Beepbeep Posted April 3, 2022 Author Posted April 3, 2022 22 hours ago, Tomek said: Hello. Hardening is not the best solution - the gears cannot be too hard because then the tracks will wear out and they are more difficult to repair. I have to have a proper hardness check of the gears and track plates to choose the right hardness of the new gears Yes, I read that recently, that the teeth should be hardened but to a lower level than the grousers. Procedure as follows - ‘Flame harden contact surfaces of teeth 1/16” deep to Shore Hardness 70 minimum. Heat to 843 degrees Celsius - quench in oil - draw to Brinnel Hardness 241-269/Rockwell Hardness C 24-27. Hope this makes sense and that it helps. It doesn’t mean much to me but I’m going to go to my local machine shop and see what they say Chris 1 Quote
M29C3284 Posted April 4, 2022 Posted April 4, 2022 (edited) The track drive lugs are hardened to Brinell hardness 534-601, so about twice as hard as the drive sprocket teeth. Edited April 5, 2022 by M29C3284 2 Quote
Beepbeep Posted April 4, 2022 Author Posted April 4, 2022 2 hours ago, M29C3284 said: The track drive lugs are hardened to Brinell hardness 534-601, so about twice as hard as the drive sprocket teeth. Wow, that’s interesting! Thank you for that Chris Quote
Beepbeep Posted April 9, 2022 Author Posted April 9, 2022 Well I've solved my problem, I hope! I couldn't find anyone that flame hardens but I found a local company that will carburise the sprockets to the hardness that I want and at a very reasonable price, so reasonable that I wonder why the manufacturer doesn't harden them as standard. 1 Quote
Patrick Tipton Posted April 10, 2022 Posted April 10, 2022 7 hours ago, Beepbeep said: Well I've solved my problem, I hope! I couldn't find anyone that flame hardens but I found a local company that will carburise the sprockets to the hardness that I want and at a very reasonable price, so reasonable that I wonder why the manufacturer doesn't harden them as standard. They should - mine are wearing badly! Quote
Beepbeep Posted April 10, 2022 Author Posted April 10, 2022 15 hours ago, Patrick Tipton said: They should - mine are wearing badly! @Patrick Tipton That's really bad and from what I've learned now there's no excuse for it. I went to two local hard facing companies and they both told me that the factory spec really isn't very hard and that there's steel plate available that has a compatible hardness, think it might have been EN31 but I'm not sure. I checked Accu-Rite's listing and our sprockets are made from hot rolled mild steel and when I checked it has a hardness rating half of the factory spec! I was also told that there are welding rods available with various hardness ratings so in theory it may be possible to repair the sprocket teeth. Weasel ownership really is a learning curve isn't it? 1 Quote
Patrick Tipton Posted April 10, 2022 Posted April 10, 2022 3 hours ago, Beepbeep said: @Patrick TiptonI was also told that there are welding rods available with various hardness ratings so in theory it may be possible to repair the sprocket teeth. Weasel ownership really is a learning curve isn't it? Indeed - a big learning curve. One of the reasons I started the site and really appreciate folks who take the time to share what they are doing - like you! Hopefully we don't all have to make the same mistakes. There is definitely hard facing arc welding rod that people use to resurface anvils and the like. My new sprockets are wearing enough that I am going to need to build up the teeth again. Not that big of a deal....weld then and shape them, but we should not be having to do this! I could have done the same thing with the original sprockets and saved myself $800 and a bunch of time drilling out rivets! Oh well....onward! 1 Quote
Beepbeep Posted April 12, 2022 Author Posted April 12, 2022 On 4/10/2022 at 10:50 PM, Patrick Tipton said: I could have done the same thing with the original sprockets and saved myself $800 and a bunch of time drilling out rivets! My thoughts exactly! An update, my sprockets have worked out a little more costly to be hardened than I thought due to the way they price these jobs. They're priced on weight so you pay to treat the whole piece but I didn't want the rear faces hardened in case they damage the track guides so there was an extra charge added for coating the areas you don't want hardened! It wasn't very much though and the four of them have still come in under £140 so not too bad. 1 Quote
Patrick Tipton Posted April 13, 2022 Posted April 13, 2022 19 hours ago, Beepbeep said: It wasn't very much though and the four of them have still come in under £140 so not too bad. Not bad....I will have hours in the repairs and even though my shop rate is cheap 😂....I bet it takes me 4-6 hours to fix these things. Learning process! P.S. I broke a grouser playing hard with the Weasel yesterday. So....time to really step up the game on the French track repair. I took another 12 grousers apart...35 to go....8 x 55 holes to drill....X 2...so 880 holes plus bolts, washers and nuts..... Quote
Beepbeep Posted April 13, 2022 Author Posted April 13, 2022 5 hours ago, Patrick Tipton said: I took another 12 grousers apart...35 to go....8 x 55 holes to drill....X 2...so 880 holes plus bolts, washers and nuts..... Oh wow! I don't envy you that job Quote
42rocker Posted April 14, 2022 Posted April 14, 2022 Took two complete tracks apart last Nov/Dec. It's a pain. Harder to remove the rubber so you can recycle the steel chain pieces. Ending up with 300 pounds of steel scrap. Wow at 10 cents a pound (it's up) $30.00. Not worth it but. Patrick Good Luck Stay Safe Everyone Later 42rocker 2 Quote
Patrick Tipton Posted April 14, 2022 Posted April 14, 2022 @42rocker You are a better man than I recycling that stuff. I can't do it. I am going to have these guys apart by tomorrow and then its time to start making a jig and drilling holes in rubber. Wooo Hooo!😂 But since I broke a grouser a couple of days ago, I can either remove a track, repair a grouser and reinstall the track....or I can push and finish this set and install them.......seems like the better plan. Cheers! 1 Quote
42rocker Posted April 17, 2022 Posted April 17, 2022 Not long ago I started grinding apart another set of tracks (Thanks again Patrick for that back up set). So, Thursday started pulling the cut bolt heads from the bands. In this tracks cases the best part is belting that can be used on another set. Like I said to you grinding and cutting the nuts off, I believe is the fastest way to get French style track apart. As I recall less time than using a 18mm socket and 19.5 inch long 1/2inch drive rachet. No matter, how you do it ---- it's a PAIN!!!! Stay Safe Everyone. 2 Quote
Beepbeep Posted April 23, 2022 Author Posted April 23, 2022 On 9/15/2021 at 6:38 AM, OZM29C said: @Beepbeep Your sprocket teeth look decidedly worn. I have got a drawing somewhere at home that shows the correct tooth profile but as a comparison, attached is a photo of my LAR sprockets and you can see the difference in the teeth when compared to yours. Unfortunately LAR don't make this sprocket any more. @OZM29C did you find the original tooth profile? I'm thinking of getting my old sprockets repaired and it would be good to know what profile I'm aiming for Quote
OZM29C Posted April 24, 2022 Posted April 24, 2022 9 hours ago, Beepbeep said: @OZM29C did you find the original tooth profile? I'm thinking of getting my old sprockets repaired and it would be good to know what profile I'm aiming for @BeepbeepI did indeed. I can scan it for you on Tuesday. I will have to use my scanner at work as the drawing is way bigger than my A4 sized scanner here at home. 1 1 Quote
OZM29C Posted April 28, 2022 Posted April 28, 2022 (edited) @Beepbeep@42rocker As promised, please find attached a scan of the Norwegian track sprocket drawing. I must apologise in having to scan the drawing over two pages. It was just too big for my A3 sized scanner. All of the dimensions are in metric but having said that if you need to convert back to the old imperial units (albeit decimal units) then divide the metric dimension by 25.4. 25.4mm = 1 inch. Cheers. Sprocket Page One.pdf Sprocket Page Two.pdf Edited April 28, 2022 by OZM29C Correct a typo. Changed multiply to divide 1 2 Quote
42rocker Posted April 29, 2022 Posted April 29, 2022 I also say THANK YOU for sharing. Stay Safe Everyone. Later 42rocker 1 Quote
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