Material and tool selection

[PJs]

Some funny lines in your write up MeJasonT! I'm glad this is taking off!

Perhaps for noobs and novices, the best lesson I learned on my mini (Peanut) was to take a touch off bite first then take a light pass to see the finish and how tough the material was. Granted the mini is a manual peanut, which allows you to "Feel" whats going on. It's definitely a light hobbyist machine which I knew going in, but I have worked some very small stuff cleanly down to 2 tenths up to large stuff like the grey bar. I'm not in production so time taken with smaller passes is ok with me, but repetition to work a big hunk to a small hunk can take it's toll on you. Besides whether its for production or home-hobby, quality is king for me, Always. The other thing to consider smaller passes is you may only have the one piece of material just big enough, so you don't want roach it trying to hurry.

This is a shaft extension with tight tolerances and a 50thou hole for press fit in the end that I built for a solar powered music box for my grandson. I was shooting for .2002 and undershot...oops, but it worked fine. Just takes patience and some time.



When I first started with it I watched a lot of Mr. Pete, Abom79, and Keith Fenner on YT. I saw these guy ripping off 100-200thou passes using carbide tools without blinking or Binking [no tool pieces to the forehead ;-P] and here I was happy to get 20-30 on aluminum...maybe. Keith taught me a lot and answered my questions graciously, particularly about carbide tooling, and I learned a lot about speeds and feeds from them all. The important upgrade for me was the QCTP I got and the TCMT carbide tool set I got. They worked on most things I did, and found the speeds and feeds a bit more flexible depending what I was doing. But found that in some cases the carbide bits just didn't "get er done" the way I wanted or needed.

I scrounged around in one of my old tool boxes for some HSS bit I knew I had but hadn't used or seen in years. After some practice grinding again after years of not, I found how much I liked what I was able to achieve with them. The mini plays well with most materials using HSS and now after time have built up a collection of various grinds I've needed. Mainly for me it's the finish I can achieve, minimizing followup finish work. But, I use the TCMT's quite a bit for getting through material quickly and reasonably well.

Probably the second most helpful thing I learned about (other than do Not Tax the machine) which John (hemmjo) brought up some really good points about angle of attack, Rake/relief and radii...and honing. I hone all my bits including the carbide (after some use) either with a stone or extra-fine diamond, it makes a huge difference in life, finish and feed rates, imho.

Coolant is a big subject as well and a lot of opinions about it out there. On the Drill Machines I used a water soluble that we used on the Mori in the shop and it worked great as long as I could get the guys to change it before it started smelling like a swamp of dirty gym socks. For me on the peanut, I just use a standard cutting fluid I picked up somewhere and WD40 and generally sparingly (unless parting) with a small squeeze bottle (drips), depending on the operation and mainly on steel only. Don't like acid brushes much but use a 1" throw away or tooth brush when working dry.

Whelp that's another 6 bits from me and my thoughts as a wanna be, when I grow up to be a Doug.