Drilling holes oversize in track shoes

[OzDozer]

The holes would certainly have been punched simultaneously, originally - but before the shoe was heat treated. It's the heat treated steel we have to deal with now.

I do like the idea of a carbide burr - but I reckon it would wear out more than one, doing the job.
I can recall lending one of my good Garryson carbide burrs to my workshop neighbour, a truck mechanic, so he could enlarge many holes on a truck chassis.

It took him quite a while (with a hand-held drill) and my burr came back considerably worse for wear!
I wasn't too upset, Joe was a good and helpful neighbour otherwise, and I owed him for help he'd given me.

At the end of the day, the amount to be taken out of the shoes is only 1/16" in depth all round - so it's not a huge amount of metal - nor would centering be 100% critical, because the links are often not positioned with deadly 100% accuracy on the track pins and bushings, anyway.

 

[epirbalex]

O.K., guys and gals, I'm looking for some tips and tricks here on drilling track shoes (or track pads to some of you).
I've got a client who owns an early 1960's D4C. He wants to buy some new D4 track chains I've got in stock.

However, the track chains I've got are 5/8" bolt holes for the shoes, and he wants to use his old shoes, which use 1/2" bolts.
I've told him it's easy enough to drill them out to 5/8" size, just takes a little bit of boring work (yeah, pun intended).

However, he's a bit unsure as to how to attack the actual drilling. I've told him, use a cobalt drill. I'm guessing there's some tricks as regards lubricant to use, too?
I'm all ears to anyone who's done this, or had experience drilling hardened steel. I seem to recall the shoes are at least 52Rc?

This job could easy take 15_20 minutes a plate , could you not find the buyer a set of chains with half inch holes

 

[Welder Dave]

I'm not sure how hard of material an iron worker can punch or if they make special punches for harder materials. I know some punches are tapered so they aren't trying to do the full size all at once similar to how a shear works. Grader blades and I'd expect things like dozer edges and end bits are also punched. I'll have to do some looking to see how hard of steel can be punched. I'd also think older pads wouldn't be as hard as modern ones.

Found reference to dozer end bits being punched but not sure if it's before heat treating. I wouldn't think track pads are nearly as hard as they are readily weldable with standard 7018. It's not uncommon to see bent track pads indicating they aren't super hard and brittle. High carbon and spring steel can be punched. You have to use a multiplier to figure out the tonnage required. Heating the material to a dull red will make punching easier as well but I'd suspect pads could be punched. Best bet would be to check with an ironworker manufacturer like Scotchman, Piranha, Peddinghaus or a number of other brands. They've likely encountered a similar application. It's possible a fab shop may have experience with track pads too.

 

[Mquinista]

I don't know if that means they're punched from the factory, but I'd look into that, find some place with a scotchman punch press and see if it's possible to get them punched relatively accurately.

Gents , Pads / shoes whatever are of special kind of steell. Otherwise they would bend and brake and it would be a mess expecially walking over stone and so on.
Factory will stamp or cast or use other method , but in the end everithing is made on cold steel, after will have to be heat treated and normalized, and this is where things change.

Heat treated parts can be punch holed , but the machine and fixture to do such a job is expensive and not all machine shops have it, wich add a cost, a job like this may result more expensive than buying the chain already padded.

between having chains in the 1/2 or pads in 1/8 certainly is all about the cash spent in the end.
regards

 

[OzDozer]

This job could easy take 15_20 minutes a plate , could you not find the buyer a set of chains with half inch holes

D4 track chains with 1/2" track shoe holes were obsolete at least 25 years ago. I think even D4 track chains with 9/16" track shoe holes could be on the endangered species list.

I'll talk to the gent who's purchasing them in the next few days, and get a handle on what kind of capabilities he's got on the Station (Ranch).

There won't anything like punching equipment, or iron working shops within hundreds of kms of his place, and he sure won't want to be paying a shop to enlarge the holes, the old D4C is just used as a Station hack, for clearing fencelines and dozing up a bit of dirt here and there.

It's certainly not a prime income earning machine, as you'd expect with a machine produced in the early 1960's.

 

[Delmer]

You may be right with the cobalt bit being easiest after all of this. Certainly worth a try for the price of a few top of the line drill bits. Easy enough to find the pressure and speed to use, I wouldn't know. The best advice I can give is stop immediately when the cuttings stop being uniform and re sharpen. If a regular drill bit won't do it, I've used a carbide masonry bit for a single hole, but for this I'd see if you can find a custom bit where a 1/2" shaft is the pilot and side carbide cutter makes the 5/8" enlargement, like a mini boring bar a line borer would use. I can't find anything like that. Another possibility would be a carbide replaceable tip drill, I've never used one but they seem aimed at that sort of material, about $100 american,

 

[Welder Dave]

A taper reamer is another option. You'd just have to put some paint or something on the reamer at the right size so the hole isn't too big. They work good on high tensile truck frames too.

 

[digger doug]

A taper reamer is another option. You'd just have to put some paint or something on the reamer at the right size so the hole isn't too big. They work good on high tensile truck frames too.

Slip a piece of pipe over it as a depth stop.

 

[LarryH]

Try it with a slow speed drill and a tapered burr. You'll be impressed with how it works. I agree a die grinder would be a disaster. How hard are the track plates?

 

[OzDozer]

They're fairly hard, they're boron steel, and heat-treated. I STR they're 52 Rockwell, and up to 58 Rc on the grousers.
Naturally, the hardened depth is limited. They can't be too hard, just toughened. A burr or bridge reamer will work on them, just not real fast.
I reckon a cutting paste like Trefolex would be a good investment. Trefolex's performance in drilling and cutting is exceptional.

There's a previous thread below on how the shoes are actually manufactured.

How do they make dozer tracks and shoes

Anyone know how track pads are made? Track links? Just curious

www.heavyequipmentforums.com

 

[.RC.]

Reamers are used to remove small amounts of metal or fix minor misalignment. They are not for changing a hole from 1/2" to 5/8"

Super Dill might be another option. I have seen one used, never used one myself.

 

[Welder Dave]

Tapered reamers will easily take a 1/16" cut all around. When they mounted extra plates on truck frames for winches they used a tapered reamer when the punched holes from the ironworker didn't quite line up. They also worked if the holes were out quite a bit. As long as the reamer could fit through both plates it would remove material so the bolts would fit. A wax type lubricant would definitely help.

 

[Tones]

Super Dill might be another option. I have seen one used, never used one myself.

This drill looks like the ducks guts. I just bought a hole saw set, this would have been perfect for what I wanted to do.

 

[.RC.]

You have never seen them at the usual rural expositions? They have been around for at least thirty years or more. At the usual places like the beef expos or the farming expos there would always be the company there with a drill press drilling holes with one of those gadgets. They are probably even more useful today with the advent of cheaper mag base drills, which sort of take away the need for your typical drill press.

 

[Mcrafty1]

Super Drill & adaptor pack Large metal drill bit

www.toolking.com.au

Any machinist or serious metal worker would want one of these. The price, for what is seems reasonable, I don't know what shipping would be to the USA but drilling things like track pads and the like this would pay for itself in one set.

 

[digger doug]

Reamers are used to remove small amounts of metal or fix minor misalignment. They are not for changing a hole from 1/2" to 5/8"

Super Dill might be another option. I have seen one used, never used one myself.

A bridge reamer is a whole different animal, different from a normal reamer.
It would work, however, the taper can be problematic.

I will suggest a core drill, to open up those holes.

 

[OzDozer]

I'm having trouble finding a core drill that is 5/8" diameter and capable of drilling hard steel. Most are larger size and only designed for tiles and concrete.
I did find some Chinese ones, but I couldn't be sure on their ability to provide satisfactory service as regards drilling track shoes.

The Super Drill Bit by ToolKing looks good. Despite RC saying they turn up at every Show and Field Day with a drilling display featuring their product, I've never seen or heard of the product before.

I don't think I live under a rock, I go to a lot of Shows and Field Days to see the latest and greatest - but I've found a lot of Eastern States products no longer make it to the West, no doubt because of the costs involved.

I've also found the Shows and Field Days are now becoming a lot more "corporate-oriented", with lawyers, grain dealers, financiers and other corporate hangers-on, putting up large stalls - while the old-style family-farmer-oriented stalls with small tool deals, innovations, and other useful knick-knacks, have all but vanished from Shows and Field Days.

I guess this is because farming is now mega-dollar operations with large corporations now holding huge acreages.
Just saw a former farmer client put his 7000 acre farm on the market for $20M, which just blows me away.
This blokes father got nearly all their land for around 25c an acre from the Govt in the '30's to the '50's, and even 30 years ago, their farm was only worth a couple of million.

 

[chidog]

With something like a bridge port with a DRO, hold it in a vise, use a pin to align the first hole.
Then I'd try a solid carbide end mill the correct size to plunge with. On a CNC I'd probe and interpolate the proper size.

 

[JimInOz]

The Superdrill is very handy.
I have a basic (smaller) set,but large is available.
I always keep a few spare cutters & 1/2 or 13mm drill bits for the pilot hole.
I usually order online.

A mate of mine in Perth might have a few D4 chains for sale,if it gets too hard.

 

[.RC.]

The Super Drill Bit by ToolKing looks good. Despite RC saying they turn up at every Show and Field Day with a drilling display featuring their product, I've never seen or heard of the product before.

I don't think I live under a rock, I go to a lot of Shows and Field Days to see the latest and greatest - but I've found a lot of Eastern States products no longer make it to the West, no doubt because of the costs involved.

Goes to show I should never assume. I just thought they would be all over the country peddling their wares, especially because for farms it is a pretty handy tool.

With something like a bridge port with a DRO, hold it in a vise, use a pin to align the first hole.
Then I'd try a solid carbide end mill the correct size to plunge with. On a CNC I'd probe and interpolate the proper size.

I have a bridgeport clone and they are not rigid enough for that, it will just wobble all over the place, plus a 5/8" carbide endmill is like all carbide metal working tools, fragile and very expensive. The end mill itself would be a couple of hundred of our dollars for a name brand. Plus if it broke, how would you sharpen it, if it could be sharpened. On top of that OzDozer said the job is to be done on a rural property hundreds of miles from anywhere.

A bridge reamer is a whole different animal, different from a normal reamer.
It would work, however, the taper can be problematic.

I will suggest a core drill, to open up those holes.

Had a look and yes they look different, tapered and all. But that would leave a tapered hole as well. Also there are a lot of holes. four holes per pad, and how many links, and two chains. Something like 368 holes to do, if they are 52hrc at least on the surface, which is reasonably hard (a file is around 62, and 4140 steel is even around 30hrc in the usual bought state), I doubt the reamer is going to last long. By core drill I assume you mean what we would call a rotabroach. again an expensive tool, not going to be able to sharpen it on site, plus it will need a custom made pilot made.


I am still leaning towards something easily resharpenable with a bench grinder, reasonably priced and will open up the existing hole in the same position it is in now, so either self centering or has a pilot guide.