Step drill bit issues

yukoff · Posted: Jun 27 2019 Post subject: Step drill bit issues

This isn't welding specifically, but has to do with building my UDS. I bought a step drill bit from Harbor Freight, I'm using an electric drill to drill 1" holes, but I'm having issues getting a clean hole. The bit seems to wobble/rattle as I drill deeper, resulting in hole that is not quite round.

I'm sure it's something i'm doing wrong. I have the barrel sitting upright, holding it with one hand, and the other hand on the drill. Maybe I need more leverage? Maybe my drill isn't fast enough?
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Greg

jess · Posted: Jun 27 2019 Post subject:

Find another way to secure your work so you have both hands to hold your drill straight and steady. Most people try to use too much pressure and speed. Slow, straight, and steady will get it done...

gandrfab · Posted: Jun 27 2019 Post subject:

I will have to agree on the slow, straight, and steady.
But pressure to a degree stops chatter.

Speed example, most cordless drills spin to fast in high gear wide open and to slow in low gear wide open.

So, with a cordless. High gear and half fast Capt.

gandrfab · Posted: Jun 27 2019 Post subject:

Side note, harbor freight is not known for it's stellar cutting bits.
Keep the bit wet with any oil will help, cutting oil is better.
I have even use water but lets not get carried away.

yukoff · Posted: Aug 20 2019 Post subject:

Thanks, I used dish soap for lube, and eased up on the speed a bit and that seemed to do the trick. It may have been the bit too, it rattled the hardest at the 3/8 and 1/2 inch mark, but before and after that, it was pretty smooth.
_________________
Greg