The EXTRA 300 EXT Build Thread

[AKfreak]

Thanks for the link to the CF rods. That Prop I have on there is just for mockup. My 20x8 Xoar is on the way in the mail. I think batteries are going to save the most weight.

 

[Enterprise]

That and ditching the wheel pants. In my 35% H9 extra I lost almost a pound going to the CF landing gear.

Also a CF wing tube if you can find a compatible one.

If you give me the OD and length I can go through my fleet and see if I have one that is correct so you source one.

 

[AKfreak]

My tube is Carbon, but thanks so much for the offer. Ill fly it as is, and if it flys like crap, ill start the 3D diet plan.

 

[AKfreak]

Hey I have a question about LIFe rx packs. I just got 4 of them, (two Glaciers from Buddy RC). When I charge them, they don't hold 100% at all. Even under Zero draw they loose voltage. The loss happens much faster under minimal draw (lexample...when hooked to a analyzer) I lost 1% of the pack in like 30 seconds during the video below. I guess it's normal, but I want to check with some of you that know.

It seems that if you loose voltage with no draw, then when you have somthing like 5 Digi servos working away, that pack will dry up quick. Again is that normal? See the video below for what I am saying.

Thanks, AKf
[video=youtube_share;jXhs7qy8Iw8]http://youtu.be/jXhs7qy8Iw8[/video]

 

[Enterprise]

You are good. LiFE packs go to 6.6V almost immediately. That is what is good about them as they run 6V servos at 6.6V. Their discharge curve is 6.6V until they are almost depleted. Even then they are more stable fully discharged than Lipos. There is a battery checker on the market that has a dozen names. I got a Hyperion branded one. It reads batteries to the hundreth of volt, which is what is required to get accurate reading on a LiFE.

http://www.ebay.com/itm/like/131111600991?lpid=82

As you can see, they only stay at 7.2V basically off the charger.

 

[3dNater]

My gut is to say it is normal and the battery checker is using a linear approach to the % vs what you are going to get in terms of power at 6.6v. Life packs will stay at 6.6v for almost their entire capacity and then drop off rapidly at the end. Put the batteries under a load. The voltage checker alone is a pointless test as it is just bleeding off the top of the charge. Those cells want to be at 6.6v really bad and that is where they end up almost immediately.

 

[3dNater]

Haha... Enterprise got here first but I didn't know what he said until I hit post on my response... so there you have it from two sources

 

[AKfreak]

Thanks fellas. At least others that don't know can learn from my ignorance. Now I feel much better. I have learned more during this build than in the whole time I have been doing RC. Tomorrow my 20X8 Xoar prop shows up so I might be able to test this baby out. then ts its on the the 50CC gasser project.

 

[Enterprise]

Now there is a big learning curve! This is the year of 60/70cc for me. Lots of cool stuff going on in that size.

 

[Dr. Gonzo]

Now there is a big learning curve! This is the year of 60/70cc for me. Lots of cool stuff going on in that size.

That class, to me is just the perfect size!