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Discussion Starter · #1 ·
Hey all,

I’ve got quite excited as I run a Porsche 997 and it’s heavy up top. So I’ve just read a term I’ve not seen before called scraping. Is there a guide on the do’s and dont’s of lightening a heavy bodyshell? I did a search here and on Google but nothing obvious turned up, probably using the wrong terms.

Thanks
 

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re member
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Down here many used a dremel with a rounded burr and just moved it around on the inner surface.
Never stop in one place for long as it is possible to over heat and melt the plastic or even go right through the shell.

Also vac formed windows and interior makes a difference too.
 

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Electric model car driver
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I use the scraping technique for removing plastic in various places as well as a Dremel type tool. Simply scrape the interior with a reasonably sharp tool like an old chisel etc. I have one that's about 6-7mm wide and it does a great job. Doing a search for vac formed windows will probably show you how to make them rather than where you can buy them 'cos they're not usually an item you can buy off the shelf. I know of a bloke who makes them and his name is munter.
 

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ParrotGod
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10,530 Posts
I do remove excessive material from scalex and carrera bodies.
The dremel is starting point. Then you have to use a scalpel to go for the most difficult parts.
Look here for the threads by Tamar on a Carrera M6 and Scalex Conti.
 

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Kevs Racing Bits
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Colin Chapman used to add lightness to his Lotus race cars apparently...maybe some form of anti-gravity the secret of which is buried within him.
 

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Agree with Munter, Dremel tool at lowest speed for a first pass. Use the Dremel bit(s) that suit the contours of the inside of the shell. Follow up with Scalpel and/or half round XActo blade.
See if you can pick up a small but accurate scale that does 0,1 gr. Be prepared to spend some time and be patient. After a while you'll celebrate every 0,1 gr as a small victory.
I've done "some" posts on the subject here and here.

With kind regards
Tamar
 

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Kevs Racing Bits
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Agree with Munter, Dremel tool at lowest speed for a first pass. Use the Dremel bit(s) that suit the contours of the inside of the shell. Follow up with Scalpel and/or half round XActo blade.
See if you can pick up a small but accurate scale that does 0,1 gr. Be prepared to spend some time and be patient. After a while you'll celebrate every 0,1 gr as a small victory.
I've done "some" posts on the subject here and here.

With kind regards
Tamar
I'd not seen either of these threads before and is also the first time I've heard of Babylon
 

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I’d do as Grunz says and in doubt follow Tamars guide, he is on another level when building cars …
 

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ParrotGod
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What I do I learned from Tamar...and a lot of swearing. And I usually screw up with the dremel going over the body!
This is one the best job I have ever done....but I managed to make a hole through the bonnet.
However, I stripped this down to a whitekit and I could repair the hole.

Motor vehicle Automotive lighting Green Hood Vehicle
 

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ParrotGod
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Yeah I do that as well. But when there are hard spots to reach you concentrate on what to remove and might forget to put the finger on the other side to check....
 

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...and a lot of swearing. And I usually screw up with the dremel going over the body!
So do I, actually I'm happy when it happens, no longer need to try making it perfect...it never is
I've read before the way to thin plastic is have your finger the other side whilst grinding so you can feel the plastic heat up.
If you feel the heat, its too late, you should have dropped the Dremel and switched to scraping with a blade.
You have to scrape very very fast to create any kind of heat ;)
To get those last tenth's you have to play the long game... but my guess is that the OP isn't going for the max.
Just a bit lighter will do...but still the basics apply.

With kind regards
Tamar
 

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Gary Skipp
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You’re in capable hands with Mr Nelwan but I’d just like to add this little example. This body wasn’t “lightened” per say, rather “lighted”. I added the windows, interior and front and rear lights. It’s still heavy AF..
Car Vehicle Automotive lighting Automotive parking light Hood

Tire Wheel Car Vehicle Automotive lighting

Tire Wheel Vehicle Car Hood

Vehicle Wheel Tire Car Automotive lighting

I like how this turned out, but it still drives like crap, and on refelection I wouldn’t go through something like this again. Lightweighting is one thing but the whole “cut out the windows” thing really wasn’t much fun for me.

The problem is that the bodies are really, really thick. So once you have your appetures you’re left with these super thick pillars that don’t look very realistic and are a pain to work with fitting the glazing. I didn’t want to go mad by removing much more material, although in an absolute sense, it definitely would have helped.

I think that lightweighting “ordinary”bodies as Tamar and Gio have done is more within the realms of plausibility, even if done to a lesser extent. But going all out on a Scalex crash resistant is not something it’d be keen to repeat!

Fun project though. Be interested to see how you get on.
 

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ParrotGod
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It is all about availability.
When you raced that car no one else was doing something decent to race.
So, putting all this extra work pays out in terms of having a unique entry on the grid.
If it turns out not to be so competitive is another story.
For the 997, I would definitely ditch the idea of converting a super resistant in something more detailed because there are so many options out there.
 

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Discussion Starter · #16 ·
For the 997, I would definitely ditch the idea of converting a super resistant in something more detailed because there are so many options out there.
It’s just about lap times at home, the 997 is top heavy and has a tendency to roll, Ive added weight down low, so taking weight off the top would be a double bonus.
 

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ParrotGod
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You can use as practice. If you have a dremel or a rotary tool with a bur, start by removing weight from the roof and - in this case that the windows are solid plastic - all the windows.
This is the easiest way to remove weight from the top.
 

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10% no sweat first pass with Dremel = 1,7 gr
20% lots of elbow grease as second 1,7gr will require carefull dremelling and follow up scraping with blades.
30% Last 1,7 gr the hardest as mentioned before, scraping and sanding sticks only.
You'll be celebrating every 0,1gr as a victory, roof will be as thin as Lexan.

With kind regards
Tamar
 
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