HW: Leveller Evo (name pending approval by Dave Mac)

[JamesDavies]

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Some progress with the frame. The arm is now on and side struts going on too.

The ram is leaking at the moment so will get that sorted tomorrow.

Hope I have sorted the problem with the chain coming off, will give it a proper test tomorrow to find out.

When the gas stops leaking and the chains stop falling off I can get to the finer details like how it looks

[adz600]

Nice start and a very different body shape, but I possible you really need the ram a bit further back you need mechanical disadvantage with hp systems

[Max]

Id be tempted to disagree, people deliberately put in a mechanical disadvantage so that the flipper doesn't move so quickly that ran doesn't have time to come up to full working pressure and so wouldn't be delivering the full possible force. But in an HP system I thought the higher pressure meant you got much better flow so I would imagine you wouldn't need the mechanical disadvantage as the ram would come up to full pressure very quickly.
I'm by no means an expert on this so feel free to tell me I'm wrong but sounds logical to me.

[JamesDavies]

Thanks, seeing as I've gone for a hp flipper I wanted it to be a little bit different.

I'd be interested to hear more theories, my thought was the opposite of yours Max- the ram at the back will give more speed at the cost of max force at the tip. Whereas ram at the front will mean it goes up slower but will have more force.

Based on what-I-reckon and the fact I can move it easily enough if I'm completely wrong, and the fact that watch ing the piston go off there's no lack of speed, I went for less speed more force.

But like I say, I could well have missed something myself so suggestions welcome

[adz600]

Mechanical disadvantage is required in hp systems, which means ram as close to the pivot as possible normally 5:1 at least, ram at the front means high force small travel but the ram will expand quickly but too fast and create a pressure vacuum reducing the force. With the ram close to the pivot you require more force to move the arm this means reduced ram speed but increased force due to less pressure drop in the hp system, that's why all really powerful hp flippers have big arms and rams very close to the pivot between 4:1 - 6:1 is about right, sorry for any mistakes posting from my phone

[JamesDavies]

Ah I see. Thanks for the explanation. In theory would a high enough flow negate that problem?

[maddox10]

Gravity 3 had a leverage of 4 to 1, and that was with 2 Burkerts feeding a 100*180 ram.

[JamesDavies]

Cheers Mario, I'll have to test it and see how it goes....

Driving test:

[JamesDavies]

I just wanted to check- there's no reason I shoudnt put water into the pneumatic system is there? I am checking for leaks and I feel it's safer to use water than gas, but just want to be sure

[maddox10]

It's called hydraustatic testing for a reason.

Normal, clean water works. But you'll have to dry the setup very well before putting any CO2 in it.
Carbonated water is acidic and can corrode aluminium.