Anybody know how an alignment turnplate is constructed?

[jdwilson44]

I bought a Hunter R811 alignment machine a couple of weeks ago - and now I'm looking into getting it setup to do some alignments. Seems like a new pair of turnplates/turntables are a lot of $$.

I'm seeing a lot of rebuilt kits out there for turnplates - so I'm wondering if I could just build myself a pair. I have a lot of steel hanging around , welders, ability to cut steel - etc.

The thing that I don't know is: exactly how these things are put together. I've been digging around and I can't find any videos or parts manuals or anything like that - that would give me any idea of how to maybe use one of the rebuild kits and my own steel to construct a pair of these things.

Anybody here have any info that might help me?

 

[FigN⋅m]

I just go super ghetto and use two steel plates with grease in between them
Would be cool to see how they actually get fabricated.

 

[whateg01]

The basis for them is just a big thrust bearing

 

[jdwilson44]

The basis for them is just a big thrust bearing

Yeah - those are exactly the rebuild kits that I see being sold everywhere.

What I'm wondering is - how is the turnplate constructed - how does that bearing fit into the turnplate?

 

[whateg01]

Yeah - those are exactly the rebuild kits that I see being sold everywhere.

What I'm wondering is - how is the turnplate constructed - how does that bearing fit into the turnplate?

It's really just 2 plates with a pivot in the middle to keep them aligned and that bearing in the middle. There's not much to them really

 

[jdwilson44]

I just go super ghetto and use two steel plates with grease in between them
Would be cool to see how they actually get fabricated.

Yeah - I've seen a number of really ghetto solutions being used out there - plastic bags and grease - stuff like that. I'm looking to put something together that I can use over and over again and that is a little more "pro".

All the alignment racks I've seen have turnplates for the front wheels - and a slide plate or whatever you call it for the rear wheels. I've seen a number of solutions used for the rear slide plates , and found some taken-apart pictures and diagrams of those. So for the slide plates I can either use some roller bearings (not sure what the official term is - but I know what they look like) - or I can use a sheet of PTFE with a steel plate on top of it.

For some reason I just can't find any breakdowns of those front turnplates that would give me an idea of how they're put together.

 

[jdwilson44]

It's really just 2 plates with a pivot in the middle to keep them aligned and that bearing in the middle. There's not much to them really

I think the part that has me wondering - is that all the rebuild kits I've seen look like they're free floating somehow - but I know they have to be held in place somehow.

 

[dscheidt]

I think the part that has me wondering - is that all the rebuild kits I've seen look like they're free floating somehow - but I know they have to be held in place somehow.

the balls go in the holes in the rings. There are some pices on the top plate that constrain it. Here's a video of someone rebuilding one. (turn your sound off, it's just horrible music.)

 

[nadogail]

You Tube University has shown many of us how to get jobs done.

 

[Milton Shaw]

Two 1/4" plates about 16" square the bottom plate has about a 4" hole in the middle. The top one a countersunk hole in the middle for a screw. The bottom plate is reinforced with two 1/4 by 3/4 side rails. The last piece is the floating pivot about 6x6" square with a nut welded in the middle to bolt the top plate with that bearing and balls installed between the plates. I also included the two bent 5/16 pins to lock them in place when pulling the car on. That kit shown above has the center bolt, center spider and ball plate and the pins with tethers on them to keep the pins from being lost. I made a set of 4 for my G111 about 25 years ago and made the center spider myself and used steel ball bearings as nothing like that kit was available then. no internet to find things like that. The large middle hole allows the plates to move in relationship to each other to let the suspension settle to allow the car to settle down.

 

[Steve_P]

I've never seen one apart, but I assume that they're basically a "Lazy Susan" type arrangement.

https://www.amazon.com/Woodpeckers-Lzy-12-1-Capacity-Hardware-Turntable/dp/B071ZD31Z5/?tag=atomicindus08-20

 

[whateg01]

I've never seen one apart, but I assume that they're basically a "Lazy Susan" type arrangement.

https://www.amazon.com/Woodpeckers-Lzy-12-1-Capacity-Hardware-Turntable/dp/B071ZD31Z5/?tag=atomicindus08-20

Close. They float laterally though. Otherwise you'd have to get the center directly in line with the ball joints/kingpin/strut.

 

[engineer2]

I've rebuilt a few Bear full-floating turnplates back in the day. Pretty simple arrangement. Two carbon steel plates with a caged circular bearing (like the Hunter pictures) sandwiched in between. I remember there was a center bolt (or something) to limit travel. Also a degree indicator for caster swing, usually 20 degrees max. was sufficient.

 

[jdwilson44]

the balls go in the holes in the rings. There are some pices on the top plate that constrain it. Here's a video of someone rebuilding one. (turn your sound off, it's just horrible music.)

Thanks for that. I actually found that video and watched it - but the music and the jerky video was turning me off. I watched a couple more times with the music shut down and it was helpful.

 

[jdwilson44]

Close. They float laterally though. Otherwise you'd have to get the center directly in line with the ball joints/kingpin/strut.

That was the part that had me a little baffled. I used a Hunter rack way back around 1991 or so at the dealer I worked at - at the time - and seemed to remember the plate pivoting and floating. I've seen a few videos online as well where it's obvious the plate floats and pivots.

It may turn out that I don't even need to build anything, I just ran across somebody selling an older pair of Hunter turn plates for a "reasonable" price (in this case about $150) - so maybe I won't have to build anything. The cheapest I've seen anything new is around $500 - for that I figured I would just build something myself.

 

[jdwilson44]

Two 1/4" plates about 16" square the bottom plate has about a 4" hole in the middle. The top one a countersunk hole in the middle for a screw. The bottom plate is reinforced with two 1/4 by 3/4 side rails. The last piece is the floating pivot about 6x6" square with a nut welded in the middle to bolt the top plate with that bearing and balls installed between the plates. I also included the two bent 5/16 pins to lock them in place when pulling the car on. That kit shown above has the center bolt, center spider and ball plate and the pins with tethers on them to keep the pins from being lost. I made a set of 4 for my G111 about 25 years ago and made the center spider myself and used steel ball bearings as nothing like that kit was available then. no internet to find things like that. The large middle hole allows the plates to move in relationship to each other to let the suspension settle to allow the car to settle down.

Great description - thanks.

 

[Jgaz]

@Milton Shaw had an excellent description of the turn table construction.
The rebuild kits link above are exactly what was inside the hunter rack turntables I used at work.

In the late 90’s I wrenched on a Formula Ford open wheel SCCA car.
Our Lo-Buck alignment set up included a stack of floor tiles set for each corner to level the car.
For turn tables in the front and slip plates in the rear we used alternating layers of Masonite tempered on both sides and heavy duty wax paper.
This wasn’t the easiest to use but it worked.
Keep in mind that this was used on a race car that weighed about 1200 lbs

 

[cgaengineer]

Aside from the ball bearing plates, they are made of stainless steel so they won’t rust from wet cars.

 

[PDM]

Aside from the ball bearing plates, they are made of stainless steel so they won’t rust from wet cars.

no, that's not true. My Rotary alignment rack front turnplates are carbon steel, not stainless.

I rebuilt mine about 6 years ago and used Por 15 on the plates after stripping them.

 

[jdwilson44]

no, that's not true. My Rotary alignment rack front turnplates are carbon steel, not stainless.

I rebuilt mine about 6 years ago and used Por 15 on the plates after stripping them.

Yeah - I've seen both for sale on Craigslist/Facebook marketplace - and I've been looking thru a bunch of Hunter literature and see Hunter alignment racks with both carbon steel (painted) - and stainless steel turn tables.

I haven't made up my mind yet if I'm going to build a pair of turn tables , in the last few days I've seen 2 or 3 turn table pairs show up for sale for decent prices. Even a some of the stainless ones that weren't ridiculously priced.

Past a certain point it's not worth it to me to go and build a pair.

 

[mikegt4]

The basis for them is just a big thrust bearing

^^^ This is what I was going to do years ago when Harbor freight sold alignment plates, they were crude and easily recreated. I almost bought a replacement parts kit but at the time I didn't have a level place to align a car. Fast forward about 20 years and my son got a pair of these off BidFTA auctions recently for the princely sum of $6, brand new still in the somewhat torn box. He has found a lot of stuff there for cheap.