Wheel-Engaging Adaptors for Car Lift
#1
Instructor
Thread Starter
Wheel-Engaging Adaptors for Car Lift
I designed these for my recently installed car lift and I have to say that they are fantastic. I wanted to come up with an easy method to lift a car by the tires. I thought this would make many maintenance tasks easier and also give the ability to store the car with the weight on the wheels like it was on a four post lift. So with that in mind I fired up the CAD/CAM system and my horizontal machining center and meditated over some big chunks of aluminum. I could see what I needed was in the billet. All I had to do was remove the unneeded material (stolen from Michelangelo, I think).
Now there are one or two lift manufacturers that offer wheel-engaging adaptors as an option. But they are not very elegant, being heavy and ugly steel weldments and they don’t fit the tires on my sports cars very well. So I made these out of aluminum, 6061-T6 and anodized them. Everything is CNC machined and there is no welding. They were designed to have maximum tire contact to minimize the possibility of flat spots from prolonged storage. Each tire is supported by the two forks of the adaptors and so the tires have about twice the support area that they would have sitting on the ground.
Not wanting to drop my 993, I did a finite element analysis which verified my initial calculations that they were very strong. The use of them results in somewhat more stress on the lift arms (because there is a twisting component) so the lift should be de-rated to about 60% of the normal capacity (this is in accordance with other manufacturers). My lift is a Mohawk System 1 rated at 10,000 lbs., so I can use these to lift up to 6,000 lbs., which, while I won’t be lifting dump trucks, is far more than enough for the only cars that matter, cool sports cars.
When loaded the adaptor forks slope down a little, but only about 2-3.5 degrees. Most of this is due to the inner lift arms rocking inside the outer arm and the adaptor rocking on the end of the lift arm. There is very little flex in the actual aluminum forks. A little inclination doesn’t hurt at all and actually increases the load capacity because it moves the center of the load inward toward the lift arm where the adaptors are the strongest.
I like them so much that they have become the normal way I lift a car if I don’t have to take the wheels off. They have two big advantages:
1) The whole underside is accessible which makes removing undertrays and side panels fast and easy. It also holds the car a little higher which is nice if you’re tall like me.
2) I can store a car with the weight on its tires just like a four post lift, but the two post takes up much less room.
I almost bought an in-ground lift, but for my garage I’m really glad I got a two-post. I have two cars in this garage, but also a motorcycle and I do some woodworking, too. The ability to leave a car in the air and park the other under it gives me a lot of room for the other things I want to do.
When I consider the time I spent designing these and tying up the machining center vs. what I should have been doing in actual work that I get paid for, I figure the adaptors only cost me about 1/3 of what I paid for my turbo. But, in the interest of mental health, I try not to think about that!
Now there are one or two lift manufacturers that offer wheel-engaging adaptors as an option. But they are not very elegant, being heavy and ugly steel weldments and they don’t fit the tires on my sports cars very well. So I made these out of aluminum, 6061-T6 and anodized them. Everything is CNC machined and there is no welding. They were designed to have maximum tire contact to minimize the possibility of flat spots from prolonged storage. Each tire is supported by the two forks of the adaptors and so the tires have about twice the support area that they would have sitting on the ground.
Not wanting to drop my 993, I did a finite element analysis which verified my initial calculations that they were very strong. The use of them results in somewhat more stress on the lift arms (because there is a twisting component) so the lift should be de-rated to about 60% of the normal capacity (this is in accordance with other manufacturers). My lift is a Mohawk System 1 rated at 10,000 lbs., so I can use these to lift up to 6,000 lbs., which, while I won’t be lifting dump trucks, is far more than enough for the only cars that matter, cool sports cars.
When loaded the adaptor forks slope down a little, but only about 2-3.5 degrees. Most of this is due to the inner lift arms rocking inside the outer arm and the adaptor rocking on the end of the lift arm. There is very little flex in the actual aluminum forks. A little inclination doesn’t hurt at all and actually increases the load capacity because it moves the center of the load inward toward the lift arm where the adaptors are the strongest.
I like them so much that they have become the normal way I lift a car if I don’t have to take the wheels off. They have two big advantages:
1) The whole underside is accessible which makes removing undertrays and side panels fast and easy. It also holds the car a little higher which is nice if you’re tall like me.
2) I can store a car with the weight on its tires just like a four post lift, but the two post takes up much less room.
I almost bought an in-ground lift, but for my garage I’m really glad I got a two-post. I have two cars in this garage, but also a motorcycle and I do some woodworking, too. The ability to leave a car in the air and park the other under it gives me a lot of room for the other things I want to do.
When I consider the time I spent designing these and tying up the machining center vs. what I should have been doing in actual work that I get paid for, I figure the adaptors only cost me about 1/3 of what I paid for my turbo. But, in the interest of mental health, I try not to think about that!
The following 3 users liked this post by utahrock:
#3
Rennlist Member
Superb, they are works of art. But even better - they are art that works.
The following users liked this post:
M. Schneider (10-12-2020)
#7
Seared
Rennlist Member
Rennlist Member
That is amazingly-beautiful design & machine work.
If I had the means, I would construct a separate shop on our property that would house all of my equipment, and allow space for an old-skool Bridgeport knee mill and a proper 5-axis milling center.
Along with real paint booth, powdercoating booth, and anodizing setup.
Good Lord.
Andreas
If I had the means, I would construct a separate shop on our property that would house all of my equipment, and allow space for an old-skool Bridgeport knee mill and a proper 5-axis milling center.
Along with real paint booth, powdercoating booth, and anodizing setup.
Good Lord.
Andreas
The following users liked this post:
M. Schneider (10-12-2020)
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#8
Rennlist Member
On the subject of finite element analysis, what is your background and what kind of business/shop do you run?
Did you do it all; design, calculations, CNC programming, machine set-up, etc.
#13
Instructor
Thread Starter
#14
Instructor
Thread Starter
Just as your other Car Lift Modification, first rate! This is what I call craftsmanship!
On the subject of finite element analysis, what is your background and what kind of business/shop do you run?
Did you do it all; design, calculations, CNC programming, machine set-up, etc.
On the subject of finite element analysis, what is your background and what kind of business/shop do you run?
Did you do it all; design, calculations, CNC programming, machine set-up, etc.
I took some engineering classes in college and I do most of the designing and a lot of the programming, but unlike the old days, in which I did do everything plus watch my young daughter, we've got 65 people now and so I have the luxury of letting others do the stuff I don't like that much.
#15
Instructor
Thread Starter
Although I didn't use them to make the wheel adaptors, we also have some Nakamura turning centers. These are quite impressive, too, because they have two tool turrets that can operate at the same time, so they're very fast and flexible. You actually write two separate programs, one for each turret. You have to be careful you don't crash them or it will be expensive. Parts for machine tools make Porsche parts seem reasonable...