1978 Craftsman Dill Press Pulley Conversion

[Mamrak76]

I recently got a 78 Craftsman Drill Press. I don’t want or need the this number of speeds. Is there anyone who has changed it over to a 3/8 or 1/2 v belt? I am planning to work on this but I wondered what info was already out there because I couldn’t find anything existing. I saw the motor frame is a Y56z which normally means a 5/8 shaft be the Z designates it was modified so it’s actually anything other then a 5/8 shaft.






Drill Press

 

[FrankLee]

I recently got a 78 Craftsman Drill Press. I don’t want or need the this number of speeds. Is there anyone who has changed it over to a 3/8 or 1/2 v belt? I am planning to work on this but I wondered what info was already out there because I couldn’t find anything existing.

I doubt you'll find much information about swapping those 3/16" belt pulleys to a larger size, but there's no reason it can't be done.

The oe bearing shaft takes 25mm bore 6205 bearings. You'd have to find, modify or make a pulley to fit the shaft.

I saw the motor frame is a Y56z which normally means a 5/8 shaft be the Z designates it was modified so it’s actually anything other then a 5/8 shaft.

The motor shaft is nothing other than 5/8" with a 3/16" keyway.



I did find a machine once where the po went the other way; swapping the 1/2" belt pulleys for the 3/16" belt pulleys. It was interesting, but why? I bought this one for the accessories and parted-out the rest.

​

 

[Provincial]

To get more speeds, and perhaps higher or lower speeds.

The 3/16" belts are available. I bought one for my 113.24611 drill press off the internet. It was a Gates 5M1150, and is 45.28" effective length. It isn't perfect for length, but works well.

I've never had this narrow little belt slip, and I have had the drill press since December of 1976.

If you do change pulleys, I may be interested in the old ones.

 

[Mamrak76]

To get more speeds, and perhaps higher or lower speeds.

The 3/16" belts are available. I bought one for my 113.24611 drill press off the internet. It was a Gates 5M1150, and is 45.28" effective length. It isn't perfect for length, but works well.

I've never had this narrow little belt slip, and I have had the drill press since December of 1976.

If you do change pulleys, I may be interested in the old ones.

Ok I’ll let you know. I recently got a combo smithy lathe mill so I should be able to turn a pulley to fit the spindle.

 

[FrankLee]

Here's a 25mm bore pulley on amazon. You may need to drill/tap for a set screw.

Amazon.com

You can't make one for that price.

 

[no704]

I’ve never wanted less speeds?

 

[Mamrak76]

I’ve never wanted less speeds?

Oh yes I have because having all those speed causes the belt size to be shrunk. This causes the lack of belt wrap which spins. Most 1/2 and larger bits require 300 and under rpm. I have a very expensive set of silver and demming bits. And in my shop having a Mill, lathe, mig with spool gun, I work almost exclusively in metal. And most of the consumer priced tools are exclusively designed for wood… part of being against societal norms!

 

[Firebrick43]

If you going to the trouble of machining sheaves maybe a poly vee belt would be better? It will be smoother and quieter running and slip less. And the smaller vee cross section tool bit will chatter a lot less than a much large A section profile on a light lathe like your smithy.

Something like a 5 or 6 rib J section

 

[no704]

Oh yes I have because having all those speed causes the belt size to be shrunk. This causes the lack of belt wrap which spins. Most 1/2 and larger bits require 300 and under rpm. I have a very expensive set of silver and demming bits. And in my shop having a Mill, lathe, mig with spool gun, I work almost exclusively in metal. And most of the consumer priced tools are exclusively designed for wood… part of being against societal norms!

If I’m doing anything that heavy it goes on the mill. What little work I do on the drill press is usually being hand held so I’m ok with belt slip vs the part spinning.

 

[Mamrak76]

If I’m doing anything that heavy it goes on the mill. What little work I do on the drill press is usually being hand held so I’m ok with belt slip vs the part spinning.

I agree I have a combo lathe mill so if I’m in the middle of a lathe operation I don’t want to break down my setup for that. Maybe one day I’ll have a dedicated machine for each.

 

[Mamrak76]

I did get the conversion done. I am thinking I might remove the top fastest location from both pulleys. The belt guard may fit then. The motor pulley definitely needs to be down a bit more. Going to have to pull it off to do that. But the Amazon pulleys both fit and work with minimal work. Running a 1/2 linked V belt

 

[Mamrak76]

Test run

 

[Provincial]

If you want to slow it down more, keep your eye out for a slower motor. I've seen several in the 1050-1200 rpm range. Often, the slower motors are physically larger in order to get the same power. Usually one frame size larger, but I see 56-frame slow motors for sale.

 

[Beerhippie]

If you want to slow it down more, keep your eye out for a slower motor. I've seen several in the 1050-1200 rpm range. Often, the slower motors are physically larger in order to get the same power. Usually one frame size larger, but I see 56-frame slow motors for sale.

That, or get a three-phase motor and use a VFD for phase conversion and speed control.

 

[Mamrak76]

That, or get a three-phase motor and use a VFD for phase conversion and speed control.

Not a bad idea there if a come across one. I had a VFD on my Wells-Index Mill and I absolutely loved it. No gear changes and no belt changes. Just had to run a piece of 12/2 romex inside a conduit. That’s the way to go for the smaller sized motors.