3D printing a new handle for a big drill

[RainbowsParticipant @rainbows]

I bought a Kango 3814 and in all respects its a superb drill, only downside is that when bought the entire back was covered in tape and a bit wobbly.

After getting the tape off the back was cracked into 3 pieces with about half missing. As a temporary measure Im super glueing it back together then gonna wrap it in tape again

As a long term solution I have a friend with a 3d printer. Would PLA or ABS have the strength to make the part? Failing that I was considering some lost PLA casting and making an aluminium handle.

Same model drill, black part to the left is broken on mine.

Functionally speaking it needs to house the speed selector switch and take the force of leaning into the drill as well any drops and bangs.

[RainbowsParticipant @rainbows]

[JasonBModerator @jasonb]

I hope your CAD drawing is upto scratch

[Nick HulmeParticipant @nickhulme30114]

PLA is fairly strong but I think it may have too low a glass transition temperature for power tool applications, if they ever get warm, ABS is better at higher temperatures and less brittle and Nylon will just bounce back where ABS breaks,

– NIck

[Jeff DaymanParticipant @jeffdayman43397]

Posted by JasonB on 16/08/2017 20:40:09:

I hope your CAD drawing is upto scratch

You aren't kidding….

[Gary WoodingParticipant @garywooding25363]

Years ago my wife managed to break the handle off of the MagiMix bowl. I first tried ordinary super glue, which didn't last long. I then tried the same super glue again, but after it had cured I drilled a number of small holes and used some 0.5mm stainless steel wire to "stitch" it together. I then covered the stitching with more super glue – as can be seen in the photo. The bowl is still fine even though it's been through the dishwasher many times in the years.

The purpose of glueing before stitching was so nothing moved when tightening the stitches.

[Clive FosterParticipant @clivefoster55965]

With that sort of repair watchwords are function before form. Rather than try to make a copy exact in every detail far better to come up with something sufficiently close to fit the mounting holes and flanges and shaped to work effectively. Dunno if there is anything inside the black casing has to pick up on but if not some serious simplification looks possible.

Seen similar welded up fabrication repairs that were basically a mounting flange, tube for body, end cap and a cross tube for the handle. Nice thick rubber pipe for handgrips / insulation. Un-pretty but effective enough. With 3 D printing it should be possible ought to push a similar basic idea much closer to what it ought to look like without bogging down details.

Clive.

[Martin NewboldParticipant @martinnewbold]

Just a thought if you making the model from a 3d printer why not use it as a former for a sand mould and use aluminum melted to create the new part. There are lots of videos on Youtube to look at

Aluminium melts at a low temperature. There is some science here and three ways of melting it **LINK** I would imagine there are far more better people on here to advise about casting process but this is what i would look at with your 3d former. Aluminium is quite easy to shape too with a file. You could also look at brass instead of aluminum. The tape wrapped around it was initially i expect to stop the aluminum transferring to the user.

M

Edited By Martin Newbold on 17/08/2017 14:24:45

[Nick HulmeParticipant @nickhulme30114]

Posted by Martin Newbold on 17/08/2017 14:24:28:

Just a thought if you making the model from a 3d printer why not use it as a former for a sand mould and use aluminum melted to create the new part.

I think there was probably a very good reason the manufacturer made the back end of an electric drill out of plastic

– Nick

[RainbowsParticipant @rainbows]

The super glue has gone pretty well so far. Now only missing one paddle and a bit of the body.

The printer can't do Nylon so ABS will be the material. And why not function and form Not having to compensate for economical mass manufacture or the limitations of injection moulding means the handle might look a lot different.

And the drill is double insulated so trying to avoid good old conductors where possible. The only close electrical connection is I believe low voltage for the speed selection and the entire thing is only 110V anyway but if possible will keep it properly insulated.

The steel wire is a good idea but the shape here is a lot more fiddly, will see how the printing goes first.

[Clive FosterParticipant @clivefoster55965]

Posted by Nick Hulme on 18/08/2017 00:21:44:

I think there was probably a very good reason the manufacturer made the back end of an electric drill out of plastic

– Nick

Yup. Cheaper and handle is naturally warmer to hold. Metal handle would need plastic or rubber grips.

Clive.

[Author]

Posts