[Tamar]

Hello mr Bourne

I sure did, check the next episodes, two of them so you can do bit of binge watching 

Regards
T

[Tamar]

Crash test Dummies, post test analisys
So those who watched the videos will have noticed that the first time I ran into the Nissan.... I chickened out.
As we checked the videos I noticed the head lights going out just before I hit the Nissan. 
Ok I had spent countless hours on getting the M8 test car "just right", the spirit was strong but the body was weak..
At the last moment... my finger had come off the throttle.
Still a pretty good hit, but with no damage to the M8...I had to do it again, no place for the faint hearted.
In the 2nd test I did keep the pedal down (trigger pressed) and hit the Nissan at high speed and with full force, a clear hit..
...with a damaged nose, a split splitter and paint chips flying off. (just love that slow-mo)


 
Directly after the crash I did some damage assesment. Frontsplitter itself had remained intact (carbon/kevlar laminated) but bend downwards with such a force that it tore the kevlar reinforcement in the centre of the grill clean out of the resin. 
The blow delaminated the gel coat (that's the first thin "cosmetic" layer of resin) of the grill from the (thin GRP) lamination behind it and caused the right side to tear.
But besides a bit less ground clearance due to the damaged front Splitter...the car was still very much drivable.


 
Back home I peeled the broken the gel coat from the grille and saw that the GRP behind it had teared as well.
The tear continued up and to the right (viewers left) where the paint chipped off, and then up straight ending in the hood just above the right headlight. 
That area I had dremelled a bit to thin to remove the excess resin from the lamination process.
 

Pictured above, you can see how far the nose flexed during the crash by the traces off chipped paint.
Such was the force of the blow and it travelled that far aft, that a bit of gell coat chipped of the lamination behind the leftside wheelarch. (picture above right)

But, the reglued front body posts to wich I had mounted the chassis...were still firmly fixed in place !!!
So definitely going for the flexible glue. And last but not least the structural integrity of the lamination was still intact on the inside of the body.



Crash test Dummies, post test evaluation: Good and bad news
I've never crashed a car like this...deliberately, but I'm glad I did it now, that I had the luxery to do it now. Because crashes like this will happen during the 24hrs.
And the speeds and forces of a hit on the 20m long 1/32 Mulsanne are a lot bigger than on the 6m  Suzuka pit straight.
So the good news is that although its bad news to the way the M8 looks....it just that, cosmetic damage which could have been easilly repaired.
The lessons I can draw from this crash test will allow me to improve the lamination process in such a way that this will not happen again...during a next crash test. 
The bad news is, to be sure that I have succeeded I will have to crash it again 
 
to be continued

with kind regards
Tamar

[Tamar]

From beginning of December till now, feels like one long turbulent flight. Trying to get the M8 ready for the Suzuka 6hrs and the 9th edition of the DiSCA LM 24hrs.
The lull I'm in now after it has been cancelled feels like the eye of the storm as most of Europe braces itself against the full force of an ill wind.
With no racing planned for the near future...perfect time for an M8 GTE Flashback. Dail back the clock to 2018.

In the beginning....
After waiting for a year, none of the mainstream manufacturers had even mentioned plans to start working on a M8 GTE. So like 4 years earlier with the Toyota TS 040...
...I decided to make my own. And this time I really had to start from scratch, as unlike with the Toyota there were also no other static scale models available of the car.
In August I discussed the project with my good friend Fola (slotfabrik). Would he be interested in a joint venture where he would do a 1/24 version and I would do the 1/32nd scaled car?
Although we're both done our fair share of manual masters we decided the first thing to do was to search for a designer that would/could do a 3d Model for us...
...because at that time ...2d, let alone 3d...there was nothing.



3D Renders of the same BMW M6 GT3, done by 4 different 3D artists....will give you 4 different interpretations of the same car...spot the differences, which one to choose 

There were plenty of 3D artist to be found via the web, some of them "specialized" Automotive modellers, but after a lot of browsing Fola and I only considered a few that we both agreed on as really good.
Because, unless one has the original files from the manufacturer, 3D modeling, like classic sculpture, is really a fine art. 
Check the 3D Renders in the picture above. All of the same BMW M6 GT3, done by 4 different 3D artists....which will give you 4 different interpretations of the same car...
all of them good...hard to spot the differences, which one to choose? 
In the end we found an artist that did freelance work for the (automotive) game industry. His portfolio contained the most accurate and detailed 3D model of the BMW M6 GT-LM.

We contacted him and he was up for it, so I provided the artist with all the reference photos and research I had collected over the year.
I left it to Fola to make a deal (he's much more a business man than I am). For a fair amount of money we would get our 3D model, but no in between work in progress updates.
No unique use of the model let alone unique rights. Deadline would be October 2018, payed half up front and half upon delivery.

And then there was...light
Oct 2 was the promised delivery date for the 3d model and behold that morning Fola got the first renders of the M8GTE. I must say..I was most pleasantly surprised.
Because in the previous weeks the project had been a giant leap of faith, had we picked the right guy, how accurate would the model turn out to be?
As the renders lit up my screen, all my concerns faded away. Proportions were good, the amount of detail immaculate, he'd done a very good job, the work of a true artist.
There were a few small details that need to be finished (mirrors and dashboard) which he promised to do that week. So by mid October we had "our" 3d model, all we had to do now was make it printable.



to be continued

With kind regards
Tamar

[Qman]

Off topic Tamar I have to ask, does your pseudonym relate to the river between Cornwall and the rest of the world?

Brilliant article though

[Tamar]

Hello Q-man, my name (although uncommon for a male in Northern Europe) is just that...my name
Never felt the need for a nickname on the web ;)

Well aware and honored that the Brits chose to use my name for their beautiful river, has a bridge over it build by my favorite engineer (Mr Brunel)
My name can be heard more frequently in the Middle East, although its origin lays even further to the East.
In Arabic and Hebrew languages it means Palm Dade, even has a small cameo role in Christian scripts (wife of job)
Pressed my dad once for the true origin of my name, as it turned out, its a derivation of the name of a pre medieval War lord in what would now be Turkmenistan
Tamarlan, also known as Timoer the Lame.
Googled him and this limping warlord had serious anger management issues. Making Djengiz Kahn look like a Choirboy.
His forte... beheading all the men in the Towns he conquered and displaying them on spikes placed in front of the city gates.

For me, as of then, Palm dade is a good enough translation of my name .

With kind regards
Tamar

[BAracer]

Tamar

I know you like to be perfect, so a little comment...when they come to deal with the insurance claim after the crash, the safety car driver will simply say "I had my flashing lights switched on at the time, the BMW driver was not concentrating!"

(Yes, boredom has now hit the UK)

[Qman]

Thank you for the (thorough) explanation, it's not often you find someone using their real name in these sort of places hence I thought you may have alluded to a location, I was going to offer (and still do if you're ever around) an invite to our humble slotcar club, just off the Tamar in Plymouth

[Tamar]

Most happy to accept the invitation, will do when I'm in that area...but do fear it might take a while before I will be ;)

With kind regards
Tamar

[Tamar]

3D printing: skins vs bodies, meshes vs solids, squares vs triangles...Babylon rules
Oct 2018, on my hard disk most likely the most detailed 3D model of a BMW M8 GTE, as an extra the 3D Artist had thrown in a perfectly detailed interior.
So what now...press "CTRL P" for print? Well I knew it was not going to be that easy,  Fola had done projects like this before.
We knew that we would need another 3d specialist to convert the model into a 3d printable file. But boy was I in for a steep learning  curve.
Some of the members on SF are working with 3D designs and prints, but for those of you that have no experience at all...a short "simplified" introduction.
A kind of summary of the stuff I was about to learn the hard way,
 
A small introduction into the world of 3DP
If you want to create a digital 3D model there are basically two methods, two ways of doing this, you can work with skins and/or with bodies.
Working with Skins is best illustrated by thinking how, in the old days, a carrossier would use sheet metal to build up the outer skin of a car body.
For working with Bodies you could best think of a scratch builder, carving that same shape out of a solid block of balsa wood.
 

On the left: Aluminum skin shaped on a wooden buck to form the body of Daytona Coupe. On the right solid blocks of Jelutong wood to be cut back to form the body of a Tojeiro Climax GT
 
Meshes vs Solids
Skins are often referred to as meshes, like a wireframe, but unlike the metal skin of the Daytona Coupe they don't have any physical properties, no thickness.
They are but digital boundaries. For example to create a cube you need to mesh the 6 faces of that form a cube, the shape of the cube would be defined, but not its contents.
If you want to 3D print that "meshed" cube you need to convert the mesh into a Body, often referred to as a solid, because...well that's what they are after conversion.... solid.
In general "free form" 3d modeling like for Film, Animation and 3D Games use meshes, 3D modeling for fabrication of physical parts prefers working with solids.

Quads vs Triangles
So you would think that each 3d software program would have a simple drop down menu with a function "convert mesh into a solid". Well yes and no.
First of all there are many 3D software programs and again there's a two way division in how they construct a mesh... quads or triangles.
In general they're split along the same lines: Film, Animation and 3D Games use quads, Cad cam and 3D printers use triangles.
Quad meshes are better for "optical use" as they provide better and smoother renders, but they require more computing time and data.
Triangle meshes require less computing power 


On the left: the original M8 GTE 3d model, as you can see the mesh is build up by squares (quads) .  On the right an example on how quad mesh "renders" better than triangles.

Babylon rules
As you've probably guessed by now...that wonderfully detailed 3d model we got...had a quad mesh needing to be converted into a triangulated mesh before converting it into a printable solid body.
Like most computer programs destined to do the same work..they don't really like to talk to each other. Unless you have someone that really knows how to convert the one into the other...a lot of the data will one lost in translation and...Babylon rules
But as I mentioned  earlier, Fola had done these projects before, he had a guy that could do these conversions for us. So we send him the file and he said he would dig into it.
In for another waiting game, in the mean while I returned my focus to the BMW M6 that we'd been using as a test hack for the development of the M8 Chassis.


to be continued

With kind regards
Tamar

[Tamar]

True Scale: To be or not to be, that is the question
Slowly working through my back log of M6 and M8 post, some recently posted pictures of the Sideways BMW M6 GT3 motivated me to write about this topic now.
First of all let me state that I.m.o "True Scale" is an ideal, and as with most ideals, in reality nearly impossible to achieve...translated to 1/32 slot cars...make that impossible.
Because if one was to truly scale down a 1/1 car a large number of parts would become too small or thin to fabricate, manufacture, let alone use as parts for a slot car.
So for me True Scale (or true to scale) is more about how well a 1/32nd or 1/24 model captures/represents the proportions of the actual car.

"Artistic Liberty" vs "Slottification"
As I mentioned in my previous post, modeling is an art form, as such there's a bit of "artistic" liberty in each model, a necessity for those areas that will become too small when scaled down 100%.
Every model manufacturer (static or not) has its own signature when using such artistic license, Tamiya modelers like to beef up certain proportions more than their colleagues at Fuji and Hasegawa.
Studio 27 can at times be more "square headed" than lets say Hiro models. Carrera dimensions tend to be more "Teutonic" than Scalex "Imperial Scale" (Scalex usually the most scale accurate).
Most of the Spanish and Italian manufacturers following that same British tradition, maybe some slight slot 'optimization' here and there or as I like to call it "slottification".
The most renowned example of such "slottification" the NSR Mosler. Anyone that has seen the difference between a Ninco Mosler and the slottified NSR will know what I mean.


 
Now most of us slot pundits will always have to accept whatever amount of "Slottification" the manufacturers have applied to their RTR cars. Which brings us back to my story...
... as one of the reasons why the M8 GTE model was so incredibly detailled..was because the 3D Artist had drawn it scale 1/1.  
As you can see in the screenshot above its digital footprint measured 562,85 cm x 247,37 cm which was a bit odd as when checked against my reference data that was way too wide and too tall.
Ok so sometimes the published car specs you can find on the web are a bit off, and unless you have the chance to measure the real car there is no way of verifying them...but the M8 was half a meter off?!?

True Scale, horses for courses and X-Y-Z axis
Back to the timeline, by now it was mid November 2018, we'd just lost 4 weeks as we needed to look for a new 3D "translator", Fola's guy had returned the job...too complicated.
Via the web I got into contact with a young Slovakian 3D student, another leap of faith needed here, but as it turned out Villiam (Vilo for his friends) was the perfect guy for the job.
We both agreed that this project would be one were we would go through a steep learning curve as this conversion would be a first...for both of us.
We knew we would make mistakes, learn stuff the hard way, trail & error or as we Dutch say "met vallen en opstaan".

In fact I made a mistake with the first step in the process, rescaling the 1/1 3D model to 1/32. The calculated Scale dimensions of the M8 would be 155,3 x 63,9 x 37,88 mm, wheelbase 90,0mm.
I knew that the dimensions of the M8 model were a bit off. For the length that could be explained by the overhang of the front splitter and the rear wing sticking out the back.
The difference in height could be explained by 1/1 car dimensions measured while standing on its wheels (which our model had not) , but I had no reference by which margin.
The width, even though this was also off, still looked like the most reliable dimension, so I told Vilo to (re) scale the whole model down to 64,0mm wide.
But when we checked the 3D model of the body against the 3d model of the M6 Chassis that Stefan Nalbach had designed...the wheelbase was way shorter than the 0,6mm it should have been.

We checked what the width would be with the correct wheelbase, 67,2mm, way to wide, even if you would account for the 3mm tolerance of the DISCA Le Mans rulebook.
So what had gone wrong? Silly stupid mistake actually... had told Vilo to rescale the "whole" model down to 64mm wide...
... had not noticed that the original 3d model and Vilo's rescaled model also included the wing mirrors sticking way outside the body. 
Our first "Babylon rules" moment, just one single word lost in translation had totally screwed up the correct dimensions. 
 


We had a laugh and Vilo rescaled the body again, measuring the max the width of the body over the widest point of the rear wheel arches... et voila @ 103% we got the correct wheelbase and width.
But mounted over the 3D mock up of the chassis something still looked a bit off.  First of all the chassis was sticking out underneath the body, and although at the correct wheelbase...
...the way the wheels sat in the wheel arches was not to my liking. Looked like we needed to mount the body lower on the chassis. 
But when I overlayed one of my 2d blueprints I noticed that the roofline was already a tiny bit lower than the 3D model and that 1/32 20,5mmø slotrace wheels are not even close to true scale.
 

 
Ok a little bit lower roofline...I could live with that, but the vertical alignment of the (too small) wheels in the arches...no. If we lowered to body @ 103% to center them, the body would rub the track.
If we enlarged the body by 105%, the body would be wider (65,5mm well within the 3mm DiSCA tolerance) but it would also be longer, bigger.. and we would need to adapt the chassis wheelbase.
But one of the advantages of 3D modeling is that you can modify the X,Y,Z  axes (LxWxH) independently.

So we fiddled around with percentages and arrived at the following "slottificational" compromise: Length and width (X,Y) at 103% which gave correct  90 mm wheelbase and 64mm width.
No point at having a 65,5 wide body with the DiSCA max allowed track width at "just" 63mm, this would only make the car look stupid with the wheels tucked 1mm deep inside the body.
No point at making the body longer or increase the wheelbase, at 90mm it was close enough to the 92mm of the LMP's, longer would also mean heavier.
We did increase the Z axis to 105%, as you can see in the image below, with the increased height the wheels were now centered in the arches, roof height an good match with the blueprint,
and the bottom of the body flush with the chassis.



Nothing we could do about the "undersized" Slotrace wheel diameter, DiSCA handout slot.it N18 and F22 tires just don't come bigger than 20,5mmø. 
But the difference is less noticeable here as slot cars also run @ much lower ground clearance than their 1/1 counterparts. 
So with the "Slottification" of the SV8 GTE dimensions set, Vilo commenced to translate the Mesh Model into something printable in true scale  

to be continued

With kind regards
Tamar