Sprocket wear - non motorcycle

[Northern Monkey]

This sprocket was made in 1927 by stuart kerr, and I'm working with a team who are rebuilding the something back to original spec.

Do you think that the wear on the teeth is acceptable, with a little file dressing, or does it look like it needs to be replaced.

I have the original drawings, but there is no indication of maximum allowable wear to remain in spec.

It's approximately 400mm diameter, and 35mm thick.

https://img.photobucket.com/albums/v284/geoffhill/9B4FDE04-0E1C-408D-906F-CDEB0EE67B88_zpshxgakwvl.jpg

https://img.photobucket.com/albums/v284/geoffhill/859FDF6E-6BA7-4992-8323-9119885C7D0F_zpsm0gtygf5.jpg

https://img.photobucket.com/albums/v284/geoffhill/64AD6C96-4FDA-4282-B9BF-1610D2A54779_zpsddtagd77.jpg

https://img.photobucket.com/albums/v284/geoffhill/B18418E2-28B1-4B6E-9B6A-96CB118717E6_zpsbfdnhizo.jpg
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Fisty: after polishing the tank with the glistenng beads of sweat from my full hot scrotum, I filled the headrace bearings with 10cc of my manmilk

[lihp]

Seen worse on JizzBunnies bikes
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covent.gardens: lihp is my most favourite member ever

[Northern Monkey]

One of the options it to build up the wear on the teeth with weld then re-machine, but I didn't want to use 'welding a sprocket' as the thread title
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Fisty: after polishing the tank with the glistenng beads of sweat from my full hot scrotum, I filled the headrace bearings with 10cc of my manmilk

[jimspeed]

The splines look pretty battered too.
What does it drive? If you have the drawings how does it compare to those ?
Interesting stuff I love old machines
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Hyosung cruise 125(passed test on, sold) Kawasaki el 252 (better than expected but sold on) Kawasaki GPZ500S first "big"bike.(sold) ZZR600 E5..Z750 2007,ER5, currently on a 2008 Enfield bullet electra x and loving it..
,"Alpha-9: Is there any correlation between dyno rod and dyno kits?"

[stinkwheel]

You may well find it's as easy to just get a new one.

They were using pretty standardised chain pitches in the 1920's and 30's. Bicycles were invariably on 3/32" or 1/8 x 1/2" pitch, just like modern bikes. Bigger chains were usually 5/8" x 3/8" or similar*.

I'd measure it up and see. You can probably buy a blank sprocket of the correct size and pitch, then it's just a case of milling the splines which, given you have the original to use as a template, should be a doddle for a competant machinist.

There's being original and then there's taking things to an extreme. You wouldn't run a model T ford on it's original tyres and brake linings. A sprocket is a wearable part, I assume you're not using the original chain if it was running on that sprocket. It's also the only one you have with the original spline dimensions.

My advice would be to keep that one for a reference template before it wears further or breaks (it's fairly pitted) and use a new one.

I also reckon it would come up nicely with electrolytic rust removal. But you will also see how badly pitted it is.

*5/8" x 3/8" is the same as the 530 chain fitted to most sports bikes.
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Northern Monkey]

Google Kerr Stewart 4415. It goes on the gearbox output spline. The drawings are very high res TIFFs, so I can email if you want
____________________
Fisty: after polishing the tank with the glistenng beads of sweat from my full hot scrotum, I filled the headrace bearings with 10cc of my manmilk

[stinkwheel]

Can I assume that sprocket is much, much bigger than it appears in the pictures then?

Usual BCF half-a-story shite strikes again.

Even so, look at the availability of commercial blank sprockets. Industrial drive chains and conveyors are constantly wearing out.

1" and 1 1/4" pitches are common.
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Vincent]

Wether or not it will keep a chain on will depend how long the chain is.....how much slack. I've seen sprockets on vintage machinery that are worn down to little more than a disc with a few bumps on but, as the chain was very short..still work, ie; the chain stays on and doesn't slip. If they don't spin very fast, and nobody is onboard, it's not as important as a motorcycle sprocket to keep in good shape. 'Course, it will wear the chain out quicker and probably make a racket but it'll still "work".

Talon should be able to make a new one up using the old as a pattern.....but it'll cost about £70.

This mob sell blanks:-

https://www.sprocketsunlimited.com/
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Space Is Deep

[Northern Monkey]

[Vincent]

[Vincent]

Is this what it drives?

https://i77.photobucket.com/albums/j71/Drewskovitch/Jap%2070s%20bike%20toys/Bike%20toys/Sprock_zps1j9bl4gy.jpg
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Space Is Deep

[stinkwheel]

[Northern Monkey]

[Northern Monkey]

https://img.photobucket.com/albums/v284/geoffhill/KS33272_Sprockets%20-%20Copy_zpszrnjkfm0.jpg
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Fisty: after polishing the tank with the glistenng beads of sweat from my full hot scrotum, I filled the headrace bearings with 10cc of my manmilk

[Northern Monkey]

Rather embarrassingly, the drawing clearly states 2 1/2 inch, not 2 inch
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Fisty: after polishing the tank with the glistenng beads of sweat from my full hot scrotum, I filled the headrace bearings with 10cc of my manmilk

[Kickstart]

Hi

The roughness on the teeth would worry me a bit more, from the wear that will do to the chain (and how rapidly they will wear away anyway). As mentioned earlier the splines look a bit worn as well.

However I think I would want to know the costs of making a new one.

All the best

Katy
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[MCN]

Sprocket is gubbed and not worth refitting.

An engineering shop can make a new one/two.
You need to find a specialist who cut gears and such.
If you speak to your local engineers they may know exactly who can do it.

I had to make a double helix hypoid-esq pinion and crown set for a 1960s 120HP 90º drive one day.

There were only two places in Europe who could cut them as the design was American and there weren't may places in Europe made American gears.

I had originally asked my engineering mates and it was them who sorted it all out.
I think the job cost about £20k but there were NO new parts and NO 2nd hand stuff and a big rig was stood doing nothing waiting for a 90º drive.

As far as Restoration Projects go:
It may not be cheap but it will be worth it.
The bastirt is 'always' in the detail.
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Disclaimer: The comments above may be predicted text and not necessarily the opinion of MCN.

[Pete.]

IF I had to get that made I'd elect to waterjet the profile then turn the taper on the teeth and hand-finish the splines. Might even be able to laser 1 3/8" plate nowadays.
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a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[Northern Monkey]

Looks like the chain is fairly standard stuff. It's ISO r606 40b1 63.5mm simplex chain. Which is just off the shelf, but for more than £1000 per 5m length

https://www.hoyertransmissions.com/?id=30208&show_product=1&action=detail&pid=0600401000

If the chain is off the shelf stuff, then getting a 13tooth sprocket should be fairly simple, and I can just machine the centre aperture and splines on the mill
____________________
Fisty: after polishing the tank with the glistenng beads of sweat from my full hot scrotum, I filled the headrace bearings with 10cc of my manmilk