Harrison's Garage's RCR 40 Build

[Brian Kissel]

I personally have only installed (8) of the 4 post style hoists. But as the others have said shimming and grout was recommended and the procedure was closely followed with great success.

Regards Brian

 

[Randy Folsom]

Harrison,
A little off the topic of GT40's but your note caught my attention.

In my past life, I was an automobile lift guy - Engineering, Service, Warranty, Product Liability, Manufacturing, Marketing and Sales. Did everything except accounting. My career spanned 45 years in the industry with two of the market leaders. I state this as my qualifications to offer some advice.

The base of the column is designed to sit flat on a surface, not by supports in the four corners. It was always recommended that when a column needed to be shimmed to make it plumb, the area under the column be filled with non-shrinking grout. Right now, you aren't seeing any issues since you don't have any weight on the unit. But once you start to lift a load, the baseplates will begin to bend. The unit will become unstable. Recommend you pack some machine grout under those bases, unless you want the thing to eventually break.

I personally, never liked the concept of un-anchored four-post lifts. They rely on the baseplates deforming until the column itself transmits the load to the concrete surface. The lift wouldn't fall over but in my opinion, wasn't very stable. Anchoring is the right thing to do, but you need to do it correctly or you will create problems for yourself.

Paul

Paul,
Good guidance. Thx much. I am considering a two post lift. It will only be used for cars weighing less than 2,500 lbs. my question is about the thickness of the floor concrete. I see a lot of YouTube videos about cutting the floor and putting in a thicker foundation but there is a lot a variety in the how-to. My question is, assuming I have a well done 4” slab, could I instead weld on larger base plates to the post bottoms to spread out the load? Thx in advance for your thoughts.

 

[PaulProe]

Randy,
Most lifts are designed to work with a 4" thick, 3000psi concrete - the typical floor found in garages and dealerships. Once you've picked a brand and model, ask them for an installation book. That will outline their requirements. I doubt you'll find it any different.

One caution: the anchor bolts need to be away from any seam in the floor and the floor needs to be in sound condition, no cracks.

I am familiar with Rotary Lift (who also own Forward Lifts and Direct Lift), Challenger Lifts and Weaver Lift. They, combined, held over 80% if the automotive lift market. All called for a 4" floor.

Select your supplier and follow their instructions.

Paul

 

[Harrison]

Harrison,
A little off the topic of GT40's but your note caught my attention.

In my past life, I was an automobile lift guy - Engineering, Service, Warranty, Product Liability, Manufacturing, Marketing and Sales. Did everything except accounting. My career spanned 45 years in the industry with two of the market leaders. I state this as my qualifications to offer some advice.

The base of the column is designed to sit flat on a surface, not by supports in the four corners. It was always recommended that when a column needed to be shimmed to make it plumb, the area under the column be filled with non-shrinking grout. Right now, you aren't seeing any issues since you don't have any weight on the unit. But once you start to lift a load, the baseplates will begin to bend. The unit will become unstable. Recommend you pack some machine grout under those bases, unless you want the thing to eventually break.

I personally, never liked the concept of un-anchored four-post lifts. They rely on the baseplates deforming until the column itself transmits the load to the concrete surface. The lift wouldn't fall over but in my opinion, wasn't very stable. Anchoring is the right thing to do, but you need to do it correctly or you will create problems for yourself.

Paul

Hi Paul,

Thanks for the valued input. I have to say I thought I looked into all possible areas of failure (my main concern was finding an epoxy that was rated for 3.25" deep holes for a 3/4" threaded rod. Red Head CP6+ fit the bill and is rated for way way more than the lift will ever see. So are the threaded rods. I never gave much thought to the base plate deforming.

First a few specs on the lift - it's rated at 7,000 (Chinese) pounds and I only ever plan to have it loaded to 2,500 lbs max (weight of the gt40 and myself). That's approximately 35% of the stated factory capacity. You do bring up a good point though in that the base plates aren't designed to keep the posts from pressing through them; I was just assuming the 3/8" thick steel base plate would be up to the task.

I secured it the way I have because it allowed me to keep the garage flooring tiles in place without much messing about with them. I also thought about cutting the tiles away where the baseplates are and bolting them straight to the concrete floor. If the plates on the base look to be deflecting even a little or I notice even the slightest wobble with the car on it, then you can bet it'll be lowered down directly to the concrete.

For now though I'm hoping the 3/8" thick base plates don't deflect under load, but I will be keeping a keen eye on them when I begin testing the lift under load.

 

[Randy Folsom]

Randy,
Most lifts are designed to work with a 4" thick, 3000psi concrete - the typical floor found in garages and dealerships. Once you've picked a brand and model, ask them for an installation book. That will outline their requirements. I doubt you'll find it any different.

One caution: the anchor bolts need to be away from any seam in the floor and the floor needs to be in sound condition, no cracks.

I am familiar with Rotary Lift (who also own Forward Lifts and Direct Lift), Challenger Lifts and Weaver Lift. They, combined, held over 80% if the automotive lift market. All called for a 4" floor.

Select your supplier and follow their instructions.

Paul

Thank you very much