Has anyone used ramps like these:

www.levo-artis.com/index.html

5 bar tread plate comes in either 3mm, 4.5mm or 6mm from what I can see. I was wondering if anyone new which thickness they use?

You would need a rather large bending brake, 3M plus, to make some full size ones but I was wondering about making an extension for my conventional ramps as they are too steep to get modern cars onto.

this guy is just round the corner from me if anyone wants me to check them out drop me a line

One of the guys at work has a set - they are 6mm IIRC. Its simply folded chequerplate, there is no reinforcement at all.

Very simple design, however the jacks are difficult to use at first as scissor jacks are not that easy to turn when they are closed. We have looked at options to use another jack to do the intial lift.


I can get some photos if you want to see more detail

Cheers

Peter

was just looking at the pictures
definatly a simple desingn and was just thinking the same about the jacks was wondering if it would be possible to replace them with a decent piece of box section to join the two ramps then just use a trolly jack

Yep...

There is a hole about 200mm from the rear edge where the pins for the rear supports go when its all jacked up.

However, due to the slope of the ramps, this hole is only 35mm off the ground when the ramps are down, and I can't find a jack that will go low enough.

Otherwise its a very simple design. There is another one in the US that uses a similar design but has the central jack point.

Cheers

Pete

It would be great if you confirm the 6mm issue. There are a couple of reasons why I think they may not be as thick as 6mm. Firstly, given the dimensions on their site I think 6mm would come in a bit over the 20Kg weight they state. Secondly, and less significant, these ramps are about 3M long and the aluminium stock holder I checked with only did 3mm in 3M sheets. Their 4.5mm and 6mm where both 2.438M sheets.

You often find all the stockholders get there metal from the same mills and the max sheet size will be a function of the width of the roller sets. The longer dimension of the sheet is typically across the coil to limit the amount of residual curve.

Won't be 6mm thick more like 3mm to me.

I used to design lifting machines made of aluminium alloy for a living --- I think this design is pretty dodgey. The design of the jacking beam in particular would worry me as a point where sudden catastrophic structural failure might occur.

One of the aspects of designing heavily loaded members in light alloy that many would be designers forget is it isn't steel, General purpose aluminium alloys generally have mechanical strength and stiffness properties just over 1/3 those of steel.

Folded "U" shaped channels aren't usually used in bending in the orientation they are used in this design. In steel it would be more than sound, in light alloy I would want to crunch the numbers very carefully.

Tractor/Farm Jacks would give greater lift

see this one

http://www.hamercarlift.com/
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