I am new to CNC and the Shapeoko forum. I am a bowl turner and often have wooden bowls 8" tall. I am looking to engrave my bowl bottoms with my logo and signature. I asked Shapeoko support about positioning tall projects and they suggested cutting a hole in the spoil board and positioning the bowl under the CNC so 1" is above the spoil board then secure it. My question is has anyone used this method for tall projects and what is their experience and advice? Thank you in advance for your comments.
There is 14" between the crossbars that hold the XXL together. If you build the structure below the spoil board to hold the bowls securely, then I think it would be possible to accomplish. Whatever that structure is would be part of the supporting tabletop that holds the Shapeoko.
Depending on the type of bowl you are turning, this may not be an option. If you are turning a segmented bowl you can engrave the bottom segment before you glue up your bowl blank. If you are using a log blank maybe you could cut a slice from the bottom, engrave, glue back, then turn. That would leave a seem and might not be desirable. But might work if it will have a raised base to sit on. Just thoughts. I would hate to go through all the trouble mentioned above unless that was 80% of what I was going to cnc.
Thank you for your comment. I agree that the Shapeoko and the support structure have to be rigid. The bowl would need to be secured to the structure. I have measured my largest bowl and I only need a 5" hole to have the bowl bottom 1" above the spoil board.
Thank you for your comment. I only turn one piece bowls from log blanks and do not want to cut then reassemble them. The bowl bottom engraving would be my initial use of the CNC. I also turn large one piece platters (max 18") but the Z is within the normal Shapeoko height. Once I get the engraving project under control I can foresee expanding my CNC use to other projects.
What about making a branding iron instead of engraving the bowl?
Thanks for taking the time to comment. I have and use branding irons for my furniture and other flat work (on a drawer side or other inconspicuous area). The area on the bowl bottom is small, prominent and always seen when cleaning the bowl. I wanted to engrave rather than burn the information with a branding iron or laser. I think it looks better.
I agree with Carbide support that cutting a hole in the stock waste board (and your own spoil board if you have one) is the best way to go. A 5" hole in the center of one half of the stock board won’t have any negative effects on the rigidity of the base. You will have that hole but you could have a removable spoil board that would make the machine usable for non-bowl base projects.
The only challenge I see is that in order to fit an 8" high bowl underneath, you will need to raise the entire machine 8" and then lower it back down or have a much larger hole on the table the Shapeoko is mounted on and fit the bowl up from the bottom. Problem with that is then you need to insert another board to support the bowl.
All in all though, I think that would be doable.
I can’t find it online right now, but I remember someone modding their Shapeoko (or it might have been an X-Carve) by replacing the stock bed with aluminum extrusions that could be individually removed to allow them to stick longer stock up through the bottom. I’m pretty sure there was an enclosure built around it, so the dust and noise were contained even when the bottom was out. The obvious advantage of this was they didn’t sacrifice rigidity, and could put the extrusions back whenever they wanted to machine something shorter. I’m sorry to be so vague - I saw it a few years ago, but I do recall it seemed really well done.
I’ll continue to google and post a link if I turn it up again. It’s not a very cheap solution, but it would probably be a very robust one.
UPDATE: Ok, I can’t find the thing I’m remembering. Maybe I dreamed it. But these guys sell this Extrusions Bed Upgrade Kit, which if you messed around with it, you could probably make work very well for your purposes. Or possibly you could just be inspired by their approach:
I would use my ShaperOrigin for this application - I love my Shapeoko and I am finding that I use it much more frequently than my ShaperOrigin, but there are some applications that just make much more sense bringing the tool to the work piece rather than the work piece to the tool.
Unfortunately if the price was not so ridiculously expensive, maybe more people would consider it. The Origin is basically twice the price of a Shapeoko XXL.
Shapeoko XXL w/ Router = $1820
ShaperOrigin = $2499
It is more expensive but not double. It also does not require expensive addons like touchprobe, bitsetter, dust extraction, CAM software etc as it is all built in.
That being said I agree it is a luxury and there are many applications where a traditional CNC will beat the pants off it, but there are a few scenarios (like cutting the bottom of a bowl) that it can do some amazing things.
I don’t disagree with the potential usefulness, just the price. BTW, I went to the store and the price quoted is in $CAD at $3,600. They are giving us a friends & family discount!
Thanks for your comment. I envision a work table with the CNC secured on the top and an adjustable shelf underneath to accommodate different height bowls. Once adjusted so the bowl is above the spoil board and the bottom is level I would secure the shelf and the bowl. The exact height of the bowl bottom would not be critical as I could set the Z once everything is secure. Thx again.
Something you may or may not be aware of is the increased vertical travel of the HDZ carriage, about double the travel. The collet nut basically comes to the bottom of the gantry. This means that you could set your bowls about 3in higher than you would be able to with the stock Z carriage.
Thanks for the comment. I did look at the increased Z travel but its not enough for tall salad bowls.
I am no expert but I would suggest if you plan on making a bunch of these, design a jig that bolts down to the frame for this specific operation.
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