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Steve Broad
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+xThis is a project I realised for Westfield Deutschland. The bonnet is quite the same "project level" and type than the one you are planning. Half a car, cf sandwich, 4 piece mold, a few difficult areas in the front section, a great plane in the back. I reshaped an original bonnet for the pattern. And your project would contain to convert a car to a flip front, which was not ment to be a flip front. Holy cow, i can't count the problems that this might lead into. I used resin infusion, mainly because I know ri very well, and because this way I had the freedom of choice when it comes to the used cloth. But even with years of experience this was quite a project. I managed never to fail an attempt, but I learnt from every one. Your "20% skill level" is not a fixed number, and there are lots of ways to improve it. For example by discussing with people with more experience. But some practice can't be matched with theory. That's why I am talking to you! I don't recognise the word problem however, I call them challenges :-) If this stuff wasn't difficult and challenging, what would be the point in doing it? Practice and experimentation are very important. When I started to replace steel bolts with titanium I thought that they were still too heavy and could be lightened. I experimented with centre drilling non strength critical bolts (titanium bolts fit between 10.9 and 12.9 steel bolts in tensile strength) and at first got through one colbalt drill per bolt. I can now drill over 30 bolts with one 3mm drill bit.
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Steve Broad
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Group: Forum Members
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Visits: 4.1K
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+xLucky for you, the Westfield grp quality is way beyond what lotus did those days. So your weight saving will be greater than mine. I managed to get the body down to 20kg. Original is about 40-45kg. Bonnet alone was 14kg and is now 3,8kg (near the bottom, you have to keep higher thicknesses against road dirt, so the weight saving of the other parts are lower). I would have been able to get to 3kg, but not with 245g cloth skin, and not within the budged. You don't know 4-5 guys who would invest in a full elan cf conversion? This would be the project, I was dreaming of since I remember dreaming of anything. I would take one for myself. Yeah, the fibreglass is over 1/2" thick in places! Too many Elan owners are purists so the thought of doing what I am doing is almost a hanging offence to them. The only fibreglass left on the Elan once I change the front clam and inner wings will be the sills, front and rear scuttles and rear wings. Floors, dash, all interior panels, bulkheads, boot lid and floor, rear wheel tubs, rear light panel and roof are all carbon. Doors will be soon. Boot went from 6 to just over 1kg! A few years ago Nick from Carbon Weezle was going to make me a body and I bought the carbon for it. Unfortunately circumstances have now precluded this from happening so I am doing it piecemeal :-)
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Steve Broad
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Group: Forum Members
Posts: 408,
Visits: 4.1K
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+xDon't be offended by my percentage comparison. You achived more than 80 % of the people who tried making some cf parts. But your current idea leaves out a few steps in the difficulty ladder. You made some fine vacuum compressed parts, even better prepreg parts, but you might need some more experience to sucessfully build half a car in one shot, especially if you are planning to use a method you you have all most no experience with (infusion). I would consider myself fairly skilled in vacuum infusion, as I am working with this for about 10 years. And it took me quite that long to get to a point, where I am able to do a project like the one attached. I don't get offended :-) You have convinced me that my best shot will be with prepreg as I have NO infusion experience. Note to self, don't scrimp on the number of mould parts :-) Very nice work, by the way.
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oekmont
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Group: Forum Members
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Lucky for you, the Westfield grp quality is way beyond what lotus did those days. So your weight saving will be greater than mine. I managed to get the body down to 20kg. Original is about 40-45kg. Bonnet alone was 14kg and is now 3,8kg (near the bottom, you have to keep higher thicknesses against road dirt, so the weight saving of the other parts are lower). I would have been able to get to 3kg, but not with 245g cloth skin, and not within the budged. You don't know 4-5 guys who would invest in a full elan cf conversion?
This would be the project, I was dreaming of since I remember dreaming of anything. I would take one for myself.
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oekmont
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Group: Forum Members
Posts: 550,
Visits: 27K
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This is a project I realised for Westfield Deutschland. The bonnet is quite the same "project level" and type than the one you are planning. Half a car, cf sandwich, 4 piece mold, a few difficult areas in the front section, a great plane in the back. I reshaped an original bonnet for the pattern. And your project would contain to convert a car to a flip front, which was not ment to be a flip front. Holy cow, i can't count the problems that this might lead into.
I used resin infusion, mainly because I know ri very well, and because this way I had the freedom of choice when it comes to the used cloth. But even with years of experience this was quite a project. I managed never to fail an attempt, but I learnt from every one.
Your "20% skill level" is not a fixed number, and there are lots of ways to improve it. For example by discussing with people with more experience. But some practice can't be matched with theory.
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oekmont
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Group: Forum Members
Posts: 550,
Visits: 27K
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Don't be offended by my percentage comparison. You achived more than 80 % of the people who tried making some cf parts. But your current idea leaves out a few steps in the difficulty ladder. You made some fine vacuum compressed parts, even better prepreg parts, but you might need some more experience to sucessfully build half a car in one shot, especially if you are planning to use a method you you have all most no experience with (infusion).
I would consider myself fairly skilled in vacuum infusion, as I am working with this for about 10 years. And it took me quite that long to get to a point, where I am able to do a project like the one attached.
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Steve Broad
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Group: Forum Members
Posts: 408,
Visits: 4.1K
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+xBut to get to the point, where you can cut the mold to get the carbon piece out, you have to get your pattern out of the mold. This is usually much harder, because of higher thicknesses and the amount of filler used. The fact, that your whole elan body is attached to your pattern won't help either. You have all ready put that much time into this car, and you are planning to invest about 1000£ worth of prepreg and foam into this, that maybe an additional 20h and 100£ would be worth it. Especially if you keep in mind that cutting out the pattern, cutting off the mould and repairing the actual part easily comes close to 20h labour. Good points, well made as usual. I'm just thinking aloud really. As you say, an extra joint or two is better than hours of struggling.
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oekmont
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Group: Forum Members
Posts: 550,
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But to get to the point, where you can cut the mold to get the carbon piece out, you have to get your pattern out of the mold. This is usually much harder, because of higher thicknesses and the amount of filler used. The fact, that your whole elan body is attached to your pattern won't help either.
You have all ready put that much time into this car, and you are planning to invest about 1000£ worth of prepreg and foam into this, that maybe an additional 20h and 100£ would be worth it. Especially if you keep in mind that cutting out the pattern, cutting off the mould and repairing the actual part easily comes close to 20h labour.
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Steve Broad
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Group: Forum Members
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+xI drew a few lines into your pic, where I would add flanges. I did not consider any changes, that have to be done, to convert it to a flip front (filling of the bonnet recess, maybe adding a backward edge). As far as I see, this would be the minimum, and you still would need to add the bottom piece afterwards, as it is at 180° to some of your cut offs. And 180° hand formed without mould making in mind are likely somewhat between 175° and 185°. Thanks for that. Looking at the photo I reckon that I don't need to take the bonnet all the way down the back of the arch, stop around half way thereby removing the section that curves inwards and negating the requirement of the joint along the wing. I can make the lower section separately, fixing it permanantly to the body. I want to build the splitter into the front in order to add stiffness. As this is a one off part I am quite prepared to, carefully, cut the mould to get it off if necessary :-) Any damage done to the carbon can be repaired. This probably sounds really bodgelike to experts, but with only 20% skill level you have to do what you are capable of. I guess the finished article will prove just how good or bad I am at this stuff.
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oekmont
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Group: Forum Members
Posts: 550,
Visits: 27K
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I drew a few lines into your pic, where I would add flanges. I did not consider any changes, that have to be done, to convert it to a flip front (filling of the bonnet recess, maybe adding a backward edge). As far as I see, this would be the minimum, and you still would need to add the bottom piece afterwards, as it is at 180° to some of your cut offs. And 180° hand formed without mould making in mind are likely somewhat between 175° and 185°.
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