TOPIC:

Cheers, Martin. I just had a look at how the transplantation of the nose from one to the other turned out...
And I'm not disappointed - feels pretty strong (and it's on straight as well).
I'll post some pics later.

Step one - making a little alloy connection plate (with very limited resources available)...
To be glued down with epoxy - as well as using fasteners.
It will also help to place the nose where it's supposed to be :



View from the other side :



Not bad at only, only a fraction of a millimeter off. Shell fits nicely :



I was thinking about a second plate on top but that may not even be necessary. Feels very solid already...
Would be nice to not cover the holy stars.
The aluminium plate is a bit bendy in itself but fixating it with epoxy gives quite the accumulative strength.
Which is what they kinda depend on when building planes and such...

There will definitely be some aftercare in the form of sanding and spraying of course - but we have a chassis!

I suppose this stuff would also be good for glueing a new piece into the wing?

Jonny wrote:

I use regular plastic kit poly glue, like this:

Anybody know a good place to get some "evergreen" - or maybe someone has some small pieces lying around?

Sorry Edou mine is in the trash since more than 15 years

Using Grasshopper technology on a new idea for a double rear shock mod!
The limitations of the rigid rear axle that's normally on the car are well known and the slotted axle mounts with the tiny springs that are on the Hornet are a well willing thought but it doesn't make much sense either.
Usually one would go for a 3rd (or 5th to some) shock mod but I kinda never really got that one...
Why make a pivot point somewhere in the middle of the gearbox and hardly take the load of the tiny springs?
So I'm going for double axle suspension! Basically Grasshopper tech from the front :



The shafts can make the correct angle towards the rear axle...
I've enlarged the holes in the brackets for that :



A plastic nut was drilled to the size of the damper shaft and will function to keep the spring centered :



Just all needs some cleaning still.
More coming soon...

Edit - if I had different tools, I would've made a custom bracket with a single piece for the damper shaft to go through. With a slightly smaller hole - and under an angle that's perpendicular to the movement of the rear axle. Still possible even...

Edou wrote:

Using Grasshopper technology on a new idea for a double rear shock mod! ...

Are you sure that's going to work? The usual problem is that there's not enough space between the motor & the right side of the chassis, so as soon as the suspension compresses (and rotates) the motor fouls on whatever you've tried to fit ... you might get away with it if you're using a 380 motor, but I'm skeptical ... if it were that easy to fix it, mods to this chassis would be as common as the 5th shock mod on Lunchkins

Another approach might be to uprate the wire springs, but TBH I think anything thick enough to be effective is not going to bend to the same shape ... If I was going to try it, I'd be thinking about drilling through the pivot point from back to front, widening it to a vertical slot at the rear, fitting a straight bit of thicker piano wire, & having it held in with a grubscrew.

I'm not going to try it though - I think the only way to make a Grasshopper handle properly at the back end is to fit the shell to another chassis That said, my DT02 'Hopper handles that well It's taken a lot of the fun out of it

Pretty sure it'll work, Jonny.
With the room you have on a Grasshopper - no... but that would make the extra shocks abundant anyway.
Using the Hornet axle mounts there's more room and the motor will only hit the bracket if the odd event would accur that the Frog shocks I'll be using are at full stroke (and man, are they hard), while the additional shocks are still in their lowest position.
That would mean I'm driving in something like a local anti gravity field.
You're right of course that there has to be enough clearance in any scenario so some fine tuning might be needed...

Forgive my ignorance, but what is the specific problem with the GH rear end (apart from massive unsprung weight, lack of independance and poor damping )? Is it that the front of the gearbox bashes randomly up and down in the slotted mounts?
Presumably those mounts are slotted to allow some rotation of the gearbox?

Forget about the Grasshopper, I don't know how many times the axle mount broke because it was absorbing impact.
On that car the mounts are not slotted but the axle is fixated...
The Hornet's setup is a bit better but mostly because of the alloy dampers. Guess it bounces a little less that way...
Putting springs in the slotted axles is a good idea in itself, were it not that it doesn't work in practice.
They're so weak that when you open the throttle, they'll end up being pushed in their end position straight away.
Guess that's what the 3rd shock mod is most useful for...
Here I'm basically upgrading the tiny Hornet springs - closer to what must have been the original remedy against rigidty.

You should use a carbon fiber plate. Aluminum is no good, it doesn't fix with the plastic and the glue and it bends...

Max

Edou wrote:

Step one - making a little alloy connection plate (with very limited resources available)...
To be glued down with epoxy - as well as using fasteners.
It will also help to place the nose where it's supposed to be :

View from the other side :

Not bad at only, only a fraction of a millimeter off. Shell fits nicely :

I was thinking about a second plate on top but that may not even be necessary. Feels very solid already...
Would be nice to not cover the holy stars.
The aluminium plate is a bit bendy in itself but fixating it with epoxy gives quite the accumulative strength.
Which is what they kinda depend on when building planes and such...

There will definitely be some aftercare in the form of sanding and spraying of course - but we have a chassis!