hotponyshoes
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Anybody know the actual size of the heli-coil taps
Specifically M8x1.25?
Specifically M8x1.25?
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grim_d
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I would Imagine it's around 10mm OD with a pitch of, understandably, 1.25mm.
It really depends on the form of the OD of the inserts and the tolerance they want to achieve.
If the OD of the insert has the same form as the ID then the tap size would be 9.6mm ish, is the drill size 8.3mm?
It really depends on the form of the OD of the inserts and the tolerance they want to achieve.
If the OD of the insert has the same form as the ID then the tap size would be 9.6mm ish, is the drill size 8.3mm?
Rannsachair
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I just measured a set I have, the OD of the tap is 9.70mm x 1.25.
hotponyshoes
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Does anybody know of anywhere that lists the actual tap specs?
I want to put a helicoil into a 3d printed part but wanted to print the thread directly into the part
I want to put a helicoil into a 3d printed part but wanted to print the thread directly into the part
Any good?
hotponyshoes
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Better than anything I have found so far!
Is it safe to assume the outer profile follows the inner one?
Screwdriver
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Surely Machinery's Handbook?
Maker
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Probably.
It's only going to be 55 vs 60 degree included angle if it is different, certainly close enough for a plastic thread.hotponyshoes
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Found the imperial ones but can't find the info for metric sizes?
hotponyshoes
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I'm open to other suggestions..
Screwdriver
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Oh I'm with you now. In fact I just did exactly that today, stuck an M4 rivnut into a plastic mounting. I just scuffed it with the dremel, heated it up and shoved it in.
as above, think you would need a coarser thread into plastic to give more of a "bite" to spread the load. Depending on the thickness of the area you want to tap. Have a search under woodworking threaded inserts, plenty of choice there, all sizes, flush or lipped. might give you more options.
do you think the 3D printed thread would be solid enough? even allowing for a fine print? might be better tapping it?
do you think the 3D printed thread would be solid enough? even allowing for a fine print? might be better tapping it?
Agroshield
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I believe they are known as STI taps (standard thread insert) so a search around this might get you what you want.
You can infer a lot about the tap spec. from the tapping drill size it tells you to use. Just as standard metric tapping drill = nom. dia. - pitch .
You can infer a lot about the tap spec. from the tapping drill size it tells you to use. Just as standard metric tapping drill = nom. dia. - pitch .
I couldn't remember the name of the ones I would use in my work as I've not designed anything plastic needing them for a while - but it came to me - Tappex. And a quick google . . .
https://www.tappex.co.uk/threaded-inserts-for-3d-printed-products-or-prototypes
Maker
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There are proper inserts for the job, they're knurled or grooved lengthways rather than threaded and pushed into the hole, usually with a soldering iron. Search 3d print thread insert, not sure if they have a posh name.
hotponyshoes
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I have used rivnuts, I tried the steel ones with the ridges on the outside, heated and pressed in. Worked ok, I think there is the potential to print a gap/recess into the part so a alloy robot could be partially "set" after insertion. The heat pressed ones ar ok against rotation but pull out easily.
Those screwfix type I tried although the ones I had were for chipboard., I had problems getting them in straight and they tended to wander off the hole center.
I have not tried using any 'proper'inserts yet!
Used nuts with success, make a hexagon recess with a small lip and snap a nyloc in. Works fine but a helicoil could slim the installation down a lot.
I have printed threads pretty successfully before, admittedly all much larger than a helicoil one, not tried tapping yet, I expect a sharp tap ((maybe a dry lube?) would work, more steps than just printing the thread in the first place though, aside from actually tapping increased wall thickness around the hole will probably need to be worked into the drawing.
I will have a go at a test bit later and see what happens...
Those screwfix type I tried although the ones I had were for chipboard., I had problems getting them in straight and they tended to wander off the hole center.
I have not tried using any 'proper'inserts yet!
Used nuts with success, make a hexagon recess with a small lip and snap a nyloc in. Works fine but a helicoil could slim the installation down a lot.
I have printed threads pretty successfully before, admittedly all much larger than a helicoil one, not tried tapping yet, I expect a sharp tap ((maybe a dry lube?) would work, more steps than just printing the thread in the first place though, aside from actually tapping increased wall thickness around the hole will probably need to be worked into the drawing.
I will have a go at a test bit later and see what happens...
