AVID Benchtop CNC Primarily for 4th axis/Rotary

[Nathaniel Banton]

I've been contemplating getting a dedicated 4th axis CNC router for quite some time now. I make small indoor bagpipes professionally and I think this could be a game changer for me. With things being weird with COVID times I think this might be the time to finally pull the trigger.

I'm wondering if anyone here has experience with the AVID Benchtop Standard vs the Benchtop Pro machines? I'm not planning on machining aluminum or taking deep cuts on anything really. My pieces are small, so I think the problem would be more with my pieces flexing then the machine itself. But my only experience with CNC routers is a few hours with the local makerspace X-Carve machine.

Knowing myself, I'll probably find reasons to use the machine's non-rotary functions, but 95% of the time it'll be dedicated to 4th axis work, both rotary and indexing work (if I'm using those terms correctly).

So the questions is, is there a big benefit for going with the Pro model, or, knowing what I'll be using it for, is there not much reason to spend the extra cash? I do want as much precision and accuracy as possible, but happy to same money if the I don't actually need the extra rigidity.

Thanks very much!

[bobby milam]

What kind of pieces are you planning on using it for? 3D stuff or something that could be turned on a cnc lathe?

[Jim Becker]

I have the same question as Bobby. 4th axis rotary isn't the same as an automated lathe. The primary benefit is wrapping 3D around the axis, not straight "spinny" work. Please be sure that your application is one that the machine is able to deliver.

[Nathaniel Banton]

Very fair question guys. I should have been explicit about that. I spoken with a couple people over at Avid a few times over the last 6 months. That was their first question as well!
But after explaining what I wanted, they seemed to think that their product works for what I want it to do.

I suppose ideally I would have both a CNC router and a CNC lathe. But I can't afford or fit both items in my shop at the moment. What I may do eventually is convert one of my lathes to CNC use.

In any case, what I really want the CNC router for, is 3D work. Not the work that a CNC lathe would do. I may try to use it as a not ideal version of a CNC lathe for some work. But The real reason I want it is there are milling type operations and shaping operations that I think are potentially ideal for a CNC router. I'm also interested in the possibility of making some shapes that have not been seen in the bagpipe world before.

[Bill George]

I'm confused... why don't you post a picture of what you really want to make?? Yes you want accuracy, get a Pro.

[bobby milam]

Here is a good rule of thumb. Buy the biggest and best CNC that you can afford the first time. If you can swing the PRO you would probably be better off in the long run just getting it and not wishing that you had at a later time.

[Jim Becker]

I agree on the Pro question.

And just to be clear, the reason that AVID and those of us here in the forum al. asked you what you want to do is that 4th axis/rotary is oft-misunderstood and one of the least utilized features that folks can get on a CNC...largely, because many people buy it without understanding what it does. That means they pay for something and then don't end up using it because it doesn't work like they imagined. Some manufacturers further confuse things by using the "lathe" word in their description of the feature which contributes to that misunderstanding.

[Nathaniel Banton]

Again, fair points everyone. i intended to supply photos, but didn't have access to them from the device I was using.

I *believe* I understand the 4th axis rotary, but I have no experience with one. Never seen one. I barely have any experience with CNC stuff at all. So assuming I don't have any idea what I'm talking about is exactly the right thing to do.

I do realize it is not like a lathe. I used to have access to a manual mill with an indexed dividing head. So, in an extremely limited way I've taken advantage of some of the abilities of what a 4th axis can provide.

These are some photos of historic instruments. Not exactly my plan but maybe they'll give a general idea of what is done in my bagpipe world.

Here's a piece that has keys on it to play extra notes.

Taylor shit from Hamon's Photobucket103.jpg

Taylor shit from Hamon's Photobucket99.jpg

Here's the piece with most of the keys removed.

Taylor shit from Hamon's Photobucket70.jpg

Taylor shit from Hamon's Photobucket72.jpg
Taylor shit from Hamon's Photobucket73.jpg

Thoughts? Possible with a 4th axis CNC router?

Sounds like my question was answered already though. The Pro version will be more accurate. Great!

[Nathaniel Banton]

Here's an eccentric piper playing such a set.

https://www.youtube.com/watch?v=i4l-ljyVqfw

[David Buchhauser]

Sounds like my question was answered already though. The Pro version will be more accurate. Great!

The Pro version is not necessarily more accurate than the Standard version. Both machines are spec'd at +/- 0.005" or better for accuracy. Repeatability for the Pro is listed at +/- 0.002", while repeatability for the Standard is listed at +/- 0.003". I think it all depends on how hard you are going to "push" the machine. I own two of the Pro versions, 4x4 and 4x2 - but have no personal experience with the Avid rotary attachment. The Pro is clearly a more "robust" machine, but it all depends on your specific needs and applications.
David

[Jim Becker]

Based on your photos, milling the outsides of the pipes with the steps for the keys may be a good job for a 4th axis/rotary indexed setup. Not sure how you'll deal with the hollowing, however. I assume you have a plan for that, however.

[Nathaniel Banton]

Yes, I just mean the outside shapes. The inside shape will already be done. Thank you, Jim.

I've read about what repeatability is, but in the real world I don't understand what the difference between .002" and .003" repeatability would mean.

I cut a lot of metal. I'm just realizing that the Avid could give me plasma cutting as an option too... You've pretty much convinced me to go for the PRO anyway, but the chance of maybe plasma cutting in the future is enough to push me to the PRO.

[Bill George]

I am kind of with Jim on this, just the main pipe OD is a 4th axis milling job. I am assuming your going to do those needed 3D CAD drawings yourself? Frankly instead of investing a few thousand in CNC equipment and learning how to use it. I would do the 3D CAD drawings first and take to some CNC shops to get some estimates.

[Paul Brinkmeyer]

As someone who recently invested in a AVID pro48X48, with the rotary, I have added some engravings to mini bats, they are 18 inches long.
this might be close to the process you are looking for.
I pretty much leave the rotary on most of the time, It's not in my way for most of the other things I am running, but I do have it set-up to take off or move out of the way pretty easily.
See AVID CNC build earlier this year for a few photo's of the machine.
615913486.jpg615913530.jpg

[Bill George]

Very nice work Paul.