CNC lathing

**handi** · 08-18-2001, 05:30 PM

Bandsawgal,

The two cuts would be parallel and slightly overlapping. in x or y does not matter unless you see more vaiation in one or the other.

However, since you mentioned that the problem seems to be fixed to one spot, I'd be looking at the table. Theoretically, if you lay down a bleed board and then mill it flat, any variation in the table should be milled out. You might want to check between the table and the frame at that spot and be sure that there is no gap there. If there was, the vacuum might not close the gap when there is just the bleed board on the table. (like when you are milling the table.) But when you lay down a sheet of ply, you dramatically increase the vacuum pressure, which may then pull that section down a little more, creating the dip that you are experiencing.

The table does not have to be super level, since the gantry runs up and down on the table frame, it will be out of level by the same amount as the table.

Hope this helps,

Ralph

**bandsawgal** · 08-31-2001, 05:28 PM

Hi Ralph, Did you miss your usual fan mail..LOL

I just wanted you to know that I'm really getting the hang of this now and I've only set fire to the wood 3 times

..(now I keep water handy just in case lol...
My boss has constructed a table that I can push the cut wood onto, and the vacuum pressure seems to be holding nicely.
My only concern is the level of saw dust (both on the table and in the air) that is created by the cutting of the plywood. I am hoping that my boss will create a proper system for the table dust to ensure that I no longer have to breath it in to such extent. On these systems, what is usually devised to reduce the sawdust from the table itself and make it a safer work environment for the employee (low paid victim

? Right now the saw dust level seems pretty high. Is this how it normally works?
Have a nice weekend
Bandsawgal

**handi** · 08-31-2001, 06:28 PM

Bandsawgal,

I used to keep a squirt bottle handy near my machine during certain jobs too.

As far as the dust goes, there should be some sort of dust foot on the machine that covers the tool during operation. While virtually every CNC has pretty bad dust collection, it should certainly keep the airborn dust down. An Anderson Stratos should have a 6 or 8" pipe moving about 2,000 cfm attached to it.

Also, if you are creating fine dust during cutting operations, you may be cutting too slow or at too high an RPM. (This would also contibute to burning/fires) A 1/2" spiral bit should be cutting through 3/4" plywood at 300- 400 inches per minute with an RPM of 16-18,000. When finished cutting, the bit should be warm but NOT HOT to the touch. You should be creating mostly chips and flakes, not dust. Your vacuum issues may not let you run quite that high, but the faster you run, the longer the tools will last.

Hope this helps,

Ralph

**bandsawgal** · 09-01-2001, 11:26 AM

Yep! Of course you are always so helpful! The dust effect is worse since we use an air pressure hose to blow the dust off the table afterwards. This forces it into the air more. I was thinking of devising some sort of shop vac procedure that would lessen the effects overall.
Also I did want to mention that in keeping with your last successful article in Woodworker's Journal, you might also consider asking to do an article on CNC operations.. since you are so knowledgable on the subject

Bye

Bandsawgal

**bandsawgal** · 09-30-2001, 05:48 AM

Hi Ralph, Its been a while since I wrote you so I just wanted to drop you a line and let you know that because of all your help the CNC is running well and I finally have a handle on what I am doing. (I do have a water squirt bottle near the machine now too

You have been really helpful so thank you so much.
Best wishes
Bandsawgal

**handi** · 10-01-2001, 08:01 PM

Bandsawgal,

I'm so glad to have helped out, and very happy that you are getting more familiar and comfortable with your machine.

Just as a teaser, I'm currently developing a new clamping system that will be usable on the Andi Stratus and will REALLY expand your capabilities

Enjoy,

Ralph

**bandsawgal** · 10-03-2001, 08:36 AM

Aha! So you've been playing with some new ideas eh? Did all my questions and whining inspire you? lol...

Please let me know what you come up with as far as clamping goes on the Andi Stratus series as you now have me intrigued!
Well have a good day in the shop
Bandsawgal