Toothbar Tutorial (my Version)

keeney · Oct 22, 2006

frank_f15 said:
did u use any cutting oil when drilling? i installed my tooth bar in 30 min. drilled 1/4 pilot hole then moved up to 3/4 bit, using cutting oil all the time. u can buy a 3/4 bit with a turned down shank to fit a 3/8 chuck, but that is pretty big for a 3/8 drill. as long as u don't make a habit of it ,it shoud do alright.

The original author noted that he used a drill geared down to spin at 600 RPM which is nice and slow and has monster torque.

You need to make sure the bit is cutting into the metal and peeling off shavings, not just burning off the metal. To do this with large holes, you need lots of pressure AND lots of torque. Its pretty tiring without a drill press to generate that kind of pressure by hand.

A typical 3/8 drill will not be able to generate the low speed and high torque required to do a good job on this task. In other words, when you press hard enough to dig into the metal, the drill will just stall and not spin. If you don't have a heavy duty 1/2" drill with a low speed gear, you might be better off with a cordless drill/driver that has a gear range selector and use the low speed normally used for driving screws.

Highbeam · Oct 24, 2006

I only needed 1/2" holes for my markham bar so I clamped the toothbar in place and used the existing holes in the toothbar as a guide to just blast the half inch holes into the bucket. No pilot holes, sharpie, or fussing. The bucket is mild steel. Why all of this pilot business.

For bigger holes like 3/4" I have purchased the blue-mol metal cutting hole saws. They use a center bit as a sort of pilot hole but and then saw out the hole. I've done 7/8" holes in 1/2" plate with a hole saw when making a 3ph implement. Lots of lube and a half inch drill.

Inspector507 · Oct 24, 2006

Highbeam said:
Why all of this pilot business.

Because I had the step bits and the other bits, but not a 3/4" hole saw. The smallest I had at the time, on hand, was 7/8". Probably took no longer than your way either.

Highbeam · Oct 25, 2006

Nothing against pilot holes, I have often read about people doing that. Thought maybe there was a reason that I didn't know about. I've never used a uni-bit but they sure look handy when pinpoint accuracy isn't required.

I had a decently sharp bit that walked right through the plate. We could race but including all of the sharpy and pilot drill business, I can't see how you could have done it faster. I clamped the TB in place, drilled the hole, shot black plaint onto the still hot metal, and ran the bolt in before the drill spun down. Ha! well a little slower since I welded on the reinforcent plates too.

Dmace · Oct 25, 2006

I am looking to put a toothbar on mine soon. I am curious as to why you put the hole at the front of the slot in the bar. Wouldn't you want it at the back or atleast centered so you have room to adjust the bar forward and backwards. By driling the hole at the front of the slot, you are limiting your adjustment to only moving the bar forward and away from the bucket. As the bucket lip wears out, a gap will open up between the lip and bar and the bar can't be adjusted closer to the lip of the bucket, right?

Inspector507 · Oct 25, 2006

Dmace said:
I am curious as to why you put the hole at the front of the slot in the bar. Wouldn't you want it at the back or atleast centered so you have room to adjust the bar forward and backwards. By driling the hole at the front of the slot, you are limiting your adjustment to only moving the bar forward and away from the bucket. As the bucket lip wears out, a gap will open up between the lip and bar and the bar can't be adjusted closer to the lip of the bucket, right?

At the advice of others at one time, I put the hole in the front. It allows the toothbar to be loosened and flipped up in the bucket without removing it completely. If I have a minor job that requires the cutting edge, I can flip it up if I wanted to. I can say that I have only done it once. With the limited use that the bucket lip will see without a toothbar attached, I really don't think I'll be wearing the lip down too much. Your mileage may vary. That's just the way I did it, you can do whatever you want and you can use whatever tools you want.