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.

3619

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?


3620

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.


3621

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.


3622

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?


3623

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/messages/33572/36721.html?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.ex?Ne=999600930&N=999602692&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

[erik_f]

What about keeping the original extrusion in place and dropping the table down by drilling some new holes in the legs, and putting your second extrusion under the first. This way your gantry is still coupled to the frame via the extrusion and not "hanging out in the wind". I think this is how I have seen some one else do it. Bob Dodd I think. Do you plan on extending your Z? The only reason I ask is you don't want to go too high where your Z won't reach.

[erik_f]

http://www.talkshopbot.com/forum/messages/28/29637.html?1210288494

Sorry about the double post, but here is the thread. It looks like Mr. Dodd drilled the side of the leg attached an aluminum plate and then bolted into the end of the extrusion...perhaps there is some advantage there for that method, but I don't see why it wouldn't also work to run the extrusion in the same fashion SB did it originally along the face of the leg...and then if you wanted to use some fish plates you could but most likely wouldn't need them. Take anything I'm saying with a grain of salt...I'm mostly a farmer tinkerer type.

[kevin_morin]

Michael, the idea Bob Dodd used is much better than mine, here is what I think I'll try, at least this confirms the idea will work and that its been done.


3624

Overview of dropped table with new extrusion BELOW the original and fully bolted to the legs and the table underneath the new extrusion.


3625

This is another point of view on the (back/end) of the "Front" side showing the extrusions stacked but using the pressed steel leg to make the two pieces rigid.


3626

Outboard view from the left of the "Front" of the Buddie48 showing the lowered deck/X-table and new extrusion in green.

I think I'll start looking for some extrusion for this change. I would like to cut on the 'top' of deeper material, not to get a Z plunge of 10" but only to work on the upper level of deeper stock. With an X table of a few inches, a cutter of 2" - 3" the clearance for stock gets down to a few inches. I'd like to cut the same few inches but on TOP of deeper material.

cheers,
Kevin Morin

[gerryv]

Hi Guys,

I bought Bob Dodd's unit last fall, mainly for my son, but he's heading off to school for about a year or two so I've not actually gone beyond tinkering with moving the axes movement a bit and I'm now waiting for my garage to warm up.

I liked Bob's approach of lowering the table and extending the Z axis because the rigidity of the frame was not compromised. I'm not sure exactly what was involved in extending the Z axis though.

Depending on where you are you'd be welcome to come and check it out or, if too far, I could get it uncovered and take a bunch of pictures.

Just let me know,

Gerry V
Belleville, ON Canada

[kevin_morin]

Gerry,
Thanks for the very kind offer, a trip from Alaska might eat into my S'Bot budget!

At this time my main interest is to gain the full 4-6" of Z space that the table and tools erode, so dropping the X table will probably accomplish what I'm trying to do? If I were to attempt deep pockets like one shown on Bob's post in Michael's link- then I'd have to start looking at the Z axis too.

Until then, thanks for your offer and willingness to help other S'Botters.

cheers,
Kevin Morin
Kenai, Alaska

[erik_f]

no way to simply move the spindle or router up a bit to gain you your few inches. Like I said earlier I have had success pushing my router up in its holder to gain a considerable amount of z.

[gordon]

There is a simple solution to gaining a little more bit clearance, approx. 2", from the Z axis. To do this, remove the spindle from the Z-beam and then the adapter plate from the spindle. Now, rotate the adapter plate 180 degrees, re-attach it to the spindle and re-mount the spindle to the Z.

This can also be done with a router to get a similar result.

The only drawback is in either case is that the dust skirt won't clear the gantry or Y plate.

[khaos]

Sweet. You know I am checking that out as soon as I get home. I am in the middle of a dust boot rebuild anyway. Great post Gordon.

[gordon]

Here is a picture that shows the height gained by flipping the spindle adapter plate end for end. The measurements are the additional Z clearance that you'll have if you were to do this.


3627

[mikeacg]

Thanks for the info Gordon! I am looking at building my Buddy tables out of one the honeycomb materials like Nida-Core or Plascore for lightness and rigidity and may need the extra clearance. I won't be limited as much in depth now!

Mike