sockets on either side of the clamp.

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2) lightly sand the ends of the stock struts and CA them to the threaded brass pushrod ends from the 'bolt-on ball links' pack.

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3) lightly sand the other ends of the stock struts and CA them to the swivel links from the 'swivel ball links' pack. before gluing, verify the total length of the rods are the same.

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4) the brass threads self-tap into the rchelitech struts. the length of the supports can be adjusted here by varying the amount of threads put into the struts.

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5) replace the horizontal fin clamp. the hardware should be assembled in this order:
2-56 x 3/4" (or 1") screw -> swivel link -> swivel link bushing -> horiz stab clamp ->swivel link bushing -> swivel link -> 2-56 nut (with loctite).

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sidenote: i actually broke my horizontal stab by being lazy and pulling it over the boom, rather than off the end of the boom. so, i took a spare servo clamp and made the same mod. i'd highly suggest taking the time to remove the tailbox if you want to remove the clamp....though the mod is probably possible without removing it...just tricker to dremel the width of the clamp.

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good luck

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if it ain't broke…break it.

Good looking mod. This should also help keep the belt centered. Have you checked to see how much weight it adds?

thanks. it really is quite helpful. there is no flex in the boom at all now unless i apply significant pressure---and this bows both the rods and the rchelitech struts. pinning the ends down definitely helps.

i dont have a scale handy at the moment. i usually borrow garage_flyer's. maybe there'll be one under the tree this year

however, i didnt have to trim the elevator when i flew it. i'll post an AUW when i get a chance to weigh it.

if it ain't broke…break it.

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