Tungesten Carbide

This forum is dedicated to those hobbyists with the 3-in-1 metalworking machines. Mill-Drill-Lathes. Tips, techniques, modification and use of these machines is topical.

Moderator: Harold_V

Post Reply
dman36
Posts: 2
Joined: Tue Apr 10, 2012 2:31 am

Tungesten Carbide

Post by dman36 » Tue Apr 10, 2012 11:10 pm

What machines can handle DIY small Tungsten Carbide parts from blank rod stock.

I am working on an invention with my partner and we need to shape, grind, mill, drill, and cut rough Tungsten Carbide road blanks that we procure. I want an inexpensive 3-in-1 machine that can work Tungsten Carbide with diamond bits and blades. I don't need a super accurate machine, tolerances don't matter as most measurements will be nominal. What I need is an affordable, versatile, tough machine that can do everything I need. I will be working with 1/8-1/2" diameter Tungsten Carbide unground raw blanks in the "as sintered" condition. I was going to use the 3-in-1 to to lathe down and sharpen or round the tips. I also have a Rotozip that I was going to add the Flex Drive and use diamond Demel cutting wheels and jewelers tools to cut rod to length. I also saw some machines made for Tungsten Carbide with little chambers listed in capacity by liters, I guess they spray oil during machining. Any suggestions.

-Thanks

Torch
Posts: 1548
Joined: Wed Mar 17, 2010 7:58 am
Location: Muskoka

Re: Tungesten Carbide

Post by Torch » Wed Apr 11, 2012 2:17 am

Sounds like most of your lathe work will be done with a tool post grinder. I don't think the power of the machine will be a deciding factor, since the grinder will be doing the work.

For milling operations, you will need to ensure that the machine is capable of sufficient rotational speed for the size of the grinding wheel or stone. Depending on the wheel size, that might mean 3,000 - 5,000 rpm.

While accuracy of your part may not be critical, accuracy of the machine still is. Very light passes are required -- each increment should be less than the protrusion of the diamond bits from the wheel surface. IIRC, depth of cut for an 80 grit diamond wheel would be less than 0.003" and for a 320 grit wheel about a tenth of that -- 0.0003". You can control the 3-in-1's depth at the first example, but probably not to the degree required by the second order of magnitude, so forget really finely finished surfaces.

I don't know of any common 3-in-1 that comes with a coolant system from the factory, however after-market and shop fabricated examples abound. One of the simplest flood-coolant systems in use is simply a shop-modified parts cleaner -- they come with the pump, reservoir and gooseneck nozzle. The home machinist just has to modify things slightly with some piping so the chip pan drains back into the reservoir and the nozzle is mounted in a suitable location. You would want to consider some splash shields, because at those rotational speeds, things are going to get messy.

Harold_V
Posts: 17956
Joined: Fri Dec 20, 2002 11:02 pm
Location: Onalaska, WA USA

Re: Tungesten Carbide

Post by Harold_V » Wed Apr 11, 2012 3:30 am

It would be my opinion that such an operation should not be carried out on a lathe. The resulting swarf will be exceedingly damaging to the ways of the machine. A (small) grinder should be explored.

Harold
Wise people talk because they have something to say. Fools talk because they have to say something.

dman36
Posts: 2
Joined: Tue Apr 10, 2012 2:31 am

Re: Tungesten Carbide

Post by dman36 » Wed Apr 11, 2012 4:07 pm

What kind of Tool Post Grinder, can you give me examples or links to the machine. I am not familiar with anything to do with machining, CNC, etc. I'm pretty mechanical as far as cars, computers, or garage tools go, I know what a lathe is and what it does, I have a bench grinder, but I don't know much about machine shops or the tools they use.

-Thanks

Torch
Posts: 1548
Joined: Wed Mar 17, 2010 7:58 am
Location: Muskoka

Re: Tungesten Carbide

Post by Torch » Wed Apr 11, 2012 7:40 pm

You can buy tool post grinders, or you can make a bracket to mount your rotozip or a mini die grinder or whatever you want to the toolpost. I have a 1/2" diameter air powered die grinder that fits nicely in a boring tool holder for my quick-change tool post. Out of desperation one day, I clamped a 4-1/2" hand grinder in the vice and used it to turn a brake disk (antique motorcycle -- no longer available).

Similarly, I turned a mandrel to fit a cup wheel so I can mount that in the milling spindle for sharpening end-mills. Kind of a poor man's Tool & Cutter grinder.

However, Harold raises a very good point in his post above. (This is typical of Harold and you should consider anything he ever says.) Grinding operations give off a lot of abrasive particles. Those particles get into the moving bits and accelerate wear. For example, the bed of your lathe. Toolpost grinders are aimed at occasional use by a hobbyist who can't justify a grinding machine. Lathes and mills are designed to cut, not grind. Anytime grinding operations have to be performed great care must be taken to cover everything first and clean the heck out of everything after; otherwise you will wear your machine out quickly. So if this is a long-term plan to produce a product, you might want to consider a more suitable machine.

In your particular case, and assuming there are some time constraints in the development of your product, you might want to consider having a machine shop make the samples. I am not trying to discourage anyone from learning machining but I know from my own personal experience that this is not something one can learn overnight. I have been at this almost 2 years now and I know that what I know does not begin to compare with what I do not yet know.

And probably the first thing you should know is that the machine is only half the cost.

Post Reply