6 spline vs 7 spline

[MudgeHollowBeaver]

I'm working on my Homelite 2100 Auto and just puzzled as to why a 6 spline drum and rim design even exists. The IPL shows both 6 and 7 spline setups. Is there an advantage of one over the other? It seems that the 6 spline setup wasn't used by other manufactuers.

 

[ZeroJunk]

I'm working on my Homelite 2100 Auto and just puzzled as to why a 6 spline drum and rim design even exists. The IPL shows both 6 and 7 spline setups. Is there an advantage of one over the other? It seems that the 6 spline setup wasn't used by other manufactuers.

Think of it like gears on a bicycle. 6 spline would give you slower chain speed and more torque.

I have never seen one either. More often they went to 8 spline to get the chain speed up for a slower turning engine than we have today.

 

[RedneckChainsawRepair]

Are you talking 6 7 spline for where it mounts on drum or you asking about 6T 7T where your drive links on chain ride?


Spine inside rim and other is outside rim?

These are 7 spline with different counts in 8T 9T

 

[grizz55chev]

Are you talking 6 7 spline for where it mounts on drum or you asking about 6T 7T where your drive links on chain ride?


Spine inside rim and other is outside rim?

These are 7 spline with different counts in 8T 9T

View attachment 1170012

looking at some old threads on the subject showed that 6 spline was for .404 chain 7 spline is .325 chain.

 

[MudgeHollowBeaver]

You are getting the spline count on the ID of the rim that is driven by the crankshaft confused with the tooth or pin count around the OD of the rim that drives the chain. The number of splines has no correlation to the speed (or 'gear') that the chain is running, only the OD (and hence the number of teeth or pins that can fit around the circumference) determines this. I am asking about the difference in the spline count.

 

[RedneckChainsawRepair]

looking at some old threads on the subject showed that 6 spline was for .404, 7 spline is .325.

7 spine 404 in 7T can take pic of the 8T in 7 spline 404 if needed.

But I think he is talking where it mounts. Just not sure. - Yep he talking mount.

 

[RedneckChainsawRepair]

Maybe this old thread with 6 spline 404 might help ya. http://chainsawrepair.createaforum.com/for-sale/404-6-spline-8t-rims/msg16344/#msg16344

Pic of them too.

 

[cbfarmall]

I'm working on my Homelite 2100 Auto and just puzzled as to why a 6 spline drum and rim design even exists. The IPL shows both 6 and 7 spline setups. Is there an advantage of one over the other? It seems that the 6 spline setup wasn't used by other manufactuers.

The short answer is Homelite was idiotic with the 6 spline drum. Sure limits your options. I've only seen .404x8, 1/2, and 7/16 rims for 6 spline. They might been doing the farm equipement thing to make you buy all their options. Like IH and the fast hitch.

If you find a 7 spline drum, hang onto it.

 

[heimannm]

If you are in need of a 6 spline drum, or .404 sprocket to go with it I have a few of each.

Mark

 

[cbfarmall]

I would love to see .404-7 or a 3/8 rim to fit.

 

[ZeroJunk]

You are getting the spline count on the ID of the rim that is driven by the crankshaft confused with the tooth or pin count around the OD of the rim that drives the chain. The number of splines has no correlation to the speed (or 'gear') that the chain is running, only the OD (and hence the number of teeth or pins that can fit around the circumference) determines this. I am asking about the difference in the spline count.

So, you are thinking the 7 pin is no larger in diameter than the 6 ?

Doesn't have to be I suppose if one is .404 and the other .375.

 

[heimannm]

This is a 6 spline drum and .404 8T sprocket. Sorry Chris, all I have is a few more 8T .404 sprockets to fit those drums.



This is a 7 spline standard (alternately called large spline); the O.D. of the hub (not the splines) is 7/8".






Why did Homelite choose the 6 spline, why did McCulloch produce .354 chain & sprockets, and why did Sabre make .315 chain & sprockets (also used by Pioneer)? I suppose it was to create a captive market so folks had to come back to them for replacements.

Mark

 

[MudgeHollowBeaver]

So, you are thinking the 7 pin is no larger in diameter than the 6 ?

Doesn't have to be I suppose if one is .404 and the other .375.

Correct... the outer circumference of the drive rim and hence the number of pins EVENLY spaced around it will depend on the pitch or spacing of the driver teeth, ie : a 7T (tooth or pin) rim for .404 chain has to be larger in diameter than a 7T for a .325 pitch chain yet smaller in diameter compared to a 7T 1/2" pitch chain. As a result, for any rpm of the engine the chain speeds will also different between the different pitches of chain if the tooth count is the same. This discussion has shifted from the spline count that drives the rim to one of the tooth count that drives the chain...2 different topics.