[pat3987]

Hello - newbie here. Disclaimer that I don't own nor have I used a CNC machine. I'm trying to come up with a solution for a tedious process and wonder if a CNC could work for this. Rather than explain (and bore everyone) with too many details, I'll just try to explain what I'm trying to accomplish. I work with bamboo-like tubes that are quite small (about 10-12mm in diameter). I then split the tube into thirds lengthwise so that I get a section of the tube/cylinder that is about 8mm wide and 3 inches long. The inside of this tube (the flesh) is then gouged out so that what remains is a thin piece of bamboo which maintains the original diameter of the initial section I split from the tube. It is gouged out in a way that leaves the center of the piece (down the length) at about .60mm and it gets gradually thinner from the center to the sides of the piece. I may be totally off base here, but as far as the carving out the center of the piece goes, is this something a CNC machine could do with precision? Would be be possible to have the program cut in such a fashion that gives the exact thickness (.60 mm etc.) measurements I've described?

I would post photos but as a newly registered member I can't yet. If what I've described makes sense to anyone please let me know if a CNC machine could be used for this.

 

[Semipro]

Hello and welcome to the router forum
You can post pictures provided they are on your computer hard drive you cannot use a link

 

[pat3987]

ok great below are some photos. The first photo is of the piece before the "flesh" is gouged out. This is how it would look before doing anything to it on the CNC. again, about 8mm wide by 3 inches long. The other photos show finished pieces so you can get an idea of the curve that remains and the thinness.

 

[Stick486]

welcome to the forums N/A...
a ball bit and router table w/ feather boards can give you what you want..

.
https://www.freudtools.com/products/18-138

 

[difalkner]

Welcome to the forum, Pat! Add your first name to your profile so it shows in the side panel and clears the N/a. Add your location, as well.

Yes, a CNC can cut that but the bigger issue is figuring out how to hold these small pieces. I suppose you can cut them long and clamp them to a fixture or the spoilboard...

David

 

[4DThinker]

Yep. Tapering them is no problem for a CNC, but rather for the person trying to clamp them onto the bed of a CNC without the hold downs getting in the way of the cut. A little custom suction jig perhaps. If mass producing them is your desire, then I'd make 2 racks for holding several each. Fixture on the CNC bed to hold a rack. Let it cut one rack's worth while the second is being loaded with blanks. Swap out racks.

4D

 

[CharleyL]

CNC machines are expensive. Both methods offered by others will work. It will just depend on how many and how fast you want to make them. For about a hundred or less I would just go with a router table, feather boards, and maybe some guides, plus a pushing device to feed the pieces through safely. The quality will depend a lot on how accurately you can prepare the blanks for size to match your setup and router bit.

Charley

 

[scottgrove]

I believe so with an indexer. I just started playing with Shopbot's handibot.
Here is a FB post show carving a skull.
https://www.facebook.com/scott.grove.587/videos/10157615352933777/

 

[ger21]

How are you currently removing the material? With something so thin, tearout may be a real problem.
As other have mentioned, holding them down will be very difficult. What I'd do, is rough cut the blanks long, so you can make a fixture to hold them at the ends. Then, after machining, trim the ends to length.

 

[roxanne562001]

Welcome to the forum

 

[MEBCWD]

Welcome to the Router Forums. I think the question here would be if the cost of a CNC would be cost-effective for your shop. Are there other projects that you could use the CNC for? If you will be mass-producing these parts I think a vacuum jig would be good for holding the parts for machining and as 4D said, a jig that would hold several pieces at a time would be the best way to proceed.

 

[pat3987]

Thanks to everyone for so many great replies already. The pieces are used to make oboe reeds and the current method of gouging or removing the material is outdated, imprecise, and overly troublesome. we basically use a small manually operated "machine" to slide a curved blade across the piece, removing one strip at a time until it get to the desired thickness. Google "oboe gouging machine." These machines are still quite expensive, from $1300-2300. Then we need multiple machines to produce a selection of results (the thickness etc. has to change with the weather seasons).

Barring how to hold the piece down to make the cuts, would a CNC machine be able to cut precisely enough so that my end result is an exact thickness? Starting with something about 2mm thick then taking it down to .60 mm. I imagine this would require a really small and fine bit? And is there a way on the programming to vary exactly how thick it will cut at exact points if the dimensions of the starting blank are programmed in? My dream, which may end up being farfetched, is for a machine like this to gouge the pieces not only precisely, but then also allow me (on the computer program) to alter exact specifications of thickness and gradation etc.

 

[difalkner]

It's not uncommon to have CNC machines that work within a few thousandths but you'll likely spend the same amount or more (emphasis on more) for a rigid enough CNC machine to hold those tolerances.

The other factor will be the environment; humid and the bamboo will be thicker, dry or low humidity and the bamboo will be thinner. You could check the thickness today and find it to be 0.60mm and 0.65mm tomorrow if the environment changes.

What tolerance is acceptable for this application? From my limited knowledge on wind instruments I'd say the tolerance is small but I know the reeds must vary from different batches and suppliers.

David

 

[marecat3]

Welcome to the forum

 

[TimPa]

to your question, i think yes. at least the machine i am using (CAMaster panther 404) with Vectric Aspire can perform the specs your are asking. the programming and tolerances can be very precise.

as you mentioned, the variable in your project would be the "external" diameter, and how linear that diameter is along the length of the blank - all with regards to a reliable hold down method. an individualized vacuum hold down jig could be designed/built that may hold down the "average' of the diameters being used. the jig would be periphery lined with a rubber gasket which could allow some diameter deviation.

the method of holding on the sacrificial ends which are removed later would also be a method to pursue..

is the external surface left on the reed, or is it shaved/machined/shaped also?