A little progress

[andyrennison]

I've been thinking about your towing dolly. I think there will be very strong forces where it joins to the frame (as Pete said). Here is how I visualise it:

With the frame bolted to the dolly, you could visualise that as a single unit, a bit like a long plank of wood. Now imagine where the engine is positioned, right in the middle of the plank.

Imagine if you put both ends of the plank up on a stand. All the weight is now in the middle of the plank.

If you bounce one end of the plank (rear wheels on trike, or tow hitch going up and down) the centre of the plank with the engine on it will try to bounce more due to the leverage involved.

Your joint between the dolly and the frame is pretty much at that point of maximum bounce.

The front forks and wheel make a bridge from the front of the engine up the plank to near the towing hitch. That will stiffen the plank a bit over that section, but its effect will be negligible.

What it will do is add a pivot to multiply the downward force at the joint.

I'm sure it can work, just needs to be a beefy connection, maybe spread the load over 3 or 4 points of contact?

Of course I could be talking complete bo***cks

[scannerzer]

yeh I'll have to do some figureing on this on this one Andy,Pete has similar concerns

[triker_Chewie]

perhaps if it hooked under the cross member

[andyrennison]

perhaps if it hooked under the cross member

I would think over chewie, as the main deflection on the joint will be downwards wont it?

[scannerzer]

I'm still thinking about this, and i get your explaination with the plank but if we relaite it to a trailer with a single 2"box draw bar and accepting that it would have some form of springs on the wheels,that draw bar would be welded to the trailer in a similar fashion, if we sat an engine right at the front infront of the wheels would we expect the draw bar to bend or brake the weld?

thats what we thought when we built it and i'm still trying to get it straight in my head if we were right so still some thinking to do

[andyrennison]

I take your point. Maybe you need to set it up and have a "monkey jump party" where we all come over and bounce on it

[scannerzer]

I like that idea ,when are y'all free

[BikerGran]

As you say the trailer would have suspension, but the trike's a hardtail isn't it?  That's going to magnify every bump.

[scannerzer]

had a problem with the plate the brake idler was pivoted on in that it was twisting under braking
which left the pedal spongy,it had quite a bend in it.

A little progress

3

A little progress

so an upgrade was called for, 6mm plate instead of 3 and a gusset

A little progress

A little progress

will this be strong enough or should i try and support the other end of the bolt as well

[Manky Monkey]

Id've thought if you manage to bend 6mm plate, you've got other problems -or arms like Popeye.

[scannerzer]

Id've thought if you manage to bend 6mm plate, you've got other problems -or arms like Popeye.

originally it was 3mm plate the replacement is 6mm 

[scannerzer]

might not be much progress for a while...me welders packed up 

think it the low voltage transformer,hopefully get it checked over the weekend

[Manky Monkey]

Chewie can probably sell you a new one -postage might be a tad expensive though, from Australia. 

[triker_Chewie]

Lol. Nah had to scrap all mine.
What's yours doing?

[scannerzer]

not feeding wire although the fan and power light are on I'll put a link to repair's when i jet a chance.