Three Methods for Making Large Holes in 6061 - Tormach CNC

Tormach on the web @ http://www.tormach.com

Overview:
Boring, pocket circular interpolation, and spiral down interpolation are compared in this application video for accuracy and finish.

This video reviews various methods for creating holes larger than can be done with standard drilling cycles. Three cutting methods are compared for speed, finish, and accuracy.

Material: 6061 T6 Aluminum
Cutter: 0.5" HSS drill
0.5" HSS rougher
0.5" HSS 2 flute
Boring Head
Speed: 900 to 2000 RPM
Feed: 1 to 20 IPM
Machine: Tormach PCNC 1100

Background:
Very large boring machines can bore and ream very large holes. When facing the task of creating large holes with a smaller machine, a machinist is faced with selecting between several alternative methods. Circular interpolation is an easy task for any CNC machine, but the resulting accuracy is strongly affected by backlash of the ballscrews and the precision of control. A boring head is slower, but generally more accurate.

This application note reviews the creation of 18 holes, each 1.27" in diameter. The holes are finished using three different techniques with the manufacturing results compared.

Read more:
http://www.tormach.com/MfgDatabase/20104_holes_6061.pdf

Key words:
6061, aluminum, boring, circular interpolation, bore gage

Category:

Science & Technology

Tags:

• Tormach
• CNC
• 6061
• aluminum
• boring
• circular
• interpolation
• bore
• gage

[Al989898]

These units are designed for the home machinist. What you are talking about is just fine for larger machines. 3-flute carbide is also not cheap as well.

[baccus61]

well that's fine if you have a larger tool bit but if you don't or can't afford $160 for one then a 1/2 inch one will do the job admirably.

Not everyone works for Boeing with unlimited resources.

[bddc201]

Boring is the way to go if the hole has to be round and concentric. Never seen a CNC interpolate even close to same level of accuracy.

[nitronovice]

are there any concerns of running lower rpm's? i've been running approx. 1000rpm on the conventional mills at school, of course, very slowly hand fed. would i be doing any harm to the tools by doing so? i'm just never a big fan of going fast on tooling jobs.

btw, breifly worked with an old haas mill and it was awesome =P

[alderaforall]

@gforce118118 this is far from high speed machining. He is crawling. Those holes should be done in less than 30 seconds each with high speed practices.

[surinderdhiman]

Informative!!!!!!!!!!!!

[gforce118118]

just wondering....why did you climb mill? i always thought that it was easier to mill an anticlockwise path with clockwise cutter/spindle rotation. mabey im just thinking of manual machining, not high speed cnc. nice video, and nice collet rack too

[MischadeBruijn]

@doctorwintercold

Leak??

This is flood collant, ist meant to do this ;)

[myatskayahoo]

Nice overhang

[myatskayahoo]

magnetic scales cut it to .0003

[doctorwintercold]

You better fix that leak or youll flood the shop!

[gnttechnologies]

Nice video and machine for home users, certainly better than a seig!