socket_head_cap_screw_iso_ISO_4762_M5_x_16_16S

[Neil WyattModerator @neilwyatt]

All is not what it seems…

[Neil WyattModerator @neilwyatt]

Well I signed up to an online repository of CAD models a while ago to get some accurate models of fixings.

After a lengthy process on one supplier's web site I got an M5 cap head screw… without any threads.

I signed up for another and downloaded a file with the impressive name of socket_head_cap_screw_iso_ISO_4762_M5_x_16_16S surely that must be better?

I finally got around to printing one but I had trouble starting a nut, I used a bit of force and the tip sheared off in the nut

I then took a close look at the STL file… this is from what claims to be a leading repository of CAD models… come back Thingiverse, all is forgiven!

[jimmy bParticipant @jimmyb]

On Fusion360 you can get files from Macmastercarr. Worth a try?

I have not tried to print from there, as it’s very easy to do modeled threads in fusion.

[fishy-steveParticipant @fishy-steve]

Looks left handed to me. 😂

[David JuppParticipant @davidjupp51506]

That is typical of fasteners with 'cosmetic threads' – intended for use in CAD assemblies, not for 3D printing.

The cosmetic thread is simply a pattern of ridges – because that is much easier to model/render, but (at first glance) gives the impression of threads.

True helical threads put huge demands on processing capability and can really bog down the CAD system.

[MuzzerParticipant @muzzer]

Traceparts is probably the main European repository for CAD models for commercial parts. I don't see any models with modelled threads. As David says, you only model the threads when necessary. It's quick and easy in most CAD such as Fusion etc.

Murray

[not done it yetParticipant @notdoneityet]

Looks left handed to me. 😂

Looks ambidextrous to me!

[egaParticipant @ega]

Have you tried the WDS website?

[Martin KyteParticipant @martinkyte99762]

It's a nail neil.

!

[Neil WyattModerator @neilwyatt]

[Paul LousickParticipant @paullousick59116]

Neil,

Try GrabCad.com for CAD models. Models are free to download in different CAD formats.

Paul.

[“Bill Hancox”Participant @billhancox]

Posted by fishy-steve on 01/10/2017 21:02:50:

Looks left handed to me. 😂

Looks neither-left-nor-right-handed to me.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by "Bill Hancox" on 03/10/2017 01:33:09:

Posted by fishy-steve on 01/10/2017 21:02:50:

Looks left handed to me. 😂

Looks neither-left-nor-right-handed to me.

.

That 'left handed' appearance is an interesting optical illusion; triggered [I think] by the angle at which the item is portrayed. …

MichaelG.

[jason udallParticipant @jasonudall57142]

Lets see if this works…if not look up ambiguous cylinder

**LINK**

[jason udallParticipant @jasonudall57142]

This editor doesn't like my phones browser

[Michael GilliganParticipant @michaelgilligan61133]

Thanks for the link, Jason

Having watched the demo … I need coffee !!

https://www.youtube.com/watch?v=oWfFco7K9v8

MichaelG.

Edited By Michael Gilligan on 03/10/2017 08:39:41

[Perko7Participant @perko7]

Looks a bit like a bolt to suit the famous 'Thrupple Nut' invented by a Michael Oxley who was a regular contributor to ME in the 1950's. It's claim to fame was that, once tightened, it could never come loose.

[Neil WyattModerator @neilwyatt]

I think the answer is simple,

I should not be a lazy b****r and design my own!

Neil

[JasonBModerator @jasonb]

Will you also be printing the Allen key Neil? Would be the safest way to prevent rounding the socket in the printed screw

[Neil WyattModerator @neilwyatt]

being serious for a moment, allen sockets in 3D prints work very well! Not sure about allen keys though.

[Neil WyattModerator @neilwyatt]

So I tried GrabCAD as the 'professional engineer's 3D site'.

I found an M6 screw among the bath plugs etc., at least it has a spiral thread but can you spot the deliberate mistake on this one?

[JasonBModerator @jasonb]

Looks like the thread has been skimmed off so you can assemble it into a tapping size hole and not get a clash show up.

[Nigel BennettParticipant @nigelbennett69913]

It's a simple error with the CAD model; the thread Vee section has been sketched such that it starts the helical cut a little way after the end of the part.

I've personally struggled to assemble a rogue screw exactly like the original illustration – i.e. with a series of grooves in it – before I realised and flung it into the deepest recesses of the workshop with a bellow of rage!.

Unless you really need to 3D print the threads in, I wouldn't bother. Why can't you use a real screw? We often produced 3D parts at work with tapping-sized holes in and tapped them out to fit later. We certainly never 3D printed fasteners unless they were an obtainable special.

As David Jupp says, the processing power needed to create true 3D threads is huge. You'd probably take as long doing it on the CAD as you would tapping out a plain hole!

Edited By Nigel Bennett on 04/10/2017 10:49:18

[Nick HulmeParticipant @nickhulme30114]

Unfortunately there's no exam to be passed before uploading solid models to the 3D sharing sites

[Neil WyattModerator @neilwyatt]

Posted by Nigel Bennett on 04/10/2017 10:49:01:

As David Jupp says, the processing power needed to create true 3D threads is huge. You'd probably take as long doing it on the CAD as you would tapping out a plain hole!

About ten minutes to do this screw, which is less time than it took to register and download the three useless web examples. For 3D printing it ideally needs the thread being made a tad smaller in diameter and the hex socket being made a bit larger.

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