BT48 to 4x8 ?

[ghostcreek]

Has any one attempted to change a BT48 to a full 4'x8' machine. I love my Buddy, but after a year of use, I could use a 8' machine. The Power stick is cool, but looks like it will take up too much shop room. Let me know of any attempts or any info. Thanks, and Happy Holidays.

[jerry_stanek]

You may be better off selling your buddy and getting a new table.

[erik_f]

I asked SB not that long ago and if I am remembering correctly I think the number was around $2500. I have a first gen Buddy, but got it when they were much less than they are now. The upgrade would still keep me about 3k under what a new PRS standard 4x8 would cost for my total investment.

[ghostcreek]

I just look at my Gantry and table frame, I look at a drawing for a 4'x8' and I see little I would need to upgrade.
I will call shopbot after I price around my idea. I am starting to get carried away looking at linear motion catalogs!

[erik_f]

Same here...would be pretty easy with a little elbow grease.

[jerry_stanek]

you still have to get table legs base plus the rails and another stepper and driver.

[erik_f]

to go 4x8 and have the same exact machine that SB sells, you would need two legs, two side extrusions, spoil board supports, guide rails, v rollers, a driver and stepper. As far as I can tell.

[jerry_stanek]

P;us two racks how long are the cables on a buddy.

[erik_f]

I was including the racks with the guides. The cable.s are a good point

[ghostcreek]

By my measuring, the cables are too short on the BT48. Making up new cables is a minor issue (for me, I work part time doing factory automation).
Looking at the drawing of a 96x48, it shows only two sets of legs. Does your experience show 3 sets of legs needed?
Not trying to get the exact same machine as the factory, just sizing it to meet my Gantry size (BT48).
On a side note, for any one looking here thinking about a Buddy vs full size, Go with the full size!
My BT48 is Great, got me started in CNC maching, paid for itself with small signs. As I started making signs had more people wanting
bigger products then my table could handle. I am motivated to upgrade by a 6'x3' sign I made on the Buddy. I really never want to do that again!

[erik_f]

I'm not sure if anyone else has posted this either, but what is the exact brand of aluminum extrusion that SB uses? I have looked at 80/20 and don't believe they are the same...maybe Bosch?
I agree on some levels that bigger is better when buying a machine...but for me I only have a one car garage to work in now, and even though I wouldn't have a problem with a 4x8 cnc in my garage...the wife type unit would destroy me

[Gary Campbell]

Eric...
ShopBot uses Bosch-Rexroth extrusions.
Gary

[erik_f]

Thanks Gary.

[gwerner]

Michael

If you are interested in BT48 legs, I will be selling 4 buddy legs very soon, like new condition. Email me and let me know. gwerner at intelliviewuas.com

Greg

[erik_f]

Maybe SB should put together an upgrade kit for the BT's that would include everything you would need to grow your BT. Just a thought.

[gerryv]

Erik, I asked for a price on getting all the parts needed to upgrade my BT32 to a BT48 some time ago. Tech support responded that they use jigs to make sure everything is aligned but, nonetheless, they were going to forward my request for a quote to someone once I asked them to. I never heard back though. It would certainly be nice to know.

[erik_f]

Maybe I'm way off here Gerald, but it would seem you could almost just get away with a new gantry center section, and 2 new 48" table cross members. Would it require much else?

[gundog]

I have a 4x8 PRS and wished I would have gotten the 5x8 or 5x10. I started making a product that uses material that comes in 54"x96" sheets. I now have to either cut 6" off the 96" side or cut the sheets in half making them 54"x48 this makes double the tool changes for each sheet or trying to hold the 6" strip. The material is expensive so throwing out the 6" strip is not an option no mater how you look at it, it now takes 2 setups and usually double tool paths and changing bits. I am not sure how much more the 5' wide table costs over the 4' but I wished I had it.

Mike

[erik_f]

It seems no matter what size machine you have, you can always use something bigger. I guess I figured when I bought the BT48 that the BT32 was just too narrow since most of the things I like to do come from 4x8 sheet material. I had a 4x8 prt and just didn't have room for it so I had to let it go. I knew I would pine for a larger machine...but honestly I haven't found anything I couldn't do with a little muck mucking. I love my little bot. I do miss my big one too!

[gundog]

After posting this I got to thinking about it and I am having them send me a quote on what it would cost to widen the table to 5'. I will need a new gantry extrusion and all new cross braces. I wonder if my old parts would have any value to anyone to help offset the cost??

Mike

[gerryv]

Erik, Exactly, I came up with pretty much the same conclusion which is why I asked. They're right about the importance of alignment of course but the process is pretty basic stuff - certainly less onerous than rebuilding or upgrading a milling machine it seems. I've got an extended Z axis on my BT32 so was also looking at buying a stock Z-axis mounting plate with V-groove rollers and adding another set of bishop- wisecarver tracks on the rear of the big gantry extrusion and then rigidly tying the front and rear plates together for additional rigidity. Spacers (washers) would be needed to make room for the steppers depth but nothing much. It's the same extrusion used on the 5' machines so I can see having a 5' wide Buddy with extra rigidity in the X axis for doing some pretty interesting stuff with a scanner and Aspire 2.5's excursion into the real 3D world. That could go a step further if SB goes ahead with the upgraded indexer software they've talked about. I've already got my 3D glasses waiting on the shelf! :-)

[erik_f]

Gerald, I'm a little confused, but I think you're saying...put a mirror image of your Y/Z car on the back of the main gantry extrusion and then tie them together. Maybe this is what you're getting at, but what about a fully functioning Y/Z car on the front and back of the main gantry extrusion with a different tool in each one for "pseudo tool changer"? The Y/Z cars wouldn't be able to be independent on the Y because of the Z motor, but you could tie them together driving them on the Y, but the Z of each could function independently with little problem. Hope I'm not confusing things further.

[gerryv]

Yes, that's what I was stumbling about trying say Erik. Your expansion on that is really a neat idea: drill, milling head, paint applicator, hmmm

Thanks!

[erik_f]

I just edited my previous post. Glad I was getting you...now this is interesting!

[erik_f]

Ok...now this may seem over the top...but I think it would be a great idea for a compact yet larger capacity machine. So I was looking at the BT48 and thinking about a moving gantry, and then the idea popped in...well if the gantry and the table were able to move? Ok now I'm going to bed

[mikeacg]

Erik,

If you split the movement between the gantry and the table, you would have less movement (making it faster) and you would reduce the overall footprint with a PowerStick by half as well. It might be a good concept for them to look at with the new 'small' machine they have been asking about in their surveys. They could test it on a miniature scale and then add it to the Buddy as both a new machine and a retrofit. I like it!

Mike

[gerryv]

I've wondered about pulling the travelling belt table off something like a sander, replacing the motor with a stepper and Voila! a giant, killer CarveWright on steroids that's not a toy. It would need roller type hold downs of course but that seems doable.

Is that nuts? :-)

[erik_f]

I don't think it is nuts...you think it would better than the Powerstick idea?

[gerryv]

Erik, I been distracted trying to choose between a Felder or Minimax combination machine so I've not been on the forum. I always hate situations where the price is high and the knowledge is low (mine that is).

Actually, I'm thinking that the modified Powerstick idea is better because it is more in keeping with the existing operating means and, I think, would require less radical surgery. I like the idea because it still allows for minimal storage space compared to just going to a larger table.

[ghostcreek]

Wow, outstanding thoughts and ideas. I still haven't gotten Shopbot to get back to me about the cost to upgrade. I am backing away from the power stick because of the troubles I have heard about with accuracy and stability. Comments about the powerstick and it use cutting full 4x8 sheets (1/2 ply up to 3/4" ply & HDU. Thanks guys for the ideas.