Not much happening in the F3b world in the US.
I did have a look at the site stats. All the worlds hackers and AI scrapers are busy these days. Stats jumped up this year. Busy looking for something to hack.....
Monday, August 3, 2026
Monday, May 5, 2025
Saturday, December 3, 2022
Monday, October 21, 2019
PC1100 Battery Post Repair
My favorite F3b winch battery is an Odyssey Extreeme PC1100. It's only drawback is the weird choice of M6 studs for the battery termination. I have been using some battery posts I machined for a few years, but I did have one of them where the stud broke. I might have over tightened it.
The Swiss team mentioned they had broken one and used a Helicoil to repair the battery. I called up Odyssey and they didn't think there was any way to drill it or enough material there. But looking at it, there clearly is a bit of lead/copper before you get down into the cell. I picked up an M6 helicoil kit.
The only problem is the tap was for a through hole. It isn't a bottoming tap. So I ground off the end of the tip to make it closer to a bottoming tap. I tried drilling a piece of lead to see how deep I needed to drill and how well it worked. It looks like I could get away with 1/2 inch. The M6 set requires a ,250 hole to tap.
I mounted the battery in the vice on the milling machine and got out a 1/4 mill I figured a flat bottom would be best to get the depth needed. I was able to go down 9/16 without any problem on the negative terminal that I was repairing.
The helicoil installed nicely. I picked up a M6 bolt on battery terminal and trimmed the bolt to make sure it would be just the right length through the helicoil. Everything looks fine. I have a usable battery now.
Odyssey started making SAE Terminal Kits for the 6mm. This is a relatively new addition. I will be switching to these on the other batteries.
The Swiss team mentioned they had broken one and used a Helicoil to repair the battery. I called up Odyssey and they didn't think there was any way to drill it or enough material there. But looking at it, there clearly is a bit of lead/copper before you get down into the cell. I picked up an M6 helicoil kit.
I mounted the battery in the vice on the milling machine and got out a 1/4 mill I figured a flat bottom would be best to get the depth needed. I was able to go down 9/16 without any problem on the negative terminal that I was repairing.
The helicoil installed nicely. I picked up a M6 bolt on battery terminal and trimmed the bolt to make sure it would be just the right length through the helicoil. Everything looks fine. I have a usable battery now.
Odyssey started making SAE Terminal Kits for the 6mm. This is a relatively new addition. I will be switching to these on the other batteries.
Friday, May 31, 2019
2019 Team USA F3b Fund Raiser
Please visit the Team USA fund raising sight and help the team make the trip to the world championships.
http://www.teamusaf3b.com/2019-fund-raising-prizes
http://www.teamusaf3b.com/2019-fund-raising-prizes
Wednesday, March 4, 2015
JR tail Servos for Sailplanes
In the past I have used 3421's then 3717HV's for higher voltage installs, especially on all my V-tail models. I just got two new servos. The JR MP31Swv and the JR NX3125. The MP31Swv is the fastest of the bunch. It is down to .08 seconds on 7.4 volts. It is a wide voltage servo so you don't have to worry about what battery pack you are using. It also has just a little more power than the 3717HV. The case size is the same as the 3421's.
The other interesting item is the NX3125. This is not quite as fast as the MP31Swv but it is an XBus servo. It's also more flexible in voltage range and it us XBus programmable to tweak the servo if you need to. What I'm really hoping for is to get the JR398 servo in a NX version and a receiver that just has maybe 4 XBus outputs to use in a sailplane.
The other interesting item is the NX3125. This is not quite as fast as the MP31Swv but it is an XBus servo. It's also more flexible in voltage range and it us XBus programmable to tweak the servo if you need to. What I'm really hoping for is to get the JR398 servo in a NX version and a receiver that just has maybe 4 XBus outputs to use in a sailplane.
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