Yet another bar drilling post . . .

[Daninvan]

I have had good success drilling bars in the past using my drill press at low speed with some lubricating oil and just a regular 5/16" hardware store Chinese drill bit.

I recently attempted to drill into the middle of a bar's nose sprocket for the first time. (Gotta get that extra couple inches of width you know, I'm sure everyone understands that!)

Anyways, long story short, I tried the usual bit, a new carbide bit, and a new cobalt bit. I guess either the steel there is superhard, or somewhere along the way I have tempered the steel somehow and now nothing is working. I got in about 1/8" and now nada. Tried both sides, same same.

The good news is that this was just a test bar, so no damage done. But I am gunshy about drilling into one of my real bars now. I'm looking for suggestions other than run it down to the local machine shop and get them to do it. Maybe I should start with the carbide/cobalt and not let up the pressure?

Dan

 

[hamish]

Will definately need a pic of where exactly you are drilling. From the sounds of things you are right into the bearing...............hence a pic would help to narrow down the area.

 

[BobL]

To drill the bearing I used a new (or newly sharpened) carbide tipped (masonry) bit, 160 rpm, lots of cooling lube - in a heavy duty drill press, a fair bit of pressure is required. New masonry bits are not always very sharp and rely on crushing the masonry so sharpening even a new one (green wheel) to get an edge and a point is worth while.

Drilling straight through can leave a bur on the bearing metal which can increase the nose bearing friction so stopping half way thru and turning the bar over prevents this problem

 

[Hillbilly3995]

The Easiest way is go down and buy a solid carbide end mill in the size you want and use it like a drill bit in your drill press...very slow speed, clamp everything solidly it is imperative that nothing squirm or I guarantee a broken end mill.

It'll cost 10 or so bucks but if you dont break it, it'll cut lots of holes in hard bars.
nice holes, little or no burr.

absolutely NO Aaron Burr, he's dead.

 

[mtngun]

Drilling straight through can leave a bur on the bearing metal which can increase the nose bearing friction

The 1" disc in the center of the sprocket nose does not spin, so I'm not getting the friction thing. :confused2: :confused2: :confused2:

I second the carbide endmill, just make sure it is designated "centercutting."

How's the new shop coming along, BobL ? Myself, I'm wrapping up the 2nd homemade wood floor.

 

[Hillbilly3995]

The 1" disc in the center of the sprocket nose does not spin, so I'm not getting the friction thing. :confused2: :confused2: :confused2:

I second the carbide endmill, just make sure it is designated "centercutting."

How's the new shop coming along, BobL ? Myself, I'm wrapping up the 2nd homemade wood floor.

Yes Mtngun is absolutely correct, it must be a centercutting end mill, I did neglect to mention that. Most solid carbide ones are anyway. but Thanks and Good Catch! Mtngun, you potentially saved someone a few bucks and a bucketload of frustration...

 

[Daninvan]

Off to Grainger on Monday to buy the solid carbide centrecutting end mill. Once the hole is drilled, will I be able to use a regular tap to thread the resulting hole, or will I need something special to thread the seemingly extra hard steel?

 

[BobL]

Off to Grainger on Monday to buy the solid carbide centrecutting end mill. Once the hole is drilled, will I be able to use a regular tap to thread the resulting hole, or will I need something special to thread the seemingly extra hard steel?

Why bother threading it at all? - non of mine are threaded.

 

[BobL]

The 1" disc in the center of the sprocket nose does not spin, so I'm not getting the friction thing. :confused2: :confused2: :confused2:

You are right - I think some swarf just got into the nose sprocket bearing, I had coolant sward and carbide dust flowing everywhere.

How's the new shop coming along, BobL ? Myself, I'm wrapping up the 2nd homemade wood floor.

I'm waiting for the electrician (he's 2 weeks away - there is so much work here for tradesmen that it is very hard to get anyone good to do anything in under 4 weeks). Normally I would do it myself but I'm getting a 3 phase line and circuit breaker board put in. Even though our house does not have 3 phase we are getting underground power in 2013 and at that point we will get 3 Phase put onto the house.

I'd like to start moving stuff into the shed but I want to paint the concrete floor with a paving paint and this means waiting for 3 months for the concrete to cure. Meantime there is heaps to do inside and out.

Currently I'm working on my dust extraction system using 6" diam PVC storm water pipe. The fittings for these pipes can be quite expensive so I'm making some from scratch including the Blast gates that fit over rather than inside the pipes, and some of the 6" to twin 4" Y's.

It's also been hot and very humid. Of the 90 odd days of summer 58 (23 and still counting have been consecutive) have reached maxima of over 85F.
The maxima for the last week has been 96, 91, 95, 97,100,100, today its 95 and the forecast for the next week is; 91, 93, 95,95,91 and .......88! Those temps are not that bad but inland Australia has had a very wet summer so the humidity is high and for 40 of those days the overnight temp has not fallen below 70, last night it only got down to 81.

 

[mtngun]

The fittings for these pipes can be quite expensive so I'm making some from scratch including the Blast gates that fit over rather than inside the pipes, and some of the 6" to twin 4" Y's.

How do you make PVC fittings from scratch ?

It's also been hot and very humid.

-3F (-19C) here Saturday. Snow drifts 3 feet deep. A good time to do saw maintenance, after I finish the flooring.

Danivan, I think tapping the bar nose would be a really, really bad idea. You'd likely break the tap in that hard metal and much cussing would ensue. :taped:

 

[Hillbilly3995]

How do you make PVC fittings from scratch ?

-3F (-19C) here Saturday. Snow drifts 3 feet deep. A good time to do saw maintenance, after I finish the flooring.

Danivan, I think tapping the bar nose would be a really, really bad idea. You'd likely break the tap in that hard metal and much cussing would ensue. :taped:

Agreed

 

[Hillbilly3995]

Off to Grainger on Monday to buy the solid carbide centrecutting end mill. Once the hole is drilled, will I be able to use a regular tap to thread the resulting hole, or will I need something special to thread the seemingly extra hard steel?

BTW those things are near brittle as glass dont drop it.

 

[BobL]

How do you make PVC fittings from scratch ?

PVC Pipe, PVC sheet, lathe, hot air gun, PVC solvent glue etc. I made the PVC and HDPE fittings for a whole chemistry back in 1986.
Here's a couple of blast gates I made yesterday.

-3F (-19C) here Saturday. Snow drifts 3 feet deep. A good time to do saw maintenance, after I finish the flooring.

Now we could really use some of that here. It also hasn't rained since before Xmas. Meanwhile the rest of the country is flooded

Danivan, I think tapping the bar nose would be a really, really bad idea. You'd likely break the tap in that hard metal and much cussing would ensue. :taped:

Yep agree

 

[MCW]

I actually find it easier to clamp a bar at the point you're drilling with a piece of steel plate on the opposite side. When that bit breaks through is when you'll damage it and the plate on the other side stops this. It also stops excessive burring.
But yeah, you get the odd super hard bar like the older (and maybe newer?) GB Titaniums. I've killed a few spendy drill bits on those I use the ARTU German made bits which are excellent. They'll drill straight through a file

 

[Daninvan]

Well I took the bar to the machine shop and got them to do it. For little more than the cost of a few fancy drill bits I got one tip threaded and the other just drilled. One was too hard even for the machine shop to thread! The threaded tip is so-so, I think it'll be fine for what I need but it is a bit ugly.

OK I'll fess up on why I am doing this now. I recently had to replace my Husky 2100 (don't ask!), and wound up with a couple Husky 3120s and 390s. It seems that the 3120 and 390 are about 1 3/4" bigger than the 2100, so I lost that width on my mill. In an attempt to get it back I decided to drill and tap the sprocket, which would get me 2 1/2".


Holes on the left were for the 2100, holes on the right for the 3120/390.

Newly drilled sprocket centres

I did some milling last week with Pete (Peterrum). Using the shortened mill, I wound up with all sorts of minor glitches. Some mill related, some saw related, some operator errors, etc. Murphy was alive and well.


%&*'ing with the ^%&*! saw. At least it was a nice day

Finally, some milling happened

Dan

 

[BobL]

Not very ergonomic by I really like the colours in this photo.

And what's this gizmo?

 

[MCW]

Yeah good photos Dan. Interesting to see all of the different scenarios and climates that people mill in We've got flies, dust everywhere, and 110°f this time of year

 

[olyman]

I did some milling last week with Pete (Peterrum). Using the shortened mill, I wound up with all sorts of minor glitches. Some mill related, some saw related, some operator errors, etc. Murphy was alive and well.

Dan[/QUOTE]

murphy??? i thought,,he only existed in the usa--and only in my state!!!!

 

[Daninvan]

Not very ergonomic by I really like the colours in this photo.

Come on, that is one of my most ergonomic milling positions ever! The colours are nice, we are not totally certain what the wood is. We were told it was maple, but present thinking is maybe a heavily spalted box elder.

I also found that with the rakers set to 7.5 degrees, the chain was a bit grabby. This wood was harder than the western red cedar that I had previously cut with a 7 degree setting. I'll try dialing it back to 6.5 degrees, maybe have one chain for hardwoods and one for softwoods.

As for the gizmo, well you've spotted one place where Murphy was involved! Since I had to move the threaded rod at the head end due to the larger powerhead, the holes in the mill would no longer align with the threaded rods new tighter spacing. So I cheated and simply screwed a block at the sprocket end of the mill and drilled a hole in it. Voila the right spacing. Clever I thought. Unfortunately the block came slightly loose and wound up tilting the mill and causing the bar to dive into the log as well as quite a bit of salty language until I figured out what was happening. (OK, Pete actually figured it out!).

 

[RPM]

-3F (-19C) here Saturday. Snow drifts 3 feet deep.

Same here Bob ....I could take some heat and humidty. On the plus side the snow that fell this weekend was so dry it was like smoke coming off the back of my skis ... cold smoke!