Monday, September 14, 2009

New & Used Milling Machines

Bixby Machine Tool Supply has it all. CNC, Milling machines, metal lathes, saws, drills, metal fabrication equipment, sanders, grinders, presses, compressors, measuring, tooling and much more.

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click for enlargement

MIL-00BPS1649C Our best selling mill year after year. 16 speed 9x49 table that is hardened and ground along with the ways. The best thing about this Bridgeport copy is the price $3995 FOB Spokane. We throw in a set of R-8 collets and have some great prices on vices and cutter sets. We bring these in six at a time and pass the savings on to you. A quality full size mill for $4200. Can be ordered in a 8-speed single phase model for the same great price.

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click for enlargement

MIL-ACR3VK-EVS
Trouble free HIGH QUALITY Acer mills. The 3VK-EVS has a 10"x50" table with 34" table travel and 16" cross travel, Baldor 3HP motor, 60-4500 rpm electronic variable speed. This mill has hardened and ground wear surfaces and table. It is our best quality machine and weighs in at over 3000 lbs. Our package price with table feed and 2 axis DRO is
$13,375.00

A Fourth Axis to the Next Level of Machining CNC Index Head

I have to confess this project was wholly inspired by 2 (two) unrelated events.

Firstly as one that is predisposed to the not too uncommon habit of reading while seated in the smallest room in the house, I was browsing the well worn pages of Dave Gingery's 6th installment in the "Metalworking Shop from Scrap Series" - Deluxe Accessories.

Secondly earlier that same day I'd visited the "Association of Backyard Metal Casters" web page, and saw a fantastically simple foam turning lathe made from an electric kitchen mixer. www.abymc.com

With teeth gritted in concentration the idea of making a lathe/Indexing head attachment for the CNC mill was born, and it would be similarly be under the digital control of the mill PC.

These are the handful of parts that I settled on for the framing and spindle of the assembly.

The 1/4" Alum plate was carefully measured and cut to size on the band saw. The saw never balked at the Alum, provided I applied a very light feed and held the work as securely as possible.

What ever time I gained by using the band saw, was lost and then some, in the hunt for a gearing mechanism to drive the spindle.

The approx ratio between the 1.8 degree stepper and the spindle is approx 5:1 giving me 1000 steps per revolution.

The spindle is a length of 1/4" rod that was scavenged from one of the numerous printers that I've husked over the years.

Using a #20 tap and an electric drill the rod was suitably threaded to allow foam pieces to be skewered and then securely held by a pair of wing-nuts & washers.

The simple collet type spindle drive was carefully tuned down on the lathe, threaded and machined.

The clamping collar was in amongst several pieces that were in my general "to be sorted pile"...

The Brass base (just behind the collar) was picked out of a scrap pile from a dead blood centrifuge or some such medical device.

I'm rather proud of this simple drive assembly, mostly as it took almost a whole day to cut a set of identical standoffs, machine the drive and line-up all parts.

Given the fineness of the gears, the counting of the teeth is just not for me, but I'll be able to determine the exact count & ratio once the assembly is interfaced to the PC.

The white plastic gear is from a ribbon positioning assembly used to set the colour band on an old dot matrix printer. The stepper motor is simply from the pile.

All of the measuring, filing, punching, drilling, threading, scratching, burping and farting have paid off.

The axis of the threaded spindle is dead on it's full distance relative to the mill-head.

This mini-project is counter to the methodology I used when building the mill itself. I built the mechanical portion first, and will attack the electronics controller second, and lastly will interface to the PC and figure out how to manipulate 4 axis of simultaneous movemen

Friday, August 28, 2009

Insert accommodates low and deep cut depths

By combining two different geometries on the same insert, Walter has created the NRF indexable insert for simultaneous heavy duty rough- and finish-turning applications in the same setup.

The insert can be applied on both low- and high-alloy steels and with the same tool, effectively halving the number of geometries users may need.

In addition, because NRF features a strengthened double groove at the main cutting edge, the doubled chip compression generates short chips.

The V-shape chip-forming area at the cutting radius leads to optimum chip breaking at low depth of cut.

Available in five basic shapes - CNMM, DNMM, SNMM, TNMM and WNMM - and in a variety of Tigertec coatings, NRF inserts can accommodate machining at low (0.8mm) and deep (15mm) cut depths, and cutting forces can be reduced because the curved cutting edge generates a soft flow of swarf.