Bed Support

[CNYDWW]

Anyone try using 1" square extruded t slot to reinforce the bed on their buddy?

[CNYDWW]

Well, since nobody's responded i'll toss in a screen shot of a 3d model.

[COBOB]

You will have to excuse me. I have never even seen a buddy. I am abpout a week away from delivery. Does the buddy have a table flex problem? If so, it looks like you have a great solution.

[gerryv]

An interesting suggestion. My guess is that it would help some. Perhaps it could be further stiffened by mounting a number of extended gussets to each side the Powerstick and fastening them to the sheet? As I'm sure you've intended, your design provides a convenient hold-down means.

[CNYDWW]

An interesting suggestion. My guess is that it would help some. Perhaps it could be further stiffened by mounting a number of extended gussets to each side the Powerstick and fastening them to the sheet? As I'm sure you've intended, your design provides a convenient hold-down means.

Dont think the gussets would be necessary If you cut the center material a little larger and put a rabbit around the top and bottom edges so it'll fit in the slots of the extrusion. It should further reinforce the structure.

[CNYDWW]

You will have to excuse me. I have never even seen a buddy. I am abpout a week away from delivery. Does the buddy have a table flex problem? If so, it looks like you have a great solution.

You can have a problem with whatever substrate you use for your spoilboard. Humidity and temperature changes could cause it to flex.

[lgutman]

Has anyone actually used this method for building a table?

[BJRphbow]

Not exactly the same thing (more involved than just a frame), but I'm a fan of the 1" 80/20 aluminum extrude (10 series). My workplace has extremely high humidity and an mdf spoilboard (only) was problematic. Zero issues since modification. If I were going to use the extrude as just a frame for mdf, I would maybe bump it up to the 15 series which is 1.5" square. It's a touch more robust and I was surprised on the deflection under stress of the 10 series over 6 feet. Sorry for hazy pic ... cracked lens on phone.
http://www.talkshopbot.com/forum/attachment.php?attachmentid=27411&stc=1

[Ajcoholic]

Not exactly the same thing (more involved than just a frame), but I'm a fan of the 1" 80/20 aluminum extrude (10 series). My workplace has extremely high humidity and an mdf spoilboard (only) was problematic. Zero issues since modification. If I were going to use the extrude as just a frame for mdf, I would maybe bump it up to the 15 series which is 1.5" square. It's a touch more robust and I was surprised on the deflection under stress of the 10 series over 6 feet. Sorry for hazy pic ... cracked lens on phone.
http://www.talkshopbot.com/forum/attachment.php?attachmentid=27411&stc=1

I am also a fan of an all-aluminum table. I did fool with trying to hold an MDF top flat for a few years, but went with a table made up of aluminum extrusions from Hubbard CNC, and love it. It will be two years this summer with the aluminum table and I couldnt be happier.

I actually was going to order a T slot top from Techno-Isel, but they were out of stock for a few months on what I wanted, so I went with the Hubbard stock. Love it!

I think Shopbot should offer an option, for an aluminum T slot table top. Some might not want or need it. But, I would have bought it. Using both for several years, Aluminum is the way to go where humidity changes. Here, it is from 30% to 85% swing, seasonally. Thats a lot of movement.

With the aluminum top, I can cut accurately to within 5 thousandths in depth when cutting sheet goods. No where near that with the MDF, as right after I surfaced the top it would start to move.

[dewey_dog]

I am in the middle of rebuilding my BT48. I have converted it to all THK linear bearings a new Z axis and will be adding a Spindle. I built a t-slot table as you can see in the pic.
http://www.talkshopbot.com/forum/attachment.php?attachmentid=27413&stc=1

[Ajcoholic]

I am in the middle of rebuilding my BT48. I have converted it to all THK linear bearings a new Z axis and will be adding a Spindle. I built a t-slot table as you can see in the pic.
http://www.talkshopbot.com/forum/attachment.php?attachmentid=27413&stc=1

You should do the 3" lift at the same time. Second best thing I did to mine, after the aluminum table/vac hold down.

Just added two pieces of 3" x 1 1/2" extrusion to lift up the gantry. Now I have lots of Z height, and no sign of less rigidity in cutting.

[BJRphbow]

I'm with Ajcoholic ... consider raising the gantry. From your picture, the gantry is already off ... that's the hard part. It's well worth the effort. For me, the stock dust skirt was a PITA to work around when changing bits. With the increased z, I can raise the spindle up and drop the skirt clear out of the way. Not to mention the set screw to raise and lower the dust skirt was awkward to reach until I increased the z. Plus, increased z for machining larger parts. The aluminum bed and raising the gantry were two of the three best mods to my machine.

[dewey_dog]

I did not layout my whole plan I have 1.25" tool plate aluminum gantry sides being cut which are taller. I will write a post detailing the build when it is near completion.

[Designer]

I really like what you have. I went to the Hubbard CNC web site and did not find anything like it. Would you by chance have a part number of some sort I could enter to find it?

I have a BT32. It appears that you also added the rollers on each side. Am I correct?

Sorry for so many questions.

Thanks

[BJRphbow]

Since rollers were mentioned, I'm guessing the question was for me ...

I didn't use Hubbard products on my bot. I used mostly 80/20 parts, specifically the following part for the platform: https://8020.net/shop/1030.html (purchased through amazon or ebay).

The roller side plates were machined from 3/16" aluminum sheet on the bot and the rollers are skateboard wheels with ABEC bearings (8 wheels per side).

The mod required me to fab some small custom parts to make the overall build work, so definitely not a design I would recommend someone try to duplicate ... there are most definitely better ways. The final build was the third iteration of my original design, so there are definitely things I would have done differently from the beginning that would have changed the final outcome and perhaps not required the small custom parts.

The takeaway message: aluminum tables are the way to go if your work area suffers from high humidity.

J