drill speed advice

[ag4l]

just go my new dremel electric rotary drill. only has one speed 3500 rpm. this is the slowest speed if can find.
is this too fast to use on windsheild.
thank's

[Brent Deines]

Is that 3500 or 35000rpm? The cordless Dremels we prefer have a low speed of 6500rpm and a high speed of 13,000rpm. I prefer 13,000rpm, but there is more control with the 6500, so that's not a bad option for inexperienced technicians, and even some industry veterans prefer the slower speed. If you get much below 6500 you may have problems with bogging and if you get above 15,000 you will shorten your bur life considerably.

We are in the process of updating our drill testing results as it was recently pointed out that our instruction manual was not changed when we switch from a 5000/10,000rpm drill to the 6500/13,000 drill. We also sell various other drills with different speeds, but our preference is to drill at speeds between 10,000rpm and 14,000rpm regardless of the drill used.

[ag4l]

sorry. it's 35,000 rpm. only has one speed.

[Brent Deines]

We used to sell those, and some people really like them, but we found they really burn up the burs fast.

[doctor ding]

Brent;
Would you mind explaining exactly why you prefer drilling at speeds between 10,000 and 14,000 rpm?

[Brent Deines]

As I said below, if you get much below 6500 you may have problems with bogging and if you get above 15,000 you will shorten your bur life considerably.

We used to sell a drill that ran at 5000rpm and found that the bur would sometimes stick or stop in the hole and stop, if you weren't careful it would break. It also took an excruciatingly long time to drill a hole.

We also used to sell a drill that ran at 15000rpm and found that the burs would get so hot they would dull very quickly which also slowed down the drilling process and would sometimes cause the burs to break because as the bur became more dull there was a temptation to use more force.

Some technicians drill in spurts or use resin to cool the bur. I have never found that using resin did anything but slow down the drilling process, and if using a speed between 10,000rpm and 14,000 have never found that using short spurts did any good either.

Everyone has their own method for drilling, and some don't care about making their burs last longer or saving 60 seconds on a drill hole, but both of those things are important to me, and my testing has led me to the conclusion that 10,000rpm to 14,000rpm is a good working range. That does not mean however that you cannot drill at slower speeds for better control and even longer bur life, or faster speeds using short bursts if that is your preference. The most important thing to remember is that you should should use a lighter (not a torch) to burn off any glass dust residue from the tip of the bur, then wipe it clean prior to starting your next hole. That will double or triple your bur life.

We try to train everyone to use what we believe to be the best practices to help minimize technical support calls, but as far as I am concerned as long you are happy with the results, drilling techniques, and bur styles, are to some degree a matter of preference.

[kenb81]

I drill at 5000rpm and have no problems. The only time when it boggs down or gets stuck
is when the battery is getting low and needs to be recharged

[patriotwsr]

I also use the cordless Dremel 4.8 volt. It has 5000 & 10000 rpm. I drill using the lower rpm and keep multiple batteries charged and ready. Prior to turning on the drill, I give the bit a couple of turns with my fingers to reduce the chance of "jumping" or "running". This is really helpful when drilling ahead of the crack. Brents advice on cleaning the bit is spot on, it definately extends the life of the bit. Have a great day everyone.

[ag4l]

thank's for the advice..i decide to return the drill,its way too fast..
so i got the cordless dremel speed 5,000-10,000rpm.
thank's again everyone..