Hi all, new to the list, an intro and a couple of ?

[WhizzbangK.C]

First off, I've been lurking here a while now reading through the archives and must say it's a pleasure to see such an informative and helpful bunch in one place. I hope to be around to soak up as much knowledge as possible from you all and maybe even contribute a little myself, lol.

My first newby question is this, is there any major benefit to running end mills in holders instead of collets with an R8 spindle?

I'm asking because I've just purchases one of the large H-F mill drills and am now in the process of setting it up and getting tooling together for it.(I know they're not really well thought of but after several years of reading everything I could find and comparing costs/benefits/drawbacks this seems to be the best thing to learn on for me, besides, if I have to send my money overseas I prefer to send as little as possible, lol).

A little about me by way of intoduction. I've spent my whole life as a mechanic of one form or another. Started in a junk yard when I was 14 pulling parts for customers (worked cash free for the experience and any parts I needed to build my first car up). Joined the U.S. Army after high school and worked structural repair on helicopters. After getting out of the Army worked aviation for several years, B-1 bomber construction at the Rockwell/NAAO plant in Columbus Ohio building nacelles for 5 years, then job shopped around for a couple of years, finally worked at TWA in Kansas City till I got laid off there and switched to working on heavy trucks (got tired of moving all over the country, lol).

My real life has always been motorcycles. Have built or helped build several show winning riders. I don't believe in "two wheeled sculpture" that's never ridden, just seems wrong to me . That's what leads to my need to machine metal. While working aviation I always had access to incredible machine shops and machinists, and could make or get made anything I could dream up.

Since then though I've been suffering withdrawl and decided finally to do something about it. Last year I bought a couple of Atlas lathes, took them apart, cleaned them up and took the best parts from the two and built myself one good one. Roller 10" with quick change gearbox and power cross feed, no measurable wear on the bed at all, and after carefull setup it cuts true to .0005 over 12", good enough for the girls I run with .

Now I've got a mill that I'm pretty sure will do what I need once I get it all cleaned up and set up.

I saved the bed, tail stock, and headstock that are left over from the lathe project (12") and plan to use them in the future for indexing fixture or flywheel truing stand, or anything else I can think of, lol.

Also, does anyone have any specific recommendations as to best sources of tooling for quality and price. I'm running on a severely limited budget (who isn't) and want to get the best deals possible without spending money on worthless crap. I do know that a lot of the import stuff is worthless and don't want to throw away a dollar to save a dime. This mill drill is the first import tool I've ever bought but there was no domestic choice available to compete with it.

I must say that H-F was very easy to work with, the manager of the store cut me a very good price (even lower than their best advertised special in years), and even let us "haul away" three 8 foot sticks of 1" cold rolled that had been setting against the wall behind the store for a while. Good to deal with, she was!

I see that this board doesn't allow indented paragraphs, lol.

[This message has been edited by WhizzbangK.C (edited 01-14-2004).]

[Rich Carlstedt]

What are "major benefit to running end mills in holders instead of collets with an R8 spindle?"

well that is really the preferred way to do it. The biggest reason is you won't "pull" an endmill. Thats when the collet can allow the cutter to creep down, caused primarily by the positive helix angle of the cutter and insufficent clamping by the collet. And this does not mean you tighten more !
In many shops, the only cutter allowed in a collet is a drill bit! .
Once you pull an endmill, you will never do it again, if the part was expensive !

[bspooh]

Collets will hold the endmill more concentric than a screw type holder..Screw type holders will not be as concentric, but will have greater holding force..Usually you have much less overhang when using a collet

brent

[SGW]

I generally use collets for concentricity and stiffness. I sometimes use an end mill holder if I need some extra "reach" for clearance or whatever.

As for suppliers:
I generally use either MSC www.mscdirect.com or Travers www.travers.com
In my experience, MSC has slightly faster service and slightly higher prices. They also seem to carry some cheap low-grade stuff in addition to the high-quality stuff. I've found Travers to be slightly cheaper overall. Not as big a selection, but I think they generally don't carry any really low-grade stuff. I've found their low-priced offerings still good enough to be useful.

[lynnl]

I'm confused. If there's sufficient force to pull the endmill out from the collet, why won't that same force pull the endmill holder out?

[sidneyt]

" Also, does anyone have any specific recommendations as to best sources of tooling for quality and price."

Since you have purchased your m/d from HF you might consider some of the other items that they carry that are IMO worth looking at. These items are not available in their stores, but HF offers very inexpensive shipping on their stuff ($5.50? handling charge and no additional shipping charge on items over $50).
6" vise with swivel base:
http://www.harborfreight.com/cpi/cta...emnumber=90360
X axis power feed. The photo they use is misleading. It fits the 33686 mill without alteration. I consider a power feed indispensible.
http://www.harborfreight.com/cpi/cta...emnumber=39745

You can buy these items from other vendors:
Enco, MSC, J&L, etc, but HF's price with free shipping is hard to beat.

Most of your tooling needs will, of course, depend on what you are making, but just about every mill will require a vise. You can buy these from a number of sources and pay a lot more than $100. As good aa they are, I would have have difficulty paying $400 for a Kurt vise (I keep looking for the $100 used Kurt in our local yard sales) to put on my $800 m/d. Others will differ on that.

The power feed may appear to be an option that can be deferred and you may do so. But, once you have one, it's hard do without.

[JCHannum]

lynnl, many end mills have a flat for a set screw, so they can be held more securely in an end mill holder. Said end mill holder being in the form of an R-8 collet, but solid, bored for end mill and equipped with set screw(s).
R-8 collets have high holding power, double angle holders more. Comments on concentricity are appropriate.
I have had MT #2 collets slip, never had a problem with R-8 if I remembered to tighten it.

[spope14]

End mills 1/2" and under I generally run in holders, but I have always had chatter problems with 5/8 on up in holders. I am aware of the "pull out" in colletts - especially on bigger end mills, but in the many years I have been doing this (say about 30 now), I have only had this once. I do NOT reef my drawbar too tight or anything, just pay attention to speeds, and the feel of the feed - not too light, not too heavy.

The advantage of holders can be the preservation of accuracy of colletts, especially when you over stress (crash) or spin the end mill. Once this is done, the collett can be suspect in concentric accuracy. The holders tend to prevent spinning.

I do often run over 1/2 in end mill holders, but as I said, the chatter becomes a factor to live with in my case. Overhang of the tool from the machine casting and quill being the main issue.

Each of us has a preference and experience, thus I am hoping for more input on all of this, and I post this in respect to the opinions of others.

[SGW]

Pulling out the end mill holder....

End mill holders have (or ought to have) a drawbar, so pullout isn't a problem.

[WhizzbangK.C]

Thanks for the input guys! It means a lot to have folks to bounce stuff like this off of.

I guess that the collet vs holder thing is more a matter of personal preference and comfort level than anything else. The main reason I asked is that from personal experience I can see that the holder extends the cutter farther out from the spindle and increases the risk of chatter in any given situation. I did also note that the collets don't have a positive engagement for the flat on the cutters. Thus I was looking for some compelling reason to use one over the other.

I have checked out Travers and MSC sites, as well as every other one I could find. Man are these things expensive . Looks like the way to go is to just get a "cheap" assortment to learn with (and break) and then purchase the good stuff as needed/when needed for specific jobs.

I'll try to get some good pics up of my shop and machines after I get a stand built for the mill and post them so all you guys with the big machines can get a good chuckle 8^) .

[doug931]

whizzbang- I think most of the guys have missed your main point. your are new to this site. (welcome) as am I. I am also a veteran of the military(22 years) and have also been a mechanic most of my life. Aero engine, automotive, heavy diesel and motorcycle. I am also in the process off upgrading from a mill-drill to a vertical mill. the mill drill has served me well for the last fifteen years in my bike shop, but I feel it is time to try some more ambitious projects. I'm thinking of milling custom triple clamps, forward controls, handlebar switch housings, and of course many of the special tools needed to work on bikes. one interesting project I made on my 6' Atlas lathe is a set of tools to replace the glass on instuments and swage new bevels ito place. time to go, the paris to dakar is on. doug

[SGW]

The name-brand endmills (Niagara, Weldon, etc.) are indeed better, IMO, but I think you'll find the "quality import" end mills plenty good enough while you're learning how not to destroy them.

[lynnl]

R8 shank on the endmill holder.... Sure. Duh! I wasn't thinking that thru.

[BillH]

end mill holder vs the collets can sometimes be a decision forced onto you by what you have to deal with.
I have a harbor freight micro mill, and I need all the space I can get, so using collets is the only real choice. Not only do the collets give you more room, but they put much less leverage on the spindle as their is much less extenstion of the end mill. That should not be a problem though with any real mill.
You'll find many of the questions you have will become not big issues when you start to make some chips. Before I started to cut chips, I had tons of questions too.