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Composite RC10T (making the mould)

Posted: Sat Jul 10, 2010 6:59 pm
by Drusky
Having a go at building a glass RC10T, starting with a two part mould of the chassis.

My first thought was to make a plug out of doam and then pull chassis from that but I quickly abandoned that idea. It would leave you with a rough outer surface. Instead I use an existing chassis as the plug.
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Wax on wax off, I apply wax to every bit of the chassis and then polish it off. I do this a few times till she's slippy. I then seal the holes with plasticine so the epoxy doesn't get out of hand. I wax my work surface too.
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I mix up my epoxy resin and get to work. I've already cut my glass cloth more or less to fit. I put 4 or so layers of cloth on, it is quite tedious work, you have to continually dab the cloth into those tight corners and make sure it hasn't pulled somewhere else.
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Once the resin has dried I trim the excess off and pop the glass off of the chassis. It's quite thin but nice and smooth.
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I'm not planning on making lots of these so I choose to use polyurethane foam glue to strengthen the part. It's quicker and easier than multi layers of cloth.
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After popping the strengthened chassis off the mirror I fill the cavities on the lip with body filler and sand it smooth.
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I after that I waxed the chassis again along with the mould, put the chassis back in the mould and glassed the other half. Once dried I strengthened the new half with PU foam as before. Hopefully this week I will be able to have a go at making a chassis.

Re: Composite RC10T (making the mould)

Posted: Sat Jul 10, 2010 7:20 pm
by RedScampi
Fascinating! Can't wait to see how this comes out!

Re: Composite RC10T (making the mould)

Posted: Sat Jul 10, 2010 7:39 pm
by GJW
a great read while sipping on my coffee, cant wait to see the end result.

Re: Composite RC10T (making the mould)

Posted: Sun Jul 11, 2010 12:51 am
by THEYTOOKMYTHUMB
Extremely interesting. Thanks for taking the time to provide details. I rebuilt a couple of shocks today and thought I accomplished something... :shock:

Re: Composite RC10T (making the mould)

Posted: Sun Jul 11, 2010 1:33 am
by THUNDERSTRIKE1
Glad to see it in action.Always wondered how to do that lol. Don

Re: Composite RC10T (making the mould)

Posted: Mon Jul 12, 2010 11:39 am
by Drusky
I'm glad I can contribute something to the forum, I'm making some mistakes along the way and learning things, never made a hard mould like this. Let me know if I should make these pics smaller, they are roughly 300kb each.

Here is the inner mould finished.
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Here the two halves next to each other.
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Hopefully this week instead of a black ally chassis in the sandwich we will have something more colourful. Reminds me of that Movie Cocoon.
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Re: Composite RC10T (making the mould)

Posted: Tue Jul 13, 2010 4:22 pm
by Seabass
Good luck with the project. I am curious to see how this turns out. I had a very similar idea like this but was worried about it working properly. Please keep us updated.

Jake

Re: Composite RC10T (making the mould)

Posted: Tue Jul 13, 2010 9:06 pm
by SteveK
That looks like it's coming along pretty well, I am curious to see how durable it is.

There are plenty of videos on how to make fiberglass parts like this, and they all seem like a real BEAR to do. No wonder than CF tub chassis is $150. I can't imagine doing a whole Formula 1 car.

I watched this whole series a while ago:
[youtube]http://www.youtube.com/watch?v=FCivvXA2FVU[/youtube]

The Fail Chassis and the new mould.

Posted: Mon Aug 02, 2010 12:51 pm
by Drusky
The quick mould process, while quick has some issues. I have found that as the foam cures it pulls the outer mould out of shape slightly. This causes the wall thickness of the tub to be uneven. I also tried to use some dark orange pigment in a small amount to get a gold colour. Didn't work either. I got pale orange soda instead. Another mistake was to attempt the chassis using too little cloth. Long story short I have one fail chassis and have bought some tooling cloth and supplies to have another go at the mould. So far I ama happy man.

Fail Chassis:

The blotchiness you see could have been averted by using more resin and cloth
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Detail is good you can see the ā€œCā€ stamp on the other side
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I have another go at the chassis, this time I make extensive use of the plasticine. You can see a mistake already. I should not have recessed the putty on the sides. Later this will make it impossible to pull the chassis from the mould.
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I use cabosil to thicken up my first 10g batch of epoxy. Cabosil makes the mixture stiffer so that I can use it to fill the holes in the tub and deal with the sharp edge between the tub and the melamine board.
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I put the mix in a bag and chop off the corner to make it easier to apply. Same technique your ladies use to ice a cake.
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Done with cabosil
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After just under two hours of working with cloth and resin we have something that looks promising.
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After a couple of hours curing I dig out the plasticine and discover the chassis going to be very difficult to extract.
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I end up using a dremel and plenty of rough handling. The mould is ok. I am going to have to fill in some spots where I created air bubbles first time around. I'm very pleased with the strength of the mould and am quite sure this one will work well.
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Once the bottom half is perfectly smooth I will attempt the top layup.

Thus far I can say that the old mould process wasn't a total waste of time. I gained some valuable experience. Most important is to think long and hard about how you plan to get your part out of the mould.

Re: Composite RC10T (making the mould)

Posted: Mon Aug 02, 2010 1:54 pm
by shodog
be careful around that cabosil. that stuff is nasty if you breath it in

Re: The Fail Chassis and the new mould.

Posted: Mon Aug 02, 2010 8:39 pm
by SteveK
Drusky wrote:The quick mould process, while quick has some issues. I have found that as the foam cures it pulls the outer mould out of shape slightly. This causes the wall thickness of the tub to be uneven. I also tried to use some dark orange pigment in a small amount to get a gold colour. Didn't work either. I got pale orange soda instead. Another mistake was to attempt the chassis using too little cloth. Long story short I have one fail chassis and have bought some tooling cloth and supplies to have another go at the mould. So far I ama happy man.

Fail Chassis:

The blotchiness you see could have been averted by using more resin and cloth
Image

Detail is good you can see the ā€œCā€ stamp on the other side
Image

I have another go at the chassis, this time I make extensive use of the plasticine. You can see a mistake already. I should not have recessed the putty on the sides. Later this will make it impossible to pull the chassis from the mould.
Image
Image

I use cabosil to thicken up my first 10g batch of epoxy. Cabosil makes the mixture stiffer so that I can use it to fill the holes in the tub and deal with the sharp edge between the tub and the melamine board.
Image

I put the mix in a bag and chop off the corner to make it easier to apply. Same technique your ladies use to ice a cake.
Image

Done with cabosil
Image

After just under two hours of working with cloth and resin we have something that looks promising.
Image

After a couple of hours curing I dig out the plasticine and discover the chassis going to be very difficult to extract.
Image

I end up using a dremel and plenty of rough handling. The mould is ok. I am going to have to fill in some spots where I created air bubbles first time around. I'm very pleased with the strength of the mould and am quite sure this one will work well.
Image

Once the bottom half is perfectly smooth I will attempt the top layup.

Thus far I can say that the old mould process wasn't a total waste of time. I gained some valuable experience. Most important is to think long and hard about how you plan to get your part out of the mould.
Yup, have to worry about the draft angle. When manufacturers make a plug for Lexan bodies, they can only undercut them so much before it becomes impossible to remove the body. Tamiya uses three piece plugs, and you can see the separation lines in all their bodies (they drop the center section down then pull out the front and rear sections).

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One of the guys from the old HPI website forum works at Nike and showed pictures of this mask being molded. They have to cut the mask off the mold because it hung under so much.

Re: Composite RC10T (making the mould)

Posted: Tue Aug 03, 2010 7:11 am
by SnoopMaxx
SteveK wrote:That looks like it's coming along pretty well, I am curious to see how durable it is.

There are plenty of videos on how to make fiberglass parts like this, and they all seem like a real BEAR to do. No wonder than CF tub chassis is $150. I can't imagine doing a whole Formula 1 car.

I watched this whole series a while ago:
http://www.youtube.com/watch?v=FCivvXA2FVU
Geat series
I have the same idea for a fibreglass chassis...lol
Are you gonna use a standard nose or do you make that one out of fibreglass as well ??

Morten

Re: Composite RC10T (making the mould)

Posted: Tue Jan 11, 2011 3:17 pm
by Sir
SnoopMaxx wrote:
SteveK wrote:That looks like it's coming along pretty well, I am curious to see how durable it is.

There are plenty of videos on how to make fiberglass parts like this, and they all seem like a real BEAR to do. No wonder than CF tub chassis is $150. I can't imagine doing a whole Formula 1 car.

I watched this whole series a while ago:
http://www.youtube.com/watch?v=FCivvXA2FVU
Geat series
I have the same idea for a fibreglass chassis...lol
Are you gonna use a standard nose or do you make that one out of fibreglass as well ??

Morten
Is it better than thicker lexan ?