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23-08-2020, 16:19   #16
Pkiernan
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For the price of an extra 4 by 2, I'd have no gaps, just a solid stack
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23-08-2020, 16:22   #17
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One tip...stae some webbing/strapping about 8 inches long to one side to use as a carry handle
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23-08-2020, 17:47   #18
RobAMerc
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wouldnt Mr costigans design be stronger and a bit taller if he put the middle layers on their edge ?
any stability issues would be removed by cross brace on top layer.
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23-08-2020, 18:09   #19
CJhaughey
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I'd buy a sleeper and cut it to whatever size I needed, they are 200x100 and solid timber.
~€20 per sleeper roughly.
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23-08-2020, 18:19   #20
kadman
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Built up layer on layer, and rotate direction of each layer by 90 degrees,

job done.
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23-08-2020, 19:55   #21
MrCostington
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Quote:
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Wood is in compression at 90 degrees to the fibre direction. In this case its weaker than if compression
happens on the end grain of the timber, as in a timberframe scenarioo.

If the timber has support directly under the tyre, and directly under each layer. Then support
issues wont occur. Support problems occur when you have timber in this scenario, either of a
thickness issue, or support issue.

This wont happen, if its basically a layer cake construction, and no unsupported layers.
Thanks. Just to clarify, I will be doing it as per my OP pics. The pics I posted today was just to see how it would hold up with just one 2x4 and no support in the middle. There was no bending that I could see and no cracks.

I will have a support directly under the middle where the tyre sits. It's 20" long, so it will have 4" support, 4" gap, 4" support, 4" gap, 4" support. That must surely be, much more, than enough to support about 450kg?

Or, do you think slotting in an extra support so the gaps are 2" is needed. And yes, each layer is 90deg to the next one.
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23-08-2020, 19:58   #22
MrCostington
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Quote:
Originally Posted by RobAMerc View Post
wouldnt Mr costigans design be stronger and a bit taller if he put the middle layers on their edge ?
any stability issues would be removed by cross brace on top layer.
If I understand you, you mean put the middle of the sandwich upright? I think that would be unstable. I'd like to keep it as simple as possible as my woodworking skills have been dormant since the Inter Cert!!
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23-08-2020, 20:00   #23
MrCostington
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I'd buy a sleeper and cut it to whatever size I needed, they are 200x100 and solid timber.
~€20 per sleeper roughly.
God ideal but I've already bought all my 2x4s and cut them up
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23-08-2020, 20:59   #24
kadman
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If I understand you, you mean put the middle of the sandwich upright? I think that would be unstable. I'd like to keep it as simple as possible as my woodworking skills have been dormant since the Inter Cert!!
Keep them flat as you have done, its simple and the best.
Slab form is what its known as.

LOts of ways this could be done, but the motto KISS works.
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23-08-2020, 21:07   #25
RobAMerc
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Quote:
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If I understand you, you mean put the middle of the sandwich upright? I think that would be unstable. I'd like to keep it as simple as possible as my woodworking skills have been dormant since the Inter Cert!!

I am not sure what you mean by upright, but what I mean is putting them on the 2inch edge. Better still if you added a fourth or fifth and maybe consider laminating them together, but the cross brace at the top would remove any stability issues.

For lack of anything better to do, I have drawn a diagram of what i mean - from side and front view.

Anyway, if its tall enough for you, I have no doubt its strong enough as is.

Attached Images
File Type: png Blank Diagram (2).png (12.2 KB, 238 views)

Last edited by RobAMerc; 23-08-2020 at 21:11.
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23-08-2020, 21:09   #26
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Thanks kadman! I'm sure you would add a few dovetail joints, and then give it a French polish!

Do you think the one support in the middle is enough?
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23-08-2020, 21:15   #27
MrCostington
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Quote:
Originally Posted by RobAMerc View Post
I am not sure what you mean by upright, but what I mean is putting them on the 2inch edge. Better still if you added a fourth or fifth and maybe consider laminating them together, but the cross brace at the top would remove any stability issues.

For lack of anything better to do, I have drawn a diagram of what i mean - from side and front view.

Anyway, if its tall enough for you, I have no doubt its strong enough as is.
Hey, many thanks! Yes, that is what I understood you were saying.

I think I'll stick to my plan as per my OP pic, and your first pic (EDIt I see they are the same but 2 views). I was playing around with jacking the car, and I don't think I'd get that height anyway, as the wheels drop on the suspension as you jack it (or course I know you know that!). If I do find I need more I'll add it to the bottom, just like in your second pic,

Last edited by MrCostington; 23-08-2020 at 21:29.
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23-08-2020, 21:41   #28
mickdw
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Keep them flat as you have done, its simple and the best.
Slab form is what its known as.

LOts of ways this could be done, but the motto KISS works.
Hard to beat a big lump of wood.
I hate axle stands. Maybe ok for supporting 1 corner but anymore and it all looks far too dodgy to get under.
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23-08-2020, 22:05   #29
unkel
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I also don't trust axle stands at all. If someone gave the car a big push, the whole setup would collapse. When I was in the OP's position many years ago, I thought of building my own wooden ramps, but I would have gone with the setup that RobAMerc has in above picture. But I changed my mind and I went with the steel ramps. They felt very safe, although I still never liked being under the car for very long.
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23-08-2020, 22:13   #30
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I'd be going higher and wider. I made something similar for my car ( E Class w212 ) basically two boxes, 18" high, and the two front wheels drop into them. The box square means that the front wheels cannot go anywhere...either forward or back, and of course no side slipping. 18" clearance from the stand ( less the 4 " or so part of the wheel that is resting in the box) and then you will have another 8" or so as the normal height, given by the suspensions. It's plenty of room to manoeuvre underneath for engine / transmission oil changes. For the rear, I use Draper heavy duty axle stand's, especially when I need the car to be 100% level. I know that you have to jack up the car rather than drive it up on them, but thats not a problem.Its as steady as the rock of Cashel, and I have absolutely no hesitation working under it .

Last edited by jmreire; 23-08-2020 at 22:24.
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