Getting serious about lo-pro

[mtngun]

Here is the 404 x 8 cut down to fit lo-pro. Every drive link meshes perfectly. Not much meat left on this ported rim, though

I experimented with annealing and then re-heat treating this 8 pin rim. That didn't go well. It only partially annealled. The machining operation still chewed up the carbide bit.

Then I heated to 1660 F and quenched it in oil. It doesn't seem that hard, I can still cut it with a file.

Hmmmm..... I may try again with a higher temperature.

Meanwhile, this is good enough to test for speed and driver peening.

 

[Brmorgan]

I'll be making an 8 pin rim this week, but my guess is that the 066 won't pull it well.

Mine will pull it OK on an 8 in up to ~16-18" Douglas Fir. I don't file quite as aggressively in that case though, and it's a bit touchier to control in general. Do-able though.

 

[Mad Professor]

BTW, the Logosol spur is a Stihl part, #1122-640-2006. I dunno if you can order it at your Stihl dealer or how the Stihl price compares to the Logosol price.


[.

Picco spur is not available in the USA from Stihl dealers, I had a good friend/dealer check

Maybe we could get Saw Troll to ship us a box full?

P.S. you can adapt an early 036 rim clutch to fit an 066 , but you'll be running the wimpy small clutch bearing.

Andy/Lakeside described this a couple of years ago.

 

[BobL]

The surface finish of the part looks plenty nice.

Annealing will cause more problems than it solves. These things look like investment castings and there's no telling what they are made of - how could you re-harden and know what you will get?

I agree, these type of materials probably need to be re-annealed and hardened in low Oxygen atmosphere so the metallurgy is probably screwed up no end by a regular annealing and hardening process

Good luck with this and thanks for sharing the project.

+1

I don't think a 404 turn down is the way to go. Looking at you turned down 404 I can see one major flat spot plus a couple of others.

I've used the lo-pro and standard 3/8 sprocket on the 441 for 3 small logs and have not see the problem of drive peening you describe, could it be the 660 just has too much grunt for the 050 drivers?

 

[mtngun]

Looking at you turned down 404 I can see one major flat spot plus a couple of others.

The mandrel used to hold the rims on the lathe is a very tight fit, the rims sometimes have to be tapped on and off the mandrel with a hammer. The flat spots you see are where I tapped the rim with the hammer. The rim is paper thin in that spot, and the half-annealed metal bends easily.

The flat spot should not effect function since the spokes do all the work, similar to a spur sprocket.

The 404 rims haven't been tested yet, though. Just as I was setting up to do a trial run, my chain adjuster snapped, and then it has snowed every day for over a week. Pic taken this morning.

I've used the lo-pro and standard 3/8 sprocket on the 441 for 3 small logs and have not see the problem of drive peening you describe, could it be the 660 just has too much grunt for the 050 drivers?

Have you actually measured your drive links ? When you get back to Oz, please take a close look at them.

Stihl sells 660's set up with 3/8 x 0.050" chain, so you wouldn't think the narrow gage would be an issue.

Thanks for your input. Keep me posted on your experiences with lo-pro.

 

[Brmorgan]

OK, tomorrow if I get time I'm going to grab my digital caliper and macro lens and take some pics and measurements of various chains, including non-LP because I'm sure I've seen more than a couple non-LP chains peened over noticeably. I always thought it was a normal part of chain wear.

 

[Brmorgan]

I took some pics and measurements of a few chains today.

First off is my old, original LP milling chain. Imagine my complete surprise when it turned out to be Stihl Picco upon further inspection! I'd never really looked closely at it before; I always thought it was Oregon for some reason. Either way, this is what it looks like:

There is some obvious mushrooming, but only on some of the drivers. Probably half are seemingly unaffected, and half of the rest not as badly as the ones in those photos. Even still, they measured between .053 - .055 at their worst. The backsides were measuring a perfect .050 with my caliper, so I know it was accurate. I'd estimate this chain has probably cut between 2000-3000 square feet of softwood. A lot of that was with severely insufficient oil too, when my old 066's oiler wasn't working properly last year.

Here's the Carlton LP milling chain I got back in February. It's only got a handful of short passes in Pine and Juniper on it; probably about as much cutting as the LP chain you started out with here.

It's started to show some minor wear on the front of the drivers; most still measure a perfect .050" though, with some hitting .051" and a couple at .052.

I don't have any pictures of the Oregon 91VX I got at the same time as the Carlton. It's seen a lot more use though, milling up a couple big Douglas Fir logs along with a bunch of Cedar and some small random Birch. Not sure if it would matter, but it's been used exclusively on a 7-pin rim, while the Stihl Picco chain above was used almost entirely with an 8-pin. I say almost because I can't remember running it with a 7, but the probability exists that I did try it at some point back then.

Just for a comparison, here's my first ever milling chain, an Oregon 73 3/8" .063" semi-chisel - sorry, I can't keep Oregon's lettering scheme straight so I don't know what its designation is.

It's peened about as much as the Carlton, many show no wear and a few are only minor. Its drivers are a lot heavier to begin with though, so I would expect that. This chain has cut probably 2/3 the square footage of the Stihl LP chain, albeit while working a lot harder since this is a 33" chain used for the wider stuff.

 

[mtngun]

Thanks for the update on your LP chains, Brmorgan. I appreciate it so much that I even forgive you for the wide images.

It sounds like you are saying that you observe some peening on some of your LP chains, but it's not nearly as severe or as universal as the peening on my LP chains ?

I enhanced a couple of your photos. These two drivers look just like mine, except you only had a few damaged drivers, whereas the majority of my drivers were severely dinged.

The question is, why does my 066 seem to ding drivers more than your 066 ?

I haven't ruled out the nose sprocket. It seems to fit well after the mod, and even if it didn't fit well, IN THEORY there should be very little stress on the chain at the nose sprocket, since it is just an idler.

Not much more I can do until the replacement chain adjuster shows up and LP testing resumes.

 

[Brmorgan]

Thanks for the update on your LP chains, Brmorgan. I appreciate it so much that I even forgive you for the wide images.

It sounds like you are saying that you observe some peening on some of your LP chains, but it's not nearly as severe or as universal as the peening on my LP chains ?

I enhanced a couple of your photos. These two drivers look just like mine, except you only had a few damaged drivers, whereas the majority of my drivers were severely dinged.

The question is, why does my 066 seem to ding drivers more than your 066 ?

I haven't ruled out the nose sprocket. It seems to fit well after the mod, and even if it didn't fit well, IN THEORY there should be very little stress on the chain at the nose sprocket, since it is just an idler.

Not much more I can do until the replacement chain adjuster shows up and LP testing resumes.

That's another reason I'm interested to compare the Oregon chain that's presently mounted on the 066 & mill. It's been used exclusively with the brand-new 25" bar I bought a couple months back, whereas the Stihl chain above was used only with the old 25" that was originally on the $25 041AV I bought two years ago, and is pretty much worn out. It'll take an .063 chain now with no problems. The its nose sprocket was worn to where even an LP chain would sit down pretty tight on the nose of the bar; I believe I already posted a picture once of the LP riding pretty high on the new bar's nose sprocket, like 1/8" away from the rails or more at the tip.

 

[mtngun]

P.S. you can adapt an early 036 rim clutch to fit an 066 , but you'll be running the wimpy small clutch bearing.

Andy/Lakeside described this a couple of years ago.

You must have a good memory.

From 2007:

Sure you can put the small bearing and drum on a later 036/360 but you'd have to be nutz, or trying to dump one on ebay.

oh.. you think you have a real reason.. sorry.. first problem is finding a decent old drum... They are no longer made.

 

[Mad Professor]

You must have a good memory.

From 2007:

I'm pretty sure you can still get the small bearing clutch parts for 034/early 036 that have never been up graded to to newer 036 clutch.

My 036 IPL lists the parts but it's an older PDF.

I'll check next time I'm at the dealer.

Also will compare an early 036 clutch to see if indeed it could be made to fit my 066. If it does, I'd be checking/greasing the bearing every couple of tankfuls until I determined it would hold up.

 

[Mad Professor]

Also found this one, another lakeside post:

http://www.arboristsite.com/showthread.php?t=58691&highlight=036+clutch+066

As you might now know, the 361 drum is in fact an 044/440 drum... and the depth IS different to an 034/036/360/029/039 (yep) etc. If you put the deep drum on a 361/044 etc you'll trash the oil pump/drive.


So.. yes, you can turn the 036 drum down (and re-notch) to fit a 361/044 etc. I've down that on similar drums before. Check the depth of the bearing support depth - you might need to skim that down from the inside also.


The bearing will not last. Check it and grease often... and try to find the steel cased version - not the plastic.

The orginal PDF on the 036 change is enclosed.

 

[mtngun]

Parts arrived for the 066 chain adjuster. Let the tests resume.

A small pine log that has been sitting in my pile for a couple of years. It's punky and checked, but I may be able to get some shelving boards out of it. 066 is set up with the modded 404x7 rim and my oldest lo-pro chain.

Purty blue stained ponderosa pine.

Slabbed a 2nd pine log, producing 8 slabs total.

The bar never got hot like it used to do when it was running peened drivers.

The chain continued to cut well so I never stopped to sharpen it.

The chain never sagged, so I never stopped to adjust the chain tension. At the end of the day, the chain tension was still perfect.

Then I measured the drive links. Most were 0.049" - 0.051", without a hint of peening. I did find one that was 0.053", and the one right next to it was 0.056". Not sure what was up with those two -- it's possible that I missed them when I was filing the damaged links.

I'll continue to use the modded 404 rim and continue to monitor the drive links, but right now it's looking like the modded rim fixes the peening problem.

Next step is to get out in the woods and puts some hours on the lo-pro and just see how it holds up.

Also, I'll keep trying to find a production-worthy method to turn the 404 rims on a lathe, but I'm not optimistic -- I'm afraid that any bit that's hard enough to cut the rim material will shatter when it gets hammered by the rim's spokes. A tool and cutter grinder would be ideal way to mod the rims, but I don't have one.

.

 

[huskyhank]

I think a tool post grinder will do it, even a homemade one like a die grinder clamped to the tool post. Or I bet you could send a couple dozen off to any grinding shop. How much are you reducing the diameter?

 

[mtngun]

I think a tool post grinder will do it, even a homemade one like a die grinder clamped to the tool post. Or I bet you could send a couple dozen off to any grinding shop. How much are you reducing the diameter?

A 7 pin 404 starts out at 1.521" OD and gets turned down to 1.435", a 0.086" reduction.

A tool post grinder could do it, but it would be very slow. I would guess something like 15 - 30 minutes per rim. And nobody likes to run a tool post grinder on their lathe. I sure don't.

My point being, if I had an easy, cost-effective way to mod the rims, I'd be glad to make them available to other CSM'ers. But, if it is something that requires a significant investment for outsourcing or equipment, then it's not in the cards.

I haven't giving up on annealing yet. I'll try one more time, at a higher temperature.

I'll probably try some cermet bits, too, but I'm afraid they'll chip or shatter when they get pounded by the spokes.

 

[Brmorgan]

I'll ask my neighbor, who is the head machinist/fabricator at the big plywood mill here. He might have an idea or two; he's done some pretty bang-up work for me in the past. I think I have a spare old .404-7 rim somewhere that I could give him to play with.

Regarding the annealing, you may want to talk to fellow member TeddyScout, since he had a bunch of custom geardrive sprockets made for his 090G and 041G a while back. I do remember some discussion about heating/hardening etc., but not being a real metalhead myself (yet) a lot of it goes over my head.

 

[mtngun]

Just got some good info from -- who else ? -- Lakeside53.

Stihl rims are actually made by Oregon.

Oregon makes the rims using the metal injection molding (MIM) process. It's basically a form of sintered powdered metal.

Sintered powdered metal can be just about anything. It's not limited to conventional alloys. For example, they may blend in things like powdered tungsten or powdered cobalt to improve hardness and wear resistance.

So -- knowing that, I think the annealing and heat treating option is out, since the rim is probably not a conventional tool steel that will respond to annealing and heat treating in a predictable manner.

I'm working on the cermet option now. Probably buy a few cheap cermet bits off the 'bay and give them a whirl. No guarantees.

 

[Brmorgan]

Yes, I do remember something about them being sintered. The word doesn't mean anything to me though other than that it's :censored: hard!

I know an angle grinder will chew away at a rim... Kinda inaccurate though!

 

[BobL]

Yes, I do remember something about them being sintered. The word doesn't mean anything to me though other than that it's :censored: hard!

I know an angle grinder will chew away at a rim... Kinda inaccurate though!

If they are sintered than means they are made from a metallic powder that is heated that fuses the powder together. If that is the case the they cannot be tempered in the conventional fashion

 

[Kicker_92]

I know an angle grinder will chew away at a rim... Kinda inaccurate though!

An angle grinder used while the part is spinning on a lathe can produce some surpringly accurate results. Just remember to measure often and use the finest flap sanding pad you can find..