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The first successful bend

A project log for Precise Wire Bending Machine

Open-source wire bending CNC machine for wires at 1mm and less in diameter.

ji-prausJiří Praus 07/07/2019 at 17:356 Comments

The first successful bend. A lot of scrapped wire was made in the process. Still, the biggest problem is insufficient adhesion of drive gears.

Discussions

Jan wrote 07/09/2019 at 07:06 point

I imagine pulling the wire through the straightening rolls is the culprit here? Is the yellow wheel some soft plastic? How do you control/set the pressing forces between the driving roller and the yellow one? Is there a spring clamp mechanism? I think looking into MIG welder wire feeding mechanisms would give a good starting point!

Here's an super easy mechanism which could be replicated by off-the-shelf parts and/or 3D printed: https://www.mig-welding.co.uk/wire-feed.htm

I think using two non-elastic rollers may seem counter-intuitive but is the key to get a constant feed. You could even count the rotations/speed of the lower bearing to compare it to the driving sprocket. This way you would know of any slipping...

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Jiří Praus wrote 07/10/2019 at 05:19 point

There is a spring beneath the yellow roller which presses the wire against the drive gear. Thank you for pointing out MIG welder wire feeding, That is exactly what I was looking for! So I just ordered those gear, that shoudl solve all the troubles :)

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Jan wrote 07/10/2019 at 07:04 point

Nice. What did you pay? I saw versions ranging from 18 to around 50€/USD...

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Jiří Praus wrote 07/10/2019 at 07:09 point

No that expensive at all, I've ordered some from China for later use
https://www.aliexpress.com/item/32932664688.html?spm=a2g0s.9042311.0.0.6e0f4c4dRdLO8m

And some from local store for $6 each. It won't be supper heavy duty, but for the soft brass wire it will work with no trouble.

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Jan wrote 07/10/2019 at 08:44 point

Ah I see, you didn't buy the whole unit, just the feed rolls!

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Jiří Praus wrote 07/10/2019 at 08:51 point

Exactly, I will build the unit myself :D

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