Machinists Corner

[Crawling Calvin]

Originally Posted by SMR 510RR

Mods/Admin can we get a subsection in Tools and Procedures dedicated to machining?

Im thinking of doing some cool tutorials/how to's and it would be cool to have a place to dedicate to machining questions and whatnot.

Anyone have any manual milling questions that would translate into cool tutorials?

These have to be some of the BEST looking videos for "how-to" on machining and the quality is top-notch

GlacernMachineTools's Channel - YouTube

[SMR 510RR]

Originally Posted by Crawling Calvin

These have to be some of the BEST looking videos for "how-to" on machining and the quality is top-notch

GlacernMachineTools's Channel - YouTube

Yea I have looked at some of those before. I want to do some cool tutorials on how to make an actual part with techniques that can be helpful if you only have a manual mill. Stuff like angles that can be challenging without a lot of tooling.

[Reflection]

Originally Posted by SMR 510RR

Mods/Admin can we get a subsection in Tools and Procedures dedicated to machining?

Im thinking of doing some cool tutorials/how to's and it would be cool to have a place to dedicate to machining questions and whatnot.

Anyone have any manual milling questions that would translate into cool tutorials?

How bout we just make this thread a sticky first, see how much attention it draws.

Lots of good advise in this thread. One very good point.....

Originally Posted by SlickRockSpider

Machine Questions

Everybody will have there way and advice. Read them all and take what you want.

If you talk to 10 different machinists, you'll get 8 different ways to cut a part or do a certain opp. Then, you'll run into different machines and what they'll do better than another.


I mainly run a handful of traditional style lathes. From small collet lathes to bigger lathes with 30" of swing. Some CNC stuff. Occasionally some mill work. The old school stuff is and always has been allot more interesting to me. I typically only work on 1-5 part runs or prototype parts, so, the manual machines is where I stay most of the time.


One thing I was taught a long time ago, if your grinding your own tools... By changing the edge break, relief angle, radius of the cutting edge or other parts of your tool, you can get different results in tool performance and/or finish.

[WLYSTLZ]

I have talked to different people running drill press hand mills and it seems to be difficult to figure out what speed to run your bits at for end milling, and is there a tooling speed recommendation between different grades of aluminum.

Furthermore when working with "soft" steel how slow should the bit be spinning?

TIA

(I should know this but metalshop was sooooooo long ago. Our hand mill was set for aluminum only)

[Crawling Calvin]

Originally Posted by WLYSTLZ

I have talked to different people running drill press hand mills and it seems to be difficult to figure out what speed to run your bits at for end milling, and is there a tooling speed recommendation between different grades of aluminum.

Furthermore when working with "soft" steel how slow should the bit be spinning?

TIA

(I should know this but metalshop was sooooooo long ago. Our hand mill was set for aluminum only)

For general 6061-T6 I run at about 400 SFM for HSS tooling and 1,000 SFM for carbide. If you get into the icky stuff like 5052 you NEED at least a constant stream of air blowing AT the tool to keep it cool and some kind of lubrication or your going to pack your tool extremely fast as for the harder stuff like 7075 maybe drop the SFM a little due to it being harder and adjust the feeds accordingly. In the end I could give a huge list of numbers but every machine handles stuff differently. Can't expect to put a 1/2" roughing end mill in a Sherline and expect it to do what a Brideport can

Other than those numbers for aluminum I love the Niagara A377 TiCN coated end mills. They are flat out amaaazing... check out Travers Tool since they almost always seem to have them on sale and since they are "made for aluminum" they really do cut nicer! I also use them all the time on plastics since the coating helps increase tool life and reduce the risk of melted plastic when I don't have the convenience of air blast

[SMR 510RR]

Originally Posted by Reflection

How bout we just make this thread a sticky first, see how much attention it draws.

That works for me, thanks!

Originally Posted by WLYSTLZ

I have talked to different people running drill press hand mills and it seems to be difficult to figure out what speed to run your bits at for end milling, and is there a tooling speed recommendation between different grades of aluminum.

Furthermore when working with "soft" steel how slow should the bit be spinning?

TIA

(I should know this but metalshop was sooooooo long ago. Our hand mill was set for aluminum only)

Originally Posted by Crawling Calvin

For general 6061-T6 I run at about 400 SFM for HSS tooling and 1,000 SFM for carbide. If you get into the icky stuff like 5052 you NEED at least a constant stream of air blowing AT the tool to keep it cool and some kind of lubrication or your going to pack your tool extremely fast as for the harder stuff like 7075 maybe drop the SFM a little due to it being harder and adjust the feeds accordingly. In the end I could give a huge list of numbers but every machine handles stuff differently. Can't expect to put a 1/2" roughing end mill in a Sherline and expect it to do what a Brideport can

Other than those numbers for aluminum I love the Niagara A377 TiCN coated end mills. They are flat out amaaazing... check out Travers Tool since they almost always seem to have them on sale and since they are "made for aluminum" they really do cut nicer! I also use them all the time on plastics since the coating helps increase tool life and reduce the risk of melted plastic when I don't have the convenience of air blast

Good advice there...

When I am manual machining I mostly just run by feel and sound. Feeds and speeds are something that you develop over time and although the tooling manufacturers typically have recommendations no 2 cuts are ever the same.

When you are taking a cut you want to hear a nice even hum coming from the tool, you dont want it to sound really choppy and broken up. In general if the tool chatters or squeaks you are either spinning it too fast or not feeding it fast enough and the tool is having a hard time taking material off, instead the tool is rubbing the surface and you are really just creating a lot of extra heat that you dont want. There is a direct relationship between the spindle speed and the feed that needs to be maintained to have a quality cut and surface finish.

Your machine will play a large role in your feeds and speeds, rigidity is the key here. Sounds like you are running on a converted drill press, typically they are not as rigid as a dedicated mill because they were not intended to have a side load on the spindle so you will probably need to adjust for that.

I would suggest that you get a scrap of your material and take some cuts in it with a couple different feeds/speeds and see what your machine seems to like. Start with a lower spindle speed then you think you should be at and make a cut, as you get more comfortable you can start being more aggressive.

[foratm]

Ok just got a chavalear surface grinder at auction and have been putting it together. I have been having a couple problems the table will feed out but when it reaches over travel and or to the end of the programmed travel it will not feed inward. Any suggestions?
Also it seems like it takes a lot of work trying to mess with the program buttons to get the hydrolic pum to engage.

[707offroad]

Anyone here have an indexing head? do you know how to cut gears? Is a 3 wire measurement important?

[foratm]

Three wire is extremely important. The reason being it gives you critical measurements fort the angles and spaces between teeth and threads. Think of it as measuring the exact spot were the gears will mesh.

[CREEPERBOB]

Originally Posted by 707offroad

Anyone here have an indexing head? do you know how to cut gears? Is a 3 wire measurement important?

Just got a universal dividing head , and reading all about it now. I have a gear I need to make for my Logan lathe. The cutter is got me stumped.
This should allow making hexes and bolt circles easier too.

[707offroad]

I have the older (grey) harbor freight 44142 3in1 with the r8 taper and I have outfitted the y and x axes with dro's. I also got a indexing head. I haven't cut gears in 10 years and the last set I cut was also my first. I have an Exceed MaxStone 1/8 that I wanted to put metal gears in and they're currently unavailable so I thought I might try to make some. Keep in mind I have a vertical mill without an adjustable knee. The setup would take a lot of work and the end result would probably be substandard. Do you think it's even worth the effort?

[dkf]

Originally Posted by 707offroad

I have the older (grey) harbor freight 44142 3in1 with the r8 taper and I have outfitted the y and x axes with dro's. I also got a indexing head. I haven't cut gears in 10 years and the last set I cut was also my first. I have an Exceed MaxStone 1/8 that I wanted to put metal gears in and they're currently unavailable so I thought I might try to make some. Keep in mind I have a vertical mill without an adjustable knee. The setup would take a lot of work and the end result would probably be substandard. Do you think it's even worth the effort?

For the jobs I do I try to use stock gears if at all possible. If I can't find gears and have to go custom wire EDM or Waterjet is the next thing I look at. The last machine I built I got the gears from SDI and machined them how I needed.(link below) They have a lot of smaller sized gears. Its been quite a few years since I've cut gears. When I did I used a horizontal mill and a dividing head with a footstock. Its a slow process and honestly I thought it was a PITA. You need the proper involute cutter to get the tooth form as well as calculating the blank size, and all other measurements to make the gear to spec. How to obtain that info can be found in the Machinsist's Handbook.

Precision Mechanical Components Timing Belts Pulleys Spur Gears Couplings Bearings Sprockets Retaining Rings Brakes Helical Gears Clutches Universal Joints

[SMR 510RR]

Originally Posted by foratm

Ok just got a chavalear surface grinder at auction and have been putting it together. I have been having a couple problems the table will feed out but when it reaches over travel and or to the end of the programmed travel it will not feed inward. Any suggestions?
Also it seems like it takes a lot of work trying to mess with the program buttons to get the hydrolic pum to engage.

We had one at my old job, not sure on the brand or anything but it was a little tricky to get it to go back and forth. It was also hydraulic but all the controls were all manual.

If you could post a picture I might be able to remember the process of getting it to work.



As for the gears its not something I have ever messed with, too much tooling involved to make it worth while in my mind when there are so many options available commercially.

You guys ignited the fire under my butt and I got my GF to buy me a rotary table/chuck for my B-Day...You are all bad influences!

[Crawling Calvin]

Gear cutting sounds fun but also VERY confusing... ive personally NEVER done it, ive wanted to try but never had an excuse yet (if Axial keeps up NOT offering their gears tho im going to start thinking of making my own ) big thing is the cutters and they aren't cheap! Sure you can grind your own but it isn't as good as buying one made for gar cutting.

This guy, in his own funny way, shows how he makes gear and i must say its quite time consuming. Ive seen it done a CNC with a 4th axis and that's speedy

Machining a Spur Gear - YouTube


707, a handy tool for doing quick hex and square stuff is a 5C collet block in hex and square. Really handy and you can use it with a stop of sorts to do all kinds of fancy indexing

[SMR 510RR]

Originally Posted by Crawling Calvin

707, a handy tool for doing quick hex and square stuff is a 5C collet block in hex and square. Really handy and you can use it with a stop of sorts to do all kinds of fancy indexing

I second the collet blocks, they have saved the day for me on a couple occasions. The only downside to an indexer is usually the size and the collet blocks are very low profile when compared to any 4th axis that I have ever seen.

I thought about getting a set but I dont have any 5c collets and by the time I get a decent set I might as well have bought the rotary table that I bought.

[C*H*U*D]

If you work with any kind of round stock, a 5C collet set is worth the investment. The square and hex collet holders are very handy, and they are so useful for so many different things.

I also like the vertical/horizontal 5C collet fixture. I used to drill my delrin crossbars on the lathe, but it was so time consuming. Now I drill them on the mill and it takes no time at all.

This is the one I have at home:



But I also like this one that we have at work:

[CREEPERBOB]

So what is the cutter called that you would cut teeth on a spur gear and where do you find them?

[707offroad]

MSC, Traverse, JT tool and Enco are the top suppliers I know that sell involute cutters

[donhd04]

I looked online and I can't find a metal strength chart as to what metal is stronger and such. Like 4130, 4330, 300m strength which ones are stronger etc. Anybody have a link to such a critter?

[CREEPERBOB]

Originally Posted by 707offroad

MSC, Traverse, JT tool and Enco are the top suppliers I know that sell involute cutters

Thanks for the input . I have a 5 1/2" dia. 72 tooth bull gear I need to cut for my other lathe.