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lame-o can't drill a freaking HOLE


Guest Anonymous

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Guest Anonymous

Ok, I'm trying to drill my mustache bar so I can mount my R230 and I'm having troubles. Is it my tools or is it the tool operating them?

I'm using hss titanium bits, and high speed cutting oil. I drilled a 3/16 pilot hole, which went very quickly. I got the idea that I would progressively enlarge the hole but I kept turning a groove (the diameter of the last used bit) in each bit. So I though, these must be the junkers I bought from JC Whitney. So I went to Harbor Freight (Not much better..) and resisted the temptation to buy the cheapest bits they had... and instead bought the second cheapest bonk.gif -- $30 for 29 titanium coated hss bits.

Sooo... I tried them out tonight. Went straight to a half inch bit. I use enough oil to keep it wet. I assume when it gets dry enough that it smokes a tad and screeches a little, it is destroying my bit, so I add more oil. I was drilling a bit, letting off a bit, etc, so the bit wouldn't get too hot..? Well, the new bits cut about 1/8" down into the bar and stop working.

 

So how the hell am I supposed to do this?

 

Be honest but be gentle. smile.gif

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Oh, I remember this trick too.

 

Those M-bars' are hardened steel. I dulled many a bit drillnig those holes. I wonder if drilling the bar heats it up enough to lose it's temper and weaken it?

 

Anyway, use a slow drill motor speed and not too much pressure. Even so, you need really good bits to do this trick, unless you anneal it first (then you should have it tempered again, I'd think).

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Guest Anonymous

Are you using a drill press or hand drill??? Your turning speed my be too fast for a 1/2 inch bit which turns about twice as fast as a 1/4 inch. I found good old American Vermont or Hanson drill bits work great at proper speed.The moustache bar may be a spring steel alloy and a little hard on the Rockwell scale. I found a blue goop called "Anchor Lube" when placed on the hole sticks to the bit of the drill giving a full time lube to the cut. You can find this at well stocked welding stores or tool stores or machinist supplies. It is cheap and saves the drill bits.If the drill bit is turning blue that means the hole is hot also and probably air-hardening from the heat to a harder surface. Slow and easy like Pete Says

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Oh...my hands are still recovering from this...I tried this just last week (R180 bar no good, and was easier to drill). I spent 5 hours trying and ended up taking it to a machine shop. They used the lowest speed on a huge drill press which still took a while. Definitely give it up and take it somewhere.

Tim

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Guest Anonymous

Oh, great. So I'm NOT an idiot. That's a relief. Wait, no it's not!

My drill press is one of those cheapie benchtop things.. It was set on 580rpm which is as slow as it will go.

Hmm.. I'm stubborn, so I'm not taking it to the shop yet. I've scraped the yellow off a few of those titanium bits. What's next? Carbide? What's a good bit to use?

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I guess my question is why are you even trying to enlarge a hole in a mustache bar?

 

When I did my R180 to R200 swap, I was having trouble finding a decent R200 bar. The guy at the wrecking yard (which specialized in Z's) told me to resist the urge to drill out the R180 bar to fit the larger R200 mounting bolts. He said the drilled out R180's inevitably cracked. He said guys came in all of the time with cracked R180 bars and that is why the R200 bars were hard to find.

 

From what I can tell the bars are tempered spring steel. The mounting holes are probably where the bar is subject to the most stress, thus it only makes sense that heating this area by drilling could ruin the temper and lead to cracks.

 

Maybe you are doing something other than what I described. I don't think the guy at the wrecking yard was just trying to sell me parts. Are a lot of guys using modified bars? If you are, how well do they hold up under use?

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No, he's trying to mount an R230. The holes are spaced differently.

 

I'm a little worried about the pilot hole. I've not had good luck enlarging holes in metal parts. It's much harder for a regular drill bit to seat its cutting edges against the material.

 

580rpm seems pretty slow, but I'd reckon it's about 300rpm too fast.

 

And oil is no good as a cutting fluid. You need actual cutting fluid. Certainly some fluids are better than others and it depends on the particular job, but I've had great luck with the thread cutting oil you can buy at Home Depot/Lowes. What it lacks in quality, I make up for in quantity.

 

If you're not ready to give up, here's what you might try. Buy a goof 1/2 inch bit. This will cost you about $20-$30 for the one bit. I've had bad luck with carbide bits - very brittle. Especially since you have a pilot hole, I wouldn't recommend carbide. It'll just snap and then you'll have a $45 broken bit :( . Setup the bar on the press so that you can just rest the bit on the bar, just mild pressure (since I think you're turning too fast). Constantly apply the cutting fluid. Constantly. It's gonna be all over the place. You might want some air handy to blow out filings too - you don't want these in your fluid if you can help it, plus the air will help cool things down. Lots and lots of fluid.

 

I also have one of those crappy benchtop drill presses. They're meant for woodworking - way to fast turning. I've actually had better luck with my Milwakee hand drill since it turns slower. Huge pain holding that thing for the hour that it will take to drill a hole like this one though.

 

I'm guessing that a machine shop won't charge all that much though - perhaps marginally more than the expensive drill bit that you're gonna need (and will likely ruin at 580rpm anyway).

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I'm guessing that a machine shop won't charge all that much though
The one I went to didn't charge me a cent, and I will now take all my machining business to them (I just picked them out of the yellow pages.)

Tim

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Guest Anonymous

Stay away from the carbide tips because the tips break off easily and are expensive!!!!!!!. a cheap source for carbide tips are cement cutting carbide drill bits but require a lube and are about good for one hole in hardened steel.Keep in mind that spring steel can get "work hardened" by drilling it too . Just about any high carbon steel is totally softened or annnealed at 1200 degrees and totally hardened at 1550 degrees and nobody can do that without a controlled furnace to be exact at that close of heating range.. Also high carbon steel is tempered (reducing the brittleness) at 450 to 500 degress farenheight USE another piece of steel under the moustache bar to drill into since that 1/2 inch drill bit rips out of the bottom with a fury and wants to break off. Definitely get a good drilling lube.

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