Swift Tail Grips & Bearings

[FR4-Pilot]

Are there known issues with the stock plastic tail grips and the radial bearings on the Swift 16 and/or Swift NX? I've been told there was a recall sometime ago, but never heard of this until yesterday. Maybe I don't have all the facts .... (?)

Since the metal tail case has been discontinued, is the NX's plastic tail case strong enough to support the extra weight and resulting forces of the triple bearing tail grips?

Thanks!
-John

[Dennis P]

Never heard of a recall but it is a common upgrade to go with the triple bearing tail grip and hub assembly part # CN2235 .Much tighter setup with a way stronger hub.Your radial bearings will last allot longer with the thrust taking the load.

[MotorRotor]

If memory serves, there was an issue related to the outside diameter of the thrust bearings on some of them . I think it was related to the metal blade grips, not the plastic ones, but it may also have been so on some of the plastic grips..

This OD of the bearing was a hair too big so they would not seat properly inside the grip.

Seems this was detected early, on so I do not think there were too many sold with them.

Another issue with any rotor that uses thrust bearings in the blade grip is to insure the thrust plate with the larger Inside diameter (ID) is towards the center and the one with the smaller ID is to the outside.

[Dennis P]

Originally Posted by MotorRotor

If memory serves, there was an issue related to the outside diameter of the thrust bearings on some of them . I think it was related to the metal blade grips, not the plastic ones, but it may also have been so on some of the plastic grips..

This OD of the bearing was a hair too big so they would not seat properly inside the grip.

Seems this was detected early, on so I do not think there were too many sold with them.

Another issue with any rotor that uses thrust bearings in the blade grip is to insure the thrust plate with the larger Inside diameter (ID) is towards the center and the one with the smaller ID is to the outside.

MotorRotor the Swift 16 and NX never had thrust bearings in the tailgrips that I know of.They have the aluminum hub with allen head cap screws for the spindle and 2 radial bearings?

[MotorRotor]

You are correct Dennis, relative to the stock tail rotors of the Swift 16 and NX which had no issues.

I was referring to the upgrade units that had the machined steel hub with two radial bearings and a thrust bearing. It was available with plastic blade grips as the CN2235, and with metal blade grips as the CN2236.

Similar units also came as the stock tail rotor on some of their bigger kits - e.g. The Swift 620SE and I believe on the initial Radikal G-20 gassers.

I was sent over to a thread in another forum where FR4-Pilot is asking about a problem he has with a tail rotor/gyro issue. I saw that someone there referred him to here. In that thread, there is a picture of his tail rotor which has the one with the aluminum grips. So I was assuming that is the one he is talking about.

[FR4-Pilot]

Thanks guys. I recently put a set of the CNC triple bearing tail grips on my Swift 16 as well as a metal tail case. I also just ordered a set of plastic triple bearing blade grips for my Swift NX which still has the plastic tail case.

On my 16, with the stock plastic tail grips (radial bearings only) it appears that one (or both) of the grips would "lock up" at operating speed (with blades attached) and not allow the pitch slider to move in one direction. Since the tail servo was forcing the pitch slider to move, and it wouldn't, the entire stock plastic tail case would twist and deform - which is why I wasn't getting decent CCW piros. The suspect is appearing to be most likely the radial bearings.

I tried a replacement gyro (gy520) and tail servo (ds650) and that made no difference at all. It wasn't until I spooled up on the bench with the tail blades on, that I saw what was going on (not recommended BTW).

[FR4-Pilot]

I now have a metal tail case with metal triple bearing grips on my 16, and the stock plastic case with plastic triple bearing grips on my NX. Looking forward to seeing the results.

So far I like the metal triple bearing grips much better than the plastic ones. After some tri-flow on the radials and grease on the thrusts, the metal grips have virtually no rotational friction at all. Not so for the plastic grips (with the same bearings and lube treatment). My guess is the bearings don't sit exactly parallel and/or concentric to each other like they do in the metal grips so there is a fair amount of friction/binding that I simply cannot eliminate.

Also, the distance between the balls on the tail grips appears to be different between the stock, plastic triple and metal triple grips (?). This leads to a different angle of the pitch slider linkage and some undesirable effects with the plastic triple grips when the pitch slider moves all the way towards the tail case - as the slider passes "over the hump" the little links continue to pivot past their normal max. angles - then start swinging back the other direction - all while allowing the grip to continue to rotate up to a point where the grip/links lock and can only be returned to a flight worthy position by manually twisting the grips in the opposite direction. When this happens the tail servo is unable to undo the condition, which is a very bad thing. In the mean time I have the limits on my NX's gyro set in a bit so the above locking condition doesn't happen during a flight (hopefully). This limits the pitch range of the tail unfortunately. Bummer for sure.

I'll try them both. If the plastic ones give me trouble then I'll replace them with the metal ones, and then put a metal tail case on the NX. The metal triple grips on the metal tail case don't exhibit this problem at all.

I then need to decide which one to put inside the scale Ranger fuselage that's on it's way ...

[Ontaeronut]

Nice scale fuse, it would look alot better on my work bench..LOL

[FR4-Pilot]

How 'bout it !

I'm not sure where I'm going to put it in the meantime after it arrives - I'm maxed out on space in my tiny area as it is ...

[Digger1973]

It should look nice when you get it flying. I have been eyeing the Hughs 500D for my gasser. My wife gets hints dropped every chance that comes up. Cough cough birthday, christmass lol.

Sent from my HTC One V using Tapatalk 2

[FR4-Pilot]

This one's been on 'lay-away' for a few months. Just made the last payment

[FR4-Pilot]

So I was still having problems with Century's plastic triple bearing tail hub & grips (CN2235) - it seemed worse recently (binding). So I decided to put on a set of TREX 600 tail grips & hub. So far they work great! They have a 5mm shaft, a 4mm set screw, but only a single radial and thrust bearing per grip. Just completed a test-hover-flight and they seem to work nicely. Had to switch over from leading edge to trailing edge though - no biggie.

Now that the $40 CN2235 is off of the heli I'll poke around and see what I can find - it really appears like the two cavities (for the radial bearing closest to the hub and the thrust bearing) that capture the bearings are not as concentric as they should be ...

The TRex parts were less than half the cost of CN2235.

[MotorRotor]

Check post #3. At the time you could have got a nes set of thrust bearings from Century for your plastic grips.

[FR4-Pilot]

Thanks MotorRotor. I must have assumed last year when you posted (#3) that the problem occurred many years in the past. I didn't think it applied to my problem and I failed to connect the dots ...

The plastic triple bearing grips and hub I purchased were brand new from Heli-World last year. I'm surprised they're still distributing/selling problematic parts, that is, if this issue occurred years ago and was already addressed by them (?)

Oh well, we'll see how these TRex parts do I guess. It's all good - nothing wrong with having alternate sources of parts

[FR4-Pilot]

Two more flights tonight with the TRex 600 tail grips/hub. 1800 and 1900 RPMs. It was windy and I did lots of big sky loops and fast passes.

Tail held great

[ame]http://youtu.be/1mxxqeLFnko[/ame]