Old Iron Drill Press Speed DP 220

[John Stan]

Folks,
My dad gave me an old drill press that had been in the family since new. It is a Delta/Rockwell DP 220. I suspect it is about 60 years old. The 1/3 HP motor runs at 1750 RPM and has 4 pulley settings. Does anyone have any suggestions on how to calculate the speed of the drill at each of the 4 settings? Has anyone done the calculations already and can tell me the 4 speeds?
Thanks,
-JDS

[David G Baker]

John,
I am sure that if you search the net you will find the chart. Look for Sears DP manuals they are good at giving out a lot of information and you may be able to get an answer from the manuals. There are ways to do the math but that is not one of my stronger areas.

[Matt Meiser]

You should be able to find the information in a manual on the OWWM.com site too, but know that that drill press was available in a "lo-speed" version as well as a standard version.

Off the top of my head, chuck speed should be motor speed * motor pulley diameter / quill pulley diameter.

[Ron Knapp]

From my manual:

Standard Speeds

The standard speeds obtained on this machine when using a 1,725 r.p.m. motor are 680, 1250, 2400 and 4800 rpm for the high speed models; 470, 780, 1300 and 1950 rpm when the slo-speed pully is used. The highest speed is obtained when the belt is on the largest cone on the moter pulley and teh smallest cone on the spindle pulley.

I second the suggustion to go to OWWM.com site. You will be able to find your manual there.

[Bill Huber]

Try this site.

http://www.csgnetwork.com/pulleybeltcalc.html

[John Stan]

I just found the site, thanks for the link. Lots of good info there. Now I need to determine if I have a low. spped or high speed model. Any tips on how to do that.

My grandfather used the Drill press for Metal machining to build metal parts for the Korean War effort. So I would assume it is more the high speed model.

Thanks for all your help,
-John

[Matt Meiser]

John, the front pulley is much larger on the lo-speed model and it required a different hat on the front from what I understand. I think I have an old Delta catalog out in the shop that lists the pulley size for the lo-speed kit.

[glenn bradley]

I have one of these that was bought new by grandpa. Very nice machine. I wish my new DP was as smooth. I believe I have the original paperwork, I'll see what I can find after work today.

[Alex Shanku]

Here is an image of both pulleys:

http://www.hunt101.com/data/500/Slow_speed_pulley.jpg

**Courtesy of Bob Vaughan**

Full article is here

http://www.owwm.com/files/PDF/FAQ/DrillPress.pdf

[George Sanders]

Speed of driven pulley = diameter of driving pulley x RPM divided by diameter of driven pulley. Clear as mud!:confused: