Since the start of this website, I have received a lot of interest in the rotisserie I used and how I rolled my Morris Minor. To address all this correspondence I have created this page with information and tips on how to put your Minor on a rotisserie.
The obvious but it has to be said... I hold no responsibility to what happens to you or your car whilst you follow instructions given on this site. The rotisserie worked for me but it may not work for you. All responsibility to what you do to your car in your own time is yours. Be in on your own head (or not).
On the preliminary examination of my Morris Minor it was noticed that the car required two new chassis legs. The current ones were badly corroded and had split along previous repairs. There are car rollers on the market that fit onto the hubs of cars and with the use of leavers flip the car onto its side. Due to this type of roller fitting on the hubs it would make the chassis repair difficult and the car itself may even collapse as it rolls.
Another consideration was the space we had available to work on the car. With the rotisserie it's possible to roll the car within its own footprint as with other body rollers the car rolls into space next to its footprint.
After a trawl of the web it was decided that Matthew Harwoord's plans for a rotisserie were ideal. These can be downloaded from the Autobody101 website.
It is also worth checking out Matthew's own site Hardwood Performance, here he gives a plan of the rotisserie with measurements.
We fabricated the rotisserie exactly using the plans provided on the Autobody101 website without any modifications.
To put the Minor on to the rotisserie some calculations need to be done. The ideal situation is to mount the car so that the pivots are in the centre of the vehicle. By doing this the car can spin with ease all the way round. If the weight is displaced too low or too high then the car will need a greater effort to turn and will probably need to be swung backwards and forwards to build up motion for the roll. As the pivots are fixed, the mountings to the back and front of the car can be at a different height as long as the car is raised evenly to an overall height.
In order to work out the best height to mount the car some maths needs to be done. First we need to work out the overall space the car will occupy as it spins. The diagram explains this best; it allows us to factor in the clearance needed to roll the whole car around.
To work out the rolling area and therefore where to pivot the car we need to find the height and width of the vehicle. This can be made into a square by picking the larger of the figures.
For example, my Minor was 153cm wide by 147cm high. For the square I take largest number, which is the width of 153cm.
Using Pythagoras' theorem of "A² + B² = C²" we can work out
the diameter of our circle of spin. For my Minor the calculation is:
153²cm + 153²cm =
23409 + 23409 = 46818
Then we find the square root which is:
√46818 = 216.37cm
We now know that the car will spin within a circle of the diameter 217cm.
By using the figure 217cm (the diameter of the circle of spin) we can divide
by two to get the distance to the pivot point.
217cm ÷ 2 = 108.5cm
We now need to take into consideration that our swing area is above the foot
and steady arm of the rotisserie so we add on the height of this metal to the
ground.
108.5cm + 15cm = 123.5cm
We now know that we need to get the centre of the car to be 123.5cm high for it to spin with ease.
Due to the design of the rotisserie it is only possible to spin a car all the way round with a swing circle of diameter 192cm. Therefore our car with swing circle area of 217cm is too big. It would still spin but it may not roll all the way round.
However, I can see no need for the car to be able to spin a whole 360°. If the car can rotate 90° left and 90° right then repairs to the underneath can be made. It is important that the car is mounted high enough to allow this turn without hitting the ground so the correct mounting height is crucial.
Due to the car needing a lot of welding, I decided to strip my Minor thoroughly. This meant that there was very little to catch fire and also meant that the car was light and easy to mount and roll. I guess it is possible to mount and roll a complete car but you would have to take into consideration the extra weight being spun. Also all openings where liquids could escape would need to be blocked.
Due to Matthew Harwood's rotisserie being fully adjustable it was easy to put mountings to any part of the car. I would recommend using a structural and strong place to mount the car to the rotisserie. At the rear of the car we put a beam of steel across the end chassis seams and sandwiched these with another plate of metal on top.
Due to the nature of our repair I did not want the front chassis legs blocked or being used. We decided to fabricate pads and fit the front of the rotisserie to the suspension damper mountings using the threaded plates already fixed to the car.
By the time it came to us putting the car on the rotisserie I had already decided that the project was not worth continuing so we just used the shell to test our metal and did not mount it accurately. However, I will explain how to use your previous calculations to help.
First, the centre of the car needs to be found. For example:
153cm wide =
153 ÷ 2 =
76cm from the side
147cm high =
147 ÷ 2 =
73.5cm from the ground
This needs to meet the pivot on the rotisserie, which is 106cm off the
ground. The car therefore needs to be raised 32.5cm.
106 - 73.5 = 32.5cm
last updated Thursday 10th June 2010