Vintage Craftsman Drill Press - Repairable?

[Gilmourisgod]

According to the original manual, where I have the belt now (smallest pulley on the motor and largest pulley on the spindle) with a 1750 RPM motor, sets it at 625 RPM. Ascending up the pulleys would be 1350, 2350, and 5000 RPM. It's been in that 625 RPM position (with a new belt or two along the way), presumably since the day my Grandfather bought it in 1947 or so. It doesn't burn the wood in that position, but has always seemed a little slow when I chuck a Robosander in it. I'm careful not to side-load the spindle too hard when using it for pattern sanding, but it seems like slow going at that speed. Maybe I'll try bumping it up a pulley to 1350 RPM to see how it runs. That will be a lot easier to do on the fly if I polish up the motor mount rods. I have the belt tension set so I can't easily pinch it inward more than around 1/4" at the center span. Is that right? I've never noticed it slipping at that tension, and short of prying the motor mount outward, there isn't any obvious way to increase belt tension.

 

[farace]

I don't think I have the belt tension anywhere near that tight, and I haven't had slipping. I'm sure it depends on the condition of the belt and whether it's at all glazed. It's not very hard for me to change pulleys if I want, but I never do.

 

[Bruce Johnson]

If you are going to buy a new V-belt for your drill press, I highly recommend the High Capacity Cogged series belts. The trade designation is 3VX in the common A Size belts, used on most small-medium drill presses. These belts have the cogs (teeth) in the inside, so they flex much tighter around small pulleys. They transmit much more torque with less tension on the belt. Quiet, smooth, longer bearing life on your machine.

McMaster-Carr

Take a look at the chart and you'll see how the trade numbers work. 3VX280 is 28" OD, for example. At an auto parts store, you can ask for a 3VX280 belt.

 

[Arie X]

cog belts are good

 

[Gilmourisgod]

I have one of the interlocking link belts on my table saw, are they any good for a drill press? Kinda pricey these days.

 

[Arie X]

i don't like those things. i've seen one come apart so that could be kinda unpleasant on your open driil press. A regular toothed or plain Gates or Goodyear belt will be just right, and a plain belt will be period correct for your machine. Well tensioned and relatively clean and cut free, it could last a decade. I would look for nicks and burrs on your pully edges and file those flush and smooth.

 

[Bruce Johnson]

I have mixed feelings on the linked-segment belts. I have them on several machines, and they've been good and reliable. One of my medium-size drill presses has been running linked belts for about 20 years with no problems. In some cases, they are a lifesaver if you can't easily disassemble a machine to get the belt on.

But, on some machines they don't work as well as regular good V-belts. Rougher running, noisier, not as much torque. Particularly higher horsepower machines where the belts are being used harder. For example, I tried them on my mill/drill machine, and they ran rough and squealed.

To me, linked belts are a good option for some particular situations. But my first choice is usually the modern cogged V-belts.

 

[farace]

I know you've dealt with your return spring, but someone else in the Facebook OWWM group just found a replacement for his at McMaster-Carr and I thought I'd share his photos (without permission) in case it comes up again.

 

[Gilmourisgod]

Thanks! Mine seems to be working so far, but since i effectively lost the temper in the end coil by heating it to bend it, i dont know if it will hold up long term. Id actually have the same issue with the McMaster springs, id have to cut off part of the loop on one end and bend it to a flat leg crossing the spring center. I had done a little research on how to re-temper a spring and got some conflicting info. Ultimately the Lazy approach won out. I still havent fixed the vertical slop issue, been using it in the interim, and it runs well, i just have to take that extra 1/8" of slop into account.