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Advice?

Advice?

Postby drbob » Mon Mar 21, 2016 5:38 am

I'm looking to invest in a CNC but I'll be a noobie walking into the process. I've got a certain amount of money to spend but want to walk into this making some good decisions. Having input from people that have been down this road would be helpful -- and very much appreciated.

First, I'm looking to buy a CNC and a LASER engraver/cutter. I'm comfortable with the electronic side of this, and have better-than-average experience with LASERs.

What I'm interested in are the remainder of the picture.

So, I'm looking at the 4x8 GreenBull or the greenLean - I like the Lean for the reduced footprint in my workspace. I'm considering the Laser/Spindle Combo as well. Option B would be to have a separate unit to deal with LASER work, maybe in the 2x4' arena, but being able to work a 4x8 sheet with the LASER would be awesome... Having 2 4x8 units would cramp my style in my workspace. LOL

Questions: Does the greenLean support the Laser/Spindle Combo? Is there a reason I'd choose the greenBull over the greenLean? I'm hoping to have the unit running often - probably daily - will either/both of these units hold up under relatively consistent use? Is there a problem having the spindle and LASER on the same assembly, from a reliability standpoint? Is this hard on the optics?

Thank you very much for your thoughts, in advance. I'm pretty jazzed about this project and hoping to put this together over the next couple of months.
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Re: Advice?

Postby ShenValleyCNC » Wed Mar 23, 2016 4:32 pm

Welcome to the forum!

The greenlean is offered with the water cooled spindle, but not the laser. However, a vertical laser product is currently offered at $6500.
https://buildyourcnc.com/Item/cnc-machine-vertical-laser-xl

So it is possible, but having no experience with lasers, I would say look at the pictures and email Patrick for info. Obviously, modifications would be necessary, but would probably have to be done by yourself.

These machines are more hobbyist than production, though they will support small production usage with constant maintenance.

The GreenBull is a more mature product, has more forum support and offers the laser option. The GreenBull can be quite accurate when set up correctly. My homebuilt version is amazingly precise.

Switching between spindle and laser would be quite problematic. Electronics, power supplies are different, software, alignment issues and constant dial in. You might try going to the moon first. :D ;)
It always takes longer than you expect, even when you take into account Hofstadter's Law
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Re: Advice?

Postby drbob » Wed Mar 23, 2016 6:53 pm

Thank you ShenValleyCNC -

At this point I'm leaning toward the 5' x 10' GreenBull with the dual head - although large, it appears to offer me the best of both worlds with the least amount of drama.

You mentioned needing "constant maintenance" - what kind of maintenance issues have you found? (I'm thinking it would be worthwhile to stock up extra parts to address the maintenance instead of being down for a period of time while awaiting the arrival of parts...)

I'm curious what software you're using to get your work done... I'm considering AutoDesk Inventor, although my second choice would be ArtCam (except for that crazy price for all the modules! LOL)

Bob
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Re: Advice?

Postby Awesomeness » Wed Mar 23, 2016 10:21 pm

I have, or have had, many of the BuildYourCNC machines, including the 5x10 GreenBull. I wouldn't really categorize them as "needing constant maintenance". I have never found myself regularly replacing any parts or anything like that. You will have to periodically (a few times a year) check that the chains, sprockets and motor couplers are tight and secure, but that's basically all I ever do, besides blowing the dust out of the computer and electronics. If you weld/epoxy/pin/etc. the sprockets in place, that's one less thing to ever mess with (mine are welded).

One thing I am personally NOT a fan of is combo mill/laser/3D-printer/drag-knife/etc. machines. It looks like a good idea on paper, and yes, technically they all share the same electronics and mechanics, but they each require different constraints that make them not really all play well together. It's like saying a riding lawn mower and a Jeep are the same thing... both have a motor, 4 wheels, a driver's seat, and you just added a mower deck, right? I haven't owned a laser+router, but the router makes a HUGE mess of dust and debris, and I can't see that being good for the optics or high voltage electronics of the laser. I understand that everyone has space issues, and blah blah blah (we're all in the same boat), but I think it's chasing a holy grail that has good reasons it doesn't exist. Notice that the commercial market doesn't even sell such machines to industry, which is always another warning cue for me... if the pro's don't do it, why?
If you don’t have time to do it right, when will you have time to do it over?
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Re: Advice?

Postby drbob » Thu Mar 24, 2016 6:34 am

I was feeling very much the same way about the combo solution, but I'm also considering that I'd be able to put the laser on/off as needed, thereby reducing that portion of the headache. Good thing is, I haven't decided yet... LOL

Wasn't sure how to interpret this portion of your opening sentence: "I have, or have had, many of the..." and this made me wonder if you were happy with them, or if you'd tried something you thought better in the low-cost arena? I'm also curious if you've used yours to cut aluminum - I'm thinking I'd like to cut 1/4" from time-to-time.

Research my options, so far, make me feel like this is the best bang for the buck, especially if you want to handle 4x8 sheets.

Money came in today, so I'll probably reach out to the company and ask some additional stupid questions tomorrow.

Bob
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Re: Advice?

Postby Awesomeness » Thu Mar 24, 2016 1:19 pm

I'm quite a "power user", so I usually find that I've pushed the size or performance limits, and need to upgrade. I'm happy with all the stuff BuildYourCNC makes, though for me it would have been smarter just to buy a $30,000 ShopBot Alpha from the start. It would have saved me a lot of time and money, and I would have had the most powerful machine available. As we speak, I have a whole set of industrial linear bearings and ball screws waiting in the garage to build a replacement Y/Z axis for one of the machines... always pushing the limits.

You should really throw out the idea of machining aluminum on these machines, and even many of the commercial ones. I won't go into it too much, as I've talked at length about it in many posts around here before. While these machines "can" do it, it's really beyond their capability, and will require lots of careful setup and toolpathing, upgrades and stiffening, and a metric ton of patience. If it's a few one-off things you need to do, you'll probably get it done, but this is the wrong tool for that job longterm, and there is a reason a big metal mill starts with a 10,000lb steel casting. If you just need to machine small aluminum things, build a small CNC metal mill (like the one I posted about yesterday that I built last year) for $3000.
If you don’t have time to do it right, when will you have time to do it over?
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Re: Advice?

Postby drbob » Fri Mar 25, 2016 7:17 am

Thank you - very much - for all the information. You were able to cut through a lot of BS to help me home in on a few points I really needed to consider. The fact that you've "been there done that" is extremely helpful.

I agree that, for smaller aluminum work, I'd do better getting a milling machine and re-working it to be a CNC - that's a great solution for relatively low cost.

I'm starting to home in on answers, so I'm looking forward to placing an order soon.
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