Where to drill forester bar
- Thread starter husqhawk8
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2412
ArboristSite Operative
What?
You want someone else to take responsibility for the design of your homemade mill?
What are you really asking?
You want someone else to take responsibility for the design of your homemade mill?
What are you really asking?
I'm asking where is the furthest spot on the bar I can drill the hole without messing with the sprocket
All of my milling bars have a hole right through the middle of the sprocket.
The middle of the sprocket has a super hard steel slug in between the two (also hard) outer layers of the bar that the rollers ride on. The slug is held in place by the ring of rivets in the middle of the nose - provided you stay inside the "rivet ring" you will be OK.
Drilling requires a carbide or carbide tipped bit, high positive pressure (don't "peck" at the hole), lots of lube coolant, and low revs, so a drill press is needed. It cannot be drilled with a portable drill.
You can use an solid (expensive) carbide bit but I use touched up masonry bits (ie cheap) as it is very easy to destroy the bit during the process.
You will need access to a diamond or green abrasive wheel to touch up the carbide.
The destruction part usually happens during the bit "break thru' the hole part of the process which is hard to control, so its better to support the nose from underneath with a piece of mild steel and not wood.
The middle of the sprocket has a super hard steel slug in between the two (also hard) outer layers of the bar that the rollers ride on. The slug is held in place by the ring of rivets in the middle of the nose - provided you stay inside the "rivet ring" you will be OK.
Drilling requires a carbide or carbide tipped bit, high positive pressure (don't "peck" at the hole), lots of lube coolant, and low revs, so a drill press is needed. It cannot be drilled with a portable drill.
You can use an solid (expensive) carbide bit but I use touched up masonry bits (ie cheap) as it is very easy to destroy the bit during the process.
You will need access to a diamond or green abrasive wheel to touch up the carbide.
The destruction part usually happens during the bit "break thru' the hole part of the process which is hard to control, so its better to support the nose from underneath with a piece of mild steel and not wood.
Edit: The 5 dots is what you call the rivet ring correct?. I just want to double check before I turn the boy lose.
Thanks Bob that is what I was looking for. My son drilled my 42" bar, but I had him about 6" from the end. He is very good with fabricating, I just needed to know how far towards the tip was safe. He sharpens his own drill bits and can drill threw material that the most expensive bits sold around town won't touch. I don't post on here often but have read most of the threads over the years. I always pay extra attention to your posts. Thanks for being such an asset to the forum! You have helped more people than you could imagine.
Twinpines
ArboristSite Lurker
Is this typical of all bars, meaning the rivet ring and being able to drill in the center? That would give me several more inches capacity.
All sprocket nose bars, yes.
"Thanks for being such an asset to the forum! You have helped more people than you could imagine." Seconding this statement seems to be inadequate to express all that BobL has given.
"Thanks for being such an asset to the forum! You have helped more people than you could imagine." Seconding this statement seems to be inadequate to express all that BobL has given.
Thank fellas. Good to know I'm helping folks somewhere.
Twinpines
ArboristSite Lurker
Got my new 28in bar in today. Headed straight to the garage to destroy it,
I decided I'd drill a set of holes for the mill i bought. Im not a fan of friction to hold stuff while cutting. So I set my drill press to make a hole in the tail end. I was surprised when I was able to punch a pilot hole then work my way right up to my desired size. I was thinking I was hot stuff. I turned the bar around and started the hole in the sprocket center. After 6 bits and barely getting through the skin, my ego was deflated.
I remember someone saying masonry bits would work. I found one, used my diamond stone to put a proper point on it and wham, it went right through. Had to clean the sprocket up a bit. Filed the holes and I think I'm good.
Thanks everyone for your posts and all the great info here. Ill update you when I get to run it on the mill.
I decided I'd drill a set of holes for the mill i bought. Im not a fan of friction to hold stuff while cutting. So I set my drill press to make a hole in the tail end. I was surprised when I was able to punch a pilot hole then work my way right up to my desired size. I was thinking I was hot stuff. I turned the bar around and started the hole in the sprocket center. After 6 bits and barely getting through the skin, my ego was deflated.
I remember someone saying masonry bits would work. I found one, used my diamond stone to put a proper point on it and wham, it went right through. Had to clean the sprocket up a bit. Filed the holes and I think I'm good.
Thanks everyone for your posts and all the great info here. Ill update you when I get to run it on the mill.
I handed my bar off to my son on Sunday.It's supposed to be below zero all weekend, but I want to try working on this giant Derecho oak before the city burns it.
Some may argue, but he says it'ss actually worse to start with a small bit first because this puts all of the pressure on the outer edges of each successive bit. He had no problem drilling my 42" bar starting with the big bit.
Twinpines
ArboristSite Lurker
I would have to agree
