Makeshift lap

[Philip Davies]

I wanted to bore several 26.5 mm holes in oak. They must be square to face and edge. I do not have ready access to a lathe anymore. The hole must be smooth. I do not, of course, have a 26.5 mm Forstner bit.
I do however have an adjustable wood boring auger:

I hope you appreciate that the wood is plumb in the vice, it’s just my posture. You can tell by the door jamb, which is plumb, or it was.
Why are my keys on the auger? This is a tip I learned at college, thanks, Danny. If the keys go away or towards you as you drill, then you’re not square. The other planes you must judge by eye. Well, this is just a tip. The bore, as expected, is not at all satisfactory, far worse than an Forstner bit, although it might do if I just wanted to run a tube through it.
I have a 25mm Forstner bit to remove most of the waste. This was the first operation.
I also have a short piece of round bar, 25.35 at the largest diameter.
This I heated red hot, and taking it outside, pushed it though each of the holes, from each side. (2 heats).
This is the result, the steel, now cold, in the centre.

The holes taper towards the middle. Now I need to remove the taper and any excess material.
The tube on the left is just under 27 mm. On the right you see an ordinary sanding spindle, 20 mm dia. I have wrapped a bit of tape around the rubber sleeve, pushed it into the tube and tightened the nut on the arbor. Then I cut through the steel tube leaving a slight excess. This is the lap which I then abraded, with it in the drill chuck and the motor running.
I ran it until I was happy with the diameter, then passed it through the holes, with very little resistance.


I suppose if I had needed to drill, say 27.5 mm, I would have sawn down the tube, wedged it open, and used more tape on the arbor.
You may think that burning the holes out made it very time-consuming. It wasn’t the only job, though, I was just using the opportunity presented by the unseasonable weather. Also, I wanted the oak hardened around the holes, as well as smooth. This is the way I learned to fabricate makeshift bearings.

[Frank S]

Making do with the tools at hand is something we all have to deal with. the Key though is knowing how.
Good job on your oak bearing holes. When I was still a kid it was my job to make split bearings for some of our older at that time farm equipment, We had a hand cranked drill press mounted on a wall in the barn with an adjustable auger bit like yours. Bore the hole to size saw in half then rasp for take up as they would wear, every winter make up a new set We didn't bother burnishing them or charring to harden. Just run the equipment for a day with the new bearings before greasing seemed to make them last through the spring planting

[hemmjo]

Very nice, we do not think much, well me anyway, of using wooden bearing much these days, have to keep that in mind!!

The key trick is a good one also.

[Frank S]

Very nice, we do not think much, well me anyway, of using wooden bearing much these days, have to keep that in mind!!

The key trick is a good one also.

Another material most don't think about using anymore as a bearing is leather. my dad and I were bringing an older truck back home to rebuild the engine but it was still running. I was following him in it when the engine started knocking whenever I let off the peddle to shift. I flashed the headlights several times to get his attention so he would stop. we found a place to pull off the road and I showed him what it was doing by giving it a little gas then letting off. We still had about a 100 miles to go and knew it was not going to make it in that condition, and that would have been a long way to chain tow it, so we dropped the pan removed the rod cap and there wasn't hardly anything left of the insert shell. He cut a couple pieces off his belt 1 a little longer than the other placed the longer piece in the top half of the rod cut holes for the rod bolts and the shorter piece in the cap Tightened it up then removed it and shaved a little off a couple times put the pan back on all this without draining the oil out of the pan. I kept the RPMs as low as possible we drove about 40MPH the rest of the way. If we hadn't done that the engine would have thrown the rod possibly damaging the crank beyond a regrind and even could have put a window in the block As it turned out we managed to save everything just had the crank turned something like .010& .020 bored the block ourselves with our Quikway, decked the block and the head with his huge file. New pistons rings bearings gaskets and a valve job. I drove it back to the customer at 60,70 and sometimes with my feet flat on the floor the 300 miles and took the bus home.

[IntheGroove]

A friend of told a similar story about a knocking engine while he was in the Army. The only tool he had was a pair of vice grips. He Pulled the pan and fixed it and made it back to camp...

[hemmjo]

Those are good stories. These days you would have to pull the engine to drop the pan. At least they have started putting the oil filters on top. But I think that is more so the "service technicians" don't get dirty when they service your car that it is for consumer convenience.

[Frank S]

Those are good stories. These days you would have to pull the engine to drop the pan. At least they have started putting the oil filters on top. But I think that is more so the "service technicians" don't get dirty when they service your car that it is for consumer convenience.

And the easiest way to pull the engine is to lift the whole vehicle off of the sub frame. A real PITA
Ford hasn't gotten that smart yet. They even put a paper resin belly pan under the engine on their hybrids 10 screws to remove it then the filter can only be accessed with a socket type filter wrench, same with the pickups.

[baja]

Making do with the tools at hand is something we all have to deal with. the Key though is knowing how.
Good job on your oak bearing holes. When I was still a kid it was my job to make split bearings for some of our older at that time farm equipment, We had a hand cranked drill press mounted on a wall in the barn with an adjustable auger bit like yours. Bore the hole to size saw in half then rasp for take up as they would wear, every winter make up a new set We didn't bother burnishing them or charring to harden. Just run the equipment for a day with the new bearings before greasing seemed to make them last through the spring planting

Another way old favorite was pork rind. I used it years ago on a Chevy six with poured babbit bearings. Don`t remember how that turned out.