Rics hubbar

[angus]

just wondering if the teeter block bolts are more/less stressed on a rics bar than another type, seeing that they are in the middle of the block instead of being diagonal like most other setups. or are there other bars out there with round teeter blocks?

[asra]

Good question Angus! Presumably these have the teeter block bolts closer together than the ones with a square block allowing wider separation, of course the only worthwhile stress on them would appear to come from the pre-rotator. However when you think about it from the point of view of hub bar integrity isn't it better to have the holes in line with the longitudinal axis of the hub bar rather than across it [even though it is diagonal] as with stamps and toilet paper?John EvansThink logically and do things well, think laterally and do things better.

[angus]

thankyou for the answer John.I thought along those lines ,i suppose it is just easier to make a square teeter block.what about the pressure on the bar where the block meets it when the blades are coneing up?

[Brian]

Angus, I'm not sure about the stress's on a Ric's hubbar but I know they can do a lot of hours without any apparent problems and that includes a bit of scrub cutting in the bargain. I have a set of Ricks as well as a set of Patroneys and the Ricks stack up pretty well and are probably the bettter set for low time pilots in my opinion.Brian

[asra]

Actually there shouldn't be pressure there Angus, as the idea is to have the coning angle bent into the hub bar so centrifugal force is pulling straight out from the bend.I recently learned that there seems to be considerable confusion about what is the appropriate position for this bend. Quite a few years ago the CAA [ a forebear of CASA ] provided ASRA with the results of an engineering analysis on hub bars, this was published in Gyro News at the time. They recommended that such bends be located in the middle, however since that made it extremely difficult to provide a stable mounting for the teeter block, they determined that it should be confined to the middle 8 inches, i.e. within 4 inches of the teeter bolt. I'm not in a position to determine how many of our manufacturers comply with this, but I am getting the impression that it has been forgotten.I guess it is fairly difficult to confine the bends to a small area like that, but it seems there are sound reasons for doing it.Perhaps we will all have to be a bit more critical of the components we accept as purchasers.John EvansThink logically and do things well, think laterally and do things better.

[angus]

thanks for the the info fellas.be along time before im trimming scrub (i hope!).is your bar straight with wedges on the end to make the angle Brian? .

[Brian]

Yes, thats correct Angus, the bar is straight with angled wedges on the end.You dont have to have a lot of time up to trim scrub!!!Brian