Makeing a drawing / model in segments for either CNC or 3d printing

[Anonymous]

Hi,

How would I approach this?

I want to make a replacement Enfield no4 wooden forestock stock

https://www.google.co.nz/search?q=no4+mk2+enfield+forend&biw=1805&bih=838&tbm=isch&imgil=PySh376WAkw...

(in either wood using a CNC or with HT CFPLA in a 3d printer (high performance carbon fibre filament).  This is about 1300mm long by 50mm wide by 50mm high (roughly)  So I am going to have to break this into 180mm long pieces if I want to 3d print it.  The question I have is, how best to approach this?  Bear in mind I need it in 180mm long pieces with some sort of "dovetail" joint to give the joint huge strength for 3d but then "remove" these joints for CNC as it will be cut in one piece.

So would I be best to make the one complete model first off and then slice it afterwards?  or make it as components and delete the joints later? I am leaning to the latter but I am not sure.   Also what sort of joint detail?  I am thinking 2 M3 or M4 bolts at each joint to hold it in place while it glues up but glue it with an epoxy for the strength and durability. 

The idea is to have most sections permanently glued but with one or two removable parts so I can change dimensions and shape to test ideas in critical areas.

Also the part has a quite difficult 3D profile along its length, how would I approach modelling this?   I was thinking of doing a 2d plan to start with but then I am a bit stuck on how to make the Curves.

[HughesTooling · Accepted solution]

I did a screencast for someone try to print a wheel split into 4 that might give you some ideas. If you keep the combine cut at the end of the timeline you can just suppress it and go back to a single part. You might also be able to use a rectangular pattern so you only need to construct one jigsaw cutter. 

Here's the screencast.

Mark

[HughesTooling]

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@Anonymous wrote:

Hi,

Also the part has a quite difficult 3D profile along its length, how would I approach modelling this?   I was thinking of doing a 2d plan to start with but then I am a bit stuck on how to make the Curves.

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I'd look at creating cross sections and using loft if the part is symmetrical you'd only need to model one half. You might need rail curves as well as the cross sections probably depend on how many cross sections you make.

Mark

[Anonymous]

Thanks, CSAs  an lofts had crossed my mind.  Yes the part is mostly symmetrical along its length, externally.  So yes, good idea I could draw it in half, mirror it and finish it off internally I think.

I also need to figure out dimensioning, is there a way I can auto dimension as I go along? 

[Anonymous]

That is a great tip/help, close to what i owndered if i could do, thanks a lot!

[HughesTooling]

It's a bit difficult to help with the best way of creating the cross sections, do you have a stock to work from?

Also take a look through this thread and the video in this post.

Mark