Mel, I have the Proxxon and it definitely isn't for something like that, it would heat up way too quickly. The AutoMach runs longer before heating up but I wouldn't use it for something like that either. With both these carvers I use blades half an inch and under.
For larger roughing out (and the biggest carving I've done is 17") I use my Dremel with the FlexShaft reciprocating attachment or my MasterCarver system with the reciprocating attachment and up to 1" wide blades. Neither system would I use for roughing out logs. I do plan on using them to finish up one hubby chain sawed off the waste wood on, but I won't be doing that till springtime....I HAVE to get it done this year or hubby's going to burn it!

I'm a little concerned about trying to finish it up, he made some pretty deep cuts. I'll post pictures when I tackle it.
Anyhow, hope this helps, good luck!

Deborah