How much play should a sprocket rim have ?

[JaIt]

I had the rim changed at a local shop and the new rim seems to have caused problems. When putting the bar and adjusting tension I can see the chain slightly getting looser and tighter as I move the chain on the bar with my hands. Maybe it was there before and this is probably normal to some extent but it's way worse... The new rim is a Carlton. This is for a Shindaiwa 488 by the way... After that I tried to get an original rim and the closest I could find was the replacement Echo part nr. 17511412530. I already mounted it (was a bit** to take out the clutch, hope I didnt f* it up...) and noticed this Echo rim has a lot of play sideways, much more than the Carlton. Sadly the shop already through away the original rim... So, does anyone know if the original rim had much play ? The only explanation to the problem I found here on some old threads was that some rims could be machined badly (uneven diameter) but even that seems awkward because it's too much...
I mean in my case even if there is too much play sideways the chain tension should keep it in place so don't think it's a problem (or maybe it is ??...).
Initially I thought there wasn't supposed to be any play at all, maybe not all 488's had rims of the same size ?
Or maybe the new Echo replacement rim is not the same as the original part ?
Thanks all.

 

[Bob Hedgecutter]

The clutch bell the new drive sprocket is driven by- could not also be worn could it?
Are you using the old chain in the new sprocket to see the chain getting looser and tighter?
What was the decision to replace the rim drive sprocket in the first place?

Old chain with marred/burred drivers is going to mash up a new sprocket in a hurry.

 

[Squareground3691]

Some of the rim sprockets have some casting from factory or is not concentric, or drum or bearing could be worn out .

 

[JaIt]

Thanks for replies. I just changed the rim, not the sprocket. The saw is in it's 4th chain (very low usage, bought around 2010), I don't think anything else is worn.
Yes, I'm using the old chain in the new rim.
I decided to change it because it was very worn out, but it was just the rim that was worn and replaced.
I still haven't cut with it, I just noticed the problem when putting the bar back on... Yep, old chain with new rim is probably bad idea....

I don't think the drum or bearing are worn out given the chainsaw is only on it's 4th chain, although to be honest the chainsaw was used pretty roughly a few times ...
I'm gonna try it out like this tomorrow, still haven't put the bar after putting the new Echo rim.... But I suspect it's gonna be worse! It has lots of play side wise. I'm not experienced with this so hopefully I'm wrong... Will report back soon... Cheers to all.

 

[J D]

A bit of play sideways (as in towards & away from the saw) is normal, it allows the rim to line up with the chain on the bar. Some rims are made slightly thinner/ thicker & will float more/ less accordingly.
The chain & rim wear together, generally the chain will wear to the rim moreso. I suspect your chain has adapted itself to your old well worn rim & is not quite the pitch it used to be. In most cases the rim & chain should be replaced together for that reason. Running your old chain on your new rim will cause both to wear faster than they should

 

[JaIt]

I did a cool experience. First, as expected I tried it out with everything the same except for the rim (old chain but with new Echo rim
replacement for the Shindaiwa 488, instead of new Carlton rim replacement). It's actually more or less the same. But now the experience... I took out the bar and chain and tried with a new bar and new chain. Now everythings new... These are even a different gauge that I had spare, it's an oregon power mach bar and matching 325 chain, both .050 gauge (the others are .058) ... With the bar hand tightened and the chain barely hanging the play is now much better, although the chain doesn't move as freely, probably needs some working out. But there is still a point where the chain clearly get more loose, although now it's a very narrow position. What I mean is that after I get to it and move forward it rightly gets back up, whereas as before I had to move it a bit more for it to return back to normal tension ... And it seems to be somewhat about the same number of teeth I move forward until it it happens again... Before it was much more extreme though...
So I guess the question is if this is normal or not, maybe it was allways there and I didn't notice, I don't think it's normal though...

 

[HarleyT]

Put up some pics.

 

[JaIt]

@HarleyT
I don't know why but I just got a terrible cold, I haven't been this sick in like 3 years, pun intended... I'll try to do it tomorrow...

 

[HarleyT]

Most times the issue is apparent, if we had some visual input. Your descriptions raise many questions about what you are describing. Whether your problem lies in excessive slop, or your problems are due to using a badly damaged stretched old chain on a new sprocket, or a bit of both, etc..

Some mismatching of rims to sprockets of differing brands is also possible, I am not familiar with Carlton sprockets.
Sprockets of certain brands have different spline sizes, Oregon has a page in their catalog that has a same size silhouette so you can put the old one on top to verify the splines are the same.
Or the problem may be something totally different, and be real apparent if only we could actually see what you are looking at.

 

[Philbert]

Could the bar nose sprocket be an issue?

Philbert

 

[IntegrityCarpentry]

So I have seen several saws with this problem and tonight I was having the same problem with my 272xp that I had recently put a whole sprocket set(bearings, clutch cover etc) on. The culprit was the sprocket. The clutch cover was out of round slightly but it was the sprocket that caused it. This was a new old stock set I had ordered off eBay thinking the quality would be better. The bearings were the main thing that was actually good sadly. Out 32$ but learned a lot in the process so I can more accurately diagnose problems.

Gabriel

 

[Duane(Pa)]

I have seen this issue many times. I blame it on poor QC and invariably move on..Rims are formed powdered metal and if the mold is off, the whole production run will be off. (not concentric) Sadly, if you want a 6 dollar rim, it's probably going to have a Chinese heritage. Did somebody say "sloppy"?

 

[IntegrityCarpentry]

I purposely ordered old oregon set. I am for sure now not going to chance chinese one. Oregon from several years ago is still good so for now it will be back on. This isn’t much of a difference but it’s enough. Only 2 of the pins were proper.

Gabriel

 

[IntegrityCarpentry]

I have seen this issue many times. I blame it on poor QC and invariably move on..Rims are formed powdered metal and if the mold is off, the whole production run will be off. (not concentric) Sadly, if you want a 6 dollar rim, it's probably going to have a Chinese heritage. Did somebody say "sloppy"?

What good brands have you found? I imagine oregon is typically good and I got one from a bad batch.

 

[singinwoodwackr]

Measure the ID of the rim and the OD of the sprocket. Is it possible that this saw has the same issue as the small mount Stihls? Stihl rims are 9mm and aftermarkets are 10…they are not compatible. Powermate, Carlton, Oregon…are all the same 10mm and will not work on the sm mount Stihls.

3 sm mount rims, 325/7