Making a race chain for gtg's. Help appreciated.

[blsnelling]

Go too low with the rakers, and you'll make it jumpy, ruining a good chain. A good chain is smooth in the cut and self feeds itself, requiring very little if any pressure. I like to grind my chains, then touch them up with a file in a Granburg File-N-Joint. I then use an Oregon progressive depth guage. I find that the File-O-Plate sets my rakers too deep, at least on Stihl RSC chain.

 

[andydodgegeek]

NO disassembly or machining on this one. The one I have in the works is getting the full treatment. It's being built for my 390XP pipe saw. But, this gives a crude idea of what goes into a GTG chain.

I have only been to a few gtg's and I havent seen a race chain as ground away as that. However, I am basically a newbie here. I am not planning on going pro here just want to have fun at the gtgs with some of the great people I have met here on AS.

 

[blsnelling]

Trust me, that's not a pro chain, lol. The guys with real chains are laughing at me right now Actually, I probably shouldn't have gone that far, but they don't leave a whole lot. Here are a few things you are after.

1. Razor sharp, however you attain that
2. Consistency from tooth to tooth, raker to raker
3. Lots of room for chips
4. A cleaned out kurf for chip removal
5. Rakers set so that it loads the saw good, but isn't grabby

I'm sure there are plenty more, but that'll help get you going.

 

[blsnelling]

One way to put that extra sharp edge on your chain is to put it on the saw backwards and dress it with a stone while the chain spins. But, I didn't just tell you to do that, lol. I've actually never done it either.

 

[awspence]

here is a PDF that Oregon put out with some really basic facts/ideas about race chain mods. not sure if youve seen this, but if not there are a few good bits in there.

http://www.madsens1.com/PDF/RacingTechfacts_93099.pdf

 

[andydodgegeek]

Thanks for the helpfull info so far.

 

[Justsaws]

The photos of the round ground chain look as the the grinder wheel needs to be profiled and not lowered so far into the tie straps. The top plate of the chain needs to have the radius of the circle cut along it's lead edge. Hollow ground, as it looks right now the top plate is being sharpened by the flat side of the grinding wheel.

That chain will cut but it will be slower than a round ground with a radiused top plate edge.

 

[andydodgegeek]

The photos of the round ground chain look as the the grinder wheel needs to be profiled and not lowered so far into the tie straps. The top plate of the chain needs to have the radius of the circle cut along it's lead edge. Hollow ground, as it looks right now the top plate is being sharpened by the flat side of the grinding wheel.

That chain will cut but it will be slower than a round ground with a radiused top plate edge.

I should be able to fix that with a hand file. I will try to get to it tommorrow and keep up on this thread. Some interesting stuff.

 

[andydodgegeek]

One other question, I have seen people using a granberg file guide for round ground chain does anyone make a guide/jig for square ground chain.

 

[TK]

This is an in-progress chain I've been working on. These things take forever to do this! And as you can see there's a long way to go. But rather than try to do it all at once, I've made a change and tested it, made a change and tested it...... Keep notes on what works and what doesn't so 5 chains down the road you've got notes as to what works, what doesn't, and you'll be able to make theories on what you want to try next..... I'd recommend only using the grinder to even things up and get you started, not to do your modifications. I tried that, it didn't seem to produce results as good right from the start.

Here's a picture from a while back, with clearly a long way to go. I've made changes since then.

 

[lmbrman]

The photos of the round ground chain look as the the grinder wheel needs to be profiled and not lowered so far into the tie straps. The top plate of the chain needs to have the radius of the circle cut along it's lead edge. Hollow ground, as it looks right now the top plate is being sharpened by the flat side of the grinding wheel.

That chain will cut but it will be slower than a round ground with a radiused top plate edge.

is there a radius on the top plate when you square grind?

 

[Mastermind]

is there a radius on the top plate when you square grind?

No, but the angle is much sharper than it is when the flat side of the wheel on a round ground setup makes it.

 

[young]

read and then read some more. great stuff.

Guide Bar & Saw Chain Menu

http://www.madsens1.com/PDF/RacingTechfacts_93099.pdf

 

[lmbrman]

No, but the angle is much sharper than it is when the flat side of the wheel on a round ground setup makes it.

I thought that angle could be adjusted?

just askin, no expert for sure

 

[HELSEL]

One way to put that extra sharp edge on your chain is to put it on the saw backwards and dress it with a stone while the chain spins. But, I didn't just tell you to do that, lol. I've actually never done it either.

Would you stone just the top of the
chain? Or would you stone the sides
too?

 

[Justsaws]

is there a radius on the top plate when you square grind?

Nope, just two nice bevels meeting up in a tight corner.

 

[Mastermind]

I thought that angle could be adjusted?

just askin, no expert for sure

It can be adjusted but then the "hook" is too great.

Would you stone just the top of the
chain? Or would you stone the sides
too?

How's it hanging Ricky??????

You should give me a call bro.

 

[lmbrman]

It can be adjusted but then the "hook" is too great.

QUOTE]

what if you take some of the hook out by changing the shape of the radius? Make it flatter?

I know it is not the same, but can you approach some of the advantages of square ground with a round grinder/grind? Alot more affordable option than a square grinder for many here.

-dave

 

[lmbrman]

Nope, just two nice bevels meeting up in a tight corner.

so,, would you say the shape of the stone is critical?

 

[mdavlee]

I've got some pictures on here of some chains I ground in some threads. I'll get some pictures when i get to the room and on the computer instead of tapatalk.

Square ground is the way to go. I have seen a good time decrease from round to square.