Was saving for a PRS Alpha when I stumbled onto this, thoughts?

[wespor]

I've had a Desktop for a few couple years and love it, I'm looking for something much larger now, was previously planning for a PRS Alpha but I just found this thing on craigslist and it has me tempted.

http://houston.craigslist.org/tls/5354473651.html

I'm meeting with the seller to ask more questions to make a better comparison, have any questions or concerns I should bring up? Foremost in my mind at least is the zeroing system, I love the aluminium plate too much to switch to anything else.

[gc3]

keep saving your money...

[dubliner]

He was robbed, that would be good for cutting foam possibly.

[chiloquinruss]

"looking for something much larger now" My first observation is that machine looks awful lightly built for a 5x10 table. My bot took two really hefty dudes to just place the gantry on my table. I agree with above comments, might be great for foam but, oak, walnut, etc. Have him show you some sample cuts on material that YOU are looking to use. Russ

[Burkhardt]

It is hard to guess the rigidity and usability just by looking at the machine. I would also be concerned about the apparently light build of the gantry. When you meet, take a fishing scale and a dial gage. Rest the gage finger against the bit (or better a straight rod in the collet) and tug on the collet with the scale in various directions while the drives are "on", maybe 20 pounds. Then divide the scale reading by the measured displacement, giving you the actual rigidity. When tugging in opposite directions, you get also a measure for the backlash.
Anything below 1000 lbs/in is almost useless. Above 3000 lbs/in it becomes a good router for wood and light cuts in aluminum, above 10,000 lbs/in it becomes quite usable for aluminum in heavier cuts. At least you can measure this on your desktop as a benchmark and compare with the big machine. Let them cut e.g. a 6"x6" square and measure with a caliper.
Of course there are other important things to look for like speeds or repeatability (return to the same position). You can use a zero-plate with Mach3, as far as I know. You won't have the same great community to support as you have here but you can get a lot of information on the CNC-Zone forum

[bleeth]

Kind of strange that he posted no specs for motors and a Kress Router is no tool for a large bed machine.
This does not come close to comparing to an Alpha.

[coryatjohn]

I would think the danger is buying in to a machine like this, regardless of specs, is it's a one off design with zero support. What happens when something critical breaks or wears out? You'd have to custom make a replacement. That may cost more then it's worth or take way too much time to deal with. The beauty of a out-of-the-box system is it has spare parts, support and years of proven design. My advice: Continue saving for the SB. Better to buy a used SB then this one off system.

[rb99]

Not what I expect from German Precision Engineering.

[jerry_stanek]

He said make offer $1000 would be about right

[wespor]

Aww, I had high hopes, thanks for the feedback though.

I really liked the bed setup, the 4x8 spoil board and 2x2 tslot separation. I was thinking of having a 4x8 PRS and keeping my Desktop on the side for similar functionality, was hoping this could be a reasonable alternative to both. I'm sure I could get a 5x10 PRS and set something similar up but I don't think I would, and there is the extra cost.

[coryatjohn]

The question you should be asking is: What do I need this machine for? If the answer is purely hobby use, and you can get the thing for really cheap, then maybe it might be worth it. If you want to do it for production and make money with it, then the big problem will probably be down time when it breaks. Without any sort of support or spares, you could be down for months from a critical failure. Hardly something you want to bet the farm on. For hobby use, being down for a couple of weeks won't matter and if the quality is subpar, then you adjust your usage accordingly. You can play with it for a while and continue saving for a replacement.

Then again, you might be able to pick up a used SB for the same or less and have support, spares and repeatability. You have to decide.

[wespor]

Not hobby but not production, I run a rapid prototyping shop. Definitely needs to be reliable through, that's a valid concern.

[myxpykalix]

The first thing that jumped out at me was...if he's only had it for 3 months and he's selling it, you have to ask yourself WHY? Plus all your support and parts are overseas. Shopbot is MADE IN THE USA. Support is here (including us!)

I'd go with another Shopbot.

[rb99]

After looking closely at it, it appears to be well made.

What materials do you want to cut?

[wespor]

After looking closely at it, it appears to be well made.

What materials do you want to cut?

You seem to be the first one to think so. Mostly plywood and foam, some aluminum now and then.

[Brady Watson]

Find another ShopBot. You'll know what you are getting.

From a mechanical standpoint, that machine is not engineered for work. It appears very much like DIY machines that people have put together. If you want something like that, build your own. Otherwise, I would buy another ShopBot. If the SB has been working well for you, why would you jeopardize your work with an unproven design?

If you just liked the red color, you can paint your bot red...The SB Standard machines are superior to the machine that you show, so don't get caught up in it needing to be an Alpha. A Standard is fine for most work.

-B

[Xray]

Tough to make any comments on its structural rigidity from viewing pics ... Weak point to me appears to be the router itself, it looks like a glorified dremel tool.

As others have stated, support/parts/repairs should be a factor in your decision as well. The guy is claiming to have $15K into it, says "no low ballers, I know what its worth" ect, then doesn't even state a price. He is probably seeking at least $10K, far too much IMO for a machine whos main selling point seems to be a parts machine made in Germany.

[Joe Porter]

I don't think that machine would have any re-sale value compared to a ShopBot. the frame looked awfully flimsy, not necessarily the components, but the component size compared to the machine size seemed small. Also, the steppers are NEMA 23 which, I believe, is not as powerful or heavy duty compared to the ShopBot......joe

[coryatjohn]

I just saw this:

http://seattle.craigslist.org/est/tls/5360390275.html

Quite a good deal if you ask me. You could probably get it for $18k and it includes the 12" indexer. If you didn't want that, you could probably sell it. That's about $5k new.

[shilala]

That is one crazy deal. Indexer, drag knife, air drill, there's everything there. And it's never been turned on.
I don't know how much he'd move on the price, but I bet he'd throw in the dust collector at his asking price.

[Tom Bachman]

I just saw this:

http://seattle.craigslist.org/est/tls/5360390275.html

Quite a good deal if you ask me. You could probably get it for $18k and it includes the 12" indexer. If you didn't want that, you could probably sell it. That's about $5k new.

That one is advertised here.........http://www.talkshopbot.com/forum/showthread.php?21879-ShopBot-PRSalpha-96-60-never-unpacked-from-the-shipping-crate-Sammamish-WA