Winch conversion from wire to chain sprocket

[thehomeengineer]

Every day is a school day. I really enjoy building projects like this, researching how others have overcome the same problems, what is commercially available and developing designing and improving something to try and meet my needs.

However doing this just highlights the void’s in my engineering knowledge. Like most projects starting from scratch can be quite daunting. Especially when it is your money you are spending and that little nagging thought in the back of your head (I hope I have got this right) Already on this project there has been mistakes that I have had to overcome. (Great feeling when you do solve them) but I thought I would share a mistake I did make which could have been expensive.

Awhile back I purchased a load of new old stock chain from an auction (only about 20 years ago, because one day that will come in handy for a project) There was quite a bit of chain and eight boxes of 3/8 Renold chain. (Useful size I must of thought, 20 years ago)

As previously mentioned I have purchased several new items for this project, one being two 3/8 pitch chain sprockets. When they arrived they looked right, correct part number etched on them, correct number of teeth etc. Now normally I would have tried the chain on the sprockets to make sure they fitted. Oh no! not this time, I will be clever and leave the chain in the sealed box so the chain doesn’t get dirty etc
Machined the sprocket to fit winch and put all back together, ready to go. Had a bit of a mockup and then the sealed box got the better of me and I had to try the chain on the sprockets.

photo below shows the dimensions of the pitch on the boxes
Clearly states 3/8 pitch

You guessed it the chain wouldn’t fit, so opened another sealed box same result. Oh dear either I have purchased some dodgy chain from auction and that’s why I got it cheap or the sprockets had to be incorrect.

On researching chain I didn’t realise British Standard chain is different to American Standard chain. Please forgive me if you all knew this but I didn’t. It turns out that 035 chain is American and 06B-1 is British. Both 3/8 pitch but other dimensions are so different.

In my defence I don’t often need to use chain drives for projects. In the past I have purchased chain and sprockets at the same time, so was unaware of the issues that I was about to face having this void in my knowledge.

Fortunately with in the lot I purchased (20years+ ago) there was a 10m length of Standard British chain to suit the sprockets I had purchased.

So next time I decide to use a chain drive with 3/8 pitch I need to purchase ASA sprockets which are readily available in the UK

hope this helps not to fall into the same trap as me