Shop sabre ?

[grace5]

I am tried of lurking,

I am abit taken with the shopsabre,I see an old thread about them but its dated 2004. Seems like a solid machine,but thats a newbie opinion.

Any users out there?

[braidmeister]

Why not a ShopBot? They have a good track record and over 10X the number of machines ShopSabre does...Just curious.

-Brady

[cncwriter]

some initial questions:

what type of application do you need a cnc router for?


what minimum travel do you need, and what size machine can your work area fit?

[GuitarEng]

Shopbots have pretty sloppy repeatability #'s...something on the order of +/-.015 if I remember right. I'm sure they work well for plywood/furniture construction, but if you need to hit lower tolerances it doesn't seem like the best machine.

I also have been looking at the shopsabres & K2's...K2's guitar making machine seems pretty solid & at about $7k seems like a good bargain for a servo driven machine.

I believe the K2 repeatability #'s are on the order of +/-.002...maybe a bit better if you get a real spindle..as TIR on the PC routers probably are not the greatest..

[grace5]

I have been looking at the 4896
and then found one at ebay(being sold by shopsabre)


Z-Axis Clearance: 8"
Z-Axis Travel: 9"
Repeatability: +/- .001

3 axis with upgrade available for 4 or 5
The one on ebay had standard equipment Servo
the software package seems to be user frendily,not a steep learning curve.

I am wanting to use for sign making,custom doors,trim,ect
Its nothing I am going to buy just yet but looking and planing for it.

[braidmeister]

Originally Posted by GuitarEng Shopbots have pretty sloppy repeatability #'s...something on the order of +/-.015 if I remember right. I'm sure they work well for plywood/furniture construction, but if you need to hit lower tolerances it doesn't seem like the best machine.

This was done on a ShopBot router...it's FAR from 'sloppy'...



This is a water pump impeller for a '55 Buick Century V8. I did it for a friend because nobody in the country had one. I did it just to see how well the Bot could pull it off. It's been running in the car now for several months. (The part is double sided 3D, by the way...)

I haven't seen anything of appreciable tolerance cut on a ShopSabre or K7 by one of their users...The ShopBot is microstepping just like the others and if you need super high tolerances, you buy a mill...not a router. A ShopSabre with servos is still slower than a ShopBot with steppers...advertised accuracy vs actual results are 2 different things, apparently. My cuts are typically within .003" of spec, even when cutting between 400 and 600 IPM. Humidity and temperature swell and move materials at least that much throughout the day...

-Brady

[GuitarEng]

that looks like a good part, but I'm still leary of the shopbot machines... I'd still prefer a servo driven machine. Also, don't they use some sort of proprietary code...i.e., they are not running off of standard G-Code. Does this limit you to their software for CAM? Or can you program a shop bot with a standard CAM package?

I'm looking into K2 at the moment...you seem to be able to get a decent servo driven machine for a reasonable price. Realistically...I'm sure there are shortcomings to all these entry level machines.

[braidmeister]

Why are you bent on using servos? A properly designed stepper system is just as effective as a servo-driven system...Sure servos are sexier, but they'll both get the job done. I have both servo and stepper driven CNCs in my shop and do this professionally...You can bet that if they were problematic or not up to par I wouldn't be using them. I don't put my name on junk...I cut everything from carbon fiber parts for a very well known automotive aftermarket in addition to reproduction instrument parts, like guitar bodies, necks, fretwork and bridges.

ShopBot's controller will run on EITHER their ShopBot language or Standard G-code, straight or converted. I run ArtCAM Pro and have never had any problems with parts being off spec or post processor problems. The implied 'limit' is actually on the contrary...you can run both.

The K2 is a nice machine, but I don't think that it is a good value considering the machinable area vs. price. You could get a ShopBot Alpha 4X8' tool with spindle, steppers with encoder feedback and be able to do both small and large projects for less money...

Whoever told you servos were 'better' than steppers probably didn't tell you the whole story...each have their pros & cons...and both get the job done with exact positioning.

Not trying to sway you any which way...just want to make sure that you get the whole picture before you wind up buying something that isn't going to take you the distance...remember to leave room to grow your business & capabilites...

-B

[GuitarEng]

I've also got good professional experience with CNC's....just not this little stuff!

I work for a major instrument maker as a manufacturing engineer & am around a lot of larger CNC equipment like Komo, Northwood, Fadal, etc.... The K2 & Shop Sabre both look more substantial to me than the shopbot...that's really the basis of my opinion of those machines (which is not bad). I'm not saying that shopbot isn't a good value...it's just not my preference...

Who do you cut guitar bodies & necks for? Is that as a hobby? If you have a website or something, I would love to see it.

[braidmeister]

I am strictly B to B and don't reveal my customers. (sorry) Most of my work comes from customer referrals, rather than web or phone calls. In addition to cutting, digitizing and programming instrument parts, I have also consulted shops who have CNCs used in instrument making that wanted to streamiline their production process. I will be expanding the digitizing department in 2007 with $60k in new equipment dedicated to high end millwork and other ornate & difficult to program parts.

If you already work in the CNC industry, then it sounds like you know what you are looking for. I know a few guys who cut out beautiful fretwork on their laser CNCs...pretty cool, but you can't cut a neck on it!

Have fun!

-Brady

[GuitarEng]

That's great, sounds like you have a good business going. What type of digitizing equipment have you been working with? We've found that for accuracy the touch probe systems seem to be the best (unless you are willing to shell out big bucks for a good Faro Arm). The bad part of those touch probes of course is that they take so long...

I assume you're talking about doing inlay work with the lasers...I've also seen some good inlay work done with them. I do hear though that over time the oils & such in rosewood can gunk up the lense...I guess as long as you keep it clean you'd be fine...

I gotta say I'm really impressed with the real low end stuff such as the shopbot, K2, Shop Sabre, etc.. I'll post if I get into anything good...

Originally Posted by braidmeister I am strictly B to B and don't reveal my customers. (sorry) Most of my work comes from customer referrals, rather than web or phone calls. In addition to cutting, digitizing and programming instrument parts, I have also consulted shops who have CNCs used in instrument making that wanted to streamiline their production process. I will be expanding the digitizing department in 2007 with $60k in new equipment dedicated to high end millwork and other ornate & difficult to program parts. If you already work in the CNC industry, then it sounds like you know what you are looking for. I know a few guys who cut out beautiful fretwork on their laser CNCs...pretty cool, but you can't cut a neck on it! Have fun! -Brady

[braidmeister]

I do a LOT of touch probe digitizing...In fact, a good customer of mine sends me stuff that his hand carver does and I digitize it, and send back G-code for him to cut on his CNC. You are correct...the touch probe takes a very, very long time...which is why I have dedicated probing machines apart from cutting machines.

I am currently building a laser digitizer (commercial components + my secret sauce) to relieve some of the back logged digitizing work I have. Resolution is better, scanning is faster, and less cleanup from data anomolies than the touch probe. I'm thinking about offering it as a service to the masses...but I am still on the fence about it at the moment...It's still brewing in the 'sky lab'.

Testing of the unit (in R&D mode) has been excellent...and since nobody offered a good (and under $40k) digitizer, I've spent the last year building my own...to my specs. Just to head off the pack...No it isn't for sale...no I won't reveal the technology (sorry)...yes I may offer this as a service...but give me a few months to complete testing. There are many smarter people than me on this board who could do the same thing if they really wanted to...It all comes down to doing your homework. (and money doesn't hurt either...)

Here are my results so far:

This was done 4yrs ago with a Roland Picza set at max res (.002" step res). This is right off of the machine with no cleanup, blown up to 22" in diameter.



For comparison, this is a quarter done recently on the R&D machine in hi-def mode. It is also 100% untouched, right off of the machine, blown up to 22" to compare apples to apples.



This is just a test scan from the R&D machine. The production machine will have this resolution and a much larger working envelope. It keeps getting better...Hopefully I will be ready for prime time Early 2007.

-Brady