Mill/Lathe

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Russell

Russell

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Apr 19, 2009
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Picked up a sweet little 10" rotary table(non tilting) . for a $100(craigslist). Nice and tight with no mill marks.
 
T

Tinsmith

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May 15, 2009
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Maryland
$20K!! Now we're talking. Seems you may be left with just filing it to size. Get it within about .001 over with the file and finish with sandpaper. Run somewhere 280-350rpm with the file should work for you. Someone else might have a more technical way to do it, but for a bushing you should be able to get it there. Practice, practice, practice.

Dan
 
Dan

Dan

Staff
May 25, 2008
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LOL, ayup Dan. $20K, 8 months of school and a few years. If I ever do get that part done, kinda gonna take all the funny out of it. Coulda bought a $2 part and modded it. But NOOoooo.

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Man am I having a blast with this. Look for scraps to play with. (Could be called practice, snork)

Gotta wait for sunrise to start most mornings and don't stop until 7 or 8 and if jobs come in. Gotta hate when work gets in the way of fun work.

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Had trouble with over hang and that part. Couldn't find a ready made live center extender. Or even a DIY one.

So took a busted up bike wheel axle and a ball bearing, ball from it and made one. Well, stuck the axle in a bit chuck on the tailstock, counter sunk a dimple in the part to be turned. The axle already has one so just stuck the ball between. Works great, stands off the tail stock and didn't heat up as I expected. (^)
 

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Davezilla

Davezilla

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Mar 15, 2014
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I've got the cut dead smooth and within .0005" or less by using a flat faced cutter and just letting it barely touch the work, keep rpm low and just feed in enough to where it's producing really tiny shavings.... basically, as soon as you see it produce any sign of shavings, stop the feed and then make 2 or 3 passes, if there's still lines and striations feed in again just enough to see it cutting and make more passes.
Also, if you have to make your own cutting tool, grind it so the cutting face is about 1/8" to 1/4" wide with a very gentle curve to the face, the curve will help make the cut super smooth.
 
Greg58

Greg58

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May 1, 2011
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Dan if you're ending up with a rough surface either your feed rate is too fast or the bit angle is wrong. On our lathe a little adjustment does a lot. You want the very tip to touch and slightly below center of the shaft you are turning.
 
Davezilla

Davezilla

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Heheh... I got the same problem at my shop since the lathe is in the back room and I can't tell if customers come up when I'm back there so it can be difficult to play with the lathe or the CNC since I need to keep checking up front. I', planning on getting some garage sensors so I can tell when people drive up so I can play in the back more when it's slow.
Other times I'l go to the shop on Sundays or stay late and close the doors then I can work in peace. Hopefully in the near future I can hire another mechanic to help out and I can break off and do my stuff in the back, but for now I just gotta set up the machine but walk up front every few minutes, make a cut pass, check for customers, make another pass, check for customers and so on...
 
Davezilla

Davezilla

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I agree... the bitr angle AND hight have a big influence on how smooth a cut is... With my old tool post if I used any cutter that wasn't exactly 5/16" it would cut aweful and I'd need to use shim stock to keep the cutter centered to the work. The angle is every bit as important, especially if using a wide cutter like I mentioned earlier.
 
Greg58

Greg58

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May 1, 2011
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Dan if you get everything just right the metal will be coming off in one continuous piece like wire, I was making replacement shafts for 72" exhaust fans in the spring, after spending a little time back on the lathe setup became easier with better results.when you get the setup right you will hear very little noise from the cutting action.
 
Davezilla

Davezilla

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Very true... a good cut setting will leave an almost continuous shaving when the cut speed and depth is in the correct range, same goes for drilling thru steel or aluminum, when the rpm and cut pressure is just right it'll produce a continuous single shaving. You can control this if you don't like long shavings by going in and stopping momentarily to break off the shaving so it's not excessively long and in the way of the work or slinging around and possibly cutting you.
 
Dan

Dan

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May 25, 2008
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All great advice and thank you all!

I did not know this but another contributing factor is my choice of material. I had not even considered it until it was pointed out.

But this grade steel, aside from finish, is a great option for what the final pc is to be and process to finish it.

Another bonus I also hadn't considered is the ruff finish adds friction and grip. It being hidden and only seen when I install it, am liking it as an option. Although I will be experimenting with other raw materials. But I ramble.

Again and I mean it, all great advice and thank you all!

Man, this stuff is a blast! dance1
 
NunyaBidness

NunyaBidness

Active Member
Jun 29, 2008
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memphis tn
Dan I for one appreciate you posting this thread and keeping all of us updated on your progress. I truly do love reading your posts. Thank you very much.
 
Davezilla

Davezilla

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You definitely want to experiment with as many different grades of aluminum, brass, and steel as you can get your hands on... Especially aluminums because their charicteristics are so different... Aircraft grade aluminum is typically the most user friendly when it comes to drilling and cutting, and the aluminum rod stock they sell at Home Depot and places like that can be very user un friendly since it's very soft and bends easily as well as having issues with loading up on drill bits and some cutters... a good practice would be to get some of that 3/8" or 1/2" cheap aluminum rod stock from the hardware store and see how smooth you can turn it then see how many shoulders you can cut on a piece without bending it... it can be a real challenge. Then try some good aluminum like 6061 T6, 7075 T6, or 2024 T3 and notice the difference each one makes.
Brass is another easy to cut metal and a lot can be done with it... Always good to have some brass bar stock on hand.
Mild steel machines really easily as well, then the harder steels like drill rod stock, spring steel, or HSS will up the challenge since you'll need to play with your cutting speeds and feeds. Some of the harder steels will require carbide cutting tools.
All in all it takes Lots of practice practice practice... but we'll all get there if we keep practicing.
Subscribe to this guy's youtube channel too... he has tons of lathe tutorials that are very useful.... https://www.youtube.com/user/mrpete222
 
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