Tensioning the Belt on WWII (Tauco/Delta) Pillar Drill

[Ross365]

This is my bellowed Tauco pillar drill (made in the USA by Delta in WWII) which I bought on eBay and restored. Recently, I was doing a bit of drilling, and at totally the wrong time, the belt started slipping. I realised that I’d never really figured out the best way to tension the belt, i.e. move the motor away from the drill.

The first pic bellow shows a side view of the drill and the second one shows the possible use of wedges (in orange) to push the motor (supported on each side by a 1” diameter steel guide, marked up in green) away from the drill.

Can anyone tell me if there is a method of tightening the belt that was advised by the manufacture or is otherwise in common use?

Thanks

 

[brightspark]

slacken the bolt off and stick a prybar in between tension the belt do up the bolt

 

[MattF]

If it were I, I'd just tension it as much as you can by hand, then slip the belt out of one pulley & move the motor a gnat's further away from the column.

 

[MattF]

slacken the bolt off and stick a prybar in between tension the belt do up the bolt

Animal.

 

[6ply]

Whenever I've used drills like that, I've just used a pry bar to shift the motor and tension the belt.

 

[tigdlo]

Animal.

How about leave a little tention on the bolts so when you can just smack it with a hammer without it sliding back?

 

[MattF]

I despair.

 

[8ob]

I always run the belts loose enough to slip if a 1/2" drill bit was to bind up, dont see the sense in murder tight belts on a drill.

Bob

 

[Ross365]

I think that ideally, it would be good to apply force either side of the support bars. For most equipment, the manufacturer's instructions advise of what sort of deflection you should be able to get on a belt, at the correct tension, when pushed by finger.

 

[m_c]

Usually with pillar drills, you just push the motor back by hand and tighten the clamp.

As per @8ob 's post, slightly slack is usually better to avoid drills snagging as much.

 

[Ali]

I don’t think you need to worry about even pressure if you’re prying or wedging from the top or bottom like in your picture, as the bars should be a good fit in the casting preventing misalignment of the pulleys. Even if you did lever from the side I can’t see it being an issue. You could use a sacrificial hardwood or nylon wedge or an aluminium lever but like others have said a gentle nudge should be plenty. If a small drill stops it needs some more pressure and with a big drill your work should be properly clamped anyway so give it a reasonable amount more or stop pressing so hard.

Lovely drill BTW.

 

[Morrisman]

Seeing as you have to re-tension the belt every time you change speed I’d have thought there’s some mechanism to do it already. My drill press has similar bars and thumb screws each side, but also a lever on the right side that pushes the motor back. I’d wager that your motor bracket/plate is not the original.

 

[Red'n'Black]

I always run the belts loose enough to slip if a 1/2" drill bit was to bind up, dont see the sense in murder tight belts on a drill.

Bob

My Fobco uses the same sort of tensioning method, I just push the motor back from the column with finger and thumb both sides. That gets it tight enough to stall the motor if I push things too hard.

The Fobco has a locking screw each side with a 1" lever on the head, not sure the proper term for them. Holding the tension with one hand while doing the screws up with the other is easy enough. The one in the OP looks to have machine screws, facing downwards, to do the same job. Replacing them with some similar ones would help.

Wedges, hammers and pry bars sounds barbaric.

 

[Morrisman]

If you dropped a length of flat bar, maybe 1/4” x 1/2” across the two mounting bars, with a short lever welded on the end, you could use it as a sort of ‘cam’ to evenly push the motor plate back as you clamp the screws.

 

[brightspark]

usedSeeing as you have to re-tension the belt every time you change speed I’d have thought there’s some mechanism to do it already. My drill press has similar bars and thumb screws each side, but also a lever on the right side that pushes the motor back. I’d wager that your motor bracket/plate is not the original.
my belt is tension-ed correctly and wont slip even with a half inch drill bit in but easy to change speed just pull the belt over the side of the larger pulley while turning it and it drops to the next size down pull the belt over the other pulley to the side and turn and on it goes on fast and easy

 

[Ross365]

I’d wager that your motor bracket/plate is not the original.

Maybe that's the most astute comment on the thread? Made in the USA, originally with 110V motors, those would not have been shipped to the UK and if motor mounting patterns were different in the two countries, the Brits may have had to provide their own 240V motors and their own back plates too? And in wartime, those backplates would have been a minimal design.

When I had the problem with the belt slipping, all I was doing was drilling out a 3/16" hole in aluminium alloy to 1/4" to fit a bush. I bought a brand new cobalt drill and had lots of cutting compound on it, as I wanted a nice fit for the bush. That should not have induced belt slip.

@Ali, thanks for the complement on the drill; this what it looked like when I got it;

 

[Morrisman]

my belt is tension-ed correctly and wont slip even with a half inch drill bit in but easy to change speed just pull the belt over the side of the larger pulley while turning it and it drops to the next size down pull the belt over the other pulley to the side and turn and on it goes on fast and easy

Mine has two short belts, and not enough slack to slip over to the next groove when tensioned. I basically only ever use two speeds out of a possible 8

 

[roofman]

Only need to have a tight belt when on the small drive pulley, it has almost no surface area for the belt to "dig in" to the groove.

 

[Erie Fred]

Maybe that's the most astute comment on the thread? Made in the USA, originally with 110V motors, those would not have been shipped to the UK and if motor mounting patterns were different in the two countries, the Brits may have had to provide their own 240V motors and their own back plates too? And in wartime, those backplates would have been a minimal design.

When I had the problem with the belt slipping, all I was doing was drilling out a 3/16" hole in aluminium alloy to 1/4" to fit a bush. I bought a brand new cobalt drill and had lots of cutting compound on it, as I wanted a nice fit for the bush. That should not have induced belt slip.

@Ali, thanks for the complement on the drill; this what it looked like when I got it;

View attachment 468718

We doo make 120/240v motors ya know !.....
50/60 hz as well......These are very common.

 

[Erie Fred]

Is there room in the rod bores for a compression spring ?