I’m ahead to printing stainless 316L of this BB cluster—there are T47 thread on it, and the vendor recommend me to machined them manually for more precise thread. Need your help since this my first times handling non standard thread like this for 3D printing, so…
Is there any workaround for this? Should I print them without thread or with it and face and ream the thread after? Basically I’m limited budget so looking for minimum viable solution for this
After speaking with both Prova and Bastion I am going to be machining the whole thread. Just haven’t decided if its going to be with the mill or the lathe. Cutting a big thread like that with BB taps, especially in stainless, is a bear.
I would, at the very least, print the thread quite “heavy” then cut it properly with a tap. But a fully machined thread will always be better if you can.
Huge thanks for the additional info from Prova & Bastion regarding this! Indeed it will very hurtful hand tapping the SS from raw, that’s why I was thinking as Joe’s approach like mentioned above (regardless with hand tap/machined).
Another follow up questions…
Are 45mm diameter is enough to be in lathe machining?
My partners has 3 & 4 clamped lathe machined but he unsure about the the 1,75-2,5mm wall thickness will be survive/or not cracking during the thread tapping, is it okay to go?
If both are okay and ready to go, most likely will print them without any thread
Already try them in resin 3D printed in 50mm width shell it’s works pretty well, perhaps few turns facing in the end of the thread in the brake side because I make them in 46 diameter thread, luckily you mention to refer PF30 standard. Then 46,5mm should be works isn’t ? or must be in 47mm?
Will be 56% silver brazed with Columbus life/spirit steel tubes, also this be my first time experimenting this. That’s why I make this thread (It is possible to braze stainless 316L with alloy steel?)—finger cross hopefully everything run with small error as possible
Any additional advice about this? Thanks a lot Daniel
I would make an expanding mandrel that sits inside the BB and holds it. You could even print in little landing pads in the BB for it to centre on the mandrel easily. That is the approach I am going to use for my BB prints which I am about to do.
If you wanted to. They are so minimal that you could design them into the interior shape and just leave it all. I’m still to model it up to see how it sits so it is just theory at the moment. I’ll come back here and post some findings when I do it.
The printed stainless should survive tapping, it is pretty tough. We accidentally crashed a yoke into a lathe, and the yoke bent and twisted; it didn’t crack.
I was suggesting printing it in the actual material and print-provider. The parts will have different warping and tolerances. Its better to practice your tapping or reaming setup on a $40 part than a $300 part that takes 1mo to reprint!
Want to share an update (and experimental) to print the threaded bb lug with standard PLA. The thread fit and works very well! Pardon the scattered GIF video
Also the engineer who will print this part admit it may printable but not that smooth, a litte reaming and facing still required at post processing. I know it’s a gambling, but it’s worth to try
Hi all, want to share an excited updates after printing those lugs (the T47 BB thread especially) in SS-316L. This ss print is based on my previous black PLA lug above
They work pretty accurate in this raw, pretty smooth first half of the thread but bit sluggish due to small grime residue on the end which is expected.
Hope this can inform anyone who have similar plan likes me. Very happy with the outcome and planned to facing them and dry fit the tubing this week. Thanks everyone for the input and the feedback
