my wife just came out to my shop and told me the turnbuckles I just added aren't doing any good, because the body is pulling in instead of pushing out on the end posts, come on guys straighten her out, she is wrong isn't she?

Thanks for your support if I'm right.

Rob.

http://webpages.charter.net/2manitowoc/00rotisserie.html

Seems to me the body of the car shouldn't do either of those things. Is that a homemade rotisserie? The body of the car looks too long for it.

TonyZ

Its made out of two advance auto parts 1000lb engine stands, and pretty heavy angle iron.
It's been on there a good year, I move it across some rough concrete edges, about 75feet to another garage, so it gets banged around a little, it works good, but I was looking at it and thought if something let loose the turnbuckles would hold it. Its on 8 swiveled wheels so I can move it all over by myself, those wings on the floor fold up, I don't know if I need them, because I've used it with those folded up.

I hook them on the rotisserie different then some I have seen, this way you can work on all the trunk and front body supports with out any interference. If the next one I do has a lot of rust I will probably hook it up a little different, or put it on the jig first. Didn't mean to talk your ear off.

Rob

One obvious problem with your turnbuckle design is that the turnbuckles will prevent the car from turning sideways for working on the top or bottom of the car. If you are worried about something breaking, you might try welding or bolting angled braces sideways from your vertical post at each end. Most engine stands are rather light metal, and I don't blame you for wanting to reinforce it.

And your wife might be right about the weight pulling inward on the vertical supports.

I was tempted to use engine stands for a rotisserie too, but decided on heavier material and a wider stance at the ends. Would you use engine stands again if you built another unit?

I don't know If I would use engine stands again, maybe, but I'm usually a little over cautious. I put the turnbuckles down low so I can tilt it way down as low as I need to. When I flip it over its quick with the turnbuckles, I usually work alone and I can flip it over pretty easy. I'm a perfectionist, to the point I'll drive a spike when a nail will work, thats not like me to not over build something, but sometimes when I have somebody working with me, I tend to get in a hurry.

I think you're idea on the angled braces is a good idea, thank you northern 396.

Rob.

Wow, I guess a picture is worth a thousand words … I was sitting here trying to figure out what you were talking about turnbuckles, now I know.

Sorry bud, you’re wife’s got this one … The weight of the car is going to want to bend you engine stand inward. I suppose if you put enough tension on those turnbuckles, the body wouldn’t allow too much compression and you might be able to tighten it up some.

The best design I have seen so far used square tubing to form a floor footing in the shape of an H, with the two ends facing the other end of the car … to facilitate 2 outer crossbraces. On these, the two ends of the H extended maybe 12” beyond the centerlink of the H. From these weld braces from the back tip of the H’s up to the highest point you can on the upright (will look like a triangle).

Another note on design, and your’s seems find as long you don’t remove the crossbraces … Is to make sure and put at least a 3rd floor footing point inward of the lift (under the car). Again this is where the thing is going to want to bend.

I have a rotator as well, but better engineered (bought it) and from what I see the only thing wrong is you don't have any adjustment between the body and the rotator where they bolt to the body. Most rotators have an adjustment up there front and back. This lets you slide the attachment up to the body so you start out straight. It's looking like you are trying to wedge something into a "V" and that is pushing your upright out which you tried to correct with the chain and turnbuckles, which as someone said will prevent you from turning the car.

You also need much wider out-riggers to keep the thing from turning over. What you have looks like it's bolted to keep the unit from tipping, but there is no contact until it starts to tip. Put those outriggers on straight and add a HD wheel to each end so it's always making contact and can't even begin to tipl If it starts to tip like it is now, you could shear a bolt and there she goes.

One solution to me and I don't know if you can do it as pictures don't show clearly is if you can adjust the bottom sleeves to pull the bottom of either end out (maybe drill another hole after sliding the tubes. This will reduce the "V" tendency and allow your uprights to be straight and take the pressure off so the weight is pushing down instead of out at the same time.

Otherwise can appreciate your ingenuity and getting to where you are. A little more fine tuning and you will have a great "tool". By the way, you wife is pretty sharp, I'd keep her if I was you LOL

Good Luck

Your wife is wrong.

The car body and the rotisserie form a rectangular box and the turnbuckles act as braces to keep the box from parallelogramming to the front or rear. It doesn't matter that they aren't rigid because one of them will be in tension at all times. It would be better to use a rigid brace because then one would be in tension and the other in compression depending on which way the force was applied. You do need to add braces to the sides, turnbuckles or angles, to keep it from falling on you if the welds at the base of your engine stands fail.

There is one thing that you could do that would brace the structure to the front and rear, side to side, and leave enough clearance to rotate the body. Just run chains and turnbuckles from near the top of the vertical column to each outside frame rail. The attach point on the frame rail only needs to be as far from the end of the rail as the height of the attach point on the column. In other words, the chain will form an angle of about 45 degrees relative to the frame and the column.

Tom

I knew i needed to be an engineer to hang out here

Just today a guy probably early 50's came over to look at my son's 70 ss clone, he was thinking about buying it. He's in a rural area in northeastern wi.,he said he has been working on muscle cars for 35 years. Said he had a camaro, chevelle etc. and a lot of buildings on an old farm, even a little area to sell misc. stuff. in one of his buildings.


Well him and I got into a little verbal exchange about matching numbers and clones. I asked him if he gets on the internet, he said he didn't have time, I told him about this site and some of the people on here, and how they help each other out, and how much he could learn.
Anyway to the point of this, there is a lot of knowledgeable, and highly intelligent individuals on here, I'm not highly intelligent, but because I'm 63 I've seen a lot , plus I'm retired and have the time to check things out on this site, and by reading the stuff on this site I can talk a pretty good game too.
Its surprising to run into someone like this that doesn't know about this site, yet he's really into these cars.

I told him because of the amount of material and muscle car dealers and private owners, that things are a little different in a lot of ways, and in just the last two years digital cameras have made a sizeable impact on availability and prices of these cars. Thanks for the feedback on the rotisserie, I really appreciate it.
Rob.

Here is my Rotisserie. I have the plans for it on my yahoo photo page below. I also have it in CAD and 3d modeled. I post this about a year ago.
http://i6.photobucket.com/albums/y208/gman7711/P1010092.jpg
http://i6.photobucket.com/albums/y208/gman7711/P1010097.jpg
http://i6.photobucket.com/albums/y208/gman7711/P1010095.jpg
http://i6.photobucket.com/albums/y208/gman7711/P1010098.jpg

There are numerous ways to build these things, mostly variations on the same principle. Overkill in design is good, in my opinion. Mine probably could handle a 10,000 pound car (if there was such a thing) or a small tank.

The one thing I would like to add is larger diameter wheels - that would make it possible to roll it outside for blasting and other dirty work. The casters only work on a hard surface.

Your wife is wrong.

The car body and the rotisserie form a rectangular box and the turnbuckles act as braces to keep the box from parallelogramming to the front or rear. It doesn't matter that they aren't rigid because one of them will be in tension at all times. It would be better to use a rigid brace because then one would be in tension and the other in compression depending on which way the force was applied. You do need to add braces to the sides, turnbuckles or angles, to keep it from falling on you if the welds at the base of your engine stands fail.

There is one thing that you could do that would brace the structure to the front and rear, side to side, and leave enough clearance to rotate the body. Just run chains and turnbuckles from near the top of the vertical column to each outside frame rail. The attach point on the frame rail only needs to be as far from the end of the rail as the height of the attach point on the column. In other words, the chain will form an angle of about 45 degrees relative to the frame and the column.

Tom

You beat me to it. You're right on the money about the parallelogram, this is like a "structural engineering 101" schoolbook example. :) Those engine stands can't bend, but might fold without a brace.