Thread Tools
Sep 26, 2002, 04:43 AM
Single-task at best...
tim hooper's Avatar
Thread OP

"We don't need no stinkin' battery ramps..."


tic,

Maybe not, but I thought I'd show you mine!

Having had plywood ramps come adrift in heavy landings (AKA 'crashes'), I read in a magazine of a fellow who successfully made a ramp of EPP foam.

Unashamedly ripping off his idea, I've made an EPP ramp too. The advantages seem two-fold; the load of the battery is spread throughout the entire underside of the foam, and the inherent flexibility of the foam helps to dissipate any shocks anyway.

The top of the ramp is faced with ply, to which the velcro attaches. A hefty balsa backstop is also epoxied between the pack and the rx to ensure consistant placement. Further blocks of EPP are hot-glued within the fuselage to prevent the battery moving in other directions.

The loop of ribbon lets me pull the pack out through the canopy without straining the leads.

Finally, just to be clear, the whole assembly fits within the fuselage, and is not strapped to the outside; this pic is just to illustrate how it all works, OK?

Sheesh......some people....

tim
Sign up now
to remove ads between posts
Sep 26, 2002, 05:58 PM
Mmmm.
Andy McCowan's Avatar
Tim,
Is that white foam EPP then? Looks like the same stuff I use to pack my battery into the Bandit fus(without a ramp)

I got it from a guy who said it was used as packing around some expensive electronic goodies, BTW I have also used it inside fuselages to support control snakes, makes removal much easier, should the need arise.
Sep 26, 2002, 07:11 PM
Single-task at best...
tim hooper's Avatar
Thread OP
Quote:
Originally posted by Andy McCowan
Tim,
Is that white foam EPP then?
Andy,

That's the stuff! Remnants of a DAW Staudacher fuselage...

tim
Sep 27, 2002, 03:32 AM
Nice foam.

But i'd hate to remove the foam from the fuse when it needs renewal after a crash.

Maby you need to attach the foam to your fuse with some tesa strips?!

Here are some shots of my home made contraption. If this ever comes loose the model won't be rebuildeble. Yes, that is carbon.
Last edited by Kimble_Schmitz; Sep 27, 2002 at 03:36 AM.
Sep 27, 2002, 03:32 AM
back piece.
Sep 27, 2002, 03:33 AM
battery in position.
Sep 27, 2002, 04:49 PM
That battery is a long way back.
You must have a very heavy motor up front!
Sep 27, 2002, 05:42 PM
Single-task at best...
tim hooper's Avatar
Thread OP
Quote:
Originally posted by fligjht999
That battery is a long way back.
You must have a very heavy motor up front!
999,

You think?

Kimble's pics show his brushless Simprop Selection. Here's mine; S700 geared + 10x2000 cells. The pack extends way back past the trailing edge.

The rx is somewhere behind that.....

tim
Sep 28, 2002, 04:34 AM
What image?

Its noy how far back it stretches, but how far forward it has to go!

With my 480/55 +g/box the battery is right up against the motor backplate.

Reckon you guys are getting all mixed up with those non-aeroplane things made of foam. (Figments of the imagination)
Sep 28, 2002, 09:05 AM
Hi
one thought about holding down the battery at all costs. if it lands bad (crash ) and the battery can't move (out) , it will rip the fuse...
think of my comet landing at ~30kph (FAST) on a rough field. if it lands in a bad spot it comes to rest in 2 meters ! if the battery couldn't fly out through the nose (rubber band), it would simply break the fuse and take that part along...

Avi
Sep 28, 2002, 12:13 PM
Becous i wanted the battery to fly out incase of a short landing (crash) i made that special carbon piece to hold my battery.
The elastic band keeps it down even when inverted at high G's.

In a crash the battery moves forward and up in a 45 degree angle for 1 cm and then strait forward. Not damaging itselfe or my expensive LRK motor.

The battery is not that far back as it is only 8 cells. The center of the battetry should be looked at, not the front or the back!

My LRK motor only ways 194 grams.

If i were to move my battery forward i would not be able to take out my motor enymore becous the battery mount would be in it's way.
Sep 28, 2002, 01:36 PM
This is what I find surprising. Most people use the battery to adjust the c.g. and I am sure you do the same or you would be adding weight to balance your model. All my Mk1 & 2 Bandits have needed the battery well forward despite (in one case) having to disgard a tailplane and replace it with a lightweight one. The model has long gone to that great thermal in the sky, but I still use the lightweight tail on the newer models. From your images I like your setup very much and envy you it

I have gone from 8 to 10 cells and am trying for 12.
Sep 29, 2002, 12:26 PM
I do have a litle piece of lead in the nose. But i rather have those 27 grams of lead in my plane then go with a different battery constraint.

Now i think of it, if i would put a regular nylon HS-81 in my tail instead of the HS-81 MG i could probebly take out all the lead in the nose.

I have made a lighter stab to. Becouse i didn't like the old one. It was weak (read flutter) and to heavy.

You have to be carefull comparing the Bandit to a Selection. The looks and the construction are about the same but that is where the similarity's end. The battery positions are just not compareble.

The point i am trying to make is that the battery position depends on so many things that i am not even going to try and count.

Don't envie my setup, just go out and get yourselfe an LRK motor!
Best setup i have used is LRK350-20/12,5w and 10xRC-3000HV with 13x9" RFM prop. Unlimited vertical and 45min flights.

Kimble.
Last edited by Kimble_Schmitz; Sep 29, 2002 at 12:41 PM.
Sep 29, 2002, 02:59 PM
Pleased to hear of your successwith the LRK motors. I have heard good reports generally and have heard that some bodies have been trying them in the Bandit. It is certainly a cheaper way to go than the 'Big Name' brushless conventional drives!

Verticals untill the battery flattens is not a problem in my experience with the Bandit. A can 480 will do the job for you. The 10 cell NiCad battery is plenty HOT, but I would like to compete with an Absolute on 14 just to be a hooligan! That is why the talk of 12 cells.

Its a Catch 22 situation though. Go to 12 and you have to carry a receiver pack as you shouldn't/can't run on BEC.


Quick Reply
Message:

Thread Tools