Is This Worth Trying?...

[big_d]

Hi all. I'm a noob to the shopbot. I have an oppotunity to try to revive one that is dissasembled and in storage, but I'm not sure if it's going to be worth it. I've been told it doesn't have a spindle/router which is not that big of a deal, but I was also told it doesn't have the computer which I'm assuming he meant the drivers and control. Here's a pic of it as it sits now, I did see another post from a member in my area that has one that I could go and take a look at and possibly get some advice/help with setup. Thanks for any help, David


8621

[big_d]

Here's another pic...





8622

[big_d]

One more...



8623

[Brady Watson]

David,
That appears to be a 1st gereration PRT, with 1:1 ratio steppers. I can't see if there is a steel table with it or not, but you can build or have one built for not a lot of money. If everything else is there, here's what I'd recommend you doing. I just bought a machine like this in similar condition and pieced it back together again, while making some much needed enhancements:

1) Buy complete 4G control box from ShopBot for $1295. This will bring your electronics up to date for the machine - on par with new PRS Standard tools and you'll have a warranty on the electronics.

2) Sell the 1:1 motors and buy [4] 3.6:1 ratio new motors from ShopBot complete with 25 tooth pinion gears for X & Y and a 20T for the Z. I think the motors are about $350 ea new from Oriental. You'll have to check with both to be sure.

3) Buy a router of your choice for $350 or so, OR a spindle directly from ShopBot.

4) If they are still available, get the Alpha style motor mounts from ShopBot to replace the AL ones shown in the pics.

As the things sits right now, I wouldn't offer any more than $1000 for it, since you'll put close to $3500 into it to get it into shape and ready to turn on and cut.

Just my .02
-B

[big_d]

Thanks for the reply Brady... He's actually asking $500 for it, so you were pretty much on target there. I thoght the PRT's were bench top models though?.. I guess the earlier ones were bigger though, I think this ons is 5' x 8'.

David

[dray]

You have all the basics, the electronics you can upgrade to gecko or another company and run g code..

All the electronics companies are a cinch the diagrams are simple (connect this to this, yada yada) the software will do the gear ratio etc for you. The hard part which is manufacturing a gantry and linear bearings is already done for ya!!



You can have it up and running in a couple days for under $800.

It may look like a mess but I can see it all up and running!.

Heres a link to gecko drives
http://www.geckodrive.com/

Gecko's are really good drives, but you can also get some here:
for pretty cheap from dave at

http://www.hobbycnc.com/

its a really fun tool to have lying around the shop or garage!! DO IT!
also..

Cruise through the archives on this forum you will find table designs and everything you need to have that sucker up and cutting by Sat!!!!



P.S. if you are local email me if you dont want to hash it out. I'll take it off your hands!

[big_d]

Danny, that's the exact answer I was looking for. That's exactly what I told my wife when I found it for sale. I was looking at DIY'ing one, but then I found this and figured just that-all the hard work would be done. I was just worried about issues hooking up after market drives, but in my mind I kept saying the steppers are just motors, it's gotta work... famous last words


Thanks, I'm going to pick it up tomorrow morning!!!

David

[dray]

Pessimism is a disease! Dont let it get in the way of anything!!

Thats a really cool deal you got on that! Wish I found it first lol!!

Damn! I saw a new line of Aquarium stands coming out of that one..

Ahh well I have enough projects going at the moment anyways

[Brady Watson]

If you just want it for tinkering & enjoy messing with electronics, doing something like Danny suggests sounds like it might be right up your alley. If you want machine specific support and some kind of reference in addition to a factory-based setup & warranty, follow the recipe I laid out. EITHER way, you WILL want to replace the motors. 1:1 ratio motors are too coarse even with microstepping drives to give you even moderate resolution. Trust me on this. I just did what you are setting out to do a few months back on a nearly identical machine. Either way, good luck with it & have FUN !!!


-B

[Brady Watson]

3.6:1 SH geared motors are actually $257 ea from Oriental. ShopBot uses low backlash versions of these motors referred to as TH geared, because they are tapered instead of straight cut like the ones I mentioned for $257.

-B

[bcammack]

Well, I _am_ jealous and I don't even have a place to put one!


Good find. Sounds to me like it's essentially complete save for the disassembled state. "Doesn't have the computer" could simply mean that the control box is there, but the PC with the SB3.EXE program to control it is absent. That sort of thing is easily rectified.

A great find and a first-rate project.

[big_d]

Brady, thanks again for for the info. I'll definately check into the motors. The ones with it are Vexta PK299-01AA 1/8" 2 phase motors which look like they are Vexta's standard series 1.8 degree motors like you mentioned earlier.



8624

[big_d]

Thanks Brett. That's what I'm hoping he means by not having the computer, I'll find out here in a few hours. If that were the case, it would truley be an unbelievable deal so I'm not holding my breath. Either way, it'll get me started. I've got to make a bunk bed for my daughters and if it ends up being anything like my sons bed, this will save me soooooo much time. I made his with my router and a straight edge which took me forever, here's a pic of it.






8625

[big_d]

Here's a shot for size comparison...



8626