Thread: Tomorrow is another (drill) day.

Originally Posted by th62

I made the mockup I spoke of earlier today. I think the problem is going to be trying to make it neat - very, very fiddly, probably better suited to a milling job.

The first pic shows the jig from underneath, the feed screw, the single winged adjuster nut and lock nut (thumbnut to come)can be seen. The next pic shows it from the top, the wing can just be seen poking through the slot. The other two are of the jig with a drill in situ.

It works well: just turn the knurled thumbscrew at the base and the single wing nut moves back/forward accordingly. When the single winged nut is in position, simply lock it off with the locknut (thumbnut). Not sure whether to continue with this design. It still needs a drill clamp and then I'll have to nut out how to mount it on a sliding base so I can flip it 180 degrees.

Hi Th62,
I like that ! A pair of side plates, like on the drawing, and you have both the drill clamp mechanism and somewhere to put the locating holes for the dowel pins.

Originally Posted by th62

Bit of confusion on my part there Franco: my grinder has a 5/8 UNC thread - not 1/2" UNC. The nuts I bought for it were whitworth and although a different form than UNC they are the same pitch and will fit. 1/2" does seem rather small for an 8" grinder though???

Hi Guys, Th62,

According to the rating plate on the motor the grinder should be 150 mm ! I hadn't noticed that when I got it. I took the guy at the scrapyard at his word. Still since I have to make all the bits needed to put it back into working order, it shouldn't be a problem using a 200 mm (8") wheel.

Grinder-01.jpg

This is the new grinding wheel that I bought for this grinder. Its 200 mm X 25 mm with a 50.8 mm (2") bore. I've already acquired a couple of suitable lumps of steel to make the mounting plates and a slice of 2.5" diameter nylon bar to make a reducer for the bore.

Grinder-03.jpg Motor-01.jpg Motor-02.jpg Motor-08.jpg

The above pictures show the refurbished and repainted grinder. The bearing were shot, (6205Z) so since I had to strip it completely to replace the bearings, I gave it a nice coat of green paint. The motor is 2850 rpm and 400 watts.

Grinder-04.jpg Grinder-15.jpg

This is a view of the left hand end of the grinder shaft and the new nut that I made to fit it.

I'll start another post dealing with the nut.

Hi Baron,
nice work as usual, thorough. Will the wheel fit in the guards or are you making new ones.

Phil

Nice looking grinder, looks new with the ProMac decal. I never see bargains like this, all they have in scrap yards where I live is scrap!

Slept on the design of the drill sharpener, and came to the realisation the jig can't be flipped 180 degrees to grind the other side: in order to do that, the locators on either side would have to be equi - distant from the drill, just like the Tormek. Not too difficult to make, but I don't have a mill or a vertical slide anymore and I'm not that keen on file work.

Oh well, it filled in a day, back to the indexing idea.

Originally Posted by th62

Slept on the design of the drill sharpener, and came to the realisation the jig can't be flipped 180 degrees to grind the other side: in order to do that, the locators on either side would have to be equi - distant from the drill, just like the Tormek. Not too difficult to make, but I don't have a mill or a vertical slide anymore and I'm not that keen on file work.

On the subject or Tormek has anyone used their jig on a regular bench grinder? I figure if you buy from the US it could be worthwhile. I can't justify a tormek but maybe some of their jigs and adapt for use on the bench grinder?

Another option I like is the Kaindl, not multi faceted but only one motion and mimics the movement I use when I hand grind. I like the pedistal type mount, I wonder if they would sell me just the bit holder

https://www.youtube.com/watch?v=7zWFQFtt-aU

Originally Posted by Steamwhisperer

Hi Baron,
nice work as usual, thorough. Will the wheel fit in the guards or are you making new ones.

Phil

Hi Phil, Thanks:

The wheel guards had been taken off ! Probably by who ever removed the stone, maybe the scrap man himself, since he said that it was an 8" machine. I need to get some 1.6 or 2 mm steel sheet and cut a couple of 9" diameter discs for each side. I was thinking of using a narrow 1.5" wide strip and forming a ring then brazing or silver soldering it to the edge of one disc then doing the same with the other disc so that one would fit over the other then a couple of self threading screws to secure it.

This machine is however not a double ended grinder. The right hand shaft is far longer and has a taper threaded section, I assume for a polishing mop, though I don't understand why it is so very long. I was looking at a mop yesterday and it was only about an inch wide and it didn't have a solid centre. The grinder on display in Machine Mart had a short shaft with a taper and a fast thread on the taper. The mop was screwed on right up to a large plastic washer and there wasn't any guard on the outer side just a plastic nut.

Originally Posted by th62

Nice looking grinder, looks new with the ProMac decal. I never see bargains like this, all they have in scrap yards where I live is scrap!

Thanks: I can assure you that the grinder didn't look anywhere near as nice when I got it. A bit of thinners and a good fettling to get rid of the old grease and grime. I admit that the shaft didn't turn when I got it but it had been out in the rain for a while but very little rust damage. The bearing were shot ! However I had a pair of new ones in stock so no great expense there. The paint was some that I bought a while ago to repaint the splash guard and drip tray for the Myford lathe. No point in wasting it

Slept on the design of the drill sharpener, and came to the realisation the jig can't be flipped 180 degrees to grind the other side: in order to do that, the locators on either side would have to be equi - distant from the drill, just like the Tormek. Not too difficult to make, but I don't have a mill or a vertical slide anymore and I'm not that keen on file work.

Oh well, it filled in a day, back to the indexing idea.

Hi Th62,
I don't think it matters. You have a movable mounting plate that sits on the grinder rest and is guided by it so the grinding angle is fixed for both edges of the drill. The relief angle is set by the grinder rest.

Am I missing something ?

Yes the dowel pins in the mounting plate and the matching holes on both sides of the drill holder will have to be accurately positioned but that is easy to achieve simply by clamping and drilling all three pieces at the same time.

Re: "Tormek" I've never seen one ! However I'll have a look on the net and see what they are.

Originally Posted by Burnsy

On the subject or Tormek has anyone used their jig on a regular bench grinder? I figure if you buy from the US it could be worthwhile. I can't justify a tormek but maybe some of their jigs and adapt for use on the bench grinder?

Another option I like is the Kaindl, not multi faceted but only one motion and mimics the movement I use when I hand grind. I like the pedistal type mount, I wonder if they would sell me just the bit holder

https://www.youtube.com/watch?v=7zWFQFtt-aU

Hi Burnsy,

Very interesting link ! Neat mechanism for holding the drill and supporting it whilst grinding it.
I'm not keen on the winding back and forth to set the amount of cut. That mechanism is going to wear and the backlash will increase with use. Unless they have some method of accounting for it the accuracy of equal cutting edges will suffer over time.