Lotus E21 construction report part 11

News on the Engine Manufacturing

This is more a tiny update just to keep the blog rollin. There will be more progress on the car when I’m back to uni finishing my mechanical engineering degree at the beginning of October. So look forward to that time!

As the engine is a fully stressed member of the car it’s very important to get a stiff and reliable connection between the engine and the monocoque as well as the gearbox. These connections I achieve with steel pins of 1.2mm diameter. On the real cars, the regulations dictates six M12 bolts to fix the engine to the monocoque as well as to the gearbox. Regulations around the engine cover bore, distance between cylinder axes, crankshaft height, bank angle, CoG, etc. With a bit of understanding of some engineering subjects and this data, it’s not that difficult to redesigned this engine from paper. It’s actually a bit like reverse engineering.

Monocoque, Radiators, Engine

Current state of the car. At the left hand side of the car, you can see the water cooler and gearbox oil radiator, rh side is the engine oil as well as the KERS radiator. Between the engine and the Monocoque you can see the engine oil tank which catches about four litres of oil.


It’s again and again very impressive, how tiny the V8 engines were. Not to speak from the current downsized V6s. In the Le mans cars, the engines are often equipped with an additional brace as they are too weak to work as a fully stressed member.


Rear upper engine stud. This stud is fully integrated into the engine structure and picks up the upper gearbox mounting point.


Engine manifold. Fuel injection system and air filter will sit in here in a few weeks time.


The water pump at the lh side of the engine. There is another ancillary item going to sit behind the water pump.


The oil pump on the lower rh side of the engine. Beside the oil pump, the hydraulic pump/manifold is placed. It’s not designed yet. The hydraulic system powers throttle, clutch, gearchange, differential, power steering and DRS actuator. The hydraulic linked suspension is a completely independent system.

Paper Dreams – a Story by David Betteridge

Hi Chaps!

A bit belated, but finally this great video, which resulted from the great work of Video Director David Betteridge in cooperation with Siemens and Red Bull Racing, shows my rise from a simple model builder to a proper Formula 1 car designer.

I just want to say a huge thank you to all the people who supported me on my way into Formula 1. Enjoy!

Lotus E21 construction report part 11

Front Wing Design and Manufacturing

A long time passed by since my last blog. Lot of work at the factory, some holiday and other stuff went on. Last week I restarted the work on my Lotus. So, building the Front Wing was great fun as usual and if you compare the result with the RB7 FW two years ago, you can see a huge step in detail work, in manufacturing quality and also in some minor engineering skills.

In general I’m very satisfied with the result of the FW. The surface quality could be a bit better in some places. But that’s more a problem with restricted access as it’s like under the small Front Flaps. The FW-Nose Assembly is with 49g pretty heavy. That’s about 8.5% of the car weight. As you can see on a picture below, the stiffness of the wing is incredible. I did a simple deflection test where the wing resisted over 500g load which would be equivalent to 500kg(!) at the real car. I didn’t measured any deflection of the wing, but the regs are telling you, that the wing should not deflect more than 10mm at a load of 100kgs. Maybe I do a proper deflection test on a rig somewhen. Just for fun (This statement is a bit sensless considering this is my hobby and should be fun all time).

Anyway, except a few dimension overrides conflicting with the front bodywork regulations, I’m pretty pleased with my new Front Wing. I hope the guys from Lotus are too.


Mainplane Inserts

Start of the Front Wing Main Aerofoil. At the top you can see the main insert, which is actually just an offset of the aero surface. The tube in the middle is a paper wrapped 1.2mm steel wire (which you usually use to build fences) which gives the Main Aerofoil the needed bending stiffness around the X-Axis. The front insert is the connection between wing and Nose Pylons. This design secures, that the flexibility between the nose and the wing is reduced to a minimum, which was a huge problem on my RB7 where the connection was very groggy…

Mainplane Inserts bonded in

Here you can see the bonded in inserts in the FIA section of the Main Aerofoil. There are more inserts to come outside of the 500mm FIA middle section. The secondary flap on the Main Aerofoil, which is behind the forward aerofoil profile is later also reinforced with a steel wire. For this, I had to provide two additional circular holes in the rearward inserts.


The Front Wing End Plates (FWEP) at the start stage. There are two inserts in it. You can see both of them in the endplate at the top of the picture. These inserts should secure, that the FWEPs have nice sharp trailing edges as well as nicely rounded leading edges all over the part.

Mainplane underside

From the laminate point of view, the front wing Main Aerofoil is probably the most impressive element on a F1 car. As you can see in this pic, and believe me, I did the laminate exactly like it is at the real car, the layup is pretty complex. That’s alyways a nice exercise for the stress guys.

1st Flap

The first flap is bonded to the FWEP. This flaps are a little bit too long in terms of regulations (something around 1mm), so they protrude into the 500mm middle section – looks like Lotus is cheating (I can’t be wrong, can I?). :p

Front Wing Front Flap

These small flaps are good fun to do. Very simple shapes, but they are looking pretty nice. These flaps are also varying a very lot from team to team. The Lotus ones have already nothing to do with the RB ones.

Flap Adjuster

Here you can see the flap adjuster where you can quickly adjust the wing in the box or even during a pit stop. Beside the DRS flap, this is the simplest thing on the car to change aero balance.

Flap Hanger

The outboard flap hanger which secures, that the slot gap between the single flaps stays almost constant. On this pic, you can also see the gurneys pretty good. Design gurneys for a real car isn’t very exciting and it’s pretty much shit when you have to do it in 1:10 scale. But if you’re designing a wing, it happens that you also have to design the gurneys.

Bonded Assembly Underside

The underside of the full assembly. Notice the very funky swept inboard strakes. Also noticeable is the trailing edge of the FWEP which ends up being 90° to the X-Axis.

FW deflection Test

The front wing deflection test. The wing wasn’t even bonded to the nose that time. As stated above, I haven’t measured the deflection. But more than 500g load, which is equal to about 0.33Nm at the pylon mounting point, is pretty impressive for a paperwing. Next evolution of Boeing and Airbus will the the invention of cardboard wing flaps. ;)


A look inside of the nose. The Nose Pins are pretty long. I will probably shorten them when the car is finished.

Top Front

A Top front view onto the outer Front Wing. It’s just a masterpiece of aerodynamic art. As I’m no aerodynamicist, I’m always impressed about the creativity of the F1 aero engineers.

Top Rear

Top rear view onto the outer Front Wing.


A few years ago, the Front Wing End Plates were just sipmle flat plates which only had to close off the wing. It’s obvious and visible that that’s not the only task for them nowadays.


The underside of the outer Front Wing. At the outer few mm you can see the glass fibre which is required by the regulations. At the very front outer edge you can also see a skid block, probably from Ti, to safe the wing from damage caused by grounding.


Nose assembled to the chassis.

Front Wing in front of the Monocoque and the engine block.

Front Wing in front of the Monocoque and the engine block.

That was pretty much it. There are still 2 layers of lacquer missing, which will be done during engine manufacturing. Now I already revealed what's up next. Yeah, It's the Renault engine.

That was pretty much it. There are still 2 layers of lacquer missing, which will be done during engine manufacturing. Now I already revealed what’s up next. Yeah, It’s the Renault engine.

Lotus E21 construction report part 10

Engine Manufacturing and Nosecone

Over the last few weeks I was working a bit on the engine and finished off the nosecone. Of course, all beside RB10 troubleshooting.

The nosecone was actually not planned to build that early, but some circumstances forced me to build the nosecone now. This circumstances are some kind of a “secret project” which I’ll show you in a few weeks. Target date is first week of April. Wait and see…

Engine: Front wall of the engine block is almost finished. Mounting points to the chassis are all done and looking very stiff. Not much to tell about the engine any more. Apart from the to expect ultra high grade of detail.

The nose is also a huge improvement compared to the RB7 one. The laminate thickness is much more realistic (not that fat as it is at my RB7). However, the nose is very stiff and the nosepins are very rigid. The front wing pylons were also a bit of a weak spot at the RB7. On this nose, I reinforced the pylons with a steel wire each side and provided another tube for picking up the FW mountings. The shape of this nose was highly complex. Especially the bulge under the nosetip and the step were very difficult to get properly done. But everything worked out quite well without any big problems. The nose is probably a bit lower than the original, but at least it’s within the regulations.

Lotus E21

Current state of the RS27 engine. I got a bit of heat damage at the lh side of the engine front. It can happen that I leave it like this to show a few signs of wear.

Lotus E21

The first attempt to attach the engine to the chassis was highly successful. The stiffness of the assemblage is astonishing. The tech regulations require 6 M10 bolts to fix the engine to the chassis. In my case the engine is fixed by six steel pins.

Lotus E21

Nose cone drawing. Loads of regulation lines to start. You can clearly see the bulge under the nosetip which wasn’t there every race. Means, Lotus had at least two nose specifications over 2013. I did not made a lot of research in that direction. As I know that I’ll build the Belgian specification there is no need to know how many different noses they used over the season.

Lotus E21

Structural nose part. Here you can see the crashbox and at the left there is the jig to bond in the nosepins.

Lotus E21

Bonding process of the nosepins. That’s always one of the most critical points of the build (as the nose should be removable). But everything went quite well to my full staisfaction.

Lotus E21

Templates for the black coating of the nose. From left to right: The sides and the lower part are one part (bulge included). Top cover is in the middle. The cutting edge was designed to be covered by the nice gold stripe. The strange looking part on the very right hand side is a front wing pylon.

Lotus E21

First attempt to fit the nose.

Lotus E21

Here you can see the internals of the pylons. The rear tube is the structural beam, the front tubes are the pick up points for the front wing.

Lotus E21

Logo fitting…

Lotus E21

I’m getting better and better doing the paint jobs. The surface of the nose is almost perfect. A few small tweaks to be done, but in general it’s a great finsih.

Lotus E21

Nothing to say about this…

Lotus E21

Chassis: E21-03; Cockpit badge

Lotus E21 construction report part 9

Chassis finishing off

As reported in the last post, the chassis was in the paint process over the last few days. This car is the first one, where I created a really planed paint process. There were four steps:

  • 1st Step, paint preparation: Sanding every single surface of the car and especially cutting edges up to 1500 sand paper. After sanding, all sponsor labels were added as quick as possible to avoid damage or whitening. Quick clean of the main surfaces to get rid of big dust particles or similar contamination.
  • 2nd Step, prime coat: Tape all surfaces that need no highly polished surfaces (means monocoque inside, chassis sides behind side pod intake). Applying first coat of clear lacquer immediately after finishing with the first step. Applying 9 layers at all. Waiting at least half an hour between applying next layer.
  • 3rd Step, main coat: Add all missing non highly polished surfaces to the chassis (monocoque underside, front bulkhead, radiator ducts,…). Applying additional five coats of clear lacquer and drying it on a radiator. Waiting at least one hour between every single coat.
  • 4th Step, subsequent improvement: Inspect painted surfaces and apply another few spray dots to faces where no polished finish yet.

And the result of this process is astonishing! I never got such a nice surface quality and highly polished finish of the car. I will apply this process from now on at every car with probably a few improvements.

After the paint process it’s obviousely very critical to work on the car (avoiding surface containment). When I’m working on a specific area on the car, I have to cover the surrounding surfaces with some tape stripes. What I also detected during working on the car shortly before the paint process is, that the monocoque is fucking extremely stiff and rigid. I was hardly struggling to get the holes for mirror assembly and nose pins done. With a hammer and a scriber and nail I was working for several minutes to get this four holes onto the car. That means, that the implementation of my thoughts about how to get the chassis stiffer and not significantely heavier has taken full effect. I guess I was never so satisfied with a chassis as I am at the mo. Although there could be some minor improvements, but that can wait till the next car.

During the paint process, which contains a lot of waiting (which I partly bridged by drinking beer), I also started the manufacturing of the engine. The manufacturing of the engine block is one of the most annoying parts of the car. Machined metal parts, the most time consuming work in paper modelling. It’s a pain in the ass!


The chassis shortly before the paint process. All surfaces were treated to 1500 sand paper. Few sponsor logos and rear mirrors missing.


Within the paint process. Immediately after applying the lacquer, the car always looks perfect, but after drying you’re back in reality… It takes an awful lot amount of time to get a proper paint job done.


Prime coat: Nine layers of lacquer results in this milky look. But the surface is already wonderfull. All edges are beatuifully blended and smooth. After this, I had to wait for 24 hrs plus, to rework the car before applying the final main coat.


One part of the car rework was f.e. the fit of the rad ducts. As you can see, I taped off the surrounding surfaces to avoid contamination of the nice surface.


This is also the first car, where I really planed a fastening system for the whole bodywork panels. And I hope it will work. It’s kind of the same system as it’s on real F1 cars. Here you can see the fit of one fastener…


“Machining” the holes for the nose pins. I would say, in combination of glue and my treatment of the paper, this components are much harder than some plastics or woods…


First pic after finishing the 3rd paint step.


Finished chassis with (non painted) heatshield.


Current state of the car with half finished radiators and in production progress being engine block.


Front bulkhead.

Here are just some pictures to show you the incredible surface finish of the car:


The Kimi logo is the only one I did by hand. There was no suitable Kimi logo available on the net.


I think in this pic, you can clearly see the really incredible finish of the chassis. Hopefully all parts of the car will get like this.


Lotus! It would be interessting to know, if I already caught Lotus’ attention with my work as it was at the RB7 and the Audi R18 TDI.


The thing I was most worried about were the side pods. Especially this extension (with the burn on it) which are housing the side impact structures. But with my now developed paint process, it got awsome…

Best wishes,


Lotus E21 construction report part 8

Chassis ready for Paint Shop

Just a short, but reasonable update. Chassis is now finished for 1st stage painting! During paint process I’ll start off with the engine.


Last minutes before the chassis goes to the paint shop!

Lotus E21 construction report part 7

Side Pod and Airbox Manufacturing

Nice progress in the past few weeks. After bonding together the two halfs of the monocoque I immediately started designing the side pods. Always one of the most challenging things. The shape of a modern F1 side pod is such a masterpiece this days that it’s really hard to model it from paper. As the proper pods surface is bent in two directions and paper is basically not drapable and just able to be bent in one direction, I had to simplify the shape to a developable, just in one direction bent surface. It actually worked out well with the usual problems at this stage.

Second big point of progess is the airbox. The E21’s airbox is the most car typical airbox since the Merc 2010/11 fin style airbox. The two PDRS (Passive Drag Reduction System) floppy ears were a bit of a pain to do and the right hand one did not got perfect, but it’s acceptable. This is also my very first airbox, I did with full details like roll hoop inside, profiled leading edge and so on. The car will propably get a bit too high (it’s already very close to the 950mm limit). I will propably measure it at RBT with a more adequate measuring tool than a set square.

Another huge improvement is the surface finishing of the car by sanding every single surface up to 1500 sand paper. This will help strongly during the paint process. The paint process itself will be 2 stepped. With a first stage lacquering of all the painted (means red’n’black surface with the sponsor labels on it) surface by approximately 7 or 8 layers and second stage will be with all aditional features like bodywork fixing flange, carbon fibre texture, etc.

Quick forecast over the next weeks. On 28th of Jan, RB10 will be launched. Hope it’s as good as the 9 end season car. :) I expect finishing off the whole stuff on the monocoque next weekend to get started 1st stage lacquering the car. And starting parallel with the engine, which shouldn’t be that a big challenge as I have already built the same one for the RB7 and have seen the engine in flesh now for many (very many) times – but didn’t took any drawings, sketches, dimensions or anything else with me. Just the stuff which I was able to memorize in my head.


The 5 stages of the side pod shape. Top left was the initially calculated shape. The next ones are all refined shapes by using my side pod jig to evaluate the perfect shape. Was a very challenging task, but I brought it to a very satisfying level.


My side pod jigs. The left hand one is for evaluating the best shape and the right hand one is/was the bond on jig for forcing the pod into the right shape during bonding on the car.


Side pod during bonding process. There were a few stages to get it finished. I also applied a glue film on the inside of the pod to give it a bit more stiffness.


First airbox test. Height check and so on. The fairing between the air inlet and the monocoque went thru the same process as the side pods.


Airbox with seperated roll hoop. I guess, what means that  I don’t know, that Lotus is using a carbon roll hoop. Even if I know that f.e. STR or FI are using Aluminium ones.


Bonded in roll hoop. It was a bit difficult in the end to get access to the (later bonded on)PDRS inlets.


Moulding of the PDRS inlet. The negative mould tool is from full cardboard and sanded into right shape.


Chassis at it’s current stage. As you can see, the first sponsor logos are already fitted. Airbox is bonded on and looking quite good.


Rear view of the car. The internal ducting of the airbox will be a bit challenging. But that’s nothing to worry about this time. That’s the problem of March or so.


Rear end of the monocoque. It’s looking really good now. I’m very satisfied with most of my work. Note the nice louvres beside the impact structure beside the drivers head. They are there for helping ventilation of the engine/radiator bay.


The nice vanes and winglets on top of the side pod. Note the nice moulded top edge of the vanes. They are sanded up to 1500 sand paper to a almost perfect shape (rounded edges, ball shaped front corners).


One of the few differences between the real car and my model (apart from the size) is my logo. There are two reasons for it: I decided to label now all my cars with at least one of my logos. Second reason, almost more important, I can hide the cutting edge between the side pod and the actual (structural) chassis. Nice turn I would say.


And a bit of fun at the end. It’s not going on so seriously during my car build all time. I might not missunderstood the sense of an airbox, but that’s definitely assembled in the wrong position.


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