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Modifying car lift ram
ian996 - 28/8/15 at 11:24 AM

I got a 1970s Bradbury 3 post lift for my garage, however the way it works means the lift ram extends out the top of the post doubling the lift height required.

Do from the to of the lift cylinder to my garage roof is 29".

Does anyone know where and how I can get the ram modified to a more modern design so I get more height on the lift.










adithorp - 28/8/15 at 11:42 AM

I've got the same lift. I can't see anyway that you could alter it. The extending ram is what pulls the cables to lift the other 2 posts. I have seen a garage with a tube (like a chimeny) in the roof that the ram went up into... they originally just had a hole with a bucket over it that the ram lifted up as it went.


ian996 - 28/8/15 at 11:54 AM

Maybe a shorter ram? That way I can lift twice it's height again. Or a screw? Anyone know who I can talk too? Can you modify the ram or buy a shorter one?

[Edited on 28/8/15 by ian996]


obfripper - 28/8/15 at 12:59 PM

Your ram leg looks the same as a mk2 liftmaster 4 post, which also has the same drawbacks with the ram leg design.
The ram is only a tube welded into the base, with a leather sealed plunger going up to join to the 2 side lift plates, and an oil return pipe above back to the reservoir to return what seeps past the leather seal.
You could remove the ram and replace it with a modern multi stage ram, however you will probably need to use a new pump/reservoir, you may need increased pressure if you need the full lifting capacity, design a new safety locking & stop mechanism, and also a guide tube to ensure the leg lifts in a straight line, as a multi stage ram may twist under a lateral load.
The length of the side plates would need to be shorter by a factor the of stages the ram used has, and would be the only thing then extending above the ramp bed.
A guide tube would only need to be the same height as the original ram.
IIRC the pump and oil gallery is all integrated into the base of the leg/reservoir, so it might be more practical to start from scratch, and keep/sell the original leg.

Dave


ian996 - 28/8/15 at 02:54 PM

It does actually have a guide tube already, it slides over the top of the post.

If my roof is say 9ft high, I could cut the ram at 4.5ft and put it back together so I get 4.5ft of lift - should be enough to get underneath comfortably. Might be the best compromise and cheapest solution.

Either that or build a post in the middle of the master bedroom, sure the wife will understand...


theprisioner - 28/8/15 at 04:34 PM

The later Bradbury 4 posters have the ram in the tread plates. I have the earlier 4 poster and one day the seals needed replaced so I had to cut a hole in the roof to get the ram out. Took 10 years for the seal to fail however.

I guess in you case the ram would come up in the middle of a room?


obfripper - 28/8/15 at 05:36 PM

What about going mechanical, and using a single 2 post screw ramp upright?
The drive screw is the only moving part, has a safety nut integrated, and can be manually wound down in the event of a fault or power cut.
You may find a broken ramp for pennies that could be salvaged for suitable parts.
There would be little projection above the ramp to worry about, probably less than the height of your car.

Dave


ian996 - 28/8/15 at 06:00 PM

Worth looking into thanks. I can't find much info on how other ramps work and which ramps I might salvage. I didn't know that was how 2 posters worked.


obfripper - 28/8/15 at 06:16 PM

Quite a few 2 post ramps use a lead screw on each side, usually linked by a chain through the ramp base.
I have used bradbury, souriau and tecalemit screw ramps, there are a fair few others, the chinese copies are mostly hydraulic though.

Dave


ian996 - 28/8/15 at 07:05 PM

Thanks Dave, just looking into that a bit closer and it could be a very viable option. Might not be too difficult to modify the existing setup to fit.


owelly - 29/8/15 at 07:52 AM

How about removing the ram and using a hi-lift jack (or similar). That's what I used for my four-post lift.


ian996 - 29/8/15 at 10:44 AM

quote:
Originally posted by owelly
How about removing the ram and using a hi-lift jack (or similar). That's what I used for my four-post lift.


Any pics? What spec ram did you use/supplier. What else did you need to drive it, control it?

All options considered.


owelly - 29/8/15 at 11:53 AM

My four-poster was/is (it's currently in storage) and old Tecalemit and looks like the working are similar to yours. It has three 'slave' posts and one 'master' which houses the hydraulic ram. The master post pulls three wire ropes that lift the three slaves. The shed I had the lift fitted to had no power so I removed the ram and welded a bracket to the edge of the cross-beam next to the master. The hi-lift was one similar to: http://www.hi-lift.com/hi-lift-jacks/index.html
Once the master corner of the lift is lifted, it pulls the ropes to the slaves via the ropes and up we go. It took a couple of minutes to get the lift up the first four feet, then I propped it with a transmission prop so I could take the jack out, fit an extension piece and lift it again to full height.
This was before the days of phone-cameras so I don't have any piccies....