Re: Machinists Corner
 

Im sure if you spent enough time on google you could find something. For my purposes McMaster has decent information on the strength of different materials.

Re: Machinists Corner
 

Onlinemetals has nice charts for each type of metal they sell.. they also have good price's and will ship in custom lengths..

Guide to Buying Alloy Steel Online | Online Metals Guide to Selecting Metals for Your Project

Re: Machinists Corner
 

One thing no one really mentioned but I think is handy is i'd much rather have 2, 4" vises than 1, 6" vise on my machine. Strictly because the 2, 4" vises fit easier onto a tiny machine table and let you hold longer work easier than the 6"... Mind you that's for a tiny machine that can't handle 2 massive vises on it for supporting work 8)

And "soft jaws"... what would I do without them. Primarily they are aluminum, sometimes steel... but they are crazy handy for cutting fixtures or for that accidental moment when end mill kisses vise :oops: tools appreciate soft aluminum much more than hardened cast iron :shock:

Re: Machinists Corner
 

Thanks guys. That helps a lot.

Re: Machinists Corner
 

So much good info!!!!

Re: Machinists Corner
 

I agree on the 4" vises for our purposes they are sufficient and I agree easier to fit on the small talbes. Of course your vise should be sized for your work and you can hold small parts in a big vise but it gets sketchy the other way around.

You have to be careful with aluminum jaws though, if your part is small enough they will start pushing into the jaw if enough clamping pressure is applied (assuming your part is harder than the aluminum jaw). I used to cut a lot of custom fixtures in aluminum jaws, the real problem is that the top of the jaw will push more than the bottom and then your part will start lifting and not sitting flat in the fixture, if you dont stay on top of it they will be way off before you realize what happened. We eventually started cutting our own soft jaws out of 7075 rather than buying the 6061 jaws and that helped a lot.

One trick I liked to use if I was going to remove and use the custom cut jaws again was to mill 2 or more slots in the Y axis to use for alignment. I would run a pair of .25" slots one on each side of the jaw and then use gauge pins to align the jaws before locking them down.

The next step above soft jaws is to cut a custom fixture that you can just clamp in the vise using Mitee-bits to lock the parts down. That was very handy when running a second op on a bunch of small parts at once, you can pull the fixture out and load it then put it against a stop and run it. Of course you can make 2 fixtures and load one while the program is running to save some extra time.

Re: Machinists Corner
 

Love those things "thumbsup" They have the CAD files online now too.

Re: Machinists Corner
 

Those glacern videos are done on the same mori-seiki duracenters I use for prototype work :D

as for the materials question, I dont believe there is a more thorough resource than matweb.com. It may be overkill, and theres a good chance you'll find comparisons on mcmaster easier to follow. Realize that heat treatment plays a significant role in how strong one material is compared to another, so be sure you're comparing apples to apples. Also, as a general rule, when a materials hardness increases, its machinibility decreases.

I typically stick to 6" vises, but for hobby size machines, a double-acting Chick 4", or two, is hard to beat. Check ebay, they pop up once in awhile. I recently discovered the glory of reverse vises, and dream of changing all of mine over.

http://kurtworkholding.com/images/3610V.jpg

oh the years of backstrain I could've avoided.:sad::cry:

Re: Machinists Corner
 

I feel you on the backstrain although that reverse vise would take some getting used to. I would probably figure it out after setting up off the moving jaw a couple times.

Re: Machinists Corner
 

Ive noticed that before... but hey nothing is perfect in life is it :shock:

One good tip when making fixtures is to store them with a piece of wood, few sheets of cardboard... between them and DO NOT DROP THEM... heck I still have some old rim making fixtures from a while ago :lmao: I made mine with 4 tapped holes for making locking rings and 4 through holes for holding rims down. Job well done :twisted:

Re: Machinists Corner
 

Thanks for that info "thumbsup", there is a lot to chossing the correct cutter :shock:.
After much reading and calculating I think I have it figured out. For the gear I want to cut I need a 14 pitch #2 cutter for my 5.131 PD gear with 72 teeth. I will also have to buy an R8 arbor to fit it, I'm guessing it will also work for slitting saws etc. as well.

Re: Machinists Corner
 

What kind of mill are you using?

Re: Machinists Corner
 

I have a Smithy 1324 I-Max, with a universal dividing head.

Re: Machinists Corner
 

sweet! did you get a 4 jaw chuck for it yet? That's one of my next purchases for my 44142. I wonder if the spindle indexing ring and bolt circle are compatible between your smithy and my harbor freight. as of right now I have seen some people make adapter plates for the 44142 to run a 6" 4 jaw but I don't think there is an off the shelf unit that will just bolt up. Also the 5c hex collet block mentioned seems like a good purchase for converting my 3 jaw to a collet chuck. I had been tempted to fabricate some kind of drawbar system for an r8, but I like the simplicity of the hex collet block"thumbsup"

Re: Machinists Corner
 

I have a D1-4 mount on my spindle, but was suprised that all 4 chucks, (1-4" 3 jaw, 2 6" 4 jaw and 1 6" 3 jaw) that fit my Logan lathe will all thread onto my dividing head. I have already got the 4" one cleaned up like new , ready for that.

Re: Machinists Corner
 

Your chuck would have to have a big pass through hole or else the collet block will be sticking out like 4 inches:shock:. Also you would have to pull the block out every time to remove the part.

Re: Machinists Corner
 

They way I use collets is in a collet chuck. The idea with collets is you dont have to do the hole job in one set up. You can remove and replace the collect or work piece with out loosing much concentricity with the spindle. If you remove the collet block from a three jaw there goes the set up. Most parts you dont have to worry or mess around with. The other great thing about collets is production. They repeat very well.

A collet block (4 sided or 6 sided) great for putting flats on a round part. Or making a custom bolt head. I just put the block in my vice and go to town.

Peace my friend and have fun.

Evan

Re: Machinists Corner
 

Here is a pick of the Logan I'm rebuilding. It looks exactly like this pic from the manual for it.


http://www.rccrawler.com/forum/attac...7666-lathe.jpg

Re: Machinists Corner
 

Now I understand...... have fun. i love rebuilding machine tools/equipment.



Evan

Re: Machinists Corner
 

You may want to look at buying the correct gear wire or gear rod to use as a blank. If it is a standard sized/pitch gear then you will probably be able to find someone that makes it. generally the rod/wire is very cheap compared to a finished gear and those involute cutters are expensive :shock:.

Of course with the correct blank you can just turn/mill the gear to the specs needed for your project.


Im thinking about getting a couple sticks of gear wire to make transfer case gears out of. The going price on the finished gears seams to be $7-10 and a 1' length of the rod is ~$20 and I could make quite a few out of that. Now I just need to figure out a good way to hold the gear in my new rotary table to finish it up, 5c collets would probably be the best bet but I dont have any so I have to do some thinking.

I am thinking that I may just cut a little fixture or pair of soft jaws to hold it so I can drill the center hole since that is the only real crucial operation I need to do.