Homemade low-speed conversion for Craftsman drill press. - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Garage - Tools
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 06-16-2012, 11:24 PM
Registered User
 

Last journal entry: '27 roadster quarter panels from scratch
Last photo:
Join Date: Aug 2011
Location: Santa Rosa, California
Posts: 68
Wiki Edits: 0

Thanks: 0
Thanked 7 Times in 4 Posts
Homemade low-speed conversion for Craftsman drill press.

I've been meaning to do this for awhile. Finally found the time today. It's amazing how simple this is to put together! Most have seen my DP before. Bought it off of CL for cheap and gave it a light restoration. It didn't come with the optional low-speed conversion. I decided to fab my own low-speed conversion 'cause most of my work is with metal.





Here's a chart from an original Craftsman w/low-speed conversion. I don't know how fast the direct drive is right off the motor but I know it's way too fast for my needs! I'm shooting for the 4th one down. 175 RPM.





If you can find an older Craftsman with the optional low-speed conversion, great! If not, these are the parts you'll need to convert it. In addition, you'll need access to a MIG welder. If you don't have a MIG, you probably know someone who can run a bead for you.



1 - 4 step, 3L pulley. Ordered mine through MSC. I think it was $20 w/corporate discount.

2- bronze flanged bushings. $1 each from Home Depot.

1 - 3" long 1/2" bolt.

1 - 1/2" flat washer (not shown).

1 - 1/2" Nylock nut.

1 - steel cap - homemade.

Closeup of the flanged bushings with dimensions and part #s.



You'll also need 2 belts (not shown). They need to be belts for fractional horsepower motors. The designation is 3L, to match the pulley. Any shop that repairs chainsaws, lawnmowers, etc. will have them. You'll need a 25" belt from the motor pulley to the intermediate pulley and a 29" belt from the intermediate pulley to the spindle pulley.

Now that you have all the parts, you need to cut a blank of 3/16" steel. I used a 2-1/2" holesaw to do the deed.



Next, measure about 3/8" back from the center of the pilot hole and centerpunch a mark. At this point, you'll need to weld up the pilot hole. Once it's welded and cleaned up, drill a 1/2" hole on your centerpunch mark. Insert the 1/2" bolt and weld it to the underside of the blank.



Now set the blank on top of the DP post. Line it up and tack it in. Check alignment and mock everything up to confirm all is good. You may have to jiggle the blank around or maybe even grind a bit off to get the proper tension on the belt. The spindle to intermediate pulley is not adjustable. So, once the blank is finished welded, that'll be your belt tension. If everything fits and the belts have good tension, de-mock it and finish weld the blank to the DP post.



Slip on a flanged bushing.......................



Slip on the pulley......................



Insert the top flanged bushing...................



Remount the motor and all the belts then install the 1/2" flat washer and the 1/2" Nylock nut. DO NOT snug the nut to the washer. You want the washer loose. As little up/down movement of the pulley as possible but don't tighten the nut down! The plastic inner coating will keep the nut in position.



Plug it in and fire it up.............you're done! Now I have a 175 RPM spindle speed. In addition, it's a multi-speed attachment so I can change spindle RPM's simply by moving the belts up or down the pulleys. This thing works great!!




    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 06-16-2012, 11:52 PM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 60
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 598 Times in 547 Posts
You should put this in the Home Made Tools site, link is at the top of the page.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 09-26-2012, 12:31 PM
Registered User
 
Join Date: Sep 2012
Posts: 2
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Hey evintho, Thanks in advance for all the info on this project. I'm new here, I was hoping you may be able to provide a part # for the 4 step 3l pulley you used. I searched the MSC site and have had no luck. Thanks again.....YO
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 09-28-2012, 01:08 AM
Registered User
 

Last journal entry: '27 roadster quarter panels from scratch
Last photo:
Join Date: Aug 2011
Location: Santa Rosa, California
Posts: 68
Wiki Edits: 0

Thanks: 0
Thanked 7 Times in 4 Posts
Quote:
Originally Posted by yophilly View Post
Hey evintho, Thanks in advance for all the info on this project. I'm new here, I was hoping you may be able to provide a part # for the 4 step 3l pulley you used. I searched the MSC site and have had no luck. Thanks again.....YO
I searched my latest MSC catalog also and they don't have it anymore. What's up! Never fear, Grainger comes through although the price has gone up..............what a shock!

CONGRESS V-Belt Pulley, 5 In OD, 5/8 Bore, 4 Step - V-Belt Pulleys - 1L843|SCA500-4X062KW - Grainger Industrial Supply
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 10-08-2012, 10:55 AM
Registered User
 
Join Date: Sep 2012
Posts: 2
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
All Hail evintho !!!!!!!!!!!!

It was cold, rainy, and miserable yesterday so I decided not to ride quads and do this slow-speed conversion.

Done!

Easy project, works great, super cheap....my favorite!!!


Thanks......YO!
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 10-08-2012, 06:07 PM
Registered User
 

Last journal entry: '27 roadster quarter panels from scratch
Last photo:
Join Date: Aug 2011
Location: Santa Rosa, California
Posts: 68
Wiki Edits: 0

Thanks: 0
Thanked 7 Times in 4 Posts
Glad to be of service!
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 07-24-2014, 10:36 PM
Registered User
 
Join Date: Jul 2014
Posts: 1
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by evintho View Post
I've been meaning to do this for awhile. Finally found the time today. It's amazing how simple this is to put together! Most have seen my DP before. Bought it off of CL for cheap and gave it a light restoration. It didn't come with the optional low-speed conversion. I decided to fab my own low-speed conversion 'cause most of my work is with metal.





Here's a chart from an original Craftsman w/low-speed conversion. I don't know how fast the direct drive is right off the motor but I know it's way too fast for my needs! I'm shooting for the 4th one down. 175 RPM.





If you can find an older Craftsman with the optional low-speed conversion, great! If not, these are the parts you'll need to convert it. In addition, you'll need access to a MIG welder. If you don't have a MIG, you probably know someone who can run a bead for you.



1 - 4 step, 3L pulley. Ordered mine through MSC. I think it was $20 w/corporate discount.

2- bronze flanged bushings. $1 each from Home Depot.

1 - 3" long 1/2" bolt.

1 - 1/2" flat washer (not shown).

1 - 1/2" Nylock nut.

1 - steel cap - homemade.

Closeup of the flanged bushings with dimensions and part #s.



You'll also need 2 belts (not shown). They need to be belts for fractional horsepower motors. The designation is 3L, to match the pulley. Any shop that repairs chainsaws, lawnmowers, etc. will have them. You'll need a 25" belt from the motor pulley to the intermediate pulley and a 29" belt from the intermediate pulley to the spindle pulley.

Now that you have all the parts, you need to cut a blank of 3/16" steel. I used a 2-1/2" holesaw to do the deed.



Next, measure about 3/8" back from the center of the pilot hole and centerpunch a mark. At this point, you'll need to weld up the pilot hole. Once it's welded and cleaned up, drill a 1/2" hole on your centerpunch mark. Insert the 1/2" bolt and weld it to the underside of the blank.



Now set the blank on top of the DP post. Line it up and tack it in. Check alignment and mock everything up to confirm all is good. You may have to jiggle the blank around or maybe even grind a bit off to get the proper tension on the belt. The spindle to intermediate pulley is not adjustable. So, once the blank is finished welded, that'll be your belt tension. If everything fits and the belts have good tension, de-mock it and finish weld the blank to the DP post.



Slip on a flanged bushing.......................



Slip on the pulley......................



Insert the top flanged bushing...................



Remount the motor and all the belts then install the 1/2" flat washer and the 1/2" Nylock nut. DO NOT snug the nut to the washer. You want the washer loose. As little up/down movement of the pulley as possible but don't tighten the nut down! The plastic inner coating will keep the nut in position.



Plug it in and fire it up.............you're done! Now I have a 175 RPM spindle speed. In addition, it's a multi-speed attachment so I can change spindle RPM's simply by moving the belts up or down the pulleys. This thing works great!!






Could you update where to get the exact 4 groove pulley and what bore since I only see a 5/8 and 1/2 bore pulley??

also when you lay out the hole on the round sheet metal. Instructions say from the very center of the hole measure 3/8 and drill the 1/2 hole.

my question is do you put the bolt (now welded) closer to front facing the head of dp or closest to the rear motor???

cant really tell from the pic but it looks like the bolt is closer to the back and right some??

thanks jr.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 07-25-2014, 01:42 AM
Registered User
 

Last journal entry: '27 roadster quarter panels from scratch
Last photo:
Join Date: Aug 2011
Location: Santa Rosa, California
Posts: 68
Wiki Edits: 0

Thanks: 0
Thanked 7 Times in 4 Posts
Well, it's been a couple of years since I built it and at my age the memory fades. I know you'll have to mock it up a couple of times to figure it all out. You'll have to search around for the pulley. MSC, Grainger, McMaster-Carr, Ebay, etc. The steps of the pulley are 2", 3", 4" and 5" OD. The inside of the pulley should be 3/4" to match the OD of the bushing. The 1/2" ID of the bushing slips over the 1/2" bolt.
Found this on Ebay. There's a phone # listed. Give 'em a call to confirm........................
4 step pulley

The welded bolt should be closer to the rear of the DP, towards the motor. As I said, you'll need to mock it up a couple of times. Get it right because where ever the hole is drilled/bolt placed and welded determines your belt tension. You only get one shot! Good luck!
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 10-11-2014, 10:30 AM
Registered User
 
Join Date: Oct 2014
Posts: 5
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
That is a sweet conversion.
Reply With Quote Quick reply to this message

Recent Garage - Tools posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Restored Craftsman drill press evintho Garage - Tools 7 09-01-2011 06:38 PM
Craftsman Drill Bits scotzz Garage - Tools 15 11-27-2009 02:16 PM
new homemade press nissan Garage - Tools 1 02-02-2008 05:57 PM
Drill Press? djjc76 Garage - Tools 39 09-17-2007 02:31 AM
Drill Press runout?? daimon1054 Garage - Tools 2 04-20-2005 06:12 PM


All times are GMT -6. The time now is 02:07 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.