Hi all,
 I'm re joining the clan after a break of around 30 years and decided that as I'm starting from scratch, electric is the way to go. Can I ask a possibly stupid question?

I am going to crash, No argument, it's cast in stone. What happens to my precious motor, batteries, ESC, JMP etc when the inevitable occurs? I've "Sort of" got my head around IC/Electric comparisons, Battery types, ESC AMP ratings etc. The  physical damage I accept, but a minor ding which stops the prop dead? Will it all overheat and cook everything or do ESC's contain a thermal cut-off, is there a separate in-line option? Do you fly with a fused system, if so what rating in comparison to the overall system rating? I'm joining my local club but no one has any real interest in electric so I'm on my own, The last thing I want to do is confirm their worst suspicions and set the flying field alight.  I've scoured the boards for an answer but I guess you guys don't crash.  If I missed it just point me at the thread.

Many Thanks in advance

TTFN
John.

Yup, I've seen one of Alan's "incidents".    See you at Rockford next week?

My experience is that for the most part electrics are pretty sturdy however there are a couple of things that can happen. I know because they have happened to me!!

In most cases the ESC will cut off the power when it sees a spike. I don't know about cheap ESC's but moderate and above all seem to have a high current cut off. Use an arming plug or on smaller motors a switch so that you can quickly cut the power from the battery quickly if needed.

Batteries are the next concern. If you crash and distort Lipos they are probably toast (or will turn into toast when you next try to charge them). Be careful with crashed batteries and look for signs of damage, bloating, distortion. I have crashed a number of e-planes and have not yet had a problem mainly because none of the crashes were severe enough to hurt the battery. Most of the time the battery is mounted near the center of the plane and short of breaking the fuse in half the cells are protected. Be sure and build the plane to that the mounting for the battery is sturdy and will hold the heavy weight of the cells during a sudden stop. I use heavy duty velcro on the side of the battery and also on its mounting surface then use a heavy duty velcro strap around the battery and a sturdy part of the fuselage (or two if the battery is  long). When in doubt about a battery check it with a balancer or at the very least charge very slowly and look for puffing or too much heat, WATCH IT CAREFULLY AND DON'T LEAVE UNATTENDED.

The most serious problem I've had with crashes is bending the motor shaft. Electrics tend to run with larger props presenting a large lever arm to the shaft when the prop strikes the ground. You also do not have the compression stroke to deal with which means you can't set the motor to stop at the horizontal position. I have bent two shaft on different motors with fairly heavy crashes. Minor bounces and glancing blows aren't too bad. After an impact check to see if the shaft seems straight. If it is not straight you will probably notice with a lot of vibration when you try and run it again. Most good suppliers should have replacement shafts for their motors and they are not too hard to swap.

The last thing I have encountered is the motor mount. Once again because of the larger props the mounts can take a beating. I try to put at least one layer of fiberglass on the mounting for strength. Stay away from the stick mounts as they are not very strong. When possible mount the motor from its front face. Mounting from the back is ok but I have seen some of them resonate at different speeds.

Now the good parts of electrics. No clean up (yeah). Reliable, easy to use, predictable, you "make" your own fuel, did I mention no clean up? Put the battery in, connect, arm and your flying, really simple.

Just thought I'd throw in my school of hard knocks experience.

Bob

There should be no problem with using a larger ESC then necessary.

Also the old high quality brushed motors are basically ok. The real revolution which has made E-Lite so easy has been the batteries. For CL, the Lipo pack's low weight and power capacity has been the difference. The A123 are a little heavier, but also seem to work well. Maybe a better choice for those first few "bumps"/

Uh Oh, is there a trend beginning concerning ground round?    Sorry to hear about the incident! 

but I guess you guys don't crash.

Well I managed to do a "Ground Round" on the Enobler today.

  Ugh, Sorry to hear about that, No need for practical demonstrations..... As far as "Pulled Pork" I won't even go there.. 

I've now progressed past the newbie stage of thinking I have got my head around power systems and realised I actually know nothing, I was assuming my brushed knowledge would see me through but there's so much more to it than I originally thought So much conflicting info out there. Steal someone elses proven package seems to be my best bet for starters. How useful are sites like this? http://brantuas.com/ezcalc/dma1.asp Do they at least give a ball park figure?

Dissecting the old Flight Streak did not go well, it's amazing how a 30 year old nylon bag of broken balsa can maintain the appearance of a reasonable wing.  I'm still hoping to save a rib profile though. The ARF version seems to be a decent option as well, I just wish it was ARC not ARF, Never did like the Topflite colour scheme. Where would I put the battery. The short fuselage points to a lot of tail weight to get it to balance, especially with A123 cells until I feel confident enough to go LiPo. Would modifying the wing to accept a "Battery box" in order to place the cells nearer the CG be an option? (Ply Doublers where necessary) or would the extra weight that entails just put me back where I started. Would moving the weight of the batteries closer to the CG help flying characteristics? Sorry for my ramblings but the start-up costs of ECL are scary, X2 when you factor in the fact that my beloved will expect to be able spend at least as much again on shoes, clothes etc. 

[EDIT] Ignore the ramblings about the battery location in the Flight Streak, Just got up to speed with the forum, If Mike Palko sticks it in the wing then that's good enough for me.  [/EDIT]

TTFN
John.

Hmm.. That's a thought, the simple ideas are frequently the best, I'd have to pay special attention to securing the cells as I plan on using A123 cells (Heavy) until I'm confident enough that I won't be making holes in the flying field every other flight.  Mind you, after Igors achievements using A123 cells perhaps the switch to Lipos may not be necessary at all.... The project has currently been delayed unfortunately as I've just been made redundant due to "outsourcing"    I think I have alternative employment lined up but just need a few weeks to confirm, so if I go a bit quiet I've not abandoned ECL just re grouping, Watch this space.

TTFN
John.

I've used prop savers on small motors, but I am not sure how well they would work with the thrust of a 12 inch prop. I've had a few "Encounters of a Close Kind" and so far the shaft has been ok.