Here’s a little project I’ve been working on. Using the things I learned from making my custom Hed3 disc (you can read about it here http://forum.slowtwitch.com/gforum.cgi?post=3681568;search_string=my%20custom%20hed3%20disc;#3681568), I decided to do a little more complicated project. The following pictures show the process of the construction from the mold to layup to final touches. Hope you enjoy!
First, I made a mold from fiberglass. I molded it off of my Form E3 saddle which I really like the shape of. The original saddle was pretty beat up so I didn’t care if it got destroyed during the molding process. Luckily it didn’t! and this gives me confidence that I can now make molds of other saddles without ruining them. I just covered it with blue painter’s tape and some mold release before glassing it. I used about 6 layers of glass starting with some fine veils and gradually getting to thicker and thicker veils then to a final layer of fiberglass woven cloth for some structure. It actually turned out to be very strong, maybe too strong of a mold (it didn’t have any flex to help get the carbon out)
I got busy with school so a few months passed until I did the layup. Here it is. I made sure that the surface layer (first piece of carbon in mold) was big enough to fill the mold so that it would look nice since it is the cosmetic layer and will end up being the top of the saddle. Next I did a T-shaped layup using strips of carbon and reinforcing with larger overlapping pieces so there would be strength at every point with reinforcement where the most force would be. You can see that there are 2 pieces going backward making a V shape which isn’t the prettiest. That is reinforcement for the future bond sites of the rails. I have a second carbon shell made with a cosmetic layer on both the top and bottom so it looks nicer. In total, I think there are about 8 or so layers of carbon.
I popped it out of the mold which was easy enough since I put a bunch of layers of mold release on the mold prior to layup. Obviously it is very ugly right now. That will change shortly. You can also see regions that lack good resin content. This was a slight problem, not so much structurally, but cosmetically it looks bad and I don’t think sanding could do the trick on this one.
Here’s another shot of the saddle fresh out of the mold. I think I may have done a little cleaning up of the edges since it doesn’t look as ragged. All those blue specs are leftover blue painter’s tape which I didn’t take the time to sand out of the mold. No worries though, they sanded out easily from the saddle shell.
I then sanded a lot and made the edges nice using a combination of a hacksaw, knife, and sandpaper. It’s still a semi-rough sanding but it’s starting to look really nice at this point and I was getting excited! It’s also really strong. I could use really torque it and it would only slightly bend. I think I over did it a bit on the layers of carbon, but since it was my first try, I wanted to over-engineer this thing so it wouldn’t shatter and impale me. Hopefully this flex will add some comfort.
Remember how I said that those spots of little resin needed to be taken care of? Well, I put another thin layer on top so that I would be able to sand it down uniformly. In this photo you can also see the rails. I had put a lot of thought into what rails I would use and all. I decided that making my own carbon rails might be a little bit of a safety issue for now at least. I have access to a 3d printer so I may make some molds for rails and see about using kevlar but that’s down the road a ways. Anyway, I took an existing saddle that I didn’t want any more and ripped the rails out. I then pulled out single tows of carbon from my fabric and wrapped them around the rails and epoxied them in. Unnecessary you say? Well, for bling factor I thought they were a must. You can’t have an all carbon saddle with metal rails, that’s such a faux-pas!!! So, for safety carbon wrapped metal rails were the right choice I think.
I did more sanding to get the rails nice and clean and then bonded them to the shell. It looks a little off center or something but that is just an illusion since the wrap job of the carbon on the rails is not exactly perpendicular to the actual rails. Don’t worry, it’s nice looking in person. 
The final product after a nice lacquer clear coat. It weighs 215g which isn’t super light but as far as bling factor, I think it’s pretty high.
So, that’s it. It’s not completely perfect if you look closely, but I’m very happy with it. This particular saddle is a gift for my brother so I hope he likes it too! I definitely have some future plans. I want to mold some other saddles (Adamo mostly) and churn some of these bad boys out. I have another shell awaiting rails right now and if people are interested, I may try to sell some since they are less work than the disc. I would like to make carbon rails eventually but I am concerned about the safety. I also want to get some kevlar to possibly strengthen and lighten everything. I’m also acquiring materials to vacuum bag so I will be able to make them even lighter. Hope you liked this post!
-Tim
