Thread: Need help with Sprocket tip on Lucas bar

Frank, Bobl might be able to help - he's our resident bloke who knows a whole heap on chainsaws.

For me, I haven't had the pleasure of needing to swap a tip on my lucas slabber, so sorry mate, I don't know

Photos will be a big help to try an understand what is going on.

Originally Posted by BobL

Photos will be a big help to try an understand what is going on.

Will get photos tomorrow. Thanks

My guess would be the rivets are Titanium. Try a masonary bit with plenty of CRC or similar for lubricant and slow speed.

Originally Posted by dai sensei

My guess would be the rivets are Titanium. Try a masonary bit with plenty of CRC or similar for lubricant and slow speed.

Titanium is not usually that hard but a masonry bit with lube and slow speed should do the trick.

These are two bar noses that I have pictures for.
The one on the left is a Stihl while other is a GB roller nose.
The rivets on the Stihl are pretty hard so following Neil's recommendations is the go but I got the ones on this Stihl out using a new Co bit.
The GB nose does not use rivets but a metal tenon with tabs that are just bent outwards to hold the nose in place.
If you try to drill out the rivets holding the sprocket you will find they are also extremely hard and you will need a carbide bit to do it

Not sure why I didn't pick it up before, but seeing Bob's pics, my lucas slabber bar doesnt have a replaceable tip - it's a solid bar and I could be wrong, but I'm sure my last slabber bar was the same too......

Originally Posted by Sigidi

Not sure why I didn't pick it up before, but seeing Bob's pics, my lucas slabber bar doesnt have a replaceable tip - it's a solid bar and I could be wrong, but I'm sure my last slabber bar was the same too......

Replaceable noses are useful for CS operators that use the nose for things like plunge cuts, but in milling situations where the nose is not used and the power source has a lot of grunt there is no real need for them provided they get enough lube. For small chainsaws a also sprocket nose reduced engine load. Some people think the chain stays on the bar better with s sprocket nose - I'm not sure about that.

Bob I think maybe Frank is trying to drill out the 6 rivets holding the sprocket in the nose of the bar, not that he has a bar with a replaceable tip, although I could be wrong.

I recently saw a chap in the US who installed a nylon roller on his Lucas slabbing bar instead of a sprocket...lemme see if I can find the pic.....

Found it...
lucas_nose.jpg

Originally Posted by Sigidi

Found it...
lucas_nose.jpg

Very Interesting - thanks for posting - might incorporate this in my next CS mill!

Right you are Sidgi, I misspoke. Should not have used the word "tip". It is indeed the six rivets holding the srrocket.
New sprockets came in from Madsens, Baileys was out of stock and had no plans for ordering evidently.
I think my problem was the piece of cardboard protecting my table top. Too much of a cushion I think. I will try tomorrow , Following the instructions which came with sprocket.
Relieve rivet with drill bit, then drive out with punch. I think a press would be better, but I don't have one.
Thanks for the help. I'll let you know how it goes.
frank

Originally Posted by Seaman

Right you are Sidgi, I misspoke. Should not have used the word "tip". It is indeed the six rivets holding the srrocket.
New sprockets came in from Madsens, Baileys was out of stock and had no plans for ordering evidently.
I think my problem was the piece of cardboard protecting my table top. Too much of a cushion I think. I will try tomorrow , Following the instructions which came with sprocket.
Relieve rivet with drill bit, then drive out with punch. I think a press would be better, but I don't have one.
Thanks for the help. I'll let you know how it goes.
frank

Hi Frank, What's wrong with the old sprocket? Unless it is totally mangled I don't see a need to replace it.
If the sprocket is bound up, soak the end in diesel ovenight and buy moving the chain back and forth you should be able to free it.

If you have to replace it I would not bother drilling the rivets but use angle grinder and just grind the rivet heads off. Don't worry if you grinder away a bit of the bar - it will survive.
Balancing a big bar under a drill press is a PITA.
It will also be much better to use a piece of wood instead of card board as protection for the table.

Since Baileys STILL doe's not have the sprocket, I ordered the weld on roller sprocket thingy above. I will try to post pics of the weld up. Part should be in Tue.

I had a 0.063 /404 sprocket nose on one of my 60" bars that I wanted to convert to 063 roller and this is how I did it.

I made an adapter plate from an old circular saw blade - it's hard enough but not too hard so it cannot be worked.
I cut the plate with a thin kerf cutting blade. The adapter is a sandwich (3 layers) of the steel to create the rails for the chain to ride on.
The long curved shapes were made with a belt sander while the small inner radiuses were made using a carbide bit in a die grinder - it took a while but it worked out OK..



Unfortunately this means different chain lengths for different bars but that's not the end of the world.