Slowing down drill press speed - Pirate4x4.Com : 4x4 and Off-Road Forum

Vortec_Cruiser · 11-06-2005, 09:24 AM

My variable-speed drill press will not slow down sufficiently to allow the effective use of large drill bits. I'm guessing that the slowest speed is about 600-700 RPM. I'd like to hook a rheostat on the power cord to accomplish this. As I remember, you can only use a rheostat on certain types of electric motors. The motor in question is a Baldor 1.5 HP single phase motor. Any help would be appreciated.

jstarnes · 11-06-2005, 09:29 AM

Vfd?

seany · 11-06-2005, 09:49 AM

variac?

or a pully change...

tdavis · 11-06-2005, 09:56 AM

Sell it and pop for a new drill press that can get even slower. A good rheostat/variable speed controller would probably cost as much.

I bought one of the Chinese made Tradesman 12" drill press from Lowes, that can go down to 250rpm. Only $119, and it's does pretty good.

Vortec_Cruiser · 11-06-2005, 10:06 AM

Quote:

Originally Posted by tdavis

Sell it and pop for a new drill press that can get even slower. A good rheostat/variable speed controller would probably cost as much.

I bought one of the Chinese made Tradesman 12" drill press from Lowes, that can go down to 250rpm. Only $119, and it's does pretty good.

Thanks, but I think I'll just hang onto my old 350+ LB drill press, in lieu of getting a "better" Chinese-made one. I'll figure out some way to make that thing run slower.

rusted · 11-06-2005, 10:34 AM

You need to fab a new pully setup. Someone here has done this, it's not rocket science. I would think an extra idler would be all you need. Variable pulleys are available at Grainger, surpluscenter.com etc.

You don't want to mess with your motor anyway. Let it run at it's normal speed, it's designed for that. Use pullies to do it. Especially if you have a big ol drill press.

This would be a great little project and one I am thinking of doing myself, but I have no time anymore. Mine goes down to 240 and that's ok, but I like slow slow slow. I'd like to have 80rpm available.

One thing is my cheap ass chuck isn't capable of handling a strong feed at low rpms on big drills. But it sounds like you have a big quality unit. Something to think about though.

u2slow · 11-06-2005, 12:22 PM

IMO a VFD is not a good idea... its a good way to wreck a perfectly good motor. It needs to be rated for drive use because of the extra stress it puts the windings through.

A variac is fine for power hand-tools and certain fans because of the motors they use... not for a split-phase/capacitor motor.

Many drill presses use a 4-pole motor... that yield slightly under 1800rpm. You could try to find a used 6-pole motor - <1200rpm, or an 8-pole motor - <900rpm.

Meesing with the pulleys is probably the cheapest if you like to tinker. Most presses just have two, but some have 3 (a middle stepped idler) for more speed range.

EDIT: its easy to post redundant info when it takes me over 2 hours to complete a post

frankenfab · 11-06-2005, 01:02 PM

The right way to do this by adding a jack shaft to your drill press.

Here is an example of how....

http://www.frugalmachinist.com/jackshaft.html

.

420willys · 11-06-2005, 04:57 PM

does adding a VFD lower the HP, you said you want to turn larger drills i would not want to lower my HP and try to turn larger drills, kinda counter productive, but if it does not rob any HP then i say try it, but dont burn out a good motor eather, jason.

frankenfab · 11-06-2005, 05:21 PM

Note: Variable frequency drives are for 3 phase motors.

ScoutIITD · 11-07-2005, 04:59 AM

/forum/shop-tools/311507-drill-press-crawler-gears-oh-ya.html

I want to do this!!!

11-06-2005, 09:24 AM	#1 (permalink)
Vortec_Cruiser Registered User Join Date: Feb 2003 Member # 17300 Location: So. California Posts: 2,405	Slowing down drill press speed My variable-speed drill press will not slow down sufficiently to allow the effective use of large drill bits. I'm guessing that the slowest speed is about 600-700 RPM. I'd like to hook a rheostat on the power cord to accomplish this. As I remember, you can only use a rheostat on certain types of electric motors. The motor in question is a Baldor 1.5 HP single phase motor. Any help would be appreciated. __________________ Ed Gilbert 1977 FJ40, 5.7L Vortec F-Toy #F006 build in-progress [email]vorteccruiser@charter.net[/email] Last edited by Vortec_Cruiser; 11-06-2005 at 09:25 AM.

11-06-2005, 09:29 AM	#2 (permalink)
jstarnes Knee Grow Join Date: Jul 2002 Member # 12575 Location: It puts the lotion on its skin OR it gets the hose Posts: 1,750	Vfd? __________________ She said her name was Bambi, I said thats a coincidence darlin cause I was just thinkin about skining you like a deer then wearing your face like a mask as I do my little kooky dance

11-06-2005, 09:56 AM	#4 (permalink)
tdavis Registered User Join Date: May 2000 Member # 908 Location: Pinole, CA Posts: 2,131	Sell it and pop for a new drill press that can get even slower. A good rheostat/variable speed controller would probably cost as much. I bought one of the Chinese made Tradesman 12" drill press from Lowes, that can go down to 250rpm. Only $119, and it's does pretty good. __________________ I take my zuk out for walks.

11-06-2005, 12:22 PM	#7 (permalink)
u2slow Registered User Join Date: Apr 2001 Member # 4243 Location: Salt Spring Island, BC Posts: 3,068	IMO a VFD is not a good idea... its a good way to wreck a perfectly good motor. It needs to be rated for drive use because of the extra stress it puts the windings through. A variac is fine for power hand-tools and certain fans because of the motors they use... not for a split-phase/capacitor motor. Many drill presses use a 4-pole motor... that yield slightly under 1800rpm. You could try to find a used 6-pole motor - <1200rpm, or an 8-pole motor - <900rpm. Meesing with the pulleys is probably the cheapest if you like to tinker. Most presses just have two, but some have 3 (a middle stepped idler) for more speed range. EDIT: its easy to post redundant info when it takes me over 2 hours to complete a post __________________ 90-93 CTD jalopies Last edited by u2slow; 11-06-2005 at 12:23 PM.

11-06-2005, 01:02 PM	#8 (permalink)
frankenfab Registered User Join Date: Apr 2003 Member # 18989 Location: Utah Posts: 526	The right way to do this by adding a jack shaft to your drill press. Here is an example of how.... http://www.frugalmachinist.com/jackshaft.html . __________________ A flash of lightning illuminated the object, wretch, hideous, filthy daemon. A new species would bless me as its creator.

11-06-2005, 09:49 AM	#3 (permalink)
seany Registered User Join Date: Jul 2004 Member # 32727 Location: mountain view,ca Posts: 45	variac? or a pully change...

11-06-2005, 10:34 AM	#6 (permalink)
rusted Registered User Join Date: May 2002 Member # 11799 Location: Cleveland, TN Posts: 1,788	You need to fab a new pully setup. Someone here has done this, it's not rocket science. I would think an extra idler would be all you need. Variable pulleys are available at Grainger, surpluscenter.com etc. You don't want to mess with your motor anyway. Let it run at it's normal speed, it's designed for that. Use pullies to do it. Especially if you have a big ol drill press. This would be a great little project and one I am thinking of doing myself, but I have no time anymore. Mine goes down to 240 and that's ok, but I like slow slow slow. I'd like to have 80rpm available. One thing is my cheap ass chuck isn't capable of handling a strong feed at low rpms on big drills. But it sounds like you have a big quality unit. Something to think about though.

11-06-2005, 04:57 PM	#9 (permalink)
420willys Registered User Join Date: Oct 2003 Member # 23452 Location: holland mass USA Posts: 2,050	does adding a VFD lower the HP, you said you want to turn larger drills i would not want to lower my HP and try to turn larger drills, kinda counter productive, but if it does not rob any HP then i say try it, but dont burn out a good motor eather, jason.

11-06-2005, 05:21 PM	#10 (permalink)
frankenfab Registered User Join Date: Apr 2003 Member # 18989 Location: Utah Posts: 526	Note: Variable frequency drives are for 3 phase motors. __________________ A flash of lightning illuminated the object, wretch, hideous, filthy daemon. A new species would bless me as its creator.

11-07-2005, 04:59 AM	#11 (permalink)
ScoutIITD Registered User Join Date: Nov 2002 Member # 14887 Location: Hopkins, SC Posts: 526	/forum/shop-tools/311507-drill-press-crawler-gears-oh-ya.html I want to do this!!! __________________ Carey

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode