PDA

View Full Version : NEW MEMBER: Production grade CNC router Vs Homebuilt CNC router advice



SweetAs
06-03-2017, 08:56 PM
Evening Ladies and Gents,

I'm in need of some advice. I run a small but expanding woodworking business and have been looking at CNCs to purchase for the workshop.

We currently carry out a lot of repetitive sign making for signage companies (1000+ units cut on the table/panel saw) and do a small amount of custom work using my home built Shapeoko2 type CNC. The shapes that we cut by hand are simple squares, rectangles, circles etc. We cut a number of rectangles with rounded corners, these suck when they are done by hand lol. I know Im pointing out the obvious but if the order is only 500 units and they all need to have the corners sanded that's 2000 corners.....it turns into a long and repetitive day!

The main purpose of the machine would be to carry out production runs of the above cut outs, to cut down timber sheet goods and with the possibility of plastic or possibly aluminium but I'm not pushing that at the moment. Also to carry out custom signage work and general CNC router work.

I've been looking at the likes of Piranha and Stoney CNCs. They look amazing and are perfect for what I need but they also have a price tag to match.

Realistically if I put up 2000-3000 would I be able to match these machines if I built it myself? I know I'm not going to get a tool changer or vacuum bed but if I could come close then it would be worth the time and cost saving. I am pretty handy and can work out most things so its not the build I'm concerned about even though it is a little daunting just trying to get the right parts to match up with each other.

Are there any build logs I should look at? I have been looking at this one recently which I think is pretty nifty http://www.embeddedtronics.com/cnc_gantry.html Any thoughts on it?

I'm thinking of going for 20mm hiwins, ally box frame, probably a chinese 2.2kw spindle and with a nice solid base/frame to bolt it all to. Other than that, I've not decided much.

I have 2 options in terms of size, either 1220 x 600 or 1220 x 1220. Depending on costings I'm all ears. If things take off further we are looking to get into a bigger unit and then look towards a 2440 x 1220 but that's a while off so I need to get an idea of what we can do at the moment.

It needs to be quick and accurate....time is money after all :peaceful:

Any help, pointers, build logs, guides etc to look at would be greatly appreciated!!

Thanks in advance!

S

JAZZCNC
06-03-2017, 11:18 PM
I've been looking at the likes of Piranha and Stoney CNCs. They look amazing and are perfect for what I need but they also have a price tag to match.

Realistically if I put up 2000-3000 would I be able to match these machines if I built it myself?

Wouldn't hold either of those up as great bench marks, all is not what it appears.!! . . With carefull buying along with attention to detail you will easily match both those in performance terms.
The build you show is something to be avoided with many design flaws.!!

If you can work with steel it will be much cheaper. Combination of steel frame and HD Aluminium profile for gantry makes for very strong machine. Combine this with profiled rails like Hi-win with correctly sized balls screws and the accuracy/performance will match any of those machines you mention.

The electronics are key part of good machine so no cutting corners in this department and it's here where it will make or break the machine. It's also the place that will set your machine apart from those costing 1000's more. It's here where we can help and guide you to buying the correct components.

I suggest you go look around the forum at some of the builds to get a feel for if you really have the skills and patience to build a machine. Be honest with your self here because there is more to this than first appears. Building a good machine requires patience and eye for detail. If done in rush or corners cut it will suffer so be sure you have the time needed.
Sometimes buying ready built works out easier and cheaper in long run because your cutting and making money sooner which pays for the machine. And you don't have the stress of building, testing, fault finding etc that does come with DIY.

If your not put off then start a build Log. Show the design you have in mind and ask any questions you may have, no matter how daft you think they are.
It's good idea to draw up a detailed design of the machine so there's no hidden surprises. Ideally a Cad model works best.

Good luck.

Greeny
06-03-2017, 11:18 PM
Hi SweetAs,
The worst bit, for me, about the build you link to, is the single rail on the y-axis!!
Practically every cnc build i have seen has two rails. One just seems daft.
It's a bit like trying to dig a hole with a shovel using only one hand !!

Here's a thread with a few completed builds to peruse http://www.mycncuk.com/threads/10066-Finished-builds-picture-menu

Prob the best way to get advice from the wealth of experienced builders here is to research an initial design and post it up for review.

Cheers

Ger21
07-03-2017, 02:54 AM
A table or panel saw is going to be a lot faster than a small, inexpensive CNC. At least for cutting lots and lots of rectangular panels.

SweetAs
07-03-2017, 09:11 AM
Cheers for the replies. Its very much appreciated!!

Jazzcnc - Could you enlighten me on the design flaws of those machines please? In terms of the build I'm not too concerned if we are being honest. I am a Surveyor by trade and build tools / renovate cars in my spare time so I have a good eye for detail. I also understand what I'm getting in terms of trade off for saving money on the machine but thanks for the advice. I will spend the next few days reading up on info and build logs to get an idea of what I am trying to achieve.

Greeny - Cheers for that. It was a LONG day in the workshop yesterday so Im putting it down to the tiredness of not picking up on that. Good eyes lol. Thank you very much for the link, that was just what I needed.

Gerry - Point taken. You are right and in all fairness I would complete the rectangular / square shapes on the saws as it is so quick and easy.

Boyan Silyavski
07-03-2017, 10:49 AM
The Stoney CNC Axiom looks right priced for what it is. Obviously an industrial sized half sheet / 4x4ft or 1250x1250/ CNC will be differently priced.

Money wise 3000 will be price of the components for a 60x90cm machine. Not bigger for that money. My signature first build could be done for that money. Industrial grade machine with servos and so will be ~8000 in parts. And that if you are clever and dont make mistakes. But the result will be a superb machine in its class.

The time spend though will be much more than you could imagine.

In your scenario, i would buy one ready, or even better somebody from forum make one for you. One reason being - unfortunately no good plans on internet. My first build is open sourced so drawings a free in the Open source section. I am seriously contemplating starting to sell plans for my big machine. In fact i sold to some people redesigning it for their specific purpose. In reality the plan i could give for free, the support is what it costs.

Neale
07-03-2017, 12:04 PM
Just as another data point, a friend of mine who runs a one-man signmaking business recently bought one of these (http://acctekcnc.com/html/products/router/woodworking_cnc_router/2016/0726/292.html), although his had a T-slot rather than vacuum bed. He found Acctek pretty good to work with; he agreed a spec for the machine via Skype, and he received exactly what he had specified. Cast iron and steel frame, ballscrews, profile rails, water-cooled 2.2KW spindle, USB interface to Mach3. It's Chinese: there are more than a few rough edges, and it needed a little bit of work to get it set up and running (things like a limit switch trigger had come loose and needed readjustment). He used a UK-based shipping agent to handle collection and delivery, and the whole thing cost around 3K. Would have been less but the Brexit vote happened during negotiations and the pound slumped. However, from his point of view, it saved a lot of time in building his own, and to be honest did not cost that much more than buying decent components would have cost. It's not the greatest machine on the planet but it's installed, working, and easily earning its keep. It mainly does text engraving on signs, and is also used for cutting hinge and lock recesses, joints for noticeboard cabinets, things like that.

JAZZCNC
07-03-2017, 04:56 PM
Jazzcnc - Could you enlighten me on the design flaws of those machines please?

The design flaws are with the Linked machine you showed. Single rail on gantry, Weakly supported gantry, too tall and narrow Z axis, Lack of support on bed frame. These are the main ones which are not little issues and define the machines abilty's.

The other's I won't get into too deep because as caused me troubles in the past but what I will say to you and others "Boyan" need to Look beyond the gloss and the covers then you'll see design issues that shouldn't be there in machine costing this much money.!! . . . . To highlight my point those with experience look at this pic and tell me whats less than ideal.?
20994

On the panel cutting front then it wouldn't be big deal to design Z axis in such way that Saw could be fixed along side spindle so have the best of both worlds.!! .. . . . . . It's all possible with bit of thought and common sense.

Washout
07-03-2017, 05:35 PM
Oooh a where's Wally competition?

I think Wally may have run off with the rest of the Z axis plate for the motor mount and the other set of bearing blocks that should be on it...

JAZZCNC
07-03-2017, 05:38 PM
Oooh a where's Wally competition?

I think Wally may have run off with the rest of the Z axis plate for the motor mount and the other set of bearing blocks that should be on it...

That's one but there's another thing missing.?

njhussey
07-03-2017, 05:52 PM
OOoooooo is that the ballscrew connected to a lovejoy coupler (and therefore directly to a stepper) with no AC bearings I see before me??!!

JAZZCNC
07-03-2017, 06:27 PM
OOoooooo is that the ballscrew connected to a lovejoy coupler (and therefore directly to a stepper) with no AC bearings I see before me??!!

We have Winner..:yahoo: (shared with Washout)
There actually is Fixed bearing at other end but still it's not good design and shouldn't be like that on machine costing that much money. These machines use smoke and mirrors and people need to start looking deeper to see the real truth.!

SweetAs
07-03-2017, 07:25 PM
:playful: haha love it.

So come on then Jazz...point me in a good direction?

Ive been having a look through some of the build logs. I like the look of this one http://www.mycncuk.com/threads/6988-routercnc_MK3

I feel I have a few long days of looking through build logs and the forums to get some sort of idea of parts that I want to look at. Happy days!!

routercnc
07-03-2017, 07:43 PM
:playful: haha love it.

So come on then Jazz...point me in a good direction?

Ive been having a look through some of the build logs. I like the look of this one http://www.mycncuk.com/threads/6988-routercnc_MK3

I feel I have a few long days of looking through build logs and the forums to get some sort of idea of parts that I want to look at. Happy days!!

That's my machine. Glad you like it and for its size it will happily cut wood no problem although you will need 1610 screws not the 1605 ones I fitted (to get the feedrate up)
But if you want to go bigger (1200 or 2400mm that you mentioned ) this would need some work. The gantry is only 80x80 heavy gauge profile and would need to be bigger or multiple profiles or steel box if double the width.
I would also recommend the raised X style machine which many others have built as this removes the gantry drop down sides. Much stiffer and not much extra work to build. Keep the ends open to feed in the sheets.
Also at this size you should look at the pros and cons of rack and pinion on the longest axes instead of ball screws, especially at 2400mm

SweetAs
07-03-2017, 09:04 PM
No probs, like I said it does look good :peaceful:

Cheers for the info regarding the screws. What sort of feed rate and depth do you use for timber at the moment? Im thinking along the lines of Birch Plywood...

In terms of beefing up the gantry, would 100 x 100mm suffice do you think or would I be better seeing if I could get a box steel frame welded together

Forgive the ignorance, what do you mean raised x style machine?

JAZZCNC
07-03-2017, 09:41 PM
So come on then Jazz...point me in a good direction?

I already did by telling you to look around the forum and have patience, do the research it pays off big time in the end. I don't do favorites so not recommending anyone over another but there are many on here that more than good enough to do what you need. All those that finish and endup with working machine are winners IMO.

I will give advise on design etc. The best design will depend on your needs really. Some are better suited than others if working large sheets.

Like been mentioned the high sided frame with Gantry sat directly on the rails is very strong design, one I've developed and used many times. Down sides are it does limit access to the front or rear which isn't always ideal for sheet work.
However Combine this with strong gantry design like the "L" shape Gantry design made from HD profile and you'll have machine that will handle most materials upto steel. ( Edit: Don't mean will cut steel but upto ie Aluminium,brass etc.)

If you want more access to the bed then a more conventional machine with raised gantry will suit better. Again if built correctly it will more than do what you need.

Both these larger machines below are built from same materials (steel, profile) and do the same job of cutting woods, plastics etc. Both are strong strudy designs and Only reason the designs are different is because each had different needs. One needed flexiblty of cutting deep materials so uses an adjustable height bed, the other is mostly for panel work etc where access is more important.

The other smaller machines will equally cut thru woods like butter but are built to work in confined space so need good access to bed while at same time not having parts hanging off sides etc so are designed such to hide parts away and save space.

Then we have ultimate in space saving when we go vertical.!! . . . . Yes vertical machine gives lots of advantages and something to seriously consider if space is premium, or not.!
I'm actually building an 8x4 vertical machine for sign maker at the moment that when done will look like the Cad model shown. At same time also building the other Cad model with 4th axis on side. Again both use Steel and HD Profile.

Any of these designs will more than do what you need. And don't let any dodgy looking Bloke from spain tell you it needs to built like brick shit house and weigh the same has tank it doesn't.!

Hope these help give some idea of design which will suit your needs and abilty's.

davo453
08-03-2017, 03:27 PM
In a production machine obviously you are paying for the development time and hope that that time was well spent.

If you make your own the key is as said already in the electronics and later on software to drive it, when I built mine I experimented with the mechanics of the thing. First off I built a very cheap mechanical prototype and gradually improved it but good electronics is the key.

I got lucky in many ways, I built my electronics BOB and drivers from kits supplied by Luc Degrande a very cost effective (if not easy) way of doing it and they have proven to be very reliable (touch wood) over what must now be several thousand hours of often 2 hour long runs.

Like many things the more you read the forums the more confusing it can be and in the case of CNC people get quite snobbish about design.

For example mine still uses plywood as a main ingredient but the use of linear rails and bearings has negated that to some extent.

Good Luck


Dave

routercnc
08-03-2017, 08:07 PM
No probs, like I said it does look good :peaceful:

Cheers for the info regarding the screws. What sort of feed rate and depth do you use for timber at the moment? Im thinking along the lines of Birch Plywood...

In terms of beefing up the gantry, would 100 x 100mm suffice do you think or would I be better seeing if I could get a box steel frame welded together

Forgive the ignorance, what do you mean raised x style machine?

I haven't cut timber for a long time now - been cutting aluminium parts for 6-12 months, but from memory cutting depth probably ~3 - 6 mm and feed rates ~1000 - 1200 mm/min (limited by 1605 ballscrews and analogue drivers). This is a bit slow for wood but worked OK and I was only doing bits and pieces / small one offs.

I don't want to prescribe a specific gantry size until you have sketched something and have decided on gantry span, but 80x80 aluminium single profile is too small for 1200/2400mm wide, and 100x100 profile is also a bit on the small side in my view.

Raised X axis means that the longest X axis rail is supported up at gantry level by structural members which are part of the bed. It can therefore be made very rigid. The gantry is then a simple beam which rides on this. Couple of examples:
21015 (Clive)

21013 (Toomast)

Opposite of this is where the X axis is level with the bed and the gantry then has to be supported by drop down sides. Although these drop down cantilevers introduce some loss of stiffness, they can still be plenty stiff enough and allow 'all round' access to the bed for big sheets. Good examples posted by Jazz/Dean:
21011

21016

Boyan Silyavski
09-03-2017, 08:55 AM
The raised sides machines have many benefits for the DIYer. Stronger, easier to level and build. Plus if you fit there thin sheet it will keep the dust more or less in bed. Cause a dust shoe in a sheet scenario works well, not so when cutting deep shapes, 3d jobs, stuff raised on vacuum table or fixture and so on.

SweetAs
12-03-2017, 05:19 PM
Thanks to all for the info. Apologies for the late reply but it didn't pop up in my email and we have been mega busy this week.

Jazz - Thanks for the info and the reply. The vertical machines sound interesting. I've not heard of them before so I will have a look around.

Davo - Agreed, the more I read the more questions it raises and I know what you mean about the snobbish crap but it's all good. I'm big enough to read between the lines 😃

Router - Cheers for pics and explaining the X-Raised gantry. I think we will pretty much looking at 4x4 for the time being. I'm not too fussed about the raised sides, my supplier will chop the 8 x 4 sheets down to 4 x 4 for no cost before delivery anyway so it's not a big issue. I don't do a huge amount of work with steel but I do know a couple of welders and a blacksmith so chances are I could get a good deal on getting a frame welded together!

Boyan - Point taken. I think some sort of surround would be a good idea. Especially if I end up doing a bit with ally sheet.

So just out of interest, I've been quoted a feed speed on 6000mm on Birch Plywood with a depth of at least 6mm on one of those machines. Do we reckon I will be able to match that or get close?

Thanks again for the input guys...its a big help!!

TheDarkKnight
24-03-2017, 11:17 PM
We have Winner..:yahoo: (shared with Washout)
There actually is Fixed bearing at other end but still it's not good design and shouldn't be like that on machine costing that much money. These machines use smoke and mirrors and people need to start looking deeper to see the real truth.!
I had intended writing an intro post first but there's so many great posts in the intro section alone as I got distracted :excitement:

Jazzcnc - I have no links with Axiom cnc machines and have never used one, but I do however want to point out that your comment about the coupler layout on this machine in question is perfectly fine and commonplace now in industry. I have seen them used on machines and automated equipment ranging from $80K, to $3.8M, and ranging from locations such as Foxconn in China, Ferrari in Italy, and onto all the large furniture manufacturers in San Francisco.

The layout performs the same in testing as the conventional layout, is cheaper, easier to assemble, cuts down on spare part inventory, is more compact and it also cuts down on inertia. The fixed end can use either a double row bearing, or 2 pairs of angular contact bearings depending on precision required.
The layout also has the added benefit of having to only machine one datum surface for the single end bearing assembly - a welded or bolted tab being all that is necessary on the opposite end to locate motor. Slotted holes are often used on this tab to tram in the screw parallelism in relation to the rails.

Instead of saying ''shouldn't be like that on machine costing that much money'', you should be saying "I'm delighted to see it feature on a machine costing so little money" - whatever that cost is :thumsup:

I would expect to see this layout more commonplace as time goes by as it spills from industry down into the pro user/hobby market.

Below is just one example of the layout on an industrial cnc. There are many more that can be found too.

21258

Just because you haven't seen something before doesn't mean its bad:thumsup:

Anyways....best get up that intro post eh!!

TDK.

JAZZCNC
25-03-2017, 09:56 AM
Just because you haven't seen something before doesn't mean its bad:thumsup:

Like wise change isn't always for the better only time tells the true picture. Which I'm sure Mr Trump will learn you soon enough.!!

Can tell you it won't be happening on any machine with my name on it.!!

Like you I've seen industry change methods over the years, often based on cost cutting rather than improving peformance and like wise seen these new methods dropped in short order. This I'm sure will be another given time.?