2 post lift install in existing single garage

[JOEPRO]

This is the beginning of a CAD setting out drawing.

The lift is a tight fit in this garage but will fit.



The red hatch is the approx area I plan on sawing and digging through the existing concrete floor. And dowel the founds and edges of concrete plus have the lift pad poured under the edges of the existing floor. It won't be going anywhere after that.

 

[owas]

My friends one is bolted to his roof rafters too because his floor was a bit thin

Out of curiosity, how wide is the garage?

 

[Pete.]

The way I see it, if the slab will support a car on four wheels it should support a car on a ramp on four points somewhere like the contact area of the four tyres.

 

[Dilkris]

The way I see it, if the slab will support a car on four wheels it should support a car on a ramp on four points somewhere like the contact area of the four tyres.

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[Pete.]

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The load on the slab is the same, adding the bit the ramp weighs. So if your car tyres has 4 contact points say 10 inches square each and you put the ramp on a H frame with pads say 14 inches square the pressure under the pads is miles less than the pressure under the wheels because 14 inches square is double the area of 10 inches square.

 

[voipio]

But the chances are that the mass of a vehicle won't be perfectly balanced lengthwise on the ramp, so there will be a tilting force on the ramp uprights, which the concrete on which the ramp is mounted will need to be strong enough to resist.

 

[Pete.]

But the chances are that the mass of a vehicle won't be perfectly balanced lengthwise on the ramp, so there will be a tilting force on the ramp uprights, which the concrete on which the ramp is mounted will need to be strong enough to resist.

The mass of a car is not perfectly balanced on the wheels.

 

[voipio]

But in a static vehicle, the force from the wheels will always be straight downwards, so that's all that the concrete has to resist. With a two post ramp, there's effectively two gert big levers bolted to the concrete, so there's not just the downwards force, which the concrete should withstand fairly easily, but a twisting force as well. On a front engined vehicle, the greatest weight will be on the front wheels, which will create a tilting force on the ramp stands towards the front of the vehicle.

 

[Beanwood]

But in a static vehicle, the force from the wheels will always be straight downwards, so that's all that the concrete has to resist. With a two post ramp, there's effectively two gert big levers bolted to the concrete, so there's not just the downwards force, which the concrete should withstand fairly easily, but a twisting force as well. On a front engined vehicle, the greatest weight will be on the front wheels, which will create a tilting force on the ramp stands towards the front of the vehicle.

I think you and @Pete. Are talking about slightly different things. On the existing proposal I agree there’s a risk of the balance being off and the leverage on the single pads being a risk. For an H frame the load would be more evenly distributed

 

[Dilkris]

This is the beginning of a CAD setting out drawing.

The lift is a tight fit in this garage but will fit.

View attachment 475077

The red hatch is the approx area I plan on sawing and digging through the existing concrete floor. And dowel the founds and edges of concrete plus have the lift pad poured under the edges of the existing floor. It won't be going anywhere after that.

You are obviously intending to do it properly, (which is great ), but to encompass the "moments" being generated I would be tempted to modify your red hatched area (ie that area you intend to excavate and re-cast) to resemble that of an "H" - it would be little extra work at the end of the day.

 

[reb78]

You are obviously intending to do it properly, (which is great ), but to encompass the "moments" being generated I would be tempted to modify your red hatched area (ie that area you intend to excavate and re-cast) to resemble that of an "H" - it would be little extra work at the end of the day.

I guess it is an H, but with the top and bottom filled in...

 

[Dilkris]

I guess it is an H, but with the top and bottom filled in...

Sometimes you just have to give in.

 

[Melvyn Best]

That’s going to be fun actually setting the arms under the car with the walls being so close , hope you have enough room to get from front to rear

 

[Beanwood]

Have you actually got enough room to (for example) pull a half shaft, or wield a BFH against something down the side?

 

[dieselsamurai]

The mass of a car is not perfectly balanced on the wheels.

The main difference if the load is unbalanced on the lift then one side of the pad will be under compression the other will be tensioning the bolts trying to pull them out of the ground . The point loading is far greater than tyres sorry but i think theres really no way you can compare the two.

 

[Pete.]

The main difference if the load is unbalanced on the lift then one side of the pad will be under compression the other will be tensioning the bolts trying to pull them out of the ground . The point loading is far greater than tyres sorry but i think theres really no way you can compare the two.

Peoiple have missed where I said H Frame. If the pads on the H frame are similar to the tyres on the car then the loads are similar too.

 

[dieselsamurai]

Peoiple have missed where I said H Frame. If the pads on the H frame are similar to the tyres on the car then the loads are similar too.

Sorry Pete my bad been a long day, yeah that would be the safest way to do it .

 

[JOEPRO]

This is also an option

Just a chain - can't see the issue

 

[JOEPRO]

One part of the control panel which was in need of repair was the push button switches. There are 3x of them and these were seized when I took the board inside.

From research these are just cheapie 12x12mm micro switches so I ordered new 12.5mm tall ones to test fit:





They were just a tiny bit too tall. So I ordered another 10x new switches for £3.19 on ebay which are 9mm tall. I think those will be perfect replacements.

The other 2x new switches are ordered. Emergency stop which has the knob missing and the power switch which also had the centre part missing.

So in the next week or so when these bits arrive I'll have the control board back to like new condition for only about £25 of parts. I'll clean it all up when apart and leave it ready for install. In my case it will attach to the wall beside the lift and I'll extend the cables from lift via conduit.

This is a great relief as a new control board is more than I paid for the lift:

 

[tom2207]

The load on the slab is the same, adding the bit the ramp weighs. So if your car tyres has 4 contact points say 10 inches square each and you put the ramp on a H frame with pads say 14 inches square the pressure under the pads is miles less than the pressure under the wheels because 14 inches square is double the area of 10 inches square.

look at the distances involved from the cars centre of gravity then rethink . a car usually balances at the base of the a post , base of the b post for bmw , allowing for daft things like porches etc , the effect of taking an engine out or engine and box has on the base plate of a ramp is dramatic I work on 4 ton two posters usually with two ton rangerovers etc on them , set into 1m cubes of reinforced concrete , we even drove rebar another meter down and concreted that in at the same time ,,,, and I still wont swing on a right bolt more than three time , or four if pushed as you set up a swaying motion ,,,,, I much prefer a four poster for suspension work , but just keep an eye on the base and the bolts , if they start to creep you have an issue