Snow Trac replacement BRONZE drive sprockets

[Bombi1]

I now have patterns for both types of ST4 sprockets.
Have been in contact with two foundries for cost estimates.
One wants around $300 and the other is about $350.
Those quotes are based on a set of four.
Larger quantity may bring it down some, but probably not much.
The foundries are in the Seattle area.


I am going to check with some others to see if they can do better.

I reread this post.
Want to clarify that the prices they are giving me, is per sprocket.

Got one more quote and it was even more.
Hope to get a pretty firm cost soon.

 

[redsqwrl]

With a line on new sprockets, I decided to stress my poly sprockets to failure.
These are hand built (with a router) they have many moose hunts on them and much summer/ all season running in sand and heavy clay and rocks.

this is my parts machine, and purist please restrain from giving me the berries. I needed to blow a little steam off and it was just the sno tracs turn...

Enjoy, I did, the high pitched whine is being addressed next... that is the cooling fan trying to move air at 5600 to 6400 RPM.

Stock gearing, 1600 Dual port off of craigs list. I show this machine no love what so ever. the working speedometer says 19- 20 MPH

https://www.youtube.com/watch?v=uLzbV1JKZRw

 

[300 H and H]

Nice job of driving, you hit nothing!!

Just like last year, there is much more snow in my neighborhood than you have...

Those poly gears are quiet, and do last a long time. Maybe not as long as the bronze alloy, but still good life..

Not to mention the price is right!!!

Regards, Kirk

 

[redsqwrl]

the photo above is what I was trying to fail. I had read the Sprocket thread in great detail trying to get my head around the various comments about shrinkage, width and thickness ect.. yet every time I run this cat I look at those hammered sprockets and think to myself... ( well you are going to be walking one of these times) so I pulled the sprocket off the machine over the weekend to see what and how the magic works. I found this. One guide that was getting eaten by a bolt. if you look up one post you can see the ends of the bolts unmolested.

I cut the excess bolt length off with a Blue wheel, and then ran it hard to see if the replaced guide had any gouging. I am happy to report the guide is fine.

With 6" of fresh snow today, I will schedule another test session and resume the flogging.... this time with a full tank of gas.

these plastic sprockets are just 1/2 in thick poly, with small spacer/ guide blocks behind them to center them in the hub. drum. Just trying to harbor some low level knowledge into this thread to help archive the experience for future keepers of these ST-4'S

 

[JimVT]

your boggies should show sings of that guide.

 

[redsqwrl]

your boggies should show sings of that guide.

that is exactly my thought. If you peek at the bogie you can see in the photo there isn't a mark in it. I found it oddly surprising that the timing of the bolt only hit the one guide.

Coachloafer to the rescue again.

 

[Kristi Kt-4]

Wowzers, I think that you will win the drifting competition... I think you thought it was a rally car! I did like the video though. A Tucker is not meant for speed and a Kt-4 might do a barrel roll if I tried that. A Kt-3 would give you a run for your money but mine is currently trackless. So.... it looks like you win

With a line on new sprockets, I decided to stress my poly sprockets to failure.
These are hand built (with a router) they have many moose hunts on them and much summer/ all season running in sand and heavy clay and rocks.

this is my parts machine, and purist please restrain from giving me the berries. I needed to blow a little steam off and it was just the sno tracs turn...

Enjoy, I did, the high pitched whine is being addressed next... that is the cooling fan trying to move air at 5600 to 6400 RPM.

Stock gearing, 1600 Dual port off of craigs list. I show this machine no love what so ever. the working speedometer says 19- 20 MPH

https://www.youtube.com/watch?v=uLzbV1JKZRw

 

[utahwilson]

agree on the drifting. I didn't know they went that fast.

 

[Snowtrac Nome]

not hard I drift through the streets of nome all the time I should video it some time things get real exiting when drifting the 2100

 

[mbsieg]

not hard I drift through the streets of nome all the time I should video it some time things get real exiting when drifting the 2100

I can see the headlines for the new movie now!! "The fast and the furious 23" NOME DRIFT!!!! All you can Handle at 8mph!!!! Vin Diesel in his newest hit ever!!!

 

[Snowtrac Nome]

it may only be 8 mph in the 2100 but those j grousers are like ice skates when on ice. its not Vin Diesel, its Ford Dorset diesel

 

[redsqwrl]

Any news on the WA sprocket process?

the WI process is under way.

I will be pulling a copy sprocket soon. Ill post here if I have success.

 

[Bombi1]

My foundry has both patterns and is going to make one of each. Am expecting to hear from him any day. They have been very busy, so it has taken longer than expected.

 

[redsqwrl]

Copy ST 30A sprocket was pulled Monday.

pattern maker corrected it for shrinkage in both the tabs and ears Tuesday.

Just got a call that 5 will be poured today.
Five more on Monday.

(these are the TWO BAND Sprockets)

if you in a bind send me a note. Ever since the Dairy queen run, My poly sprockets are skipping steady now on the right side. I could not wait. I need to use the machine to pull Ice houses off the lake.

Sturgeon spearing ends Sunday, fish houses have to be pulled off before 3/2

I got one yesterday, our warm weather and warm water temps are eating the ice from both sides.

 

[300 H and H]

So what did this years fish weigh?

Glad you got those sprockets getting poured. Just remember where you got the one you made the pattern from!!

Can't wait to see how they turn out.

Regards, Kirk

 

[Bombi1]

Finally got a sample of both sprockets cast. They turned out good.
Have a picture but could not figure out how to post it here.
Anyone interested in a set can PM me and I can email the picture
and we can go from there.

Thanks
John

 

[SnowTrac Hunter]

300 H&H had posted dimensions previously for sprockets. Neils sent me an STP file which I could open with Wedge, but without having a compatible version of AutoCAD I couldn't dimension.

The dimensions that were posted in this thread were slightly incorrect, so I am trying to correct per layout. I am going to try and make a weekend trip to verify. Three hour drive and couple mile hike in to cabin. The dimensions below are what I have come up with so far. Please feel free to correct me if I am off base.

Outer Tooth Diameter - 17-1/4" (17.25")
Outer Tooth Radius - 8-5/8" (8.625")

Base Diameter - 15-3/8" (15.375")
Base Radius - 7-11/16" (7.6875")

Tooth Degrees - 90*, 77.1428571*, 51.4285714*, 25.7142857

Circle Circumference - 54.19247"
Tooth Center to Tooth Center - 3-7/8" minus (3.8708")(14 Teeth)
Tooth Tip Width - 1" (Need to Verify)
Space at Base - 1-1/2" (Need to Verify, May need to be 2" for grouser which would take out slope)

Thickness - 1/2" to 1" UHMW depending on model.

Hope this is helpful. I have an older two band model. I would like to start out with 1/2" and see if it is durable enough before I modify my sprocket to fit thicker UHMW. Prices of UHMW vary depending on location. I purchased a piece of 18" x 10' for $350 in Anchorage, Alaska. You may be able to find cheaper in the Lower 48.

Thanks,
Joe

 

[SnowTrac Hunter]

Dimensions will need to be modified from what was posted -

Tooth Width - 3/4"
Tooth Space at lower radius - 1-7/8"
Mounting Hole radius - 5-7/8"
Mounting Hole Size - 1/2" for 3/8" bolt
Inner Hole Radius - 5-1/8" (10-1/4" Diameter)

Will update picture of template when finished modifying for new dimensions.

Thanks for your patience,
Joe

 

[Cidertom]

Finally got a sample of both sprockets cast. They turned out good.
Have a picture but could not figure out how to post it here.
Anyone interested in a set can PM me and I can email the picture
and we can go from there.

Thanks
John

Back on the trail of sprockets. Are these a send check, get sprocket item or still a one-by-one prototype?

Or who has >right now< st50/52 3 band sprockets for sale or short turn around time.

CT

 

[Cidertom]

bump.

 

[Bombi1]

PM sent

 

[Cidertom]

New sprockets arrived to replace the slightly worn ones.

It appears the previous owner(s) never flipped them.

Thank you Bombi1

 

[DAVENET]

Holy cow. Actually seeing a new one of those has been a long time coming.

 

[300 H and H]

Yes it has. Some are being made out of UHMW plastic as well. They probably will not last as long, but will be quiet and easy on the grousers in the track.

Regards, Kirk

 

[Cidertom]

I really thought about using UHMW plastic. If I had the older type, I probably would have gone that way. I just didn't like the long unsupported spokes of the ST52. Thought about doing a hybrid, metal core and using the older style for the drive part. Then thought my time would be better spent drinking beer, and not re-inventing the drive wheel.

 

[JimVT]

The bolt pattern very on the st4 and I'm curious if you need to redrill them.

 

[Cidertom]

They have no holes as yet. Going to clamp the old to new and bore them.

 

[Beartooth]

Are the ST-30a two band being produced. I have two machines and would put UHMP on one and bronze on other for a test. Either way I need them.

Doug

 

[Cidertom]

send a PM to bombi1, but he may be slow to respond due to mother nature.

 

[Cidertom]

Got time to drill and mount the new sprockets. They are thicker than the old ones. Not enough to be an issue though. But the nylocks barely have enough stud. Going to go through the mounts this weekend and check bearings etc.