My mother has a 15 year old dog that she is going to have to euthanize before long due to health problems. She wants me to make some sort of marker for the grave. I decided aluminum would be best, so I bought a couple 6x12x.25 plates of 6061. I used one of them to do a little practice, and the results were mixed.
The drag engraving always turns out good, but it doesn’t have a deep enough relief for what I think the projects really needs. The V bit does, but I don’t know what all I did wrong. I used a whiteside .25 90 degree carbide bit, and used the quick engrave function to carve at .0125 (I think it went deeper than that though). I noticed the lines were jagged. my settings were 30 ipm feed, 30 ipm plunge, and I had the router turned all the way up probably running 25000 RPM.
If anyone known what went wrong let me know. Another theory I have is maybe the V Wheels on the machine need to be tightened, and maybe the belt too. It is pretty cold in my garage right now. Let me know what you think. Thanks.
You should crank the rpm right down. What did you do the texture in?
I did aluminum on a much smaller scale in:
and noted my very conservative speeds at: https://www.shapeoko.com/wiki/index.php/Materials#T6_6061
1/8" thick 6061-T6 alu. Plate http://www.shapeoko.com/forum/viewtopic.php?f=32&t=6377&p=53731#p53729
Feed 215mm Depth 0.2mm Plunge 27mm Bits 1/8" 2 flute carbide and V-bit
It wasn’t a texture. It was a cross hatch engraving toolpath using the quick engrave function in Vcarve Pro. It was supposed to be a 45 degree series of lines spread far enough apart to the top of each square was flat. There is a shot of the 3d rendering in Vcarve.
So according to your numbers I need to slow down to about a 9-10 IPM feed? I had mine at 30. Is there any risk of a carbide V bit getting too hot even at shallow depths going that slow?
It also looks like your flat depth is wrong or you have some other setting wrong (but I agree on more conservative feeds and plunge, at least half the feed rate for plunge). Compared to your preview, your cross hatched texture shows the in both directions, you are too deep, and consequently, too “wide” so every other row is getting the sides cut out of it. So it does one side of a row correctly (call it Row 1), then but at the same time is too wide on the row next to it (Row 2), even though it thinks it is correct. Then when it moves one path over, it cuts the face of Row 3 (that is towards rows 1 and 2) correctly, but it is also too close to Row 2, so it makes Row 2 too small on both sides.
I wouldn’t think it would matter what size V-bit you would use although I would try something steeper, maybe a 60 or 30 deg bit, so that you get “steeper” walls on the textures. Also don’t forget that your V-bit most likely does not come to a point, it has a flat area. The larger the bit, the bigger that flat point will be, which may also cause the issue.
Regarding the wavy lines on the sides, for cutting metal you have to be absolutely sure that your V-wheels are tight, and your drive pulley set screws are tight along with belt tension. Also, I use two wrenches to make sure that the bit is tight in the collar. You can’t tighten it with just one wrench and the button enough. Watched your video, and you are correct that you need some lubricant, which you figured out.
Yes, you can overheat carbide — compare the suggested numbers in Carbide Create w/ the ones from the wiki, then test in scrap, then cut.