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which CNC Router should i buy?
I’m in the process of buying a CNC router and need help from the more experienced so as to avoid an expensive mistake!
We need this router for a very specific application: Edge finishing acrylics.
In our shop we make acrylic pieces that need to have a rounded edge. At present we cut the sheet into the appropriate blanks with our Eurolaser, use a table router to round the edges and then sand, sand, sand before either flame polishing or buffing. This takes us about 30 minutes a piece.
The pieces have a shape and average 4 ft wide by 2ft. high. Thicknesses are mostly 1/4" and as much as 1/2" clear cast acrylic.
To be competitive, our idea is to continuing cutting the blanks with the laser, then put them on the CNC to obtain the rounded edge, top and bottom in one pass with an Onsrud carbide bit. It’s imperative to get the best machined edge possible so that we only need to buff and flame polish.
To do this we realize that we don’t need a heavy duty industrial router since all we’re doing is a finish pass. What we need is a light, high precision 2D CNC.
For positioning access purposes we would like a table that will take most of our pieces width-wise so we’re looking mostly at 60" wide tables, the length being a secondary consideration.
While we’re happy with our Eurolaser lasers, the maker of the table, Zund, offers a router on the same table. However, it’s steel belt driven and in our laser if the odd piece gets into the belts they can be damaged.
Besides it’s us$ 70K
Have been surfing the web and looking at several machines.
Right now my inclination is to go with either a Shop Sabre 4890 (www.shopsabre.com/cnc-router-4896.htm) with a Colombo 5-7hp spindle and upgrades that would bring the speed up to as much as 600 ipm. With both vacuum and a T slot table this would bring the cost to some us$25K
Still haven’t go the quote on the AXYZ 4004 and 4008 with a similar configuration.
This is a huge decision for us and any input will be most appreciated! -
21 Replies
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hi there Carlos
i would say you cant go far wrong purchasing an AXYZ router. in the uk, i have found them the most competitively priced routers, without compromising quality. ive been running ours about 6 or 7 years now & if i chose to upgrade ide probably go for the same make again.
being in the states, you might want to have a look at this website, prices for their routers seem very good. http://www.shopbottools.com/one thing I’m not 100% on what you have wrote… why not go through the full process on the router? what i mean is… cut the shape then without moving it, cut the radious as required?
my guess is that you want the laser as it will polish the edge as it cuts but ide think applying radious top and bottom you will not be left with much, if any flat? (hope i have understood you right on that?)
axyz offer the multi head option for their routers. so the machine would come down, cut the shape as required, lift the head then down with the next head holding the radious bit to complete the job all in one operation.
i also know (in the UK) they do custom sized beds. saw one 6 metres long by 1.5 metres wide. the company that required this only wanted this size for speed. basically they could leave the machine routing two jobs at once “unmanned”. -
Thanks for your quick feedback. I like the AXYZ tables but reading old posts I’m unsure how to evaluate the drives – AXYZ uses a rack & pinion system while Shop Sabre uses ballscrews. Our older Eurolaser uses rack & pinion and we have no complaints but we’re looking for precision.
I looked at the Shop Bot and it has good reviews but I remain unconvinced – it looks a little clunky.
You have a point on using the CNC for the whole process. However our business is cut-throat competitive and with the laser we can get better yields and better nesting – Besides there is no dust and better still it’s paid for 😀
If we use the CNC for a final finishing pass it won’t be so hard on it and we can achieve higher speeds. We can always switch down the road with the bigger table.
We have some experience with top of the line laser tables, having a 240W and a 400W and the fact remains that their edge is not all that good, certainly not to a finished product look with the striations. There are lots of tradeoffs. if you want speed you’ll get a worse edge, if you want a quality edge it’s slow and you always have to be looking for fires under the material. When we use the table router the striations make the bearing skip and they get translated to the edges. -
i wasn’t convinced myself with the shopbot one but like you, saw/read good reviews.
I’m certainly no expert when it comes to routers, just used one for years on run of the mill work, so when it comes to this kind of accuracy you require, i cant really advise. that said, AXYZ machines are more than capable of 3d routing. i watched them being demoed running visions numeric “type-3” software. the guy advised me that unlike axyz routers, many routers are not capable of the accuracy needed to 3d route metals etc… with that in mind ide think the machine would be ample for what you are wanting it to do.with regards to the process using 2 machines. i understand 100% what you mean by you own the machine so its better to put it to use, also the fact it doesn’t create the mess. but… when accuracy is paramount like you say. how do you manage to remove something from one router, then set it up on another and still get this level of perfection?
i say that, asking the question. i do not know and i am interested in how it is done? 😀
my guess is that you would require an auto alignment sensor like you get for contour cutting digital prints? if so… is this process really that accurate? i know of “slight” imperfections on prints and the like. so “I’m guessing” allot more can/could go wrong with a router? -
On aligning, we can’t use a spoilboard because the bit has to go under the acrylic and we do make a lot of different products, so we’ll cut fixing tools on the laser and t-slot them in with a vacuum holdown for the actual piece. Fortunately all our products have installation holes so we can get a quick alignement with studs
By precision I mean chatt3r-free. If the bit goes beyond the cutting line all it will do is to shave a little more material.
I’ve seen the vision systems out there. They will actually find the edge and follow it. It’s really neat but at @ us$18K 😳 not worth it yet. Others can find register marks on artwork.
Are you happy with the rack & pinion? Do you have to adjust it for backlash?
Much appreciated! The $$$ are burning a hole in my pocket! -
im happy with the machine, we use a vacuum bed with waste board… ive never had to adjust our machine since purchase. like i said though, we are only cutting 2mm aluminium & perspex letters/logos, that sorta thing, so im probably ignorant to what your needs mate. 😕
i guess the holes are as good as anything for alignment. also helps hold it firmly in place ide guess? i know letters/shapes can drift when lots of small shapes are nested and cut. -
This is such a useful site!
I found some back posts by Rodney Gold with excellent advice although he doesn’t cover ballscrews vs rack & pinion.
Regardless when we’re about to dump a load of bucks on a machine, the sales reps are probably the last we should use to evaluate. One mistake and you get a piece of kit that underperforms.
Actually we make boat windshields in Florida and the parallels with the sign industry are plenty. We cut, form, screen print, polish, etc.
Fortunately the pieces are quite large so we don’t get stuff picked up by the dust colletcor. -
For the best pex finish and to do what you want , you dont need a very powerful spindle (2kw at worst ), but what you really need is a very high speed one , 40 000 rpm and combine this with a water coolant system , you will get VERY very good edges. A custom diamond tool will allow a perfect finish off the machine and a good carbide routing tool will give an almost a polished finish. With a routing tool , Rgidity and speed will be important , you will want to go very fast into the pex and remove as much material as possible very quickly along with ANY heat (the problem with pex is the heat generated during machining which stresses it or promotes remelting etc , a fast traverse speed and a fast rotational speed and swift swarf removal using bits with lots of clearance will put the heat into the swarf and not the pex – The operations you are currently doing on your pex and those you contemplate doing are pretty bad for the material , the heat generated by flame polishing , machining and lasering are major causes of stress and using solvents near the pex or on it are almost guaranteed to promote stress cracking.)
As to ball vs rack and pinion , recirculating ball type bearings on a lead screw are infinitely better in terms of backlash and precision. The bigger the diameter of the leadscrew , the better.
At the end of it all , the way you fix the pex will be important as there is no use spending money on a rigid router if the part can chatter or move. You need a clamping system that is as near to the edge you want to profile as possible. You can use a spoilboard as long is its slightly smaller than the shape , IE has the edges “hanging off” by a few mm.
We use Tekcels and find them ultra reliable and buiilt like tanks.You could also try a much cheaper option and that is to use a table mounted inverted router with a diamond tool and feed by hand whilst using a water based coolant spray.
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Rodney, you de man! This is invaluable information.
I know that I stress the acrylic but when we’re done we run an annealing cycle that seems to take care of it. We find that the laser isn’t that bad but the flame polishing is.
Correct also on the tool – I was going to have a tool for each item that I can bolt on the T-slots and then vacuum down, giving me about 1/8″ inboard of the cut. To cut a rounded edge I can’t use a spoilboard because it protrudes too deep and tears it up if I’m doing lots of different items in low quantities.
I’m pretty sold on the AXYZ (Rack & Pinion) so far but will look at the other one. I hunted for custom diamond bits but they all seem to be for straight cuts rather than a bullnose. The problem with using a table router is that I would need to run a bearing but with a similar tool perhaps it’s practicable if alone to see how it works.
By the way, we have a diamond edge polishing machine but it doesn’t do roundovers or radii so it’s pretty useless 👿
With the speeds you’re talking about we should be able to really blow through jobs and be more productive.
Thanks again! -
I have just joined this forum and found lots of usefull information in a very short time. I don’t know how useful my info will be but here it is. I have recently been trying to start up my own business and have been looking at what different companies have to offer. They all seem much the same with very similar specifications. Multicam, AXYZ and Pacer all offer exceptional machines for around the 40-50k mark. Multicam and AXYZ swear by rack and pinion but Pacer says that ballscrews are better. Any router I have used in the past have been ballscrews and i’ve never had any problems. I have also contacted Shop Sabre to inquire about the 4896 and find it unbelievable that I can get a 8×4 machine with servo drives and 5.5hp spindle with 10 position tool changer delvered to this country for under £25000 inc vat! Does any one have any thoughts or experience on these machines. They seem geniune enough and i never have any communication problem with them. The only downside is that should the machine break down it’s a long way to the Usa, but there are plenty of good service engineers here that could fix it no probs.
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Ahh the same predicament!
Got the samples back from the AXYZ operator and they’re not that good either (for my application). Also had an opportunity to see the Multicam and it’s a solid machine and the owner swears by it – specially in the tech support area. Their web site is sorta convoluted, though.
On paper it would seem that the Shop Sabre would be my choice also but it’s always suspect when you get that combination of capabilities and price.
I think I’ll contact Shop Sabre and go see one in action. I’ll let you know how it went! -
Another manufacturer I had previously looked at was Techno. Their prices are on par with Shop Sabre and have good communication. On reading their customers feedback I found a company that makes plastic display products and they seem more than happy with the Techno’s. Maybe you could contact the company and ask for some input from them. It’s always worth a try.
http://www.techno-isel.com/CNC_Routers/ … istory.htm
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OK, saw the Shop Sabre and made the decision to buy it on the grounds that it has the ball&screw movement and servo drives, which none of the others have. It’s not as beefy as the rest but in my application I don’t need it to be.
I’m ordering it with a dual router, one of them a screamer at 40,000 rpms per Rodney’s advice for edge polishing and another beefier one in case I want to do some serious cutting.
With the servos the table speed maxes out at @ 1200 which ain’t bad.
I’ll pass on the automatic tool changer for now because I can add it later if I feel that I need it. -
"A custom diamond tool will allow a perfect finish off the machine and a good carbide routing tool will give an almost a polished finish."
Rodney:
Where cam I get a diamond tool for a CNC and what would it look like?
I’ve been Googling them and can’t seem to find what I’m looking for for this application. Diamond tools seem to favour flat edges only and I really need a bullnose… -
I have never seen a diamond bullnose tool , I have only seen em used on flat edges to "polish" flet edges.
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I feared that. But I’m hoping a carbide tool can do a pretty good job so I’ll sand as least as possible to get a polished edge – Thanks Rodney!
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Take the mans advice…….
Tekcel…..
look them up….built like tanks, top quality finish, top quality motors…
Aussie built…Aussie tuff…
buy something else…its only because you have been fooled..
regards
Peter 😎 -
We ended up buying the Shop Sabre with an automatic tool changer and having operated it for a time I’d like to report that we like it. Since we had no prior experience with CNC’s the learning curve has been rather steep. It’s as precise as advertised and the only problem we have so far is that we ordered it with the table and since it’s bolted together when it goes into a curve it shakes enough so that it will influence the cut. We will have to weld the table together and maybe beef it up.
Support has been good although we haven’t needed it that much.
The auto tool changer is nice to have but we also have two router heads and changing from one to the other is a bit of a pain since they’re not both mounted at the same time and must be manually replaced. -
I missed this thread first time around. I’m glad you are happy with your router. There was some very good information in this thread. We’ve run a Gerber Sabre for 6 years now and it has been great.
There sure is a difference in machining Cast Acrylic vs Extruded. Cast is expensive, but sure cuts and machines smoothly with very little clean up. Rather than rounding over, possibly a chamfer (45 Degree) edge would work. Have you tried finding a diamond chamfering bit? -
I’m sure there are diamond chamfering bits but our customers demand a highly polished bullnose. We have a diamond edge finisher which leaves a beautiful finish but it has to be flat and no radii, that’s why we got the CNC. We get a bullnose and it sure is faster than sanding a bullnose in with 320, 400, 600, 1500 sandpaper. We CNC, then with 1500 grit and either flame or buff. We can’t seem to get a perfectly straight edge with the CNC, there are always a slight wave, else we could go straight to flame. These waves are made obvious with the shine.
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quote Robert Lambie:hi there Carlosi would say you cant go far wrong purchasing an AXYZ router. in the uk, i have found them the most competitively priced routers, without compromising quality. ive been running ours about 6 or 7 years now & if i chose to upgrade ide probably go for the same make again.
being in the states, you might want to have a look at this website, prices for their routers seem very good. http://www.shopbottools.com/one thing I’m not 100% on what you have wrote… why not go through the full process on the router? what i mean is… cut the shape then without moving it, cut the radious as required?
my guess is that you want the laser as it will polish the edge as it cuts but ide think applying radious top and bottom you will not be left with much, if any flat? (hope i have understood you right on that?)
axyz offer the multi head option for their routers. so the machine would come down, cut the shape as required, lift the head then down with the next head holding the radious bit to complete the job all in one operation.
i also know (in the UK) they do custom sized beds. saw one 6 metres long by 1.5 metres wide. the company that required this only wanted this size for speed. basically they could leave the machine routing two jobs at once “unmanned”.Hi rob,
Your words about AXYZ helped. We have made final decision to get AXYZ millennium from UK. -
It’s a bit late to suggest anything, but for what it’s worth, we’ve just bought an old Esab signmate1000 router, which was upgraded in 2001 with the latest Tekcel K series 2 drivers & controllers.
It’s got a 16 ft bed, but because of the arrangement of the gantry, it’ll only rout 2.0 x 3.6 metres.
The spindle is a 3 hp Perske.
It’s built like a tank, and has rack & pinion on the x & y axes- leadscrew on z.
We’re using Enroute Plus, because that’s what came with it. It’s easy to use, though expensive!
Telcel’s service is very good.
They’re a popular machine over here. I think they are very similar to the gerbers in USA.
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