How to embed a bolt  

RE: How to embed a bolt

Another idea is to print the knob upside down, with a first few layers to cover the top and then a cutout the size and shape of the bolt head. Plus print a plug the shape of the bold head with a hole in the middle the diameter of the bolt. Insert bolt into knob. Slide plug onto the bold and push into the cutout in the knob. No supports needed. 

RE:

A few other ways.. get a part that is a very small circle.. you'll print this, but it is sacrificial.. put on the build plate.. Then right-click and add part.. select your knob.. and place it ABOVE the build plate using the MOVE icon at the left. You can position it where ever you like.. I'd then paint on supports, using the 'snug' option. You can slice and look to ensure you have enough support. The printer will bridge so you might not need a lot.. and it is the underside of the knob, so it doesn't look like it needs to be pretty. Likely you need to outline the outside and around the centre hole. You can't delete your sacrificial part or the knob will fall to the build plate.

You can also design-in support in the model. Something that will break off. Maybe an outer wall 1 or 2 walls thick and extruding down 5mm or your bolt length .. it only needs to touch at a few places and can break off. Repeat with an inner circle.  Some do this with a support part being separate, but both bodies lumped together in the STL and imported together.

RE: How to embed a bolt

Thanks for your suggestions I will give them a try. I hoped PrusaSlicer would have been smart enough to add supports automatically when I print a part in 'mid-air'. The suggestions seem nice workarounds. Thanks again.

RE: How to embed a bolt

Hi LJ, 

try the attached .3mf file!

It's in a Zip file 

M6 Knob
 

Partially complete nut, support surrounds the sleeve for the threaded section, the M601 code, moes the extruder out of the way and sends a message to the display telling you what to do

you insert the bolt, below the level of the print, 
then use the LCD Diplay control, to resume the print

the print completes,

And when you peel off the supports, it looks like this

you ca look at the .3mf file, and see how I set the printe objects up, the thread tube allows you to add the nut head at an elevateposition, and keeps the supports under control, 

I painted support blocker inside the recess in the knob, where the nut head resides. to prevent the thread tube filling with supports
regards Joan

RE: How to embed a bolt

Thank you  for your time Joan, very instructive!

RE: How to embed a bolt

Good luck

Joan

RE: How to embed a bolt

Hi Joan,

I really like your method, but how can I use this with different bolt sizes? Say 3mm, or 5mm? They all have different head sizes. I've got an MK4 if that matters.

RE: How to embed a bolt

I would model a new knob for each size. 
regards Joan
alternatively, you could consider scaling the models to re size them, in prusa slicer. but that could get messy, if the bolt length remains the same

RE: How to embed a bolt

Instead of modeling a new knob for each bolt, you could also just use a generic fully solid knob model, and use negative volumes to "model" the bolt inside -- just a hexagon and a cylinder. Would just need to measure the hex width/height, and the thread diameter (accounting for tolerances of course).

RE: How to embed a bolt

Thanks Joan and Carl, I think I'll come back to this and ask for help, when I actually need to embed a bolt. I don't have any that I need to do atm, but I do from time to time.