Drilling holes oversize in track shoes

[Welder Dave]

A slight taper may not matter much if the hole is very close to the bolt size. The pads could be done from both sides to lessen the taper if desired. A tapered reamer would be worth a try. An annular cutter is similar to an end mill but is hollow and cuts more like drill bit. If a spacer was used that fit the centering pin it would keep the bit from moving around. I think there are carbide annular cutters too.

 

[OzDozer]

An annular cutter is not worth the effort, with only 1/16" to come off each side of the hole. The bridge reamer or the Super Drill Bit look like the answer to me.
The cutter on the Super Drill Bit only has to be dragged a few times over a diamond lap to sharpen it.

 

[digger doug]

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.

Tapered holes, yes, that's why I suggested the core drill instead.

Core drills are normal (usually MT) drills with 3-4 flutes, originally made for opening up as-cast "cored" holes.

Easily hand sharpened much like a normal drill bit.

Not a rotobroach by any means.

 

[.RC.]

OK, I have not come across them before. They look like the tool designed for the job.

Norseman Type 134-AG 5/8

www.mrmtool.com

 

[Delmer]

Just measure your bolts before you order 5/8" vs 41/64" or whatever.

 

[Welder Dave]

An annular cutter is not worth the effort, with only 1/16" to come off each side of the hole. The bridge reamer or the Super Drill Bit look like the answer to me.
The cutter on the Super Drill Bit only has to be dragged a few times over a diamond lap to sharpen it.

I only mentioned it in reference to a suggestion of using and end mill. I don't think the taper from a bridge reamer would be a concern. You could take a little cut from each side and the taper would be negible. If the pads were held in a vise it would be easy to go from each side. A bridge reamer would center the hole and could be used in a hand drill. A variable speed would be nice because you could control the bite so it didn't try to break your wrist.

 

[epirbalex]

I rather hope one of these work , My son has to replace his D47U chains sooner or later and we've given no thought to the problem

Trade Me

www.trademe.co.nz

can be bought for a third of the price and gather a few would be needed

 

[.RC.]

No they will not work. I would not waste my money. They are for light metal removal like burrs and such.

 

[Welder Dave]

A carbide burr would take a long time and hard to keep the hole round.

 

[epirbalex]

I'm going to run a die grinder bit to see what can be done . I've been asked if a little heat in the hole would lose enough temper to use a drill , not much material needs to be heated .

No they will not work. I would not waste my money. They are for light metal removal like burrs and such.

I have used a die grinder to shape teeth after they were replaced with weld , biggest problem was slipping and taking too much off . The scale of doing 70 odd plates runs into a weeks work no matter whats used

 

[Welder Dave]

If they aren't too hard for a bridge reamer it wouldn't take that long to do them. Less than 5 minutes a pad.

 

[ih100]

I’d go a boron drill if the cost isn’t too much. Whatever you try keep it cool, even running a hose while drilling. Sound crude but it’s heat that kills most cutters and drills.

 

[OzDozer]

How do I acquire a couple of those Norseman Whole Hog core drills in 5/8"?
The M & R Machine Tool site says nothing about their shipping policies, and whether they ship internationally or not.
I can't find any Australian company importing or supplying them.
I tried to buy them and their site said free shipping for the purchase of 2 of them, but when I went to pay with a verified PayPal account, the site said no shipping option was listed for my address.
The owners of the site obviously think the civilised world ends at the shores of the Continental U.S.

 

[1693TA]

If you have problems let me know, I'll get them ordered and ship them to you. I have friends in Alice Springs and have shipped them many antique Mack truck parts. Takes a while to get there of course, but Parts have always arrived safely.

 

[Old Magnet]

Try here....

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

 

[epirbalex]

How do I acquire a couple of those Norseman Whole Hog core drills in 5/8"?
The M & R Machine Tool site says nothing about their shipping policies, and whether they ship internationally or not.
I can't find any Australian company importing or supplying them.
I tried to buy them and their site said free shipping for the purchase of 2 of them, but when I went to pay with a verified PayPal account, the site said no shipping option was listed for my address.
The owners of the site obviously think the civilised world ends at the shores of the Continental U.S.

Plenty on NZ Trade-me site , Aussie companies sell on it . Not so many fit a standard drill bit though . Four pages of bits . Usually takes a week for parts to land in NZ , then the fun starts , currently I have a Kioti wheel tractor diff testing patience thats been in NZ since last Wednesday not here yet

Trade Me

www.trademe.co.nz

 

[joe--h]

So what's the answer to this one?

Joe H

 

[OzDozer]

I've arranged for 1693TA to acquire a couple of the Norseman core drills for me, as I can't find anyone in Australia dealing in them.
This choice was made on the basis the Norseman drills are a superior alloy steel to HSS, and they're specifically designed for hole enlargement.

Hole enlargement is very hard on regular drills because there's major load right in the outside corner of the leading edge of the drill. Hopefully, the Norseman drills live up to their promises.

This is not going to be a fast project, just the lead time in getting them Down Under is probably going to be nearly a month. I'll update with further news as we progress.

 

[Welder Dave]

Some of the wax type lube should be good for those core drills too.

 

[joe--h]

It's been several years since I sent anything to Australia but it used to get there in a week of less via USPS priority mail.

Things change I guess.

Joe H