In addition to better software skills since the last try at a hard drive clock, I also was sent a new spindle (see my comparison of spindle choices) and an engraving bit from Zen Toolworks. I also now have a much beter way to fixture the platter than previously. It’s still not perfect; depending on how much I tighten the platters, there can a bit of difference in how high each side of the disk is.
In the case of the UF engraved platter, a portion of the platter was low and not properly engraved. The solution I came up with was to increase the final cut depth from .012 to .016 in the affected area. This worked nicely to correct the problem.
I haven’t experimented too much with this, but .002″ per stroke seems to be a good depth of cut for the ZTW machine to handle when cutting a HDD platter. With the speedy “fast 8s” lead screw, I’ve been setting the feed to 30 Inches per minute (IPM) and it seems to zip along pretty fast (since I’m using a 7×12 model, only one axis is that fast). Another advantage is that I didn’t have to set the “safe height” – how high the spindle has to be between cuts – too high as the path never passes over my fixture in the center.
Above are the results of my labour. Although I’m getting better, I still decided to try it the pattern out first on a scrap piece of wood. The finished clocks should make nice Christmas presents along with a third random tree model that I made. Some of the other details about how to go from logo to engraving can be found in my other post about turning logos into engraving.
The only minor imperfections are that a couple of the Gator teeth are more grey than the others, and some burrs resulted on the sides. As the mirrored finish of the HDD platters is really the cool thing about this, filing them seems out of the question. Also, it seems that I scratched the USF platter while putting a washer in to hold everything together, so be careful with that. Any suggestions as to how to remove burrs on something like this would be appreciated. Update: I’ve made an even cooler one with a color engraved logo – A Clemson Tiger Paw!