21-09-2012, 10:19 AM
Chuck is in for a suprise this evening, I've done a little more on the Yak
I had the motor mounted in the air frame all ready to go, then I had an after thought. Remembering the trouble I had with the magnets coming un-bonded in the earlier Turnigy G160 motor. I decided to take the new motor off the fire wall, pull it apart and give it an internal inspection.
This motor is from a different production run than the earlier one, it's KV rating is slightly different. It came from the HK Aus warehouse and it has a different sticker on which is printed Turnigy D6364 290KV. On the old one is printed G160 and 245Kv. Other than that they look identicle
I must say the old one, in the Big yellow Yak Has run quite nicely, for many flights, now that I've re-bonded the magnets and grouted them in.
The magnets on the newer motor look to have been bonded with a different adheasive. It could be some kind of unfilled epoxy reson but it's hard to say. There was a decent fillet of it around the edge of the magnets. much more so than on the earlier motor. I'm not sure if it's only whishfull thinking, but to me, it looked better.
I decided to grout the magnets in and compleetly fill the space between them using West Systems epoxy resin mixed with West Systems Micro Fiber Blend filler. I grouted the old moter with some special epoxy wich had some unknown filler already added to the reson (it was black and especially for grouting magnets) But sadly there was none of that left.
Micro fiber blend is a great filler for high strength bonding aplications it's moderatly heavy and difficult to sand so it's not for every aplication. However it makes the epoxy as tough as hell and greatly increases the bond strength especially where epoxy is used to both bond and fill gaps. So it will have to do
I also trimmed the excess length of shaft from the back of the motor as it probably weighed close to an ounce.
Before re-assembeling it I checked the balance of the rotor and found it was not 100%. You can see from the first pic how much I had to remove to balance it up. I will have to pull the motor of the other Yak and check it at some stage too.
The second pic shows the filled epoxy grouting between the magnets.
I had the motor mounted in the air frame all ready to go, then I had an after thought. Remembering the trouble I had with the magnets coming un-bonded in the earlier Turnigy G160 motor. I decided to take the new motor off the fire wall, pull it apart and give it an internal inspection.
This motor is from a different production run than the earlier one, it's KV rating is slightly different. It came from the HK Aus warehouse and it has a different sticker on which is printed Turnigy D6364 290KV. On the old one is printed G160 and 245Kv. Other than that they look identicle
I must say the old one, in the Big yellow Yak Has run quite nicely, for many flights, now that I've re-bonded the magnets and grouted them in.
The magnets on the newer motor look to have been bonded with a different adheasive. It could be some kind of unfilled epoxy reson but it's hard to say. There was a decent fillet of it around the edge of the magnets. much more so than on the earlier motor. I'm not sure if it's only whishfull thinking, but to me, it looked better.
I decided to grout the magnets in and compleetly fill the space between them using West Systems epoxy resin mixed with West Systems Micro Fiber Blend filler. I grouted the old moter with some special epoxy wich had some unknown filler already added to the reson (it was black and especially for grouting magnets) But sadly there was none of that left.
Micro fiber blend is a great filler for high strength bonding aplications it's moderatly heavy and difficult to sand so it's not for every aplication. However it makes the epoxy as tough as hell and greatly increases the bond strength especially where epoxy is used to both bond and fill gaps. So it will have to do
I also trimmed the excess length of shaft from the back of the motor as it probably weighed close to an ounce.
Before re-assembeling it I checked the balance of the rotor and found it was not 100%. You can see from the first pic how much I had to remove to balance it up. I will have to pull the motor of the other Yak and check it at some stage too.
The second pic shows the filled epoxy grouting between the magnets.
“The knack of flying is learning how to throw your machine at the ground and miss.”
"When once you have tasted flight, you will forever walk the earth with your thoughts turned skyward, for there you have been, and there you will always long to return." ~Leonardo Da Vinci