Welding pannier rack to frame with mid drive motor inatalled on it

[afs01]

Hello guys.

I have a bafang BBS02 mid drive motor installed on my aluminum bike and I want to MIG weld a custom made rack pannier on the back.

I know I should disconnect the battery to do this safely.

But what about the motor? Would it get damaged or it is safe?

 

[DingusMcGee]

Bolt the motor frame to the stays or whatever members. Save the integrity of the alum bike frame.

 

[DingusMcGee]

Visit the Colin Furze website and look at his welded electric vehicles. He has some YouTube vids too of him making them. If you can imitate his style of welding and craftsmanship you may not have to move anything out of the way.


See. https://m.youtube.com/watch?v=cfM0qCd7p9g&ebc=ANyPxKp7ZjjUnCy7q_9BgufhN3LNP90cZPk7xIv-APtvih8_xSlzRYIw9vSY0BvrreWje_zTdnwQo2gYT8Wl3VeHaXh12iSmtQ&feature=emb_imp_woyt

 

[JackFlorey]

But what about the motor? Would it get damaged or it is safe?

Are you going to heat treat it afterwards? You'd have to remove the motor anyway when you do that.

 

[Chalo]

[...]my aluminum bike and I want to MIG weld a custom made rack pannier on the back.

Understand that the as-welded strength value of 6061 aluminum that engineers use for design purposes is less than one-quarter of the heat treated strength. Usually, modifying an aluminum bicycle frame without subsequent heat treatment is a bad idea.

 

[calab]

Really need a hard consensus on this for 6061 frames, the consensus is it needs to be heat treated and maybe what I read differently is implied but I thought the key was just the rods used 5356 or 4043
https://www.thefabricator.com/thewelder/article/aluminumwelding/which-filler-wire-is-best-for-welding-6061-t6-aluminum-5356-or-4043r

 

[Chalo]

Really need a hard consensus on this for 6061 frames, the consensus is it needs to be heat treated and maybe what I read differently is implied but I thought the key was just the rods used 5356 or 4043

It's not the weld by itself that's the problem. The heat affected zone on either side of the weld is weakened by removing its heat treatment.

 

[CONSIDERABLE SHOUTING]

I think it would also just be easier for you afs01 to use clamps and epoxies or hanging it off the back of the seat post. You could like, clamp it back there, then bend some simple channel or steel rod to a clamp and attach it opposite to the chain for support.

 

[ATinkerer]

There are several other techniques other than electric arc welding. Considerable Shouting mentioned adhesive bonding. There are also several flame soldering/brazing products that work well with aluminum and do not require the higher heat that arc welding produces.

 

[tigcross]

I've had great success bonding aluminum and dissimilar metals using carbon fiber and kevlar strands dipped in epoxy. You just mix up some slow-set epoxy, dip you strands and use them to wrap your parts. Carbon Fibre does not want to be in direct contact with Aluminum so If you are using unpainted aluminum you must first put on a layer of epoxy and let it set before starting your wrap job. you can't sand kevlar so I use kevlar first and then a bunch of layer of carbon so that it can be sanded for a smooth finish.
another tip is to warp your wet layup in electrical tape to compress it all and then once it is set pull the electrical tape off and do your finish sanding.

 

[calab]

Many types of welding, of course.
Powdered welding, I saw a guy doing it the other day on yt on a cast cover for a big machine, but you can get powder for any metal.
https://www.youtube.com/watch?v=zgv9gAXssgM

The consensus is and I have looked that 6061 needs heat treatment, I do not know if brazing is stronger but thats been argued before to.

Metal flaked epoxy might do the trick for a crack, then wrapped in cf/fg

There are several other techniques other than electric arc welding. Considerable Shouting mentioned adhesive bonding. There are also several flame soldering/brazing products that work well with aluminum and do not require the higher heat that arc welding produces.

 

[Chalo]

There are several other techniques other than electric arc welding. Considerable Shouting mentioned adhesive bonding. There are also several flame soldering/brazing products that work well with aluminum and do not require the higher heat that arc welding produces.

Permanent loss of strength in heat treated aluminum alloys starts in the 300s of degrees F. There is no way to weld or solder aluminum in a structurally sound way that won't cook off its temper.

 

[CONSIDERABLE SHOUTING]

Yep. It's why you can't re-title a car destroyed by fire.