Auto Rotisseries: Everything You Ever Wanted to Know and More

February 2, 2013 by

RotisserieEverything you ever wanted to know about auto rotisseries will soon be revealed to you. There will be no doubt in your mind about wether you need one, if you should build one, buy one, or how to build one.

Take a look around and you will soon find out how much of an investment is required for you to purchase a finished street rod or muscle car. The values and prices of these classic cars are going up faster than ever before. Because of the prices, more and more guys are turning to building their own cars in order to save quite a bit of money.

One of the best ways to build a car the right way, is to do a complete frame-off restoration. What better way to do a frame-off restoration, than with the aid of a rotisserie.

The purpose of this information is not to try and convince you that you need a rotisserie. If you didn’t already have your mind made up you wouldn’t be reading this article. The purpose is simply to let you know about what features are important to look for and what you can probably do without.

What to look for in a car rotisserie design:

Strength of materials

One of the single most important aspects of an auto rotisserie is the strength of the materials. Iv’e seen some pretty flimsy looking designs over the years. Most of the flimsy designs are for one reason only, money.

Some companies that build rotisseries try to cut costs in any way they possibly can. Two of the most common ways to cut costs are in the materials and the shipping. If you use lighter materials it’s not only much cheaper to build, but also cheaper to ship. Unfortunately, this will come at the expense of the customer buying the rotisserie. The expense comes from the added safety risk to the person working on the car as well as the car itself.

This could be argued as only an opinion, but I have always considered any rotisserie’s main frame being less than 3/16”, as cheap and flimsy. The same thing goes for all the parts that support the car directly. There can be a lot of stress on the parts that will be holding up and spinning a car.

Some guys might argue the fact that the car they are building is relatively small and light. They might figure they don’t need a big beefy rotisserie. They might be right, but I have always wondered who would complain if the rotisserie was over built? You never know if you will someday build a different car or even sell the rotisserie to someone who will. I doubt the guy buying your rotisserie will complain about it being built too strong. Why risk too light of a rotisserie for a lousy $100? That’s not to say the money isn’t important, but it is not as important as your safety or your car’s. You will get your money back at the time of resale of the rotisserie. If you do the math, you will see that the overall savings by going with lighter materials will not add up to much.

Welding

Another aspect of the strength has to do with the welding. If you are going to be building your own auto rotisserie, you need to make sure that you are able to handle the welding of it. If not, you should strongly consider hiring someone that is a good welder to weld it for you. It won’t cost too much since the welding part of the project is a relatively small part (time wise) of building a rotisserie. If you were to cut all the materials and tack it together, the actual welding time will be between 1 and 2 hours depending on the welding machine and the process.

What features are important to you?

Hydraulic Jacks

There have been many different rotisserie designs out there over the years. Some of them have some very good ideas incorporated into the design and some seem like a waste of time and money.

One of the biggest misconceptions I have seen and heard over the years is that hydraulic jacks are needed in order to find the perfect center of gravity for the car body. When you see a model with a hydraulic jack system, the only thing the jacks are for is to find a good working height of the car. It is not used to find the center of gravity so it will spin better.

I have always considered the jacks to be more of a luxury item rather than a necessity. Of course there are some cases where the jacks are needed simply for ceiling clearance issues in a garage. Nothing would be worse than to have a fixed height rotisserie and not be able to flip your car body because it hits the ceiling.

The jacks are also handy for raising and lowering the car body to a good working height for any position the car is in. You need to consider the extra cost vs. the extra benefit. After all, the car is on a rotisserie, how hard can it be to find a good position for working? Does it really need to go up and down as well as spin? If you can do without the jacks, you will easily shave $150 – $250 off of the price of building your rotisserie. That’s assuming that you wouldn’t buy the cheapest hydraulic jacks on the market. You’d be way better off not installing jacks than to buy the cheapest ones possible.

It’s also worth mentioning if your’e going to buy a rotisserie, be sure of the quality of jacks you will be getting if you order a model with jacks. Many companies will send you a rotisserie with the cheapest Chinese jacks in order to save themselves money. This will end up costing you in the form of headaches.

Balancer

Another feature I would consider to be a luxury, is a system to find the car’s center of gravity. Finding the center of gravity simply means that when the car is on the rotisserie, it will be balanced, not top or bottom heavy. You want the car to be able to spin as balanced as possible. This will make your work much easier as well as much safer.

The most common way to do this is with some kind of threaded rod installed. Once you get the car body onto the rotisserie, you can raise or lower the car in reference to the pivot point. With the jacks, the entire assembly will move. With the balancer, the pivot point will stay put and only the car body and hanger brackets will move.

I’m not saying that these systems don’t work or aren’t a good idea. I’m just saying that I don’t feel they are very necessary since you only need to find the center of gravity once. Once you find it, you’re not going to move the car, so why do you need a fancy system for doing it? The center of gravity can be found quite easily with nothing more than a floor jack and a block of wood. I’m sure that if you look around your garage or shop you will find those 2 items. This may seem a little primitive, but why spend the extra time and money on something you will only use once per car you restore.

I can get an argument from guys either way on this, but my feeling is, if you have the money go ahead and build/buy it. If not, don’t. This holds true for most of the design options available.

False frame

One option that has more to do with the condition and strength of your car instead of the rotisserie itself, is the “false frame” or “substitute frame”. A false frame is nothing more than a fixture for your car to sit on for support. It acts like a frame, but it provides a greater amount of separation than your car’s frame will. In other words, you will have more clearance between the car and the false frame than you would with your car’s frame. This will make it easier to repair body mounts and other problem areas of the bottom of your car.

The reason for using the extra support is if your car is in too rough of shape to support itself before repairs are made. Convertibles can also use this extra support since there is no help from any roof support. Obviously unibody cars shouldn’t need this extra support, and if they do, I would think about finding a different car to restore.

Safety stop

This seems to be a popular selling point for many rotisserie manufacturers. Usually this is some kind of a spring loaded pin that will slip into a hole or a notch to hold the car from spinning when it is on the rotisserie. The idea is a pretty good one and I’m certainly not against increasing the safety of a rotisserie, but I’m just not sure of why you would need this if you take the time to get your car balanced in the first place.

A quicker and easier to build option would be to just install a set screw or pinch bolt to stop the rotation. If you use a pinch bolt, everything is going to be nice and tight when you are working on your car. If you use a safety latch, you will still have some play in the mechanism itself. If you have a hole that is only a 1/16” bigger than the pin, that will translate to a few inches of movement at the outside of the car body.

Storage

Being able to easily break the rotisserie down for storage is a definite plus in my opinion. Some models do this better than others. The only thing I would watch out for is that the design of the rotisserie doesn’t suffer for the ability to be broken down easily. In other words, if some of the parts that should be welded are bolted instead, just for storage, I would look for a different design.

One manufacturer has stated that the main frame of their rotisserie is bolted together for easy storage. I can’t really say that this is wrong or weak, but I have always liked welding parts as important as that.

Casters/tires

Here is an option that completely depends on the surface you will be working on. There are no right or wrong opinions about what you need for casters or tires. The only thing that I will warn against is buying the cheapest tires you can. You need to be sure that the tires will take the weight of the car body as well as the rotisserie.

The most common sizes of tires are 10” and 12”. The most commonly used casters are 6”. If you are absolutely certain that you don’t need to move the rotisserie around, you can probably get by without using anything. Just make sure to factor in the height difference you will be loosing. You would hate to mount your car on the rotisserie only to find out that it hits the floor when you try to spin it.

Center connect

A center connect is simply the tubes that run between the 2 halves of the rotisserie end frames. This is an important feature to have since it will keep the end frames connected by more than just your car. Without the center connect, your car body will be the only thing holding the rotisserie halves together. There is also the risk of the end frames wanting to tip over if your car is rather heavy or the body mount brackets are too long.

Some manufacturers offer rotisserie models that don’t include the center connect for a cheaper price. Just beware of what you are doing if you don’t have this installed. I feel it is important to use the center connect just for the added insurance.

Body stiffener

A body stiffener is a tube or pipe that connects the 2 halves of the rotisserie end frames together over the top or through the windshield and back window of the car body. I can see the theory behind this, but have never built one or thought that it was that necessary. My feeling is, if the car can’t support itself somewhat, you should do a frame on restoration or use a false frame.

Pivot point bearings

There is no question that using bearings as a pivot point would make it much easier to spin a car body. A pipe inside of another pipe adds much more friction than bearings would. There are 2 schools of thought on this subject. If you decide to go with bearings, you will definitely need some sort of a latch mechanism to stop the car from spinning. If you use the bearings, you just added quite a bit more cost to the project.

I have never had any trouble spinning a balanced car using a pipe pivot point. The amount of leverage you have at the outsides of the car far outweigh the added friction you get from using pipe. Using bearings seems like a bit of overkill for a problem that doesn’t exist. Bearings are used on parts that need to spin many revolutions over the life of the part. How many times are you expecting to spin the rotisserie over the course of your restoration? Even if you were going to spin the rotisserie 2,000 times, it still wouldn’t even come close to wearing out pipe.

Mounting arm length

Having too short or too long of mounting arms offers up a different set of problems. Too short makes it hard to get between the rotisserie and the car body to do your work on the front or the back. Too long will make the end frames want to tip forward increasing the stress on both the rotisserie and the car body. I’m a big fan of making the mounting arms adjustable to find that happy medium for any car.

Endless amount of accessories

There is no shortage of accessories to go along with a rotisserie. Some companies will lead you to believe you will need everything under the sun in order to work on your car. This is something that you will need to decide on your own since every car is different. Just be aware of the added costs these accessories will add up to if you are going to buy a rotisserie.

 

 

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Body lift and roller plans building notes.

May 16, 2009 by

These are the notes that come with the plans.

These building notes are put together as guidelines and are placed in no particular order of importance. I would suggest reading through them before starting the project. I would also recommend reading through the instruction manual as well. That will give you a better idea of the project and how it works as an end result.

The body lift & roller is made up of 8 different main parts and many different pieces to make up the main parts. The main part names are as follows: Legs, Main beams, Cross braces, Hoops, Hoop connectors, Hoop hook up, Body mount bracket, And Body mount. I have made drawings of all the individual parts as well as the main parts.

All nuts should be welded on at least 3 sides and that is if you are a good welder, if not they should be welded all the way around. It has been my experience that using smaller nuts not only dents the tube you are pressing against but over many uses of the rotisserie the nuts can become stripped out. Not to mention more warping during welding making them hard to use. A quick tip is after welding the nuts, run a tap through the threads after it cools down. This will make life a lot easier for using the unit in the future. Also, unless otherwise stated in the drawings, all nuts to be welded are 1/2”. Most of the parts have both through holes and pinch bolts to hold everything together. The through bolts are for safety and the pinch bolts are for taking the slop out of the mating parts. It is strongly recommended to use both.

The caster plates are a for a standard 6” caster. If you are going to use a different size I would recommend getting the caster first and making the plates to fit your casters.

The .188” thickness is a standard tube size that not only makes the body lift heavy duty but also makes all the tubes slide inside one another quite nicely. I wouldn’t use lighter tube because of strength reasons as well as the amount of slop in between mating parts.

You will notice in the prints that I call out some weird hole sizes. I drill all my holes 1/32” bigger than the bolt I use to make life easier down the road. There is nothing wrong with making the holes exact size or 1/16” bigger. It all depends on what drill bits you already have. If I call for a .813” hole and you only have a 3/4” bit by all means use it instead of going out and buying a new bit. If you have a 7/8” bit, use it, you get the idea. If I call for a through hole that means all the way through the other side of the tube.

You will notice on some of the 4 view drawings that some of the views are out of proportion  with the others. This is for clarity and to give you the biggest view possible for standard paper from your printer. Please note that drawings are not to scale, so don’t measure off the drawings. there is enough information on each part to build each part. If you have any problems figuring something out, just look at another print that has that part on it or a picture view. This body lift & roller was drawn with common sense in mind, it is not rocket science. If there is something really important I made a note of it on the drawing or building notes page, otherwise it is no big deal.

You will see on the leg internal parts drawings that I use a couple of 3/4” brass flat washers

per leg. This is to reduce friction from the nut turning against the top cap. I used to build the legs without them but I found using them really helps make lifting the unit up and down a lot easier. I would have used plastic washers but they will melt due to the heat from welding the nut on top and the steel flat washer underneath. Also it is a good idea not to sandwich all the washers too tightly against each other. Give them some clearance so everything will work smoothly after welding.

The hoops that are dimensioned on the prints will have an end result diameter of 8’4” tall. It all depends on how long the hoop sections and hoop section splice ends are. Here is the formula for figuring out what size you need with your garage ceiling clearance in mind.

Hoop section = 25” and hoop section splice end = 12.5” an end result of 8’ 4” diameter will occur.

(this is the way the prints were dimensioned)

Hoop section = 23” and hoop section splice end = 11.5” an end result of 7’ 6” diameter will occur.

Hoop section = 21” and hoop section splice end = 10.5” an end result of 7’ diameter will occur.

I hope this isn’t too confusing. The bottom line is: the smaller the hoop parts, the smaller the end diameter will be. The reason I went with 8’4” diameter for the plans is that you will never find a car too big to fit nicely in that size hoop. Conversely, I wouldn’t make my hoops any smaller than 7’ diameter or you will be pretty cramped even with the smallest cars.

You will notice on the plans for the legs I use 3/4” ACME threaded rod and nuts for the telescoping. This is a little harder to come by than regular threaded rod but I’ve tried the regular stuff and I ended up pulling my hair out trying to get it to work properly. Believe me there is a reason that machines with moving parts all use acme thread (lathes, milling machines) they can travel over and over again and the threads still work. Depending on how big of a town you live in you might have to order it. Just search for acme threaded rod on google to find a place to get it. I used to get mine from Williams Steel & Hardware in Minneapolis, MN. Most larger hardware stores will have it or at least order it for you.

In all of my pictures you will notice that the hoops were made of pipe instead of square tubing. This is because I used to build many of these things and it was a real time saver to have pipe rolled to the diameter I wanted and just cut it into quarter sections. Because of the expense in paying someone to roll your hoops, I chose to show it in sections of square tubing that can be welded together. If you have the equipment and/or the ability to roll pipe or tube that would be just fine, but I felt that most people wouldn’t even bother. I know I wouldn’t if I was only going to build one. The only reason I went with pipe instead of square tube was that, the cheapest company to do it could only roll pipe. The concept is the same no matter what material you use.

Let’s talk a minute about the fact that I did not dimension any hoop hook up procedures. All the parts needed are dimensioned. There are way too many variables involved for me to give hard dimensions on the hoop hook up procedure. The fact that I don’t know your garage ceiling height, your car width, not to mention that if all of the hoop sections got cut even 1/4” shorter or longer will drastically change the over all dimensions, is why I did not dimension the procedure. If I did, someone would build all the parts without reading these building notes and then realize that it won’t work. It is a very simple process and it goes as follows:

Once the body lift is built and put together, raise the legs about 6” higher than their lowest position. (Make sure you have the casters installed). Also make sure the body lift is put together at least 7’ wide. (Around 7’ seems to be the best). Next, install the hoop hook up tube to the main beam short tubes sticking out. Then put the fully assembled hoop in front of the lift like the print shows on the hoop hook up instructions page (the hoop should be touching the ground). Once both sides of the hoop is touching the hoop hook up tubes you will want to tack weld them to the hoop. (Tack them in a couple spots so they won’t break off when you remove the hoop from the main beams). Once that is done you can put the hoops on a bench for welding and installing the gusset plate. You now know that once the car is on the body lift and you go to install the hoops, the legs will be able to be lowered all the way, so the hoop is on the ground, and the legs can be taken off. I hope this wasn’t too confusing. You might want to read this again due to my lack of writing ability. I won’t leave you high and dry, so here is my cell phone # Matt Kline  I hope you won’t need to call, but just in case, there it is. You can also contact me anytime from my website www.redwingsteelworks.com or .org. Another good reference for this is all the pictures on my website and the instruction manual.

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Auto rotisserie plans building notes.

May 16, 2009 by

These are the notes that come with the plans.

I have built and used many different auto rotisseries. The exact replica of this one is among the best and cheapest to make. This is a “no frills” rotisserie, after all the trial and error building different features these seem to be the best.

The rotisserie is made up of 7 different main parts and many different pieces to make up the main parts. The main part names are as follows: End frame, Hanger bracket, Pivot point, Pivot arm, Mounting arms, Body mount bracket, And Body mount. I have made drawings of all the individual parts as well as the main parts.

All .75” nuts should be welded on at least 3 sides and that is if you are a good welder, if not they should be welded all the way around. It has been my experience that using smaller nuts not only dents the tube you are pressing against but over many uses of the rotisserie the nuts can become stripped out. Not to mention more warping during welding making them hard to use.

Many of the parts are designed with ease and usability in mind. For instance The body mounts and body mount brackets are optional. If you don’t think you need them for easy hook up for your car then don’t build them. Just drill the hole in the end of the mounting arms that I call out in the part drawings. The caster plates are obviously optional and only needed if you want to be able to move the rotisserie around. The caster plates are a for a standard 6” caster. If you are going to use a different size I would recommend getting the caster first and making the plates to fit your casters.

The gusset plates are more for added welding surface than they are for structural integrity (except for the pivot point gusset plate, it is for both reasons). If you want to make the gusset plates bigger that is fine, but I wouldn’t make them any smaller.

The space between the hanger bracket and the end frame is enough in case you wish to add a hydraulic jack to raise and lower the pivot point up and down the end frame vertical tube.

The .188” thickness is a standard tube size that not only makes the rotisserie heavy duty but also makes all the tubes slide inside one another quite nicely. I wouldn’t use lighter tube because of strength reasons as well as the amount of slop in between mating parts.

You will notice in the prints that I call out some weird hole sizes. I drill all my holes 1/32” bigger than the bolt I use to make life easier down the road. There is nothing wrong with making the holes exact size or 1/16” bigger. It all depends on what drill bits you already have. If I call for a .813” hole and you only have a 3/4” bit by all means use it instead of going out and buying a new bit. If you have a 7/8” bit, use it, you get the idea. If I call for a through hole that means all the way through the other side of the tube.

You will notice on some of the 4 view drawings that some of the views are out of proportion  with the others. This is for clarity and to give you the biggest view possible for standard paper from your printer. Please note that drawings are not to scale, so don’t measure off the drawings. there is enough information on each part to build each part. If you have any problems figuring something out, just look at another print that has that part on it or a picture view. This rotisserie was drawn with common sense in mind, it is not rocket science. If there is something really important I made a note of it on the drawing or building notes page, otherwise it is no big deal.

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