VCarve Pro Tool Database Feeds and Speeds

How realistic are the values in the VCarve Database?
Is there any chance that the folks who have been demoing the heck out of the handibot the past few months could add a few values that have been working for them to the database?
(What was used for the two color plastic key rings, etc?)


Thanks,
-Dave

Dave,
sure wish we'd get some staff help in here!

Anyway, from everything I've been able to find all feeds and speeds are SWAG, that is scientific wild ass guess and will have to be adjusted as necessary.

M

I was hoping to avoid the guessing process when it came to trying to duplicate something that the ShobBot folks were doing as a demo, over and over at multiple faires.

It really isn't as bad as all that. It only takes a few test cuts in different materials and differnt bits to get a feel for your particular machine. The values shown are USUALLY a good place to start. I personally don;t run as fast oras hard as the values shown but then again I have an older machine with older drives etc,. Vectric or any software compnay can only give you guidelines because they don;t know your machine or material specifics. If I'm cutting big box ply I have different feeds / than I do some other really good ply. I mostly run my machine by ear. If the bit is screaming I am going to slow. If I'm making sawdust I'm going to slow. The chips should be warm and the bit should be cool (make sure the spindle / router must be off first!). Mostly in keeping with the ShopBot way - ask lots of questions here and on the ShopBot forum. Russ (bot owner since 08).

Hi Mark,

We have put a lot of effort into making those SWAGs as good as possible. Since we offer a wide range of tools with different capabilities, and with many variable outside our control, it is hard to give a number that will work for all.

The best approach to a feed/speed question for Handibot is to let your decisions be guided by chipload calculation with move speeds not to exceed 2" per second.

There are a lot of resources out there, the easiest to get to is built into your Shopbot control software in Tools-Chipload Calculator.

Here is a link to a document with some other useful information:

Router bit basics

-David

Mark Evans Wrote:
-------------------------------------------------------
> Dave,
> sure wish we'd get some staff help in here!
>
> Anyway, from everything I've been able to find all
> feeds and speeds are SWAG, that is scientific wild
> ass guess and will have to be adjusted as
> necessary.
>
> M

Which Demo? I will get the feed/speed for you.

-David


Da3v Wrote:
-------------------------------------------------------
> I was hoping to avoid the guessing process when it
> came to trying to duplicate something that the
> ShobBot folks were doing as a demo, over and over
> at multiple faires.

David:
while I do have a flair for the dramatic, I did run across several cautions on the main shopbot site saying feeds where estimates. That said, so far I have found that in woods anyway close is good enough.

I find experienced operators are reluctant to give feeds/speeds. They've long since learned the value of well-made bits and know those can be pushed harder than cheap, big-box bits. They're also careful to make sure they're working with sharp bits…a dull bit can't be pushed as hard and somebody watching costs likely can't cut as fast (due to dull and/or cheap bits).

That said, one of the easiest ways to reality check your rpm/feedrate combinations is via the "chips not dust" rule of thumb. When making really fine dust, the bit is spinning much too fast for the feedrate. As a result, the bit will run hot…possibly hot enough to create problems, but that's a bit of an edge case.

Bits that run too fast/hot don't last as long. For getting started, don't fret too much about maximum bit life. Look at the quality of the cuts being made and figure out if you're making dust or chips. The PDF user manual for the big ShopBots should be available online…there's a page in it that talks about how to figure out the proper feedrate for your bit and your matieral….well worth tracking down (it's a quick read).

I like working fast (I get impatient) so I tend to push things harder than many others and find my bits last quite well. For my handibot, I'll likely have to be a bit more gentle due to the 2"/sec max feedrate recommendation.

Tim S.