Rotisserie design

Steve (69 Cat);
Some time ago Steve asked about my rotisserie design and the attach points. He recently asked about my bracing also.
I will say that I did not use any bracing as I did not think I needed to as my car had ‘just a little’ rust, the sills were solid and just the front floors were replaced, one at a time and only the front half. The rear half was solid. I could be faulted for the piecemeal job but that seemed to be workable at the time and it came out ok.
Others may have opinions as to the need for bracing, chime in if you desire.
Here are some other photos of the rear and front attach mounts for my car. I will add that I used the rotisserie on my MGB GT first so some of the metal seen is for the MGB and not the Jag. Hope it is not too confusing.
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This is the rear mount as I am building it. The IRS attach points are used (1/4" plate) and the square tubing is thick walled 1 1/4" I believe.
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This shows the mount extending to the rotisserie pivot. There is a stabilizing plate from the rear of the car (license area) to the mount.
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This is the rear rotisserie mount, the stabilizing plat has been removed. It was bolted to the car and mount.4-Floor%20replacement%2070%20Jag%20008
This shows the front mount attached where the central frame rails attach, top and bottom, and the ‘extra’ metal is placed for stabilization. I agree it is not a thing of beauty.

Steve I hope this answers some of your questions, if you have others let me know.

Regards, Joel.

These are fantastic. Hopefully more will chime in with photos of their design. I still have yet to see a photo of the rear license plate stabilizing connection for a series 2.

One of the questions I have as I contemplate the replacement of the sills/floor pans is how to check/maintain/adjust the accuracy of the car. It appears to be fine, but from what I have determined the critical points in the design are the dimensions of the IRS mounts to the front frame lower mount plates, the dimensions of the lower and upper front frame mounting plates, and the symmetry of the car from left to right.

It seems like these critical dimensions would need to be set on a flat surface and not on the rotisserie.

Here’s on old photo of the rear mount I fabricated. It’s basically two pieces. The first is a bird cage structure that bolts around the perimeter of the boot board ledge. The second piece is a hoop with one flat plate bolting to the bird cage, and another flat plate bolting to the pivot on an engine stand. The two plates are joined (welded) to a thick walled length of box steel. That hoop goes up and over the rear edge of the boot door opening and offset enough that all exterior sheet metal is accessible…including the boot floor and the IRS mounting structure. The boot floor ledge is plenty stiff to carry the load…much safer than the rear license plate panel. I might be able to find more detailed photos if there’s an interest. By the way tub is suspended over the catch basis I constructed to recycle a continuous flow of Evaporust over the sheet metal (second photo).

rust3

Steve;
I found a few more pictures. There are a couple of the rear stabilization plate that is bolted to the rear (license area) of the car.6-Soda%20blasting%2070%20Jag%20010
This shows a view of the front mounting.
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This is the car being soda blasted, the stabilization plate is there but not easily seen.
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This photo show2-Soda%20blasting%2070%20Jag%20004 s the stabilization plate better. There is a ‘doubler’ plate inside of the car.
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Applying ‘Metal Prep’ after the soda blasting and washing residue off the car.

Regards, Joel.

I started out with license plate and front frame attachment points, but found way too mich flex in the body and was pretty scared of removing sills and floors with that arrangement. So I rebult mine using a jig which doubles as a cart when it comes off the rotisserie. The jig is structurally solid so it was easier to keep things level and straight

The rear mount attaches at the suspension mounts

and the front on the top of the tunnel. I did this so I could mount the front frames while on the rotisserie since I needed to replace the x-panels in the footwell and the frame mounts on the bulkhead and sill and therefore needed all the frame attachment points free. It also has the advantage of being able to mount the bonnet and get everything absolutely lined up.

This is the bracing I used.

This whole setup was extremely solid.

John North
S1 Roadster
S2 Coupe

John, VERY impressive!

John;
Very solid set up. You put a lot of thought into it and I am sure it worked well.

Regards, Joel.

If it were me this is the proper way to insure a properly supported tub. In my opinion ,and I’ve never done a similar repair, there is too much room for flex by supporting the tub by it’s firewall and “tail”.Chuck at Monocoque went to great lengths to have an industrial set up like this.

Well done John.

As much genius and energy as is put into these, and as many as have been built, I would think there would be quite a collection of them gathering dust and rust. I’ll bet there would be a market for them.

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Sorry to dig up a zombie thread.

Eric, do you have a picture of the structure that you used inside of the car?
For my 2+2, I’m thinking about coming through the rear opening rather than going under the boot.

Thanks, John.

[quote=“64etype, post:3, topic:376189”]
rust3

My thread may be of help. I coblefabricated mine together for zero dollars.

The Harbor freight engine stands should be extended 9" not 8 like I did! The backbone through the car needs to start at a plate inside the car license plate, go up 4" (or so, weld in place) over the IRS hump, then drop down 4" and continue through the bell housing hole to the front stand. Just weld I used old rusty boat trailer square tube. The stands HF engine stands have to be cut and the top swivels leveled. I just cut them and reset them with a 2"(?) round pipe passing through both stands to ensure they were level with each other and pivoted at the same height above the ground. I’ll have to cut the backbone to get it out of the car when done. Also I lied in that first post. It doesn’t quite clear the stand to roll over completely. I’m a 1/2" short. Just make the extensions 9" not 8 like I did!

Here you go. Finally found them in an old laptop. That bird cage around the perimeter of the ledge in the boot was fabricated by simply laying the sections of square tubing on the shelf and tack welding it together. Then removed for final welding. The square tubing is very inexpensive from any steel supplier (it’s steel fence/gate material). The rest is scrap yard steel. I had to drill two holes in the rear boot ledge…the rest are already there. This is an extremely rigid mounting arrangement with zero chance for distorting any of the vehicle structure. Note the short pieces of square tubing that spread the load under the ledge.

Here are some additional photos related to rotisserie and follow-on trollies.

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Well, I got the rotisserie mounts finished this weekend. Thank goodness for a metal band saw, a knee mill and an ESAB welder.

The front mount is .120 2" square tube. I cut the tube down to 1.25" where it slides into the channels in the transmission tunnel.

I puttered around for a few hours trying to figure out the best way to mount the rear of the body without getting too carried away. There have been a lot of really ingenious solutions in the past. I took the rear bumper off and in looking, the mounting framework makes for a really solid attachment point. Once a cross member is attached, it does flex up and down a bit but is solid side to side. There is a mount inside of the boot for the gas tank that I used as well as bolting an angle on the shelf right behind the passenger seat.

Once it was all welded up, I am able to lift the rear by hand and it is very solid. If it prove deficient in any way, I have other places where I can attach supporting brackets.

Edited for picture issues.