What's new
What's new

New guy looking for some beginner advice?

jlsmithseven

Plastic
Joined
Jan 13, 2017
Hey guys,
I just started my second semester in CNC Machine Tool in College and I'm looking for some basic how-to's, good charts and basic beginner handouts that could help me with class.
I finished my first semester pretty well and learned all the basics. I have no real background of machining metal but I have run a planar wood machine in the past for a little bit.
I know how to do basic operations on the lathe and mill. Our first project has to do with threading on the lathe and I've already looked at so much. I just wanted to introduce myself here and see if you guys could point me somewhere in the forum that is a good place to start for beginners. We are just getting into MasterCAM and Inventor as well. We can run the Prototrak A.G.E. 2 as well. Thank you!
Justin
 
Hey guys,
I just started my second semester in CNC Machine Tool in College and I'm looking for some basic how-to's, good charts and basic beginner handouts that could help me with class.
I finished my first semester pretty well and learned all the basics. I have no real background of machining metal but I have run a planar wood machine in the past for a little bit.
I know how to do basic operations on the lathe and mill. Our first project has to do with threading on the lathe and I've already looked at so much. I just wanted to introduce myself here and see if you guys could point me somewhere in the forum that is a good place to start for beginners. We are just getting into MasterCAM and Inventor as well. We can run the Prototrak A.G.E. 2 as well. Thank you!
Justin

Why are they having you learn Inventor? Its not bad software, but hardly any companies use it. I'm not even sure if it's in the top 10 most used CAD?
 
When I was first getting started, our tool salesmen would drop off little speed/feed slide rule charts for quick reference. I imagine if you went to their websites, something similar would be available for download. Heck, theres probably a phone app you could find these days. Niagara Cutter made a good one back then. Starrett also makes a nice tap drill/ drill size chart.
 
jlsmith: Welcome to the forum. I would like to recommend that you find the Homeshopmachinist forum. It is probably better suited to your questions at this time in your level of experience in machining. I would urge you to hang around to this forum and learn from these guys, there are hundreds of years of experience here. Good luck and don't forget to bone up on the stickies on any forum you frequent. Good luck.

JH
 
My advice is to learn how to use a file.

When you can make the thread you are cutting on the lathe with a file, and can make a perfectly square block or perfect sphere with a file, then you will have learned something.

Knowing how to use a file is the difference between a master machinist and a button pusher.

If the file is too complicated to start off with, you may want to begin with the chisel. A chisel is similar to a file, except it has only one tooth.
 
My advice is to learn how to use a file.

When you can make the thread you are cutting on the lathe with a file, and can make a perfectly square block or perfect sphere with a file, then you will have learned something.

Knowing how to use a file is the difference between a master machinist and a button pusher.

If the file is too complicated to start off with, you may want to begin with the chisel. A chisel is similar to a file, except it has only one tooth.

It's funny you said that. One of our very first projects was draw filing the end of a block square within .005. Long story short, I got extremely frustrated with it. I had to start a new block and eventually I filed the thing down to within .001 and .002 on all sides. So that's my story. But I understand that and thanks for the recommendations! All these forums are for metal or wood right? I'm in the metal field. Thanks again!

Oh yeah, I spent about 26 hours total draw filing...
 
I don't think tool salesmen will visit students. Perhaps some visit the school's shop instructor and you could ask him if any handouts are available. There are many suppliers on the web and generally you can get their freebees from their web sites. Starrett is mentioned above and they do have a bunch of charts for many machining tasks. They are on the Starrett site, but you have to do some searching.

Catalogs

The last time I looked, their catalog had a lot of charts in the back. Of course, that may have changed.

As for a screw hole chart, I like my own. I have never found a chart that gives ALL the information that I am always looking for when working with screw holes. My chart combines:

Nominal OD
Tap drill size (75%)
Clearance hole size (BOTH close and free fits as well as best fractional size)
Wood screw pilot hole size (for both soft and hard woods)
Countersink diameter (useful when designing so the CS does not go over an edge or into other features)

It is a work in progress in Microsoft Excel format, but here is a link. I still have to add things like sizes for sheet metal screws, counterbore sizes, and, of course, metric. My goal is to have it all on an easy to read, 8.5" x 11" sheet.

Oh, it is also free but you do have to print it.

Dropbox - ScrewHoleSizesChart17114.xls



When I was first getting started, our tool salesmen would drop off little speed/feed slide rule charts for quick reference. I imagine if you went to their websites, something similar would be available for download. Heck, theres probably a phone app you could find these days. Niagara Cutter made a good one back then. Starrett also makes a nice tap drill/ drill size chart.
 
i don't think tool salesmen will visit students. Perhaps some visit the school's shop instructor and you could ask him if any handouts are available. There are many suppliers on the web and generally you can get their freebees from their web sites. Starrett is mentioned above and they do have a bunch of charts for many machining tasks. They are on the starrett site, but you have to do some searching.

catalogs

the last time i looked, their catalog had a lot of charts in the back. Of course, that may have changed.

As for a screw hole chart, i like my own. I have never found a chart that gives all the information that i am always looking for when working with screw holes. My chart combines:

Nominal od
tap drill size (75%)
clearance hole size (both close and free fits as well as best fractional size)
wood screw pilot hole size (for both soft and hard woods)
countersink diameter (useful when designing so the cs does not go over an edge or into other features)

it is a work in progress in microsoft excel format, but here is a link. I still have to add things like sizes for sheet metal screws, counterbore sizes, and, of course, metric. My goal is to have it all on an easy to read, 8.5" x 11" sheet.

Oh, it is also free but you do have to print it.

dropbox - screwholesizeschart17114.xls

thank you!
 
You can write to any tool supplier you can think of thats what I did many moons ago when I was at your age.Told a few porkies said I was building a small company up and would be intrested in any feed/speed charts they had available so I could study them before stocking up on tooling.Got loads back-Send an adressed stamped envelope for return,
 
Why are they having you learn Inventor? Its not bad software, but hardly any companies use it. I'm not even sure if it's in the top 10 most used CAD?

Sketching in Inventor is a pain, but building solids is very easy. Also, with Inventor PRO you get the simulation and FEA tools. I think the HSM module is meh, but it is great for first op roughing at least.

To the OP, stick around here, you will learn plenty. ;)
 
Thanks for all the initial help guys. Can I just ask one quick question.

When I go to make my Center Drills for live centers on my lathe workpiece, I'm having issues. It seems I have to use way too large of center drill to make sure that the dead center doesn't touch the back inside the hole. I used to use a number 2 or 3 I think but now I have to go all the way up the #4 center drill to make sure there's enough clearance. Is there any sort of little trick I can use to help me? I round the nose of my dead center as well..
 
Drill portion should be long enough not allow angle to bottom out?
Good trick on a manual lathe is to tool bit start a center scalp to an indicated part for a part with no OD stock to take..

Center Drills, HSS, Set of 5 (Numbers 1-5) 123 - LittleMachineShop.com

[When I go to make my Center Drills] never thought making them a good idea as they are cheap enough to use and toss IMHO. I did not even like sharpening them unless I could hold .002 or better on point center. A center drill with an off-point off center can start off center and loose a no-stock part.

We used to spin an end down of a used center drill and then make Allen extractors of them.. with grinding a sharp corner hex a few thousandth larger than a Allen wrench, with the sharp corners and tapped in with a small hammer they would pull almost any washed out hex screw.
 
Drill portion should be long enough not allow angle to bottom out?
Good trick on a manual lathe is to tool bit start a center scalp to an indicated part for a part with no OD stock to take..

Center Drills, HSS, Set of 5 (Numbers 1-5) 123 - LittleMachineShop.com

sorry I don't understand what you're saying. yes I don't want the end of my dead center to hit the inside of the hole. so ive been drilling much further on the center drill to make sure it doesnt happen. i put a round radius on my nose too so i dont understand whats happening. is there a good way to measure this so i know i won't hit the inside.
 
I've found center drills work best when you only drill about 2/3 of the way up the 60deg taper. That leaves enough clearance for the tip. IIRC if you drill too deep you'll run into the problem you're having. May have that the wrong way around though.
 








 
Back
Top