Commercial Router Choice.

[Smackre]

Well i finaly got the ok to purchase a cnc router. Now i need something that is fairly heavy duty. I will be mostly 2d routeing. But its gotta be done with accuracy. I have looked at alot of the routers. And so far the ones i like the best are:
Larken Cnc
Techno Isel
Shop Sabre (not sure how i would like the roller bearings on this one)

What are you guys optinion on the rack and pinion. Seems like all the cheaper cnc's have that. I always was under the impression that ballscrews would be more accurate. Right now Im leaning toward the Larken Cnc System 60. It seems heavy duty and nicely built. It costs about 16000$ but for the $$ it looks about like the best one. One thing i did notice is it uses steppers and i notice most of them use servo's. Do you guys think this will cause performance issue. As for speed and rapids and that. I am not doing production. Speed is not a issue at all. Accuracy is the main issue.

[padhome]

If you want accuracy, I would go with servos. They use feedback to control their position. This is not required (although it can be used) with steppers. You just tell those to step a certain number of positions and they do so. If you hit a knot or for some other reason skip a little, a stepper system will not know it (unless it uses feedback as well). A servo system will get back on line and only cause a little blemish, rather than ruining the whole piece.

I built a system with servos and it is accurate to ~ .0005 of an inch. It has lots of power and moves quickly between cuts.

[Smackre]

Well you can get the Larken with the servo's. It just costs 1200$ more for it. Id rather have the servo's my self. Just because i have herd alot of people say they are better.

[aerowright]

What do you mean by roller bearings on the ShopSabre? I own a ShopSabre 4896, it uses THK linear bearings. I went with servos and it's one solid performing accurate/repeatable machine.

[gabhart]

Larken, Techno, and Sabre are not heavy duty routers. An example of a heavy duty router is a Thermwood or Anderson. However, if you're not in a production environment you won't need a heavy duty router. Even a 5 year old used heavy duty router won't be less than $25-30K but you get what you pay for, also.

Definitely go with servos even if you're getting a light duty machine - as the previous poster mentioned, if the stepper machine misses a step for some reason (knot, computer glitch, etc) it won't know it and will keep right on cutting in incremental mode, ruining the rest of the part.

Gabhart
RouterCenter.com

[Smackre]

I know it those aint top of the line. but we do not need the best. We aint running 10,000 parts a year. This is not going to be a production machine. it will be a run ever other day for a hour. but when i run it its gotta be accurate.

Sorry about that comment about the roller bearings. I had shopsabre mixed up with EZ-Router.

[Ciaran]

Last year we bought a Wadkin 8'x4' cnc router with an 18hp cutting head.We have found this machine very heavy duty and accurate and we have cut aluminium up to 1"thick.The machine has a mist system to stop the aluminium sticking to the cutters.However..I then descided that for better accuracy we needed a cnc mill and this maybe another option that you could look at as there are some large used cnc mills at reasonable prices if you look.What materials will you be machining?Regards Ciaran.

[Smackre]

i will be machining only plastic. its a acrlic type of plastic.

[Ciaran]

hi,
we do alot of acrlyic and polycarbonate sheets.Any router of 4hp and around 24000rpm with a good vacume table should be fine.If you find you are loseing accuracy slow down the rapid moves so maybe try buy a machine with a seperate switch that allows you to set rapid moves at 25% 50% etc without effecting the internal program feed rates.Single and two flute cutters are best in HSS.Regards Ciaran

[Zumba]

What's your budget? I'd lean toward the Techno.

Judging by the construction of the Larken (I looked at their photos), It just doesn't look like a very rigid machine that will hold tolerance.

Also, for the price you mentioned, it only includes a porter cable router, which I believe has .007 runout right out the box. You'll definitely want a real spindle - colombo or similar.

[Smackre]

Kinda sucks but the boss said we dont have the funding right now for a new machine. Originaly he though we did. He thinks we will be able to do this on our new mill we are buying. I just dont know if a mill with a slow spindle can do this. The mill has a 6000rpm spindle. I set our router we have now at 7000rpm and tried cutting some plastic. Had what looked to me aton of chatter. We are using a 1/16" Carbide router bit. I think our old router may not be heavy dutty enough to cut at that rpm. Also it only uses a porter cable router. I am hoping that the better mill spindle will be able to cut the acrylic with a smooth finish. its gotta be perfectly smooth.

Haas has told us if it dont have enough rpm then they can sell us a speeder tool holder. They said its a tool holder with gears in it to double or even triple the rpms. So it could run 18000 rpm. However that does cost 3500$. But that is cheaper than a new router. If this does workout i think it will be great. As i think the mill will be more accurate than the router would be. But if not then i think we will eventualy just half to spend the $$ on the good router.

[Geof]

Smackre;

On one line you say 6000 rp, spindle and further down mention Haas. Are you talking about a Haas MiniMill? The Super MiniMill with the 10,000rpm spindle and much faster rapids and tool change is a significantly better value for money. 10,000rpm will cut polycarbonate and Delrin very nicely. I have not machined acrylic on SMM but I assume it should be not too bad.