Tarkers
06-06-2007, 07:02 AM
Hi All,
I had cause to rebuild my Swift head recently with a full CNC unit and after a few issues with the anti rotation pins which eventually got sorted, I had another reason to visit my LHS and took my part built head with me.
Whilst re-assembling the head, with the guy from the shop, I asked about the note in the instructions that says the larger thrust bearing goes closer to the head, the smaller thrust bearing goes closer to the blades.
I purchased my Swift ARTF, so the head was pre-assembled and I had no cause to read this instruction - but obviously I came across it whilst re-assembling myself.
Anyway the guy at the shop confirmed the larger one goes on the inside and started to measure all four of them up to identify large and small using a vernier - it turns out I have three small and one large washers on my factory pre-assembled head...!
I have a couple of points really,
First, having two small thrust bearing washers on the spindle could cause binding/tracking issues, this in turn could possibly cause the elusive swift vibration we all know about. (It would also explain why some people experience it and others dont AND why it would occur on spool up and spool down as the inertia involved may free up the bound thrust washer above a certain RPM)
Second, after having the Swift for 7-8 months, can I go back to century and ask for a replacement? Partly because it feels a bit cheeky :shock: , but also because I should really have stripped my head and found this out before now :oops:
Just as a point of note also, I'm a very inexperienced pilot at present and the point re the vibration is just an idea - if a small amount of insulation tape can rebalance blades, then a 1mm differential in blade length caused by a bound thrust bearing could easily cause such a vibration....couldn't it?
Please feel free to correct my assumptions as I may have completely missed something obvious
Anyone else experienced this mis-match ?
I had cause to rebuild my Swift head recently with a full CNC unit and after a few issues with the anti rotation pins which eventually got sorted, I had another reason to visit my LHS and took my part built head with me.
Whilst re-assembling the head, with the guy from the shop, I asked about the note in the instructions that says the larger thrust bearing goes closer to the head, the smaller thrust bearing goes closer to the blades.
I purchased my Swift ARTF, so the head was pre-assembled and I had no cause to read this instruction - but obviously I came across it whilst re-assembling myself.
Anyway the guy at the shop confirmed the larger one goes on the inside and started to measure all four of them up to identify large and small using a vernier - it turns out I have three small and one large washers on my factory pre-assembled head...!
I have a couple of points really,
First, having two small thrust bearing washers on the spindle could cause binding/tracking issues, this in turn could possibly cause the elusive swift vibration we all know about. (It would also explain why some people experience it and others dont AND why it would occur on spool up and spool down as the inertia involved may free up the bound thrust washer above a certain RPM)
Second, after having the Swift for 7-8 months, can I go back to century and ask for a replacement? Partly because it feels a bit cheeky :shock: , but also because I should really have stripped my head and found this out before now :oops:
Just as a point of note also, I'm a very inexperienced pilot at present and the point re the vibration is just an idea - if a small amount of insulation tape can rebalance blades, then a 1mm differential in blade length caused by a bound thrust bearing could easily cause such a vibration....couldn't it?
Please feel free to correct my assumptions as I may have completely missed something obvious
Anyone else experienced this mis-match ?