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Since you said you don't know what you're doing and I saw the spindle speed post, I'll offer some general advise for spindle speeds.

Every workpiece material has a surface feet per minute, often called simply cutting speed (SFPM or CS).

If you know that CS, there's a simple formula that can help set your spindle speed. For general shop work you can use some ballpark CS for your materials.
High Carbon/tool steels ~50
Mild steels ~100
Aluminums ~ 200

I'm attaching a pic because formulas don't always type well... IMG_6886.jpg

This works for HSS cutters in good condition. If you're using carbide cutters you can get close to tripling the result of that formula depending on the situation (cooling/cutting oil/chip evacuation/etc)

Also, with aluminum I'd recommend using a 2-flute cutter rather than a 4-flute as it will clear chips better and have less tendency to pack up the flutes.

For drilling and milling we're using the diameter of the cutting tool in the formula. If turning a part on a lathe, we're using the diameter of the stock (unless drilling into the end). For reamers, cut the results of the formula in half if you value your reamers!

For insert carbide tooling on a lathe...that formula result * 3 is usually about right. Carbide inserts need a fair depth of cut to work properly too, they are not sharp but instead rip away material via heat and pressure. If you're not generating heat and pressure the insert won't give predictable results.
Bro, this is fantastic. Thank you!

Shows how far off my intuition is. On basically everything! That's interesting about the 2 flute cutters. The majority of things I build will be aluminum so knowing this really helps me not waste a bunch of money when I go to stock up on new cutters.

Thanks, man. I really appreciate you taking the time to explain all this.
 
Bro, this is fantastic. Thank you!

Shows how far off my intuition is. On basically everything! That's interesting about the 2 flute cutters. The majority of things I build will be aluminum so knowing this really helps me not waste a bunch of money when I go to stock up on new cutters.

Thanks, man. I really appreciate you taking the time to explain all this.
EuroMoto That's Pretty Handy.

I'm Printing it out and gluing it to my cutter shelf

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I have found that 3-flute cutters do pretty well as an all around tool on aluminum, brass, bronze, and mild steels. If you're getting into tool steels then 4 or more flutes tend to work better. Feed rates are tough to regulate on a manual mill unless you have a good DRO with feed rate function. Feed rate is a product of spindle speed and chip load (how thick is the chip for each tooth and how many teeth are there).

Your eyes, ears, and fingers (for vibration) are your most important tools. If it's squalling/high pitched you're probably either spinning too fast or not feeding fast enough (high pitch typically means rubbing rather than cutting, which builds heat). If you're machining steel with HSS cutters use oil or coolant of some type, chips shouldn't get discolored much (tan rather than silver is bordering on too much heat), if you're getting blue steel chips from HSS it ain't good. Chip formation is king, if they look good and it's not making racket you're probably on the right path.

Also, on anything except light cuts, if you are side milling on a manual mill you should be "conventional" milling. Which means the rotation of the cutter is pushing back against your feed into the part. "Climb" milling means that your tool rotation and feed are trying to pull the tool along the part on its own. Most manual mills with some age have backlash in the tables and the tool will cause the table to get jerked around a bit. CNC machines have backlash compensation so Climb is preferred for the better finish.
climbvconv.jpg

If you're of the youtube persuasion, I'd recommend BlondiHacks for someone who is basically a self-taught hobbyist (and shares her mistakes), or for more advanced stuff and math I'd say Joe Pie Machining is a good one. Both stick with strictly manual machines and both are good communicators. BlondiHacks does more than machining, she recently formed and soldered a model steam engine boiler so has varied content. Neither can replace hands-on experience but both do interesting projects and have great tips.
 
All I can say is thank you for taking the time to share your knowledge.

I do follow Blondihacks. She's a great teacher.
 
You can get away with climb milling on low depths of cut with a manual machine if DOC is limited to a few thousanths- you'll feel the cutter pulling on the work- but its handy for finish passes. I usually try to operate at 50% to 80% of the specified sfm, I'm not in a rush and having burned up some expensive to replace tooling I like to preserve the cutting edges. I've found lousy surface finish has more to do with dull cutters, poor setup or machine out of tram- and some material is just gummy and nasty to machine.
 
All I can say is thank you for taking the time to share your knowledge.

I do follow Blondihacks. She's a great teacher.
Very welcome! And gpounce has some good advise on reducing sfpm for tool longevity. The formula kicks out numbers for sharp, non-chipped, good quality tooling. If you aren't producing parts for money it rarely hurts to slow down the RPM a bit.
 
I miss having access to a good media blaster. My compressor isn't remotely close to pushing enough air for one.

Are you using air for chip evacuation on the mill? I don't know how much of the finish on that part was due to chips tearing up the surface, but it's a potential problem. You also might your tool holder for runout.



Maybe it was just a bad mill, but you can check for other problems easy enough.

Funny vid. That "unknown" collet(1:53) is an SYOZ style in case anyone wanted to know..😁
 
Wanted a non-marring pecker to tap the drawbar bolt to loosen the collets. Figured on the other end of the wrench would be a handy place for it. Aluminum plug felt kinda light so added some brass for some heft. Plenty of sloppy mill work, but the press fit alignment pins turned out on the money. I ain't mad about it.
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So I was going to ask you f you guys had seen chipwelding when manually tapping a hole, but then the tap had other ideas. Guess I am doing something else today :doh
 

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So I was going to ask you f you guys had seen chipwelding when manually tapping a hole, but then the tap had other ideas. Guess I am doing something else today :doh

fcckkk if I only had a dollar for every tap I've broken off in a part...:rofl helps to toss the dull taps so you don't risk everything each time... I should take my own advice.
 
Luckily its a through hole so it shouldnt be too bad, can always helicoil it if need be. On the plus side it gave me the time to make a new set of soft jaws for my next project, yall will like that one I think. Pics to come tomorrow after work when I get the first few made!
 
Worst broken tap for me was when cleaning up exhaust header mounting threads after drilling out the broken bolts on an engine block- this one did not use studs just threaded holes.. used a sharp 70's vintage Craftsman tap that I thought was good but apparently was made of chalk. Got lucky and teased out the fragment with a punch, then fit timeserts to clean up the mess.

Got away with it despite those d$&#n kids 🤣
 
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