Here is a video if how I cut aluminum.
In this example I am making a 1/2" thick illuminated aluminum logo
I have doing this for over a decade in commercial shops with high end clients.
I rough with 6mm and finish with a 1/8" single flute endmills, no coolant.
These are just cheap ali-express coated endmills.
I switched a couple years ago from using Belin and Onsrud brands for a fraction on the cost
The coating is was makes them better
You can see from the photo I can achieve a really nice finish.
**I should not that the finish on the curved sections looks like absolute crap unless you increase the steps on The X and Y axis to 4000. The stock setup of 400 steps per revolution is not enough to get a nice finish on anything but linear cuts along a single axis.
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Based on this, I tried increasing my ppr to 4000 to get a better surface finish around curves when cutting wood. I’m not sure it made any improvement. I still see what look like little lines on the curved portions of my cuts, which are particularly noticeable as the curve transitions between perpendicular and parallel to the end grain. Has anyone perfected surface finish on hardwood?
Really when I comes to wood it doesn’t really matter, but in plastics and metals you see all every little mark.
I think when you see faceted curves it is related to the geometry of the vector, check the nodes to see.
Even with 400 PPR you have .001 resolution and you would not see that even in metal in my opinion.
My 2 cents worth.
Pat
@PezWoodworks You can see from the video above that I clean my vectors. No facets at all just smooth lines, i do this with every file I get. I am a professional sign builder and have been doing this since the late 90’s. Even while cutting G02/G03 arcs it is rough not just with G00/G01 moves. While .001" resolution might look good on paper to achieve this in practice it will need to be much higher. Closed loop steppers still gave following errors and higher resolution with also increase repeatability. I appreciate your input but your 2cent opinion seems to lack in real world experience.
Here is a short that clearly shows a difference in the edge finish on aluminum when using 4000 vs 400 steps.
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I believe I see these marks on hardwood on curves at 4000. It could be that I’m seeing the effects of deflection or that I could improve it by cutting in the opposite direction. I’m going to test both ideas, but I want my edges to be perfect so I don’t have to sand any marks off.
Maybe you’re taking too heavy of a cut and that could be chatter? Also, these machines produce quite a bit more resonance than a traditional square gantry shaped machine. I guess I should have realized this before I bought it but these round tubes are basically like wind chimes. They just ring out.
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I get this even when I have a .1mm finishing pass. I could try a thicker finishing pass in case the chatter is deeper than .1mm.
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You might be correct about the roughing past creating shatter that’s deeper than 0.1 mm. Try taking off multiple cleanup passes until the chatter disappears.
If you do a dry run and just run the bit in the air cutting no material. Does the motion feel smooth?. To me at 400 steps it feels very rough and even at 4,000 steps you can still feel each step but it’s 10 times smoother.
I am actually in the process of converting my machine to AC servos and getting rid of the steppers all together.
I also wonder if I need to switch from climb to conventional. I just got done looking at my scrap, and I don’t think I see that chatter on that side of the cut.
I wonder if filling the tubes with concrete or granite epoxy like some people do with the aluminum extrusion machines would make any difference
I have thought about this myself, it wouldn’t take to much to figure out and it is something I have considered. I have to make a better table first but won’t be doing that until I move my shop which is planned for later this year. I’ve got a crap load of old nuts and bolts which combined with epoxy would fill they tubes up pretty nicely. I would need to look into the load of the bearings.
@adamfenn28 I only use conventional milling for super soft foam products like EPS but even harder PVC foam (sintra, palight, komacell) or urethane foam will give a better finish with climb milling. I have made at least 100 cedar signs over the years and I only use climb mill on those as well. With wood i would think grain type would be more important (face, edge, end) in how much sanding would be required after the cutting is done. though I will admit I mill much less wood than I do plastics and aluminum so different woods probably behave in other ways.
Here is a photo of a huge 5’x10’x4" “welcome to” signs I made back in 2009. I made 7 of them by pretty much by myself, i planed each rough 4x6" board on a cnc machine, glued it up with dowels and urethane glue, flattened it on the cnc again and Vcarve the text with a 90 degree bit and the logo with a huge 2" wide 120 degree bit. They wanted natural finish so they could see the wood grain and I use 1-shot sign enamel and hand painted all the carves. They are all still standing though the city has repainted them a few times over the years.
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Buzzfab,
No doubt that in your video the 4000 looks better than the 400 but really neither looks acceptable to me, I currently own and have for 35 years now a large industrial machine shop. These machines (1F) are made to cut wood and some plastic, if you want to cut any metal be it brass, steel or aluminum it will be with much comprimise in time and final quality of product, they are just not ridgid enough. My 2 cents opinion here comes from my real world experience with these wood routers, I cut out a lot of 3/4" to 2" thick hardwood like Cherry, Maple, Walnut and Oak parts for furniture and other things I create, I hate sanding and when I cut the parts out there is little to no sanding afterward, ( I also can’t tolerate parts that look like hell). There a so many factors to having a good finished cut as you mention, grain direction, RPM, Climb or Conventional Up cut down cut and non and on it goes.
I know what works for me in my real world and I have changed the resolution on my machine to 2000 from 1F 400 and honestly not seen much if any difference at least not as much as I thought I would, I guess it might be that my results were pretty good to begin with.
Pat
Cutting aluminum on a router is super common dude. Didn’t say anything about steel. That finish that I just showed you on the 4000 steps can be primed and painted without any sanding at all and it’ll turn out perfect. When set to the 400 steps it requires sanding. Did not short. It’s not even the best finish I can get. It was a rushed video. Look at the original video I posted at the top and you can see there are no striations in the edges. A second cleanup pass will go a long way on non-ferrous metals. I’ve literally been cutting aluminum signage on wood routers since the late 90s for commercial sign companies. No large industrial machine needed to cut aluminum, in fact, I mostly used wood tools when I worked for one company. The best tool to use is the one you have. I also have a precision Matthews pm833tv bench top mill in my garage that i am converting to CNC for parts from other metals but I just cut a 42" single piece illuminated sign from 1/2" aluminum last week for a client, tell me how I would do that on a mill with its limited movement.
I don’t know why everyone thinks woodworking tools can’t be used for aluminum, I literally do it every day.
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At 400PPR you have a resolution on 0.04mm.
That will clearly be visible in aluminum.
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Would you please share which end mill you are using?
The result is really impressive, thanks
Hi, beautiful sign product.
Just out of interest, when you say these hobby machines are weak - is it the machine or the router you are referring to. I am asking as i am considering a metal working low RPM spindle for my Onefinity.
Cheers
I found them cheap on aliexpess. Now we buy them in large amounts where i work.
look for the “single flute aluminum endmills with rainbow coating” there are numerous brands that make them… I have been running these types of machines commercially for over 20 years, the coating on these bits produces a better finish on aluminum than any American made ones I have ever used and these are a fraction of the cost.
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its the machines rigidity is the weak part, the spindle i use is a 2.2 kw spindle which is plenty for aluminum. I was cutting a 2.5" thick chunk at my job with 2.2kw spindle yesterday and I had no problems. this photo is roughing with a 6mm bit 1.25" deep before flipping it over and doing the other side.
the round tubes resonate way more than any traditional square shaped gantry style machines i have operated. think of the onefinity tubes like wind chimes.
These machines are capable of a great finish if you change the motors but in a commercial enviroment they would be to slow… too many passes needed at a much slower speed than every other machine i have ever used. I have only use commercial machines so i am not comparing it to hobby machines which i admit might be unfair.
i cannot suggest these frame for real metal work.
I actually just did a major overhaul on the electronics and wire on my elite foreman…
info can be found here… Replacing STEPPERS for DMM-TECH AC Servos
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