How does something like this happen ?

[Xxray]

I'm stumped.
As you can see, the machine was apparently ordered to cut down an extra 1/8th or so at one spot, ruining the whole piece.
It starts the cut from the right cross. Before & after, everything is perfect.
New drill bit, new precision collet. Wood straight as a board, and securely tacked to the table.
Is it possible the code is getting botched somehow while calculating ? I have made more than a dozen of these, most come off without a hitch.

I just can't see how, if it were a tooling or machine error, how everything would be find both before & after.

[gravirozo]

hi xray

your z axis need some spring or other something helps agains gravitation...
the spring need at least so strong, that it can hold the router or spindle...

the picture clearly shows it was in the corner and on a deep point... you can ask why it did not made earlier on other side... possible the motor on z already was overheated some... very possible it was going from the rigth side of board, and in the corner the bit spiral made an excessive force compared with other points... means not only the depth, also spiral of the bit as grabbed on 180 deg the depth, the z motor was not sufficient to lift off your axis...

after its lost step while it came out of the deepest point, the x or y axis started, and by lost steps your z got a different point...from that point i marked as first point, from that point the carving is close same heigth (except where again stacked)

well... still you can looking for other causes, this is the most possible of this picture...

best regard
viktor

[Gc3]

have had the same issues, lost steps.

[Fleming]

Xxray,
If you are using Mach3 then maybe you are experiencing the same problem that Spinningwood had. See his solution in http://www.vectric.com/forum/viewtopic.php?f=29&t=11833.

Fleming

[Xxray]

Thanks for the input folks, made another using the same cut files, same everything and this one turned out Ok ,, So I think gravirozo may be correct.
I use Win CNC

[bsouthnow]

xxray;
You appear to be getting very good detail with your carving. Can you share some more information regarding size of the model and the type and size of your cutter.
Thx.
Bill

[Xxray]

These blocks of wood are about 12x6", the actual model a bit smaller. I rough with a .25 end mill, and finish with a 1/8 tapered spiral @ 8% stepover.

I like the looks leaving it roughed in the wood like that, it started off as a mistake.
I did the one pictured below out of poplar, and there was an unexplained gash in his right arm. Also, the cutout was off by about 1/8. I was about to trash it, but couldn't bring myself to do it.
So it sat around months, and I finally decided to clean it up. I put a light stain on the figure, and a dull clear coat to the whole thing. I liked the effect so much that I am now leaving them in the wood intentionally.

[bsouthnow]

They do look very nice! I'll have to give it a try.
Thanks for all the info. Love this place.
Bill

[rej]

have you thought about doing a chip carve texture on the wood around the carving?
might look good.

[gravirozo]

hi xray

good to see you got trough with this.. nice result you have..

one more tip could be there... if you were using acme screws on you router, before a longer run, a finish try to lube... that also reduce friction, and the chance to losing steps..

viktor

[Xxray]

Lube - Good thought gravirozo, as usual. I do lube, but possibly not enough.

rej, how would you go about doing a doing a chip carve texture ?
Bear in mind, I do not have Aspire.