Refurbishing an old drill press

[Teejay]

I'm currently in the process of stripping an old drill press and wanted to address an issue I noticed when I used the machine previously. There's a handle which is used to adjust the belt tension by moving the motor housing forwards and backwards.

Two problems exist with this though.

The first is that when turning the handle, it can come loose inside the casing and that involves taking quite a lot of the machine apart to get to it and put it right.
The second is that the motor housing is bolted to a bracket, which is connected to two large rods that move inside the casting. There is nothing to stop the rods from travelling too far and coming out of their support holes (I wish the rods were slightly longer to stop this happening).

I can tell something is missing, although I am not sure exactly what. It appears there was something gripping onto a groove machined into the right side rod. Also, the lever is connected to a casting, which connects to the right side rod via a groove in that rod.

Does anyone have any idea what I need to do to sort these issues out?

 

[toolsntat]

Rods travelling too far, could it be you need a shorter drive belt ?
Cheers, Andy

 

[ChaiLatte]

The first is that when turning the handle, it can come loose inside the casing

Please describe this is more detail. In what way does it become loose? Does the casting rotate on the lever? Does the lever move in and out (left and right in your picture)?

It appears there was something gripping onto a groove machined into the right side rod.

That is not a groove. It is a flat. A groove would be used with a circlip. If there is room/space, buy a shaft collar and secure it using a grub screw (https://www.bearingboys.co.uk/Shaft-Collars-2548-c) If the room is limited, drill and tap the end of the shaft and secure a washer there. With some care, you could use a Dremel to grind a circlip groove on the other shaft. You could drill all the way through the shaft and use a roll pin.

Externally, tie a piece of string between motor plate and main casting, When it becomes tight, it will stop the two parts over-travelling.

Edit: if you go for the shaft collar, make a small divot in the end of the shaft in which the grubscrew can locate and then it cannot slide off.

 

[Teejay]

Thanks for your replies. I replaced the drive belts with identical ones to those fitted on the drill prior to me having it.

You have described the movement. The grub screw on the inside rod attached to the handle comes loose so the casting can move side to side and that allows the casting to disengage with the sliding rods and pop out from the left side mounting hole. It also happens when the rod extends beyond the reach of the casting. Then it cannot be rectified without taking everything off the top.

Based on the shaft collar recommendation, is it possible that's what was originally connected to the "flat" where there is evidence of something once being secured there? If so, it could be that's where a shaft collar was mounted originally and it would be fitted there rather than the end of the rod?

 

[niall Y]

I would never assume that the belt fitted to a machine when you got it is the correct length[ If fitting a shorter length belt will cure the problem then I would go with this option.
As for the absence of some form of collar on the rod, then would improvising some temporary one allow you to experiment and see if this solves the problem.?

 

[ChaiLatte]

Based on the shaft collar recommendation, is it possible that's what was originally connected to the "flat" where there is evidence of something once being secured there? If so, it could be that's where a shaft collar was mounted originally and it would be fitted there rather than the end of the rod?

With regard to the lever, a grub screw just pressing onto a shaft is a friction rather than a mechanical connection. If you drill or dremel a small divot where the grubscrew touches the shaft, a better connection is produced. Wrap some PTFE around the grubscrew to discourage it from unscrewing. Blue loctite is another option.

With regard to the shaft, I am now understanding that the flat is mid-way along the shaft rather than at its end. Sorry if I misled in the above.

There is a threaded hole in the casting adjacent that flat. Perhaps the shaft should be rotated 90 degrees so it faces that hole. Then a bolt through the threaded hole would bear on the flat and lock the motor in position. That would explain the witness marks. That bolt would also serve to retain the shafts providing you only undid it half a turn to allow the shafts to slide.

That is what you have to consider looking at the whole machine: if you use the lever to _tension_ the belt, what keeps that tension in place? Right now, I am on the fence whethere the possible locking bolt is to keep tension on the belt or to keep tension off the belt (see below).

I have seen drills where there are springs on the shafts between the drill body and the motor plate (see this one: https://www.tooled-up.com/artwork/ProdPDF/38255ins.pdf). The shafts free-float in the casting, controlled by the springs, so any local veriations in the belt can be accommodated.

The tension lever on the left of your picture is used to compress those springs (so it is actually only a DE-tensioning lever). De-tension the belt, tighten the locking bolt which holds the motor against the spring pressure. Slip off the belt and reposition on the pulleys, release the locking bolt. The springs tension the belt.

The Draper model above has been cheapened to the extent that it does not have the mechanism inside the body to remove the belt tension (the lever you have) - on the Draper you have to grasp the motor itself and pull against the spring pressure.

You have to stand back from the machine and assess how the belt changing procedure is done. In use, you need the belt to retain tension, but you need a quick and easy method of slackening it and keeping it slack while you change to another pulley combination. You then need a quick and easy way of returning the belt to its tensioned state.

 

[Teejay]

Thanks both for your replies.

ChaiLatte in particular, you're post was really thorough. It makes sense, there is a bolt on the left and right of the machine and if the rod is turned to face the hole, that would engage/stop it moving too far forward or back.

It wouldn't hurt to add a collar to each rod to stop it happening in case the bolt on the right is loosened too much. Also, it would be good to add a spring to the inside or the outside on the left rod to make movement easier. I'd be interested in obtaining one of the right size/strength/dimensions. Any recommendations on sources/what to look for to get one that's suitable?

The manual is really helpful and interesting to read, even if it's for the 2014 onward model.

 

[Teejay]

What's a medium purpose grease?

 

[ChaiLatte]

What's a medium purpose grease?

One that is thicker than a light grease and thinner than a heavy grease (sorry!).

It is not a great description. Maybe a better wording would be 'general purpose' grease. In other words, the most common form of grease you could buy at an auto parts store. It almost defines itself by what it is not: 'non-specialist' grease would also be a good term.

Think of it as equivalent to the most standard form of milk you can buy (blue top before they all became transparent).

The manual to which I linked was just to show pictures illustrating the belt adjustment method I was poorly attempting to describe. I have not one clue whether it has any relevance to your particular machine so perhaps read any specifics of it with some caution.

 

[Teejay]

Haha!

Like this then?

https://www.ebay.co.uk/itm/172948629153

What would I use to remove all the old grease before applying new?

Something like this or more specific?

https://www.ebay.co.uk/itm/233804541632

 

[ChaiLatte]

Like this then?

That will be good. It is something I would buy from a store as it might be risky entrusting a plastic tub like that to some of the delivery companies.

If the machine is working OK, I would just wipe off the old grease with rags and refresh it with new. I do not think it would need to be surgically clean.

The cleaner to which you link is water-based rather than solvent-based so I would keep it away from any areas that need grease. White spirit, WD40, petrol, kerosene, brake cleaner (all solvents) might be better for those places using the water-based one for general grime on the body of the machine.

If it were a car engine, I would use the water-based one on the outside of the engine, but not on the inside (if that makes sense).

 

[Teejay]

Great, so that's a suitable product then.

I have 5L of surgical spirits/98% isopropyl alcohol but when I tried it before on the thick grease it wasn't fantastic.

I want to take the quill assembly apart, I can't see how to take off the chuck and other parts.

 

[Teejay]

Making progress. How do I remove the bearing from the shaft? How do I clean out the bearings/disassemble to remove old grease and check ball bearings and then apply new grease?

Is it likely that the bearing with a dent in the top is damaged?

 

[ChaiLatte]

How do I remove the bearing from the shaft?

Conventionally, using a press.

Is the spindle hollow?If so, pass a piece of threaded rod though it with a nut and washer at the splined end.

Use a piece of tube that bears on the bearing (inner race if at all possible if accessible) and a large washer to bridge between the tube and threaded rod. Tighten a nut onto the threaded rod and it will pull/push the bearing off.

If the spindle is not hollow or the only way to remove the bearing is by pressing on the outer race, either leave it alone or replace it with new once off the shaft.

Wash the bearings in petrol. They do not dismantle any further than shown. Oil lightly and spin on your finger. If there is any lack of smoothness, replace.

The dent is only in the metal shield of the bearing, which is a cover to keep out dirt. If it passes the spin test, it's OK.

It amazes me when people refurbish drill presses that the only part they do not dismantle is the chuck. To me, that is like a full restoration of a classic sports car and then putting the 1960s crossply tyres back onto it.

 

[Teejay]

Thank you very much

Not convenient when you don't have a press!

The base of the spindle is hollow but not the whole way through, so guess I need to leave it.

How long do parts need to be left in petrol?

I've ordered a brand new keyless chuck. How is the chuck dismantled further?

 

[Teejay]

I presume brake cleaner spray is effective too?

 

[Teejay]

I've used mineral spirits and they are clean. I have the medium grease ready, how should I apply it and should it be applied to the open bearing?

 

[Teejay]

 

[Teejay]

Started stripping down back to bare metal. Which is more effective for getting perfectly flat sides, a random orbital sander or belt sander?

Also, how do I deal with the pitting from the cast? If it were a cast iron skillet once sanding is done oil is added during seasoning.

I'm going to be painting it, so should I be using car body filler or another method to tackle the pitting prior to painting?

 

[TomGW]

I’m trying to figure out the sequence of the photos. What are the random hex head screws for? Have you then added filler (DevCon??) and then ground it off again?
I’d be inclined to get someone to weld the casting to fill any pitting/holes then file/grind it flat.