Buddy Z-height

[mwpfeifer]

I keep hitting the upper Z-axis limit on my Buddy due the thickness of the material I'm carving and the necessary length of the cutter so I'm wondering if anyone has designed or already fabricated a modification to raise the Y-axis beam which would provide an additional inch or two in the Z-axis.

Any suggestions as to the best way to go about a mod of this type?

[erik_f]

I ground off the little tabs on my router and slid the router up in the mount. The only problem being if the router us up too high the stock dust boot won't work.

[kevin_morin]

Michael, could you buy some extrusion like the 2" or 3" square version of the 2" x 6" side rail extrusions on the Buddie and just use the T-Slot aluminum plates to stack this 'lift box' under the side rails? Wouldn't that then the YZ gantry fasteners and mounts up by lifting the entire 6" side rails?

I'm thinking of the exactly this modification and the Buddie has only been out the crate a week.

cheers,
Kevin Morin

[mwpfeifer]

Kevin,
That is the same idea I have come up with and seems to be the easiest solution. I queried Shopbot about a potential mod for raising the Z and they replied in the negative. I'm guessing they just haven't thought about it yet. Seems like a pretty good idea to me for various reasons.

I had considered using solid aluminum bar stock but, I like your idea regarding the extrusion better. Have you any idea where to obtain the same style of extrusion??? I remember some of the forum members mentioning exrtusions for t-track being available on e-bay, might be a good place to start looking. I know I'm getting really tierd of thumping the upper Z stop and I expect I'm not doing the stepper any good either. Five inches of Z travel sounded adequate before I bought my Buddy but, I didn't understand one needed to subtract the length of the cutter. That was probably obvious to most folk but sometimes I'm not the brightest bulb in the box. Of course the excitement of getting a new toy probably has a tendency to cloud one's brain a bit also!!!!
Mike

[myxpykalix]

Not sure if this is what you are referring to, but would 8020 extruded aluminum work for your application?

[kevin_morin]

Michael,
I've made some images of the idea to jack up the Buddie48 using some of the existing 80/20 1.5" x 6" extrusions.

39275.jpg

These images had to be reduced to a point they aren't as useful as a few more kB files might be, so I hope the idea comes across?


39276.jpg

This is the way our Buddie looks at the "Front" or back of the 'right' side rail, I've colored the pressed deck or main table frame lighter so the image was more easily understood.


39277.jpg

I just copied the existing side rail to make the drawing faster to do. The new extrusion side rail is green here to show that it's not part of the original.


39278.jpg

There are a variety of ways to support these piled/stacked extrusions. I figure that the 80/20 side plate (PN 4370, shown, or PN 4423) would do the most good as any side-to-side deflection would be tension along a pair of these on each side?

I also put in a piece of flat bar that would help if drilled along the end pattern, and I show some 1.5" x 1.5" of the same extrusion series that might be a help?


39279.jpg

Last image shows a pair of 1/4" x 3" bars that could T bolt to both the vertical extrusion and the two longwise 1-1/2" x 6" pieces that were stacked.

I think all the brackets could be machined on the sBot and the extrusion is available on eBay or 80/20 Garage Sale, maybe other manufacturer's T-Slot extrusion would match up (?) so Bosch or some of the others might work too?

If the side rail were kept rigid, in column, I don't see why this won't work, I hope the Tech Support Guys wills advise why its not recommended- if there reason it might degrade the sBot's performance. All I want to do is get the advertised Z, right now I'm a bit shy of that envelope.

cheers,
Kevin Morin

[erik_f]

If tech support doesn't approve I would think its because the two pieces bolted together wouldn't be nearly as rigid as one solid piece. I'm no engineer...but, if you look at the gantry being bolted to a piece that is bolted to a piece that is bolted to the frame. The way it is put together now the frame bolts into the aluminum extrusion and the grantry is bolted into the same extrusion...the extrusion is more of a tie together point...but I don't see any reason why your system wouldn't just fine.

[mwpfeifer]

Kevin,
Great pictures! How did you do that?? Looks like you have been spending a few brain cells on this idea today. I did some shopping on e-bay today and have on order 1.5 x 1.5 and 1.5 x 3.0 8020 extrusions which it turns out is what Shopbot uses on the Buddy. Apparently the earlier Buddys were assembled a little differently than those with the power stick X drive. (See the following post http://www.talkshopbot.com/forum/mes...tml?1234245684) The legs are on the inside of the extrusion. I planned on tying into the leg/extrusion attachment using a 1/4" plate and a 1/4" spacer then a 1/4" plate on the outside similar to your idea. The reason for both the 1.5 and 3 inch extrusions is to test test to rigidity. I'll use the 1.5" first and if that checks out ok then replace it with the 3 inch.

[khaos]

I have not shopped around for price but I found some extruded bar in many sizes here(prices shown per inch):
http://www.fastenal.com/web/products...2692&Nty=0

HTH,

[kevin_morin]

Erik, I agree that the two extrusions stacked isn't as rigid as a taller extrusion but I didn't happen to find any taller than 6"- yet. [The Y/Z gantry seems like its 3"x8" but I haven't found that either] So I figured to put the fish plates on and stiffen them in tension, don't know if it will be rigid enough but it looks like it will be. I could weld the two extrusions in stitches along the interface at their long edges? I don't think they'd distort with a few little TIG stitches?

Michael, there is an existing online SketchUP 'component' or pre-made model of the Buddie48 so I downloaded it and edited to the Buddie SBot sent.

cheers,
Kevin Morin