Learning the Messerschmitt Jig

Monocoque Jig

ome years ago Russell Church looked at making up new monocoque frames having at the time a KR200 in bits with a rotted out frame. Being Russell this expanded into the construction of a jig to ensure the frame would be identical to original and I became involved by the loan and supply of various test bits. Another jig featuring a ram to bend the monocoque tubing to the correct shape joined the main jig. The side tube is not as you would expect a perfect curve but actually a straight bit, curve and then a straight bit.The side tube is not as you would expect a perfect curve but actually a straight bit, curve and then a straight bit. Then a further jig was required to put in the bend to horizontal where the box section fitted on down to the pedal mounts. The pedal mount itself required a tool to be created and tested in a press to get the required finished shape replicating the original. This done the formed cut frames could be put in the large jig to be welded together with a box section/crossmember.

The crossmember had previously been made up, as it is mainly flat sheet cut out and in its raw state a pretty simple array of parts and cheap to source. Indeed it can be supplied thus but is not that simple to assemble loose. Once again Russell produced a set of jigs to aid building the parts up into a finished item. The first for drilling the suspension mounts on the end plates to ensure correct alignment for the suspension, a second to build the drilled crossmember up on using these crucial holes and a third rather satisfying one for flaring the cable tube ends. Thus the crossmember can be offered up as a subassembly onto the main jig and welded onto the frames to produce the basic rigid framework of a 'new' Messerschmitt. This crossmember is available from Partsmart as a stand-alone item and we do not propose to supply any against that item before the question is asked.

The tub jig was cross-referenced with several original monocoques being placed in it and measured. This served to prove that the margin for production error on Messerschmitts is much larger than you might care to know. Taking the mean and square figures the jig was adjusted and then the rotten car's monocoque totally restored on it. One benefit of the jig through this procedure is it automatically places the crossmember at the correct angle in relation to the rest of the frame. It is not as you might expect mounted with its top parallel to the axis of the floor but about 5° up to it. This clearly is crucial to the resultant suspension geometry of the finished car as it dictates the angle of the kingpin to the surface of the road and thus caster, camber and Ackermann position and adjustment — something to bear in mind when looking at a totally restored car not made in a jig; telling if such a car wanders about the road or exhibits odd steering in use. This, Russell's own car, was eventually put together and painted by Mike Cooper and put to the road with Colin Archer's help and is a prime, if gently modified, KR200 that Russell still owns, though you might be able to buy it as his home priorities change!

Welding: Kevin the welderThose involved with all this work waited with baited breath for developments. However it seemed that club interest in monocoque production was scant and Russell's attention moved to other challenges; engineering and the associated problem solving is his hobby not his business, and the tooling remained unused. Frustrated, I bought a few tube sets from Oliver Herbolzhiemer and some crossmembers so I was ready to rebuild some of my rougher cars. As panels came available on the open market, with or without cars, I bought them up and stashed them, year on year, as anyone who had seen the spare bedroom would testify.

Come May this year and with 'schmitt projects getting hard to find and a few deals needing to be done I traded several kit 'schmitts to be restored for some cars I wanted. It cleared hard work away from me for easier or more diverse projects. A chum, Jules, also wanted a car to do up too. It was time to take the kits of parts out of store and to turn them into monocoques with the main jig now on a long loan with permission for use for being stored in my annex. This to provide the basis for the project cars swapped in the deals.

From this moment the momentum of the project started to run away with itself. Jules had a friend, Kevin, who is a very good welder who was interested in doing a few tubs in a private deal with Jules. Kevin has no urge to own a 'schmitt himself and interest would wane eventually as money is not his motivator, so quickly it became a requirement to crack on with using the sets of steel in hand while we had a skilled welder interested. So a date was set in the sunny June weather in Faringdon and a tube set put into the jig and away we went. We had to find the way to do the task best and tweak some panels to fit. The job took most of two days to create a measured up finished monocoque from basic and flat panels. At the end it was a deep breath and measure the various diagonals. Bung perfect and better accuracy than the original item alongside used as reference. A well-earned shandy all round.

Bath Rally was on the upcoming weekend so Jules and I decided to take the bare tub down with a rough nose as a discussion point. I loaded up with enough panels for another 5 tubs, as production was moving to the Bath area. Kevin popped in for an hour or so as well as he lives just down the road to the event. Not sure he could see what all the fuss was about but at least he could see the 'end' product driving around. It was very interesting that some folk were immediately hostile to the idea. Critics abounded as expected but the more senior enthusiasts provided more level input and constructive comment as hoped and we took away some clear tweaks that needed to be input plus the advice on some improved tooling.

Though not present at Bath Russell was most supportive after being debriefed on the feedback and immediately made available his intellectual heritage with the rest of the tooling on a loan arrangement as well as the already loaned main jig. Many hours of thought and work went into this assembly of tools and not an insubstantial amount of investment in money in the steel it is constructed from. This tooling will greatly cut back on the preparation work, perhaps to a day each tub to construct by dint of tools unavailable on the first attempt.

Therefore a logistics trip was required to shift the tools to Bath. During this shuffle and having partially bought into stock to do a production run himself some five years ago Russell had tubing for further sets of frames of steel tubes stored. It was agreed we buy up this material clearing his garage a bit and releasing his dead funds tied up in that stalled project giving us the capability to do a few more monocoques. This will also see all the effort put into creating the tooling at last pay a dividend. This will deplete the stash of panels I had created so quite how far we can get on with finished units is dependant on panel availability. Hopefully as this is an independent initiative there should not be a problem but if the interest and take up of the project is such that there is a supply problem it may be necessary to initiate a new source of reproduction panels. That is in the future though and I am sure a solution can be sorted out; buyers obtaining their own panels for instance. The fact remains that eleven monocoques are spoken for already and several more look like they might be taken up. There are therefore only a few left unsold of those in hand despite the project barely going live as I write this.

Interestingly, on showing the monocoque off there was immediate comparison made to the old Tri-Tech monocoques made for Partsmart over a decade ago. So those hopeful of a £750 tub were immediately disappointed. Interestingly I was told a skilled 'schmitter occasionally can be persuaded to replace a floor and sides on an original tub for £600 these days for comparison to that price. Pricing the project up correctly with all costs on the spreadsheet the horrifying fact is inflation and Government induced costs have seen just the purchase of all the steel panels and materials rise to over £1,000 taking into account some published prices are very incorrect! Then there is the use of the jigs and a skilled welder to pay for on top so creating a tub that is actually accurately made to the correct shape without any birdshit welds proudly displayed on the incorrect butt jointed crossmember of the prior £750 offering.

This is a proper item that the Tri-Tech ones never wereThis is a proper item that the Tri-Tech ones never were, being as they were one-off manufactured units made down to a price offered for the stock. You get what you pay for and I like many others wanted nothing to do with the Tri-Tech stock which is why Partsmart got stuck with them and were, perhaps, then frightened to then get involved with the new version made in the correctly researched way by Russell. There is more to ordering spares than price and one element is confidence to be bold which a poor experience can influence even if that decision was based on an error itself. The very reason to have a group that includes successful entrepreneurs, engineers and an accountant type to manage an efficient large spares service without any deadweights applying leverage to buy the wrong things as this skill based grouping balances out risk, quality and need. We private monocoquers do not have this luxury so we are underwriting the project with our own money and taking a risk.

So the ex works price is reluctantly set at a high sounding but very competitive £1,750. Those wanting cheaper options or inferior products can look elsewhere.