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  1. #1
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    Default Help wanted. TIG weld repair to Waldown NH pulley.

    Hi all,

    I am afraid my own stupidity has caused me to break a piece of the motor pulley of a Waldown NH drilling machine. I really can't live knowing I broke it so I need it fixed even though there is probably not much of a problem leaving it as is.

    I am looking for someone to TIG it up and turn it back to shape for a reasonable price. For scale purposes the piece broken of is around 25mm long. The pulley is Aluminium and is machined all over.

    Here are the photos of it.IMG_20180505_135011.jpgIMG_20180505_135006.jpgIMG_20180505_134959.jpg

    Regards

  2. #2
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    With all due respect it would would be a complete waste of time

  3. #3
    BobL is offline Member: Blue and white apron brigade
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    purely for cosmetic purposes I would clean it really thoroughly and try some JBWeld epoxy on it. Ive used that stuff on big chainsaw that have super vibration and 11 year later its still there and doesn't even look like its close to coming off.

  4. #4
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    Quote Originally Posted by BobL View Post
    purely for cosmetic purposes I would clean it really thoroughly and try some JBWeld epoxy on it. Ive used that stuff on big chainsaw that have super vibration and 11 year later its still there and doesn't even look like its close to coming off.
    It is only for cosmetic purposes that I want this fixed. Unfortunately I still havent found the piece that I broke off. Do you think I can use JB weld to build a new bit of flange?

  5. #5
    BobL is offline Member: Blue and white apron brigade
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    Quote Originally Posted by lamestllama View Post
    It is only for cosmetic purposes that I want this fixed. Unfortunately I still havent found the piece that I broke off. Do you think I can use JB weld to build a new bit of flange?
    Yep, foully have to build up a sort of a dam with something it won't stick to like HDPE plastic - once hard it files and sand like hardish car body filler and you can even get some with Al power in it that will look a bit like the original. Just make sure you scrupulously clear the contact area.

    You will find it's not cheap.

    I did many a repair on chainsaws with this stuff, mainly on the out housings but this one is the only one I have before and after photos for.
    In amongst the corrosion were a dozen or so pin prick size holes in my chain saw oil tank that were probably caused by corrosion from the previous owner cutting a palm and leaving palm juice around the clutch.I could see then only by sticking a torch into the oil tank and looking on the outside in semi darkness.
    It was a horrible area to work with because it was so grubby but I followed the instructions bogged it up and repainted it and it has milled up at least 70 trees since.

    076repair2.jpg

  6. #6
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    Just concerned abut this pulley spinning around at 2800rpm it it likely to just fall off?

  7. #7
    BobL is offline Member: Blue and white apron brigade
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    Quote Originally Posted by lamestllama View Post
    Just concerned abut this pulley spinning around at 2800rpm it it likely to just fall off?
    Its unlikely but I guess it might?

    What do you estimate it will weigh?

    25mm long x 3 x 5 mm = 550 mm^3 with a density of about 2 g/cc or 0.002 g/mm^3 means it has a mass of about a gram.

    2800 rpm on a 150 mm pulley = 22 m/s so it will have a KE of quarter of a joule.
    By way of comparison air gun pellets weighing half a gram required a minimum velocity of 101 m/s to perforate skin, that's a KE of 2.6 J.
    Shop of projectile is important so it might be less.
    By way of another comparison ~ 0.75 J is needed to cause an eye injury but it will also be shape dependent

    Does the pulley have a cover?

  8. #8
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    Quote Originally Posted by BobL View Post
    You will find it's not cheap.
    It's normally less than $15 isn't it?

  9. #9
    BobL is offline Member: Blue and white apron brigade
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    Quote Originally Posted by Com_VC View Post
    It's normally less than $15 isn't it?
    It's been about 10 years since I bought the pro (10oz) pack and I think it cost me about $40
    I think I might have been comparing it to regular bog rather than other epoxy based products.

  10. #10
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    I bought some about 5 years back, I think maybe from masters when it was around. I still have plenty of it left. It does come in handy.

    https://www.ebay.com.au/itm/Jb-J-B-W...3ee5%7Ciid%3A1

  11. #11
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    isnt a flat belt drive rather that a V

    I'd just take off any sharp edges so edge of belt wont catch.
    wonder if balance will be a problem..probably not on drive pulley

  12. #12
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    Quote Originally Posted by eskimo View Post
    isnt a flat belt drive rather that a V

    I'd just take off any sharp edges so edge of belt wont catch.
    wonder if balance will be a problem..probably not on drive pulley
    It is indeed a flat belt.

  13. #13
    BobL is offline Member: Blue and white apron brigade
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    Quote Originally Posted by eskimo View Post
    isnt a flat belt drive rather that a V

    I'd just take off any sharp edges so edge of belt wont catch.
    wonder if balance will be a problem..probably not on drive pulley
    I doubt it would be a problem. If it was it would just be a matter of removing about a gram of material on the other size of the pulley.

  14. #14
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    Eric,

    The fairly shabby repair shown below ( directly above the belt in the centre of the photo ) on my Tough drill's motor pulley was executed several years ago using Devcon Plastic Steel. The section rebuilt is roughly 25mm x6mm. I drilled and tapped the broken edge radially and screwed in a pair of 1/16" machine screws before cutting off their heads. They act as barbs to encourage permanent attachment. Always overzealous, I used Loctite Retaining Compound to ensure the screws stayed put. I created a simple dam both sides of the pulley using masking tape to locate the epoxy.

    Devcon is a bit harder to sand and shape than body filler and as can be seen below, attention is required to avoid entrapped bubbles. When I filed and sanded the repair I made it slightly lower than the level of the original aluminium to avoid full contact with the belt.

    The Plastic Steel dries a very dark grey. Devcon make an aluminium putty which might be closer in colour to your pulley but I have not been able to find it in small quantities while searching online. JB Weld is probably its equivalent.

    Bob.

    IMG_20180507_150325922_LL (Large).jpg IMG_20180507_150431521 (Large).jpg

  15. #15
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    Default JB weld bodge.

    Just for completion for all those who posted. I couldn't let his pulley keep mocking me so I have found the two tiny missing pieces and used JB weld to stick it all back together. I don't really expect it to have the durability of a TIG weld repair but maybe I will be proven wrong.

    IMG_20180510_115525.jpgIMG_20180510_115531.jpg

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