Brook Drumm I met up with Ian Lewis at London Hackspace again last night,

gplus
discussion
(Mark “MARKSE” Emery) #1

@Brook_Drumm I met up with @Ian_Lewis at London Hackspace again last night, those moulded Delrin bearing clamps are lovely! Full dismantle tonight ready for rebuild with updated photography Wednesday, GT2 belt permitting.

(Whosawhatsis) #2

The clamps are nice, but it looks like when they put that X axis piece on the brake, it almost broke!

(Mark “MARKSE” Emery) #3

While there are stress lines on the outer skin of the bend they don’t look to be cracks that extend into it. Maybe a bit more heat is needed to soften the metal more before bending? Either way I think it’s cosmetic, the thing’s quite solid.

(ThantiK) #4

@Mark_MARKSE_Emery , it’s because they’re using a brake for a sharper bend than the k factor of the metal should theoretically allow, and it’s causing damage to the metal

Looks like @Brook_Drumm is going to have to upgrade his machinery from a simple universal brake, to some professional forming tools. Or at least design that part to be a little bulkier with maybe some testing on different relief shapes.

Something like this: https://www.youtube.com/watch?v=pKv_pD_oREk

(Maybe not quite so slow) and the right forming tool would help make that bend with a larger bend radius, stressing the metal less and making it so it wouldn’t fracture like that. Factoring in the appropriate bend radius would be the “right thing” to do.

(Mike Miller) #5

There’s some work hardening, but the structure throughout its cross section looks fine. It’s NOT an Aircraft part, and doesn’t have near the loads and stresses of one. I suspect they’ll change it a little, but they really wouldn’t need to. The forces in 3d printing are so low.

(Mark Fuller) #6

True, I’d be more concerned with the fatigue over time.

(Mike Miller) #7

Nah…there’s nothing there to fatigue. You’d be more likely to use up the bearings and belts than that structure.