3D negative Skullbones in aluminum

[metalworkz]

I cut this aluminum coaster tonight and I think it turned out pretty good. The letters would look better at about half as much depth, but they are legible and I wanted them to be recessed like the Skullbones section. I limited the finishing toolpath to the modeled area only by tracing the model and selecting the trace along with the model for the finishing toolpaths.
This saved me about 1 hour on the finish toolpath cutting time and it saved the time it would have taken to clean up the toolmarks on the top surface of the aluminum which is a regular 5052 aluminum finish to begin with. Take a look. Hmmm, I just noticed two teeth look to be unfinished; maybe it is minor enough to overlook?

[Phil]

Very nice job Wes. I have a request for a small aluminum job. I'll be cutting a name in an aluminum plate that is .250 thick. The letters will be VCarved. They are about 1.25 tall and the text covers 10". What speed and feed rate and depth of cut per pass would be suitable. I don't know what type of aluminum I am working with. I'll be using a 90 degree V-bit. Thanks in advance.

Phil

[Greasetattoo]

Wes,
Very cool!

Could use them as cookie cutters, or for the kids, Play-doh molds!
Jello molds!

Love your metal work!

I will be doing some aluminum work here before Spring hits.
I have to make some parts for my 51' panhead.

[calgrdnr]

Great job Wes, I don't know if I would want to eat a cookie with skull and cross bones on it though
My old timer self would be thinking poison ... every bite ... Oyeah at my weight it is

[metalworkz]

Thanks for the kind remarks guys!

Phil,
What are you using for a spindle? RPM's? I normally use my mills spindle which has a top speed of 3600 RPM, but I have been using a Rotozip motor since my spindle quit working about a month ago. I don't know anything about your machine either so it may be best to start out with a test piece at slower feed rates and increase the feed and pass depth until you have the best combination of feed rate and surface quality etc. I have been using pass depths of .02", feed rate of 30 IPM with my rotozip spindle and I have even reduced the feed rate(15 IPM) some with the 3D toolpaths. My rotozip spindle mount has a small amount of flex in it also, so I want to make something more rigid to fix that. Those are some of the reasons I haven't been trying a faster feed rate.
I would think with a large router motor you probably will be able to use 60 IPM feeds and .030" pass depths or maybe better, but it is probably best to do a test and work up to that 'sweet' zone where all is good. I have not done any Vcarving in aluminum either and that may involve more material removal than regular passes so when you do your test try to do it with all the conditions the same as the part you will make. Sorry I can't be of more help with some precise feed rates etc., but it is all relative to the machine anyway.
The aluminum I have been using is 5052 H32. I use 6061 T6 when it need something stronger.
Grease,
The parts for the '51 panhead sound like an interesting project. I still have my motocross motorcycle but never was able to acquire a Harley.
Kent,
I guess we all would be hesitant to eat cookies with a skull and bones on it, but the negative impression may be good for the play-doh or something.

[Phil]

Wes

Thanks for the info on cutting aluminum. I'm looking for a starting point and this helps. I have a Shopbot with a 2.2 HP spindle.

[JamesB]

Cool application and nicely executed.
Cheers,
James