Machinists Corner

[foratm]

I would like to start a thread of Q's and A's for anything to do with machining.
I am a machinist and i see many other guys on here are as well or are trying to become a DIY machinist to save money in these hard times.
So whether you have a question on how to do something specific to CNC or even hand milling/ turning or an answer to the question post here.
Keep Chit Chat to a minimum to make it an easy to read and find thread.
Between my boss and I we have over 35 years experience as machinists.

[krawlfreak]

I like this idea

We may need to talk to the mods/rcc folk to maybe even get a sub section.

[CREEPERBOB]

X2 , I'm moving from a drill press and scroll saw to a mill/ lathe now.
My machine came from Ann Arbor.

[Crawling Calvin]

This is awesome. I only have a few years (2) experience but owning and trying to make your own equipment sure teaches you a lot fast

One little money saving tip I know, and it sounds silly, is to make as much of your own clamps and stuff as you can if possible. You would be surprised how fast that stuff adds up when you really add it up and never underestimate C-clamps, they do come in handy

[CREEPERBOB]

I'll through out the first question. Will I need a follow rest to turn 4" long pieces of 1/4" titanium rod to 3/16"? The rod is 12" long , but want to turn 4" at a time.

[Crawling Calvin]

Originally Posted by CREEPERBOB

I'll through out the first question. Will I need a follow rest to turn 4" long pieces of 1/4" titanium rod to 3/16"? The rod is 12" long , but want to turn 4" at a time.

I can't see why it wouldn't hurt. Due to its hardness titanium is great stuff but it also can flex like mad... someone made a little "bearing follower rest" that was part of the insert tool holder. Really neat idea!

One tip when turning titanium. Oil and an air blast on the tool, even low PSI really helps blow the chips away and keep the smoke out of your face and the area cut cooler.

[CREEPERBOB]

Thanks for the input Calvin, when I just purchased my machine the steady and follow rest was on back order so I'll have to wait a couple weeks till they are in stock.

Originally Posted by Crawling Calvin

I can't see why it wouldn't hurt. Due to its hardness titanium is great stuff but it also can flex like mad... someone made a little "bearing follower rest" that was part of the insert tool holder. Really neat idea!

One tip when turning titanium. Oil and an air blast on the tool, even low PSI really helps blow the chips away and keep the smoke out of your face and the area cut cooler.

[Die-Laughing]

Cool idea. I will help when I can.

7+yrs of CNC experience.

[dkf]

Originally Posted by CREEPERBOB

I'll through out the first question. Will I need a follow rest to turn 4" long pieces of 1/4" titanium rod to 3/16"? The rod is 12" long , but want to turn 4" at a time.

So you basically want to reduce the diameter of the entire 12" rod down to 3/16"?

Problem with titanium is it eats the cutting edge and puts a lot of force on the cutter which causes deflection. For turning a diameter that small on a conventionial engine lathe yeah a follower rest will help if you have one small enough. Honestly thats a centerless grinding or swiss lathe job.(sliding headstock and bushing) Best bet is to save the aggrevation and buy a 3/16" piece of stock.

[klabeaume]

Originally Posted by dkf

So you basically want to reduce the diameter of the entire 12" rod down to 3/16"?

Problem with titanium is it eats the cutting edge and puts a lot of force on the cutter which causes deflection. For turning a diameter that small on a conventionial engine lathe yeah a follower rest will help if you have one small enough. Honestly thats a centerless grinding or swiss lathe job.(sliding headstock and bushing) Best bet is to save the aggrevation and buy a 3/16" piece of stock.

He said just 4" at a time but I agree. Buying a 3/16 rod would save a lot of time and aggravation.

[WLYSTLZ]

I have been metalworking for about 10 years but recently got into machining (again) recently. I use a cheapo drill press from HF, along with a cross slide vise bolted to it. The vise I found on eBay for 50$. I just bought a band saw and non-ferrous metal cutting blade from HF for about 120 which works awesome! The cross slide vise is a bit sloppy, but tighten the adjustment screws, keep my math skills somewhat current, and I'm doing ok with what little I have. I wanted a jet hand mill of course, but let's just agree having a toddler and house shifts priorities a bit. So far I made axle mounts, ax10 tranny mounts, bumpers, frame rails, tools and more and I learn more each time to make something! I noticed one super important thing: the slower I go, the better the piece turns out =P. just my two cents.

[ohh EPiC FAiL]

hopefully this thread sticks around, i'm going to school(takin prerequisites now) for precision machining

[SMR 510RR]

Also willing to help anyone out who has any questions. 7-8 years of 4 axis CNC milling experience and of course some manual machining experience as well.

Got myself a little bench top mill now since I dont work as a machinist anymore, had to since I was getting the shakes for machining withdrawals haha .

Here are my tips for the weekend warriors out there:

1. Keep your machine, tooling, fixturing, measuring, etc. clean. The cleaner the better, I cant tell you how many times I had a little chip ruin a part becasue it either lifted the part or dinged it. I swear sometimes it feels like 75% of being a machinist is cleaning.
2. Planning Planning Planning...Before taking your first cut brainstorm for a little while about the complete process you are going to go through on your part. There is always more than one way to go about making a part, often times my first idea isnt the best way. If your part is going to take multiple operations figure out the proper order they should go in and verify that you will have a reliable way to hold and locate your part for each opperation.
3. Fixturing. This could be as simple as sticking a block in a vise or as complex as cutting a custom fixture for your part. Obviously having a solid fixture is the only way to maintain precision. Again refer to step 2 and make sure you have a plan before starting the work.
4. Make at least one extra. If you are making a 2 op part and features need to align make sure you have a "test part" or two or 10 to get everything dialed in.

Patience is the key to getting good at machining. Any time you start to rush you will probably screw something up, dont worry we all do it!


I will have to snap some cool pictures of stuff that I have made, I have some cool stuff I have lying around.

Now I just need to justify a CNC conversion on my little mill so I can make some more complicated stuff without it taking me forever.

[CREEPERBOB]

Originally Posted by dkf

So you basically want to reduce the diameter of the entire 12" rod down to 3/16"?

Problem with titanium is it eats the cutting edge and puts a lot of force on the cutter which causes deflection. For turning a diameter that small on a conventionial engine lathe yeah a follower rest will help if you have one small enough. Honestly thats a centerless grinding or swiss lathe job.(sliding headstock and bushing) Best bet is to save the aggrevation and buy a 3/16" piece of stock.

Actually the rod will have 3 or 4 O.D.'s 3/16" 75% of the length,and I wanted to buy the follow and steady rest when I purchased my machine but they are still on backorder.
Thanks for all the input guys, this thread already "ROCKS".

[CREEPERBOB]

Originally Posted by SMR 510RR

Also willing to help anyone out who has any questions. 7-8 years of 4 axis CNC milling experience and of course some manual machining experience as well.

Got myself a little bench top mill now since I dont work as a machinist anymore, had to since I was getting the shakes for machining withdrawals haha .


Here are my tips for the weekend warriors out there:

1. Keep your machine, tooling, fixturing, measuring, etc. clean. The cleaner the better, I cant tell you how many times I had a little chip ruin a part becasue it either lifted the part or dinged it. I swear sometimes it feels like 75% of being a machinist is cleaning.
2. Planning Planning Planning...Before taking your first cut brainstorm for a little while about the complete process you are going to go through on your part. There is always more than one way to go about making a part, often times my first idea isnt the best way. If your part is going to take multiple operations figure out the proper order they should go in and verify that you will have a reliable way to hold and locate your part for each opperation.
3. Fixturing. This could be as simple as sticking a block in a vise or as complex as cutting a custom fixture for your part. Obviously having a solid fixture is the only way to maintain precision. Again refer to step 2 and make sure you have a plan before starting the work.
4. Make at least one extra. If you are making a 2 op part and features need to align make sure you have a "test part" or two or 10 to get everything dialed in.

Patience is the key to getting good at machining. Any time you start to rush you will probably screw something up, dont worry we all do it!


I will have to snap some cool pictures of stuff that I have made, I have some cool stuff I have lying around.

Now I just need to justify a CNC conversion on my little mill so I can make some more complicated stuff without it taking me forever.

Lots of good info .
I plan on at a later date to get the DRO retrofit for my machine to help with any backlash issuses that cannot be adjusted out.
There is a CNC retrofit available too, but I don't think I will try that route myself.

[SlickRockSpider]

Originally Posted by CREEPERBOB

I'll through out the first question. Will I need a follow rest to turn 4" long pieces of 1/4" titanium rod to 3/16"? The rod is 12" long , but want to turn 4" at a time.

Just center drill on one end and use a live center in the tail stock. This will take any question of rigidity. Rigidity is one of the keys. If the machine is set up right you are in.

The best is finding 3/16 dia rod. Dont make more of a job than it needs to be.

I dont make anything without a drawing it on cad. Simple cad. That way I dont worry about the design and concentrate on the part.


Be very careful and have fun



Evan

[dkf]

Actually the rod will have 3 or 4 O.D.'s 3/16" 75% of the length,and I wanted to buy the follow and steady rest when I purchased my machine but they are still on backorder.
Thanks for all the input guys, this thread already "ROCKS".

Ah ok. You may want to pick up a nice sharp smooth flat file if you need a somewhat consistant diameter. Turning something that small out of a tough material, you will get taper and belly over the cut length.

Just center drill on one end and use a live center in the tail stock. This will take any question of rigidity. Rigidity is one of the keys. If the machine is set up right you are in.

Helps with rigidity but doesn't do much of anything to prevent the part deflection and keep the diameter consistant across the cut length. The farther the part is entended less rigid it will be even with the center. On really small diameter, long parts the material could even be pulled from the live center.

[rlockwood]

New to the site, but over 10 years experience here as well. The majority of it as a standalone programmer/prototype-for-production machinist supporting about 10 full-time engineers. In the last year, I programmed and machined over 300 unique aerospace parts

[SlickRockSpider]

Originally Posted by dkf

Ah ok. You may want to pick up a nice sharp smooth flat file if you need a somewhat consistant diameter. Turning something that small out of a tough material, you will get taper and belly over the cut length.

Helps with rigidity but doesn't do much of anything to prevent the part deflection and keep the diameter consistant across the cut length. The farther the part is entended less rigid it will be even with the center. On really small diameter, long parts the material could even be pulled from the live center.

dkf

You are correct in everything you said. It is so hard to tell what turning a dia really means. What is important the ends or the center or all. What kind of tolerance and surface finish. What tool type to use. I have a tool post grinder for my lathe. If i want the better I use my tool post grinder. Best I send them out to be center less ground.

Part deflection is a major part of machining.
Yes if you push to hard on a small dia the tool will try to get under the rod.
Yes if you don't spring cut you my find an ugly amount of dia change. Even thought Ti is tough I use high speed steel on finish cuts because carbide requires more pressure than HHS.


Machine Questions

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

Who I am:

No production here. I take it as slow as I need to get the final product I want. If I don't then I will be disappointed and I will have to do it again.

Thanks dkf great comments

Evan

[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?