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View Full Version : I could use a better wooden cnc table plan



Steve knight
03-20-2007, 12:52 PM
I am about ready to build my shopbot cnc wooden table. I have their plans but I will only use them for reference I don't want to build it out of solid wood. it iwll be made from 3/4" batlic birch laminated for thickness. there is a fellow who made a nice table first name of Dirk who has done it right but the pics only show so much here is a link to the pictures http://s154.photobucket.com/albums/s266/knighttoolworks/?
but having plans would make life easier. I used to build tables in my head but since making hnad planes for 7 years and making a table for my kid this christmas I found out how much I Have forgotten. having a measured drawing would make life far better.

Perry Brock
03-20-2007, 1:03 PM
Steve,

I have a friend who built the ShopBot table then they told him his Alpha model would only work with their metal table. You might want to check that out before investing the labor and materials.

Steve knight
03-20-2007, 1:17 PM
I think I told them I was building the table from wook. I have found a few people who have built one for the alpha. now the new one that is coming out or just came out won't work with a wooden table. but I missed it by 2 months (G)

Perry Brock
03-20-2007, 3:18 PM
He bought his last year. I assembled it for him and the carriage rollers for the Alpha are V shaped and travel in metal angle welded on 45 degrees. Other than dealing with that I don't see why a wooden table won't work if it is ridgid enough.

My friend was very frustrated that he was able to order the alpha without the metal table and then they tell him he has to have it for that model.

I am just trying to save you the same frustration he had.

Steve knight
03-20-2007, 3:22 PM
mine will have angle iron for the rails to attach too. I wish I had the money to buy the metal table but I ran out.

Perry Brock
03-20-2007, 4:22 PM
He built a vacuum table that utilizes his dust collector but he has problems holding smaller pieces. He mostly blocks out cabinet panels from 4 x 8 sheets but does some sign work.

I play with it when time permits and have been meaning to see if the shopbot software will accept Corel files. Do you know whether it will?

thanks,

PLB

Steve knight
03-20-2007, 4:31 PM
He built a vacuum table that utilizes his dust collector but he has problems holding smaller pieces. He mostly blocks out cabinet panels from 4 x 8 sheets but does some sign work.

I play with it when time permits and have been meaning to see if the shopbot software will accept Corel files. Do you know whether it will?

thanks,

PLB
I am doing mechainical clamping for awhile.
what do the files end in? the normal ones are eps dxf dwg ai wmf pic but importing to autocad or turbocad would give even more options.

Steve knight
03-20-2007, 7:08 PM
here are some new drawings. this design is simple and easy to build and looks very strong.
http://s154.photobucket.com/albums/s266/knighttoolworks/
http://www.knight-toolworks.com/pictures/three%20quarter%20view.jpg

Keith Outten
03-21-2007, 5:57 AM
Steve,

I just assembled my second ShopBot, both are 48" by 96" PRTalpha models with steel tables. I considered building a wood table for my ShopBot to save some bucks but decided at the last minute to bite the bullet and buy the steel table. I am glad now that I did, the machine needs to be as ridged as possible. I expect that your cost to build a wooden table will eventually be about half of the steel table, you might consider waiting, save your pennies until you can afford the prefabricated steel.

The Alpha is very fast so the forces involved are considerable. Your table needs to be able to provide support for heavy sheet materials as well as provide as ridged a platform as possible for the machine itself. Corian is about 125 pounds per sheet, a large thick table top will most likely be heavier. The ability to plane large table tops might be sacrificed if the table is unable to provide the proper support. Precision may also be sacrificed and your ability to machine inlays and parts with a close tolerance fit may suffer. Should you ever feel the need to upgrade to a spindle they are much heavier than routers, your table will need to support more weight and withstand higher forces when the router switches direction...very quickly.

Had I known in the beginning what I know now I would never have even considered a wooden table. ShopBots are like laser engravers, you never know what kind of work you will be doing on a given day and the more you learn the more you stretch their capabilities.

ShopBots ship with two programs, PartsWizard for drawing and the Control Software that actually runs the machine. You can design in any program you like for the most part as long as it will export your vector file to PartWizard for assigning toolpaths. PartsWizard will import several files (dwg, eps, ai, etc) I use Corel Draw in my shop most of the time, I export Corel files to eps then import them into PartsWizard. Lots of people use CAD software for design work and export their drawings. At CNU we just purchased VcarvePro for sign work, it is well worth the price ($500.00) and it will create sbp files with toolpaths that are ready to run in ShopBots Control Software. PartsWizard will only vcarve ten built-in fonts, VcarvePro will vcarve any font on your computer. Artcam Pro will set you back $7,500.00, I haven't found the need for ACP yet :)

For the record after three years of owning my ShopBot I am still a novice, you may get a totally different opinion from others with much more experience.

.

Ed Lang
03-21-2007, 8:51 AM
Steve,

Read and then read again what Keith wrote above.

Then think about this......


The second ShopBot, a 5' X 10' machine I assembled about a month ago almost got a wooden table. I bought a steel table from ShopBot for the 48"X96" Alpha a year ago. I am glad I did. The 5'X10' machine has a home built steel table that is designed after the ShopBot table. BMG Metals cut and delivered the metal for about 1/4" the price of the ShopBot table. This big table is welded, not bolted. Welding is the key to a stiff machine. I will weld the smaller table one day as well. Heavy is better here. Lots of weight in the table will make for a smoother cut. Of course you have to tune up the machine as well.

Now if you are going to buy one of the new PRS machines, you cannot make your own table anyway so all of this is out the window. The table is part of the machine now.

Good Luck.

Ed

Steve knight
03-21-2007, 12:52 PM
I wish I could have gotten the metal table. but I ran out of money and had no real choice. I don't have the tools to really work with such large peices of metal to do my own.
but I will be adding cross bracing to it and it should be plenty strong. it was a choice of a metal table or a spindle. and now looking back to get a spindle later would mean sending the cotrol box back to shopbot to rewiring where a table I would just ahve to swap out later.

Mike Ross
03-21-2007, 3:42 PM
Steve,
Congrats on the shopbot purchase. Hold up a 7-11, borrow from your inlaws, whatever it takes to get a metal table. Ed and Keith seem like 2 really smart experienced people and they seem pretty certain wood is not the way to go. I am not that smart, but I live an hour from Portland and I own a shopbot. Last week I watched a 9 ply stress laminated Hard Maple board corkscrew in less than 2 days.

Wood moves even when laminated and especially in our climate.

Built my own steel table off shopbot plans with a drill press and a rigid metal chopsaw. Steel was less than $400.00 and the bolts came with the machine.

Feel free to shoot me an email anytime. Its always nice to have another shopbot guy around. Especially during assembly and when you turn it on the first time.

Good luck,

Mike Ross

Keith Outten
03-21-2007, 8:45 PM
Steve,

Welcome to our growing group of ShopBotters here at The Creek. Whatever decision you make concerning your Bot and its configuration you will find it is an excellent machine and a great value.

.

Steve knight
03-22-2007, 12:57 AM
got the wood and the screws and no extra money so I will make it work (G) I will make the top a torsion box and that should add quite a bit of streangth to it.
I am sure I will need some help. getting all the power taken care of will be fun with a 3 phase spindle.