wooden car stand (cribbing) project

Nope...that's the beauty of these.... jack the vehicle up... and insert the wooden stands on the frame rails...if you want to protect it...use some rubber or hockey puck lightly higher than 2x4s and you're golden.

If your car has pinched welds...use hockey pucks for sure...otherwise you can bend the weld areas not reinforced.

 

But then the car is only lifted 13" off the ground which is a lot less than what my jack stands can do.. I'm not really seeing the benefit to these.. I've never had a jackstand be so in the way that I can't do my work just fine


EDIT: not to mention I'm fairly sure my trucks frame is more than 13" off the ground to begin with

 

You're concerned about the designs you posted and structural stability. Why would it bother you if it would hold up a house? Wouldn't that be a good thing? haha. I HIGHLY doubt, if you used those there would be anything to worry about, I think you answered your own concern("Wouldn't I have to worry about the shearing force if these aren't glued together or screwed together?") by the opening statement , but no the tops would be together, the bottoms wouldn't shift... And the weight thing, again only the top pieces would be attached together, so actually it'd probably be easier to move around vs what you've put up, and like I said easier to store.. Four of what you posted is gonna take up a lot of room, if that doesn't matter then, OK.
However I understand if you're trying to budget with the 2x4's. It was just an idea out of the box you've put up.

You honestly don't need to be a structural engineer or architect to figure this out, although you've had some experienced people chime in on the topic.

 

Instead your truck. Don't want this.

 

I thought about that too, but then thought, he'd have to unbolt it if he wanted to have more room to store and not deal with the weight.

 

Say what ? I mean bolt each tower together

 

I think this thread is getting off topic. Oz and Doording was saying that I have to worry about later shear force. I was saying they are contradicting themselves. They say I need structural screws...sound advice if this is a house where there is earthquake, wind force, etc... but I was getting the to the point which I doubt many can answer is what are the lateral forces involve.

I was looking for someone who is a TW member who happen to have experience tell me the numbers that make sense.

BTW even though you joke about the person trapped under a file cabinent... if you notice...cribbing is used by firefighters. It's used to leverage the force away from the victim to get them out of harms way.

The thread is moving away from informational and practical. 6x6 is heavy...

I found this:

http://www.awc.org/pdf/codes-standards/publications/design-aids/AWC-DA6-BeamFormulas-0710.pdf
If you look at figure 24...this is what I am looking for.

This website uses these formula for calculations.

http://www.woodbin.com/calcs/sagulator/

Seems like a 12" span which is more span than my design:

notice that it's listed as KG instead of lbs...so either way... 1100 lbs is acceptable load. My span is 8.5"...so I a 2x4 or 2x6 can handle this load easy.

 

Good luck OP , post pics of your final build

 

Salute you sir....for helping others and saving lives.

 

I completely aware in more ways than one the picture I posted was a training scenario, and that 4x4's/6x6's are used in rescue most time to stabilize a vehicle, be it a transfer truck or a Toyota Tacoma. It was intended as a little joke to, not that it was even funny.

You're right I was part in taking your thread off topic. I saw another solution with the 4x's and mentioned it. I only tried to help, I mentioned in one of my earlier post a way that would work with 2x4's to help you gain a little height/strength. For one it's not ideal trying to explain things thru a forum.

Either way, good luck be safe, hope you can get the answers you're looking for.

 

I know. I was saying if he just attached the top boards (to address concern for any shifting at initial point of contact). The bottoms could be left loose. That way it'd would be easier to store if needed/wanted and lighter bc not together when moving. Where as if they were bolted together, they'd be a little more of a pain trying to store, that's all. With the 4x4's there really wouldn't be a need to attach bottoms, they wouldn't give or go anywhere, once the weight was on them.

 

Thanks for all the concerns...I have another question and I modified my design so it should be safe now. I have a choice between.

GRK RSS14212HP RSS HandyPak 1/4 by 2-1/2-Inch
or
GRK RSS10212HP RSS HandyPak 10 by 2-1/2-Inch

I think the 1/4 are larger than #10 screws...but is this too big for 2x4s...especially if the screw goes in the center of the wood?

Here's a new drawing that should remove any concerns:

The blue are the GRK RSS (not to be confused with ROUS (princess bride)) and the yellow are the GRK R4 screws (#9).

So appreciate an answer so I can order.

 

GRK RSS14212HP RSS HandyPak 1/4 by 2-1/2-Inch should arrive tomorrow. I should be able to start cutting the 2x4s and 2x6s and start assembly. I hope the 1/4" diameter is not too big for the 1.5" width lumber. I did receive the GRK R4 screws...they are nice...I can see why they are pricey and seems worth the money. Thanks for the suggestion.

Update I see the GRK R4 have an AVG ultimate load of 876 lbf for #9 screws. Given that there will be at least 4 screws row...I think these would be more than adequate for this project...but I already order the GRK RSS, so should be fairly stout, I also bought some band clamps secure the stand while it cures with titebond II.

 

If I was putting my truck on it, and getting under it, pushing and pulling on stuff, I'm doubling up on the 2x4's in the center.

 

If you look at the original picture example, there's no center support at all. The span is 9" at max... even in home construction, the spans are greater than 12" generally it's 14.5" apart if I remember. So I already have a center support there. I just wanted to know if the 1/4" screws are too big for 2x4/2x6 thickness.

 

I missed answering this one. My stock truck is 9" off the ground. While it's true your jack stands can go above 13"...can it go 21" or higher? And not get in your way? The idea is that these are wheel stands...you inserted under your wheel, so 9" + 13" gives me 21" of ground clearance under the truck. If you need these stands to sit on your frame rails to work on your brakes you can... So it's 13" off the ground while you work on the front or back wheels off.

If your lifted truck is already and it's 13" off the ground... make a shorter wooden car stand or just stick 4x4 stacked and you also have more ground clearance to do what you need.

 

Never in the history of the internet have so many words been written about a simple stack of cribbing.

 

True, but the wood is also stacked flat.

 

If you think my design is radical... take a look at this link:

http://www.clubwrx.net/forums/tutorials-diy/134366057-diy-wooden-wheel-stands.html

Now regarding the flat part.... if you want to break something... which side do you think is weaker? the side that's 1.5" think or the side that 3.5" thick. Did you look at the sag calculator in the previous page?

The only real advantage I see of stacking the 2x4's flat is that there's less chance of racking. It's also easier to add more height since you simply just add wood and screw from the top.