ti to carbon dropouts
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ti to carbon dropouts
I am looking for options on ti dropouts and how you all have them affixed to carbon SS and CS. Pictures would be awesome, and maybe your favorite supplier. Thanks for the help.
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I'm not a composites expert, but I'm pretty sure any metal dropouts have to be specially designed to have the proper bond surface area to be attached to carbon tubes. In other words, they need to be designed with a lug or plug that gets bonded to inside or outside surface of the carbon tube. Dropouts designed for welding are not going to work with carbon tubes.
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Ideally they are a plug in fit with a step that meets the end of the carbon tube.
I have seen ones on Ceeway that look exactly like this but I'm not sure what they were actually intended for. They might be steel.
Nick Crumpton has done a buildalong showing plug in type bonded dropouts. He likely had his specially made.
In practice a longer tang of metal can be suck inside a tube with a blob of strong epoxy and hold up forever if the end is tapered and wrapped with tow. I think some of Calfee's tow wrapped carbon frames look more like this. Really just like putting dropouts in bamboo tubes. If they hold up in bamboo they will hold up in carbon.
There was a guy on Velocipde putting out feelers to see if anyone was interested in properly made ones. Not sure it anything came of that
I have seen ones on Ceeway that look exactly like this but I'm not sure what they were actually intended for. They might be steel.
Nick Crumpton has done a buildalong showing plug in type bonded dropouts. He likely had his specially made.
In practice a longer tang of metal can be suck inside a tube with a blob of strong epoxy and hold up forever if the end is tapered and wrapped with tow. I think some of Calfee's tow wrapped carbon frames look more like this. Really just like putting dropouts in bamboo tubes. If they hold up in bamboo they will hold up in carbon.
There was a guy on Velocipde putting out feelers to see if anyone was interested in properly made ones. Not sure it anything came of that
Last edited by Canaboo; 10-28-20 at 06:39 PM.
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I was pondering this same problem a while back.
You could use some cast, socket type, steel/stainless steel drop outs. Turn some spigots, one end to fit into your carbon tube and the other to fit in and braze to the drop out socket.
You can get these from Ceeway but they are aluminium and look a bit cheap and nasty from the photo's. Havent seen them in the flesh.
I think if you want Titanium you will be making them yourself, starting from scratch.
You could use some cast, socket type, steel/stainless steel drop outs. Turn some spigots, one end to fit into your carbon tube and the other to fit in and braze to the drop out socket.
You can get these from Ceeway but they are aluminium and look a bit cheap and nasty from the photo's. Havent seen them in the flesh.
I think if you want Titanium you will be making them yourself, starting from scratch.
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I think some people prefer the look of machined parts to cast ones. I heard somewhere though that casting results in better mechanical properties. Does anyone know if this is true?
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Certainly watching a titanium part being printed like a glorified sandcastle doesn't inspire much confidence.
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Probably depends on the material and any treatment it undergoes after if any. You can polish up cast parts but Aluminum soon looks pretty dull shortly after unless anodized.
Certainly watching a titanium part being printed like a glorified sandcastle doesn't inspire much confidence.
Certainly watching a titanium part being printed like a glorified sandcastle doesn't inspire much confidence.
I was just reading a bit about casting vs machining and basically it's complicated. It seems both can work very well but if you are machining something you may need to respect the direction it was originally rolled in and that kind of thing.
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I was working on the fatigue resistance of 3d printed parts before the world ended. I think it's okay though, people are selling them after all.
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3D printing usually results in quite poor mechanical properties although it is no doubt improving all the time. It is impressive what they can do. Personally I spend enough time in front of the computer and would rather actually make something by hand
I was just reading a bit about casting vs machining and basically it's complicated. It seems both can work very well but if you are machining something you may need to respect the direction it was originally rolled in and that kind of thing.
I was just reading a bit about casting vs machining and basically it's complicated. It seems both can work very well but if you are machining something you may need to respect the direction it was originally rolled in and that kind of thing.
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They probably cut them out of a sheet of aluminium and so have a pattern that crams as many as possible onto a square or rectangular sheet of whatever dimensions they get from their supplier. This means rotating them all over the place like a sort of game of Tetris.
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There is a difference in the material properties of rolled aluminum depending on which direction the rolling was done. It's probably not enough to overcome the safety factor designed into parts though.
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I would also wonder if the welding heat cycle changes the grain direction/strength issue. Or the after welding heat treating/aging too. Andy
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definitely changes if you weld, but nothing in the machining process does anything to the grain structure.