beginner milling questions

john april

john april

Joined
Feb 27, 2006
Messages
5,191
hi, i read here a month ago its a bad idea to use a drill press and crossvise as a milling machine because of safety hazards. i ordered the grizzly G0781. its the second smallest one they make. 177 lbs, 3/4 hp. i have noticed there are different kinds of spindles, this one has an R-8. does that spindle accept the round shank carbide end mills i have been using in the drill press ? if i am going to mill a 1/4" slot for a guard, would it be better to use a 1/4" mill or do two passes with a 1/8" ? i use mostly nickel silver, 3/16". what rpm would you suggest ? thanks for any help. i also ordered a book, "the milling machine for home machinists" by harold hall. hopefully that will answer my future questions.
 
No it will not. You will need to purchase a set of R8 collets for your mill. They can also be purchased individually but at added expense. When milling a guard slot I always go slightly undersized on the milling operation and finish fit the guard with a file for a more precise fit.
I use only carbide end mills now simply because they work with titanium and last longer than HSS end mills, especially if your not using cutting fluid to cool the work piece. Purchase 4 flute end mills, trial and error on the rpm's , make small cuts and keep the heat down as best you can.
 
If you are going to do a guard mark your center lines and drill a hole then you can plunge your end mill and mill in both directions. I concur on undersize milling and you will ultimately have to file the corners square to finish and get a good tight fit. Nickel Silver is easy milling and you can get away with using Cobalt end mills much better than High Speed Steel end mills and less expensive compared to solid carbide end mills. Check out Enco supply for your R-8 collets they sell them separately and you can maybe get by with just a 3/8" collet and purchase your end mills in 3/8" shank diameter.
 
Little machine shop and ebay are great too.
I started with all carbide as well but after reading about
The speeds for carbide and the lack of speed on a mini mill I've been buying HSS and have been having really good success. However I'm no machinist and ymmv.
4 flute like the others have said and 2 flute for aluminum.
 
i started with carbide, but switched to hss because i could get 2 times the tooling for the price. (plus i snapped two $35 bits before i even used them. pushed the go button before i wanted and they hit the hold down bolts in the jig... this would have broke the HSS bits too, but they would have been a heck of a lot cheaper) try to spend a little more then just buying the cheap Chinese stuff and it will last longer as well. but for beginning, id stay with HSS. your machine wont have the guts to use carbide. if you do use carbide, dont spray it or oil it. it will heat check and crack. one thing that will help is a low pressure air nozzle pointed at the tool (for hss). caution as this will blow chips in the air as well, but it will help keep the tool and part cooler and will keep you from re-cutting chips. (that kills tools faster then speed and pressure.) have fun learning... its VERY addicting and will most defiantly keep you up at night thinking about...
 
Just a heads up....You will need collets, end mills, mill vise, test indicator (needed before you do any milling to ensure the vise is square to the spindle)...the mill may or may not be "Trammed" my guess is not that means that the spindle/Column may be off a few thousandths...you will need a dial indicator to ensure the column is square and plumb....a few thousandths difference may not seem like much but when you have .003 on the left side of the table and you scratch your head when you measure something you just milled and its wrong. Take the time to shim the column left to right front to back square parts are happy parts....:D
 
Nathan the Machinist said:
^ was that a problem?
Click to expand...

Yes it was for me.

Not to be too cross forum-ish

but

It's "The Friendly Machinist Forum"
trying to be the anti Practical Machinist forum.

The fellow who started that site (is a lawyer) who stole entire threads from Practical Machinist, home shop machinist forums and others because he needed content from knowledgeable members.

Then he chased any knowledgeable members away.

http://www.practicalmachinist.com/vb/american-machinist/hobby-machinist-still-stealing-posts-237521/

It MAY have been legal, but it caused a commotion.

He is hyper ban hammer especially against those who he thought had a connection to other forums.


I think I suggested that classified ads have a standardized format with the location like country and state in the titles, or at least in the listings.
I was banned.
THEN they created a new rule against criticism of the site.

http://www.hobby-machinist.com/threads/the-site-rules-please-read-before-registering.14345/
6. You agree not to disparage or make any negative comments about this forum
Click to expand...

THOU SHALL NOT PUBLICLY QUESTION THESE RULES:
Click to expand...
Here at BF we call that the tech service and support forum, but at Hobby, it's your ticket to ban.


It appears that he now has trouble recruiting new members.
http://www.hobby-machinist.com/threads/forgiveness-amnesty-truce-call-it-what-you-want.38025/
As far as I'm concerned that forum and the owner can go piss up a rope.


There are lots of other forums which have been around longer, and they are populated by good members that have been banned from Hobby

http://www.chaski.org/homemachinist/
http://bbs.homeshopmachinist.net/forum.php
http://metalworkingfun.com/
http://www.homemodelenginemachinist.com/
http://madmodder.net/

plus many more
 
Oh, you meant Read the rules THERE, you can get banned THERE in a heartbeat for something you never expected. I thought you meant something here. We're pretty laid back here. :thumbup:
 
i appreciate all the information, the videos from MIT were especially informing. how they squared up the machine and table was very interesting. i never realized i would need all that stuff like dial gages and test gages and collets. i am looking forward to buying everything i need to get it running right.
 
If any of those videos told you that you would spend as much on tooling as you spent on the mill, they were right. If they didn't, be prepared lol.
 
woodster said:
i appreciate all the information, the videos from MIT were especially informing. how they squared up the machine and table was very interesting. i never realized i would need all that stuff like dial gages and test gages and collets. i am looking forward to buying everything i need to get it running right.
Click to expand...

Once you get the machine and start to understand its capabilities the Cost of the Mill is nothing compared to tooling.....I've been a machinist for 30 years and it still amazes me what I have purchased over the years....:eek:
 
Count - Thanks for the history on the forum I recommended, I didn't realize it had such a toxic past. I'll check out some of the other forums you recommended.
 
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