Can't tighten feathering shaft screws without locking up blade grips!?!?

lovespicyfood · 05-12-2012, 01:58 AM

Hi Everyone,

I am going through a used 450X I bought. I went through the feathering shaft and found out the screws were not even tightened. However, when I try to tighten the screws, the blade grips become immovable.

I have double checked the setup and it is correct. From the head block out there is: brass washer with "bump" towards the grip, outer blade grip bearing, blade grip, inner blade grip bearing, large diameter washer, thrust bearing (inner race with larger ID/thrust bearing with balls facing head block, smaller ID race), and then screw w/ washer.

I can barely tighten it without getting notchy or immovable blade grips.

I am confused. Any advice?

The guy I bought it from had one crash and said he replaced the feathering shaft. I just wonder, could he have installed an incorrect feathering shaft? I wonder because there are no spare feathering shafts and don't they come in two packs?

Thanks for your advice!

Pete

Talesin · 05-12-2012, 02:06 AM

It's quite possible/likely. Grab a set; they're cheap and easy to replace. He might have tried tossing on a feathering shaft from the B400 or B450 3D, which are different part numbers (so at least theoretically different dimensions). Sounds like /something/ is wrong, and that'd be the first place to look... along with making sure the thrust bearing races aren't backward. There's a specific 'inner' and 'outer' race, with a hundredth of a millimeter ID difference (inner is larger).. but normally you end up with there being a ton of play/slop in the grips when that happens.

lovespicyfood · 05-12-2012, 02:39 AM

Thank you for your reply! I had a set on order at the lhs so I will grab it tomorrow and try it out. Will report back...

jperkosk · 05-12-2012, 04:07 AM

+1
I had a similar case when trying to rebuild B400 with a TR clone feathering shaft, turned out there was a difference in length about 0.75mm...

Sambuka · 05-12-2012, 05:30 AM

I think you'll find the wrong feathering shaft was put in. Looks like you have all the other parts in the correct order so that would certainly be the first place to look.

lovespicyfood · 05-12-2012, 03:17 PM

OMG, the one he had put in was quite a bit smaller than the 450X one! Wow. That is why I do not recommend people buy used unless they go through the heli and know what they are doing, or at least have help.

Supposedly two servos were replaced too so I am going to start from ground zero on setup.

I will try to post a pic later of the size difference. I'm guessing I won't have a problem installing the grips now!

Talesin · 05-12-2012, 03:51 PM

Definitely do a full setup and crash inspection, as well as main motor lash adjustment (just loosen the four motor mount bolts, slide it away from main gear, put a strip of normal paper between main and pinion, push together snugly, tighten bolts (crosswise pattern, standard) then rotate the head to have the gears feed the paper out. Should come out with nice crisp crimps). Also move each servo up and down, if any of them grind or click AT ALL instead of just a smooth whirr, replace the gears.

I'd personally treat it as more of a kit-copter at this point, and check EEEEEEEEVERYTHING, if not do a full disassembly and reassembly/mechanical setup/digital setup after resetting the BX unit to zero (power on, hold BX button until the light goes solid, release. Hold button again until it blinks rapidly, about 10 seconds. Reset to 450X defaults from the 450X manual. Use the AR7200BX manual from the Spektrum website to do setup and parameters again... it's nowhere near as hard as it looks so long as you have a bullseye level ($2 @ home despot, to shim under the skids so the BX is level), the swash tool ($8), and a bevel box or RC Logger pitch gauge ($30-40)).

Check EVERY part for bends, cracks, glue, etc, as it sounds like the person you bought it from is a bit shady to begin with.

lovespicyfood · 05-13-2012, 12:30 AM

Talesin: thanks so much for posting this info! My plan was to do all that; I'm especially looking forward to working on the AR7200BX since I'm probably going to put one of these on my unbuilt Align 600 EFL PRO.

Check out the size difference of the FS that was installed...GEEZ!

whodothevoodoo · 05-13-2012, 08:01 AM

Oh, you probably could have used a couple of washers and some good lube and it'd been good as new.

05-12-2012, 01:58 AM	#1
lovespicyfood Registered Users Join Date: Dec 2006 Location: Westlake Village, CA	Can't tighten feathering shaft screws without locking up blade grips!?!? Hi Everyone, I am going through a used 450X I bought. I went through the feathering shaft and found out the screws were not even tightened. However, when I try to tighten the screws, the blade grips become immovable. I have double checked the setup and it is correct. From the head block out there is: brass washer with "bump" towards the grip, outer blade grip bearing, blade grip, inner blade grip bearing, large diameter washer, thrust bearing (inner race with larger ID/thrust bearing with balls facing head block, smaller ID race), and then screw w/ washer. I can barely tighten it without getting notchy or immovable blade grips. I am confused. Any advice? The guy I bought it from had one crash and said he replaced the feathering shaft. I just wonder, could he have installed an incorrect feathering shaft? I wonder because there are no spare feathering shafts and don't they come in two packs? Thanks for your advice! Pete

05-12-2012, 02:06 AM	#2
Talesin Registered Users My HF Map location Join Date: Jan 2012 Location: Kansas City, MO	It's quite possible/likely. Grab a set; they're cheap and easy to replace. He might have tried tossing on a feathering shaft from the B400 or B450 3D, which are different part numbers (so at least theoretically different dimensions). Sounds like /something/ is wrong, and that'd be the first place to look... along with making sure the thrust bearing races aren't backward. There's a specific 'inner' and 'outer' race, with a hundredth of a millimeter ID difference (inner is larger).. but normally you end up with there being a ton of play/slop in the grips when that happens. __________________ *Blade*: mCX2, mSR, mSRX, Nano-CPX, 2x mCPX (v1), mCPX-BL, 120SR, 450 X Spektrum DX8, DX6i

05-12-2012, 04:07 AM	#4
jperkosk Registered Users My HF Map location Join Date: Dec 2009 Location: San Luis Potosí, México	+1 I had a similar case when trying to rebuild B400 with a TR clone feathering shaft, turned out there was a difference in length about 0.75mm... __________________ Jerry Trex 700N Pro fbl, 600N Pro x 2, 450SE v1, 250 v2 fbl, Compass 6HV fbl, Blade 450x, 400, 300x, 130x, mCPx, 120SR, mQx, mSR, Rotor Concepts HPQ1, Walkera CB180Q, CB100, Novus FP, CP, Esky Hunter, Big Lama.

05-12-2012, 03:51 PM	#7
Talesin Registered Users My HF Map location Join Date: Jan 2012 Location: Kansas City, MO	Definitely do a full setup and crash inspection, as well as main motor lash adjustment (just loosen the four motor mount bolts, slide it away from main gear, put a strip of normal paper between main and pinion, push together snugly, tighten bolts (crosswise pattern, standard) then rotate the head to have the gears feed the paper out. Should come out with nice crisp crimps). Also move each servo up and down, if any of them grind or click AT ALL instead of just a smooth whirr, replace the gears. I'd personally treat it as more of a kit-copter at this point, and check EEEEEEEEVERYTHING, if not do a full disassembly and reassembly/mechanical setup/digital setup after resetting the BX unit to zero (power on, hold BX button until the light goes solid, release. Hold button again until it blinks rapidly, about 10 seconds. Reset to 450X defaults from the 450X manual. Use the AR7200BX manual from the Spektrum website to do setup and parameters again... it's nowhere near as hard as it looks so long as you have a bullseye level ($2 @ home despot, to shim under the skids so the BX is level), the swash tool ($8), and a bevel box or RC Logger pitch gauge ($30-40)). Check EVERY part for bends, cracks, glue, etc, as it sounds like the person you bought it from is a bit shady to begin with. __________________ *Blade*: mCX2, mSR, mSRX, Nano-CPX, 2x mCPX (v1), mCPX-BL, 120SR, 450 X Spektrum DX8, DX6i

05-13-2012, 12:30 AM	#8
lovespicyfood Registered Users Thread Starter Join Date: Dec 2006 Location: Westlake Village, CA	Talesin: thanks so much for posting this info! My plan was to do all that; I'm especially looking forward to working on the AR7200BX since I'm probably going to put one of these on my unbuilt Align 600 EFL PRO. Check out the size difference of the FS that was installed...GEEZ! Attached Thumbnails

05-12-2012, 02:39 AM	#3
lovespicyfood Registered Users Thread Starter Join Date: Dec 2006 Location: Westlake Village, CA	Thank you for your reply! I had a set on order at the lhs so I will grab it tomorrow and try it out. Will report back...

05-12-2012, 05:30 AM	#5
Sambuka Registered Users Join Date: Jan 2012 Location: Gold Coast, Australia	I think you'll find the wrong feathering shaft was put in. Looks like you have all the other parts in the correct order so that would certainly be the first place to look.

05-12-2012, 03:17 PM	#6
lovespicyfood Registered Users Thread Starter Join Date: Dec 2006 Location: Westlake Village, CA	OMG, the one he had put in was quite a bit smaller than the 450X one! Wow. That is why I do not recommend people buy used unless they go through the heli and know what they are doing, or at least have help. Supposedly two servos were replaced too so I am going to start from ground zero on setup. I will try to post a pic later of the size difference. I'm guessing I won't have a problem installing the grips now!

05-13-2012, 08:01 AM	#9
whodothevoodoo Registered Users My HF Map location Join Date: Jan 2012 Location: SW MI	Oh, you probably could have used a couple of washers and some good lube and it'd been good as new. Last edited by whodothevoodoo; 05-13-2012 at 09:10 AM..

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