3D printed knobs for drill press quill handle.....

brino

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Recently one of the three knobs came right off my drill press quill handle.
It is a plastic knob with a rubber grip coating.
The plastic barrel was cracked and broke out:
old_knob.jpg


Looking at the other two knobs they are no better:
old_knobs.jpg


Since the ball-turner for the lathe is still on the long project "to-do" list, and I am just starting to feel almost, slightly comfortable with Fusion-360, I decided to 3D print some new ones.

I drew a flat cross section:
1520565887924.png


I rotated it about the centre line:
1520566125453.png


and added a 10mm dia. hole in the bottom:
1520566082798.png


Here it is during printing:
printing.jpg


Done printing:
finished print.jpg



Then I tapped them M12x1.75 and installed them:
new_knob_installed.jpg


-brino
 
I have to agree, that is very cool. I can think of many times when I wished I had a 3D printer. Its fun to watch your progress, Brino!
 
What did you print them in? PLA?
Looks like an improvement over original.
Nice job!!
 
Hi Russ,

Yes that was just black PLA. I believe they are much better/stronger than the originals.

I have some ABS and HIPS in stock, but haven't used them yet. With ABS I read you _at least_ want a thermal tent around the printer to reduce draft induced temperature changes. Some people are putting a heater in the tent. Plus I am certai that ABS would be too stinky for the basement where I have it set up now. I'd have to (temporarily) move it out to the shop.

I use the blue "painters" masking tape on the heated bed to help release parts better. There's a bit of a balance between not accidentally letting go of the table during printing (...and the part being dragged around as more molten plastic is spewed out into a "birds nest") and having the part stick too well to the table. In the latter case you need to pry it off with a knife hopefully only leaving marks in the printed object and not the table.

-brino
 
Looks very good. Well done. A lot easier than trying to purchase the spare part.

I needed a knob for a jig so I printed one. I found an existing STL file on Thingiverse.

I can see making more knobs in the future. I purchased some PETG filament since it is meant to be almost as strong as ABS but easier to print.
 
Could you print the threads right into it?

Could I have more details on the printer? I’m thinking of going for it...
 
People make a big deal about ABS, but it isn't THAT bad. A heated bed is enough to get good prints most of the time. Getting some protection from drafts is a good idea though. The smell isn't too bad, though I do prefer to open a window a little when printing it. HIPS is super easy to print, but doesn't hold up as well as ABS and PLA for me. PETG has a lot of nice properties as well.

You can print threads into parts, but they often need a little cleanup. They can be harder to model in the CAD programs, so people will often make the walls thicker and cut the threads in with the bolt/screw. Larger pitch threads tend to work better for me when printing. I suspect it's just the tolerance for errors is higher with bigger features.
 
Could you print the threads right into it?

Could I have more details on the printer? I’m thinking of going for it...

It is possible to print the threads. I downloaded the AXA dial indicator MPete222 printed in one of his videos. This has the threads embedded. It uses smaller diameter dial indicator than I have so I have not actually tested how well the threads fit.

The threads will likely have sharp crests rather than the rounded crests from a die.

I am having trouble with getting the CAD program to be able to render the threads. I purchased my computer for browsing the internet not for CAD.

I have not tried Fusion360. I have tried OpenSCAD and FreeCAD. I think FreeCAD may be better at the threads but my recent attempt to render a knob with a thread got to something like 996 out of the 1000 counter then crashed. I tried changing Windows priority to give FreeCAD more of the CPU but still crashed at the same point.

I gave up and printed a knob which is designed to have a nut inserted for the thread.

I did a similar design in OpenSCAD and this rendered without any problem.

FreeCAD does fillets a lot easier than OpenSCAD.
 
Could you print the threads right into it?

Yes. I think.
Fusion-360 should support that, but I've never done it.
What I have seen previously (when trying to make holes that a dowel could be pressed into hand tight) was that the holes turn out a little smaller ID than specified in the model. I would expect the internal threads to act similar. Perhaps a tweak in print parameters (nozzle temp., bed temp., print speed, etc.) could sort that out.

Could I have more details on the printer? I’m thinking of going for it...

Here's my introductory thread on my 3D printer:
https://www.hobby-machinist.com/threads/finally-made-the-jump-to-3d-printing.62834/

This is where I post the info on my specific printer:
https://www.hobby-machinist.com/threads/finally-made-the-jump-to-3d-printing.62834/post-518159

-brino
 
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