A curious comparison between me (the beginner) and you (the pros)

If you are looking for a mirror finish use a fly cutter with a freshly sharpened tool in it. I agree with an hour or less while taking my time.
 
If turning the raw material into something that has good finish and is also square on all corners/sides, then the process on a manual mill is at least 5 setups unless you have sufficient material on one side (talon-grip vise jaws help here) to be decked off, then it would be two setups. Some good practices are covered in this video. Assuming (as in your case) that the material has to be decked off with 5 setups, given the size of your part, that would take me about 20 minutes (and I'm not a pro). As far as the tooling goes, on something like 1018, I would either be using a 5/8" carbide end mill for the finishing pass, or on the wider surfaces a 3 or 4" face mill with positive rake inserts (APKT) like this one. I have the insert tool you show, but the insert geometry is not ideal for good surface finishes in steel. But I would also expect to take the finished part to a belt sander (Kalamazoo or similar - this is what I use with this belt) with a blue scotchbrite belt to debur and brighten the finish. 1018 HSS is difficult to get a good finish on - sharp tools help.
 
Shootymacshootface said:
If you are looking for a mirror finish use a fly cutter with a freshly sharpened tool in it. I agree with an hour or less while taking my time.
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I agree with this if you don't have the bucks to invest in a quality 4" face mill. This tool is really great and decently priced - it fits in a 3/4" collet. If surface finish is your goal, and you don't have hundreds to make, I would actually use the insert specified for use with aluminum on 1018 with something like a 0.002" DOC - you'll burn up the inserts twice as fast as the one designated for steel, but the finish will be amazing. And with 4 cutting edges per insert, that's not super expensive.
 
Seems you got some pretty sound answers. Now we want to know what brand of guitar!
 
Maplehead said:
Hi All
So pictured below you see to mild steel blocks. The one on the left is cut from my bar stock without anything else done to it. The one on the right is a "finished" blank. Later it will be milled into my guitar bridge.
Stock block
L 2.92"
W 1.668"
H .986"
Finished blank
L 2.79"
W 1.625"
H .955"
My comparison here is a question. How long would it take you pros to turn the block on the left into the finished blank on the right?
I have added into the pic the tool I use to do the above. I get nervous about heavy cuts with these little circular blades on the tool so I only make at most .010" cuts.
I run the tool at 1000 RPM's. (I usually start with .005" cuts until the patina is off then I go to .010" cuts, and I use my x axis powerfeed running slowly.)
When I get within .010" of my final dimension I then go to a .005" pass, then a .003" pass, then .002" pass and finally two .001" passes at double the speed.
My goal with the small cuts is to minimize the depth of the swirls because I do the real finish with hand sanding.
I'll share with you later how long it all takes me. For now I'm curious and I would love to know how long it takes you pros to make the finished blank.
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7-10 minutes on the band saw to get the blank
2 minutes with hand file deburring edges
Large sides on the blank: less than 10 minutes
small sides on blank: less than 5 minutes

Coat scale liberally with heavy cutting fluid each pass
Touch tool off on part,
first cut 0.010-0.020 deeper than the scale.
1/2" carbide end mill, climb cutting around the edge then onto the center (saves deburring time between sides)
Finish with flycutter taking 0.002.
 
Mitch Alsup said:
7-10 minutes on the band saw to get the blank
2 minutes with hand file deburring edges
Large sides on the blank: less than 10 minutes
small sides on blank: less than 5 minutes

Coat scale liberally with heavy cutting fluid each pass
Touch tool off on part,
first cut 0.010-0.020 deeper than the scale.
1/2" carbide end mill, climb cutting around the edge then onto the center (saves deburring time between sides)
Finish with flycutter taking 0.002.
Click to expand...
Nice breakdown.
I think my bandsaw is a little slower. For the rest of it its been taking me about a good 2 hours.
I too am doing this for fun but also for the intention of making and selling guitars and I want to decrease my time doing so.
 
Can anybody further extrapolate on that "scale"? My assumption is that its harder than the steel underneath. If so then why wouldn't I want to take shallower cuts with it than what you all say, a deeper cut? Not wrapping my head around that one.
 
Maplehead said:
Can anybody further extrapolate on that "scale"? My assumption is that its harder than the steel underneath. If so then why wouldn't I want to take shallower cuts with it than what you all say, a deeper cut? Not wrapping my head around that one.
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You are cutting with the very edge of the carbide insert. By getting the edge mostly under the hard scale, the edge doesn't wear as much as it would if trying to cut directly through the scale, instead you are peeling the scale off.
 
rabler said:
You are cutting with the very edge of the carbide insert. By getting the edge mostly under the hard scale, the edge doesn't wear as much as it would if trying to cut directly through the scale, instead you are peeling the scale off.
Click to expand...
Ah, I can see that. Makes sense and thank you
 
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