Another drilling issue

[blackieNYC]

I followed the earlier thread on drilling.
I've been using a bit of WD40 on my Irwin cobalt unibit. But I have a buildup of melted aluminum on the bit. I've set to press to a speed of 950, which is printed on the press as being the recommended speed for 15/32.  This makes it a little slow for the smaller holes but they don't seem too difficult.

Can I get this aluminum off the bit?
I really don't want to have to change the belts around on the press, and I don't know - is this speed a problem?

[PRR]

https://www.fnal.gov/pub/takefive/pdfs/Drill_Press_Speed_Chart.pdf

This government-approved chart suggests 1,500 for Al that size.

> don't want to have to change the belts around

Do it. Get good at changing RPM. It's important.

[blackieNYC]

Thanks. What drill bit is most like the unibit though?  A twist bit? Looks more like a bullet bit in that it starts off with a small tip. The speed of one type is twice the other on that chart.

[blackieNYC]

Bump. Paul- whaddya think?

[Groovenut]

Most of the stepper drills I've used have more of a shaving action than a cutting one. I tend to run my 1/8"-1/2" at around 1000-1200RPM and it does a fine job. It definitely needs a bit of cutting oil to keep the aluminum from bonding to the bit. Incidentally I find that the titanium coated stepper bits bond to the aluminum much more than the regular tool steel stepper bits. My 2 cents...