gun stock question

Topics related to wrapped rotary machining in Aspire or VCarve Pro
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ohiolyons
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gun stock question

Post by ohiolyons »

OK looking for someone to confirm my limited understanding or set me straight.

Been playing with the wrapped tutorials from 9.5 and let me congratulate Vectirc on their current version 9.511 and the associated tutorials.

But it appears that the current version is heavily oriented on spindle like turnings. Not a complaint just my impression.

My example is a gun stock, while I can import an existing gun stock it still has to be "forced" into a round blank.
Not terribly efficient use of wood by carving a gun stock out of a dowel, a very large dowel.

Router Bob, when he worked at Laguna has a video on Youtube showing a gun stock being cut out of a rectangular blank.
A much more efficient use of wood, less waste and reduced machining time.
Granted he did say it was created in Rhino.

So is my understanding correct? If not please set me straight!!!!!!
I'm certain Vectric is looking into this for Version 10? Hopefully So.

Vectric staff please chime in here.

Thanks for your thoughts/insights on this subject.

John
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Re: gun stock question

Post by 4DThinker »

The best way to cut a 3D gun stock is to use the 2-sided option rather than the rotary option. You could even use your rotary axis for the job, but not the rotary feature or the wrapping post processor and do the top half like a normal X/Y/Z job, then use your control software to rotate the blank 180 degrees, then cut the bottom half.

4D

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Re: gun stock question

Post by ohiolyons »

I agree with your concept, but it is a work around isn't it?

You would have to have 2 different double sided machining files, one for the sides and one for the top and bottom.

I guess you could import a model for the sides and save that as one double sided job, then import the same model and rotate it 90 degrees and save that as the top and bottom.

But creating a gun stock in Aspire with 2 different double sided jobs would seem to be a registration nightmare.

Again I am not complaining I'm just trying to understand the capabilities and limitations of Aspire.

So in summary current vectric 4th axis implementation does not allow machining a gun stock from one file?
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Re: gun stock question

Post by larrybadgett »

Use Cut3D and do a four sided operation.
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Re: gun stock question

Post by LittleGreyMan »

larrybadgett wrote:Use Cut3D and do a four sided operation.
Basically, that's what the video shows. Except it uses Rhino for the CAD part and Rhinocam (VisualMill integrated in Rhino) for the CAM part.
I don't know VisualMill, but it seems it manages specific raw material, and not only parallelepipeds as Vectric software. No idea if this feature is included in the basic version of RhinoCAM (CAM only) which price tag here is the same as Aspire (CAD+CAM).
More features, but more expensive.
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Re: gun stock question

Post by bravesoul »

This topic is very interesting to me, I have always wanted to use the rotary for making/carving gun stocks but just haven't devoted that much time since it didn't appear to be that simple. After giving this much thought I don't see why it couldn't be designed as 4 layers and only rotating the stock 90 degs for each section. Seems to be much simpler that way, just merge the 4 different toolpaths into one file and manually edit the file to rotate 90 deg for each section.

I will follow this thread to see how you or anyone else completed this.

Joe

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Re: gun stock question

Post by ohiolyons »

So I’ve been thinking how would you do this double double sided job.

I would draw the sides as a double sided job. Then to avoid registration issues I would export that model as an STL. Then import that STL into another double sided job and rotate the component 90 degrees during the importing process.

My first guess at the process, any thoughts?

Will try to model a simple one and report back. It will not be a real gun stock, but a representative model to verify the above process works.
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Re: gun stock question

Post by TReischl »

John, you might want to consider adding some registration "features" to your model so that you can make sure things stay where they belong.

One thing that helps tremendously with this sort of work is starting with accurately milled stock. Square, flat and to an exact size.
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Re: gun stock question

Post by rscrawford »

Aspire is not really a 3D CAD/CAM program. More of a 2.5D that has a few work around to let you do some pseudo 3D work. But it is an excellent 2.5D program!

It would be very easy to cut your gun stocks with 2 sided machining.

These legs were cut with 2 sided machining, then the mortises were cut on a 3rd side, very similar to how you would cut a gun stock. To make the jig for the 3rd side cuts, I used the model to 'subtract' from a rectangular model, and then I clamped my leg into the jig and centred the bit where I wanted the cuts. I just used pocket screws to hold the jig to my spoil board, and clamped the legs in the jig.

When doing 2 sided machining, you get a much better result if you set the zero plane below the centre plane. For instance, I cut those legs using a 1/2" ballnose bit, so I set the zero place 1/4" below the centre so my bit would go past the centre line and fully cut each side.
Attachments
This leg is very similar in concept to a gun stock.  Very simple to get the shape cut in 2 sided machining
This leg is very similar in concept to a gun stock. Very simple to get the shape cut in 2 sided machining
Then the jigs help align and cut the 3rd (or 4th) sides.
Then the jigs help align and cut the 3rd (or 4th) sides.
leg mortise 3.jpg
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Re: gun stock question

Post by martin54 »

Russell is that not the point of using a limit plane? Not done muchy 2 sided machining lately but thought the limit plane was to allow the tool to cut past the centre on 2 sided jobs :lol: :lol:

If you haven't seen it the 2015 user group meeting had some tutorials on multi sided machining, there are a few but this one was on doing 4 sided machining

http://support.vectric.com/tutorials/V8 ... rts_4.html

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Re: gun stock question

Post by rscrawford »

Martin, if you are importing a model you can set the limit plane right in the import menu and it works great. If you are building the two sided model yourself, I have not figured out how to set up a limit plane and so I use the zero plane with a -.25" base instead.
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Re: gun stock question

Post by mtylerfl »

Hi Martin,

Your Limit Plane method works fine, but it is very easy to set up a negative Zero Plane (to function as a Limit Plane but has no thickness of its own) from scratch on two-sided jobs. Take a look at my January 2019 Project of the Month. The two-sided file has the Limit Planes set up that way (i.e. Zero Planes with a negative offset below the center to force overcarves on both sides).

Once you see the plane settings, you’ll have no problem setting up those for yourself when required.

TIP: The negative Zero Planes must be set to Merge!

EDITED - got Martin and Russell confused! How’s that possible??? Russell doesn’t use smiley faces! :D
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