Mini-Dozer Track Research
The tracks on the mini-dozer have always been the weak point. Dad used a cast iron style link with attachment ears that he bolted some tire treads to. When it held together, it worked okay, but usually the cast iron links would break, and off would come the tracks. Because of this, it very rarely was used, and as a kid, it was always collecting dust. As a teenager, and after Dad had passed on, my brother and I got the track pieced back together with enough spare links, and got it working again for a bit. Unfortunately, the links broke again, and then we parked it. It has basically sat since then because of the weak track design.
Today as an adult, and after finishing the Miller Snow Dozer, I’d like to get Dad’s mini-dozer working again, and that starts with a new and improved track.
But first, let’s take a closer look at what is there for the existing track:
The links are 1.625″ long, ~3/4″ wide on the inside, the sprocket is 11″ in diameter. Hub to hub is 26″, with about +/-3″ of travel adjustment.
That calculates to a track length of 86″ +/-6″
Doing some interative math, 54 links at 1.625″ gives me a track length of 87.75″, and still allows room for stretch, and loosening to install or remove.
If you go to this link, you can see the information on the dozer from Struck.
In that the assembly manual, in the text on page 9, step 30, it says the chain is #550-K1 Medium duty or #550-K19 heavy duty.
So far I have had a heck of a time finding this chain. The problem is the attachment ears, as that is not very common. Some people say that this chain is used on bale conveyors, but what I’ve been able to find is that those chains are a stamped steel, that are not pinned together.
Images courtesy of Farm Chains
Not what I’m looking for!!!
Image courtesy of Farm Chains, CA550
Similar chain is CA550, but without the attachment ears. I do not want to just weld plates to the chain, as welding will weaken the links, and also damage the roller portion of it.
After doing a lot more digging, I found a good link at Practical Machinist Forum where someone is looking to solve a similar problem.
In there, someone posted a picture out of a catalog that had the correct looking chain, but the website link didn’t work. But at least I knew it was out there. Someone else mentioned another website for chain called US Tsubaki conveyor chain, and at their website I was finally able to find the correct chain, but no pricing. They also documented all of the correct nomenclature for the attachments, so now at least I had confirmation that the chain is available.
Here’s the main page for that series of chain.
From there I did some more looking, and found a website that makes this chain in China, and also had the correct image, but poor explanation on the attachment style vs nomenclature. By cross referencing to the Tsubaki website, I was able to look at the right one.
I have sent them a request for pricing, 2-2-15.
Some ideas I have for the final chain/growser/tread:
I can cut off plates of steel, 5/16″ thick, 1.625″ wide and 6″ long, and bolt them on.
Another idea I have is to get a tire that has the correct diameter, cut off the sidewalls, and bolt the steel chain on the inside, forming a heavy duty continuous rubber track. I like this idea the best so far.
From above, I calculated the length to be 87.75″, from which I calculated a tire diameter of 27″. From there, a person has to back calculate to come up with the actual tire size.
Tires are sized weirdly: for a 235/70/16, the 235 is the section width in millimeters, the percent of tire profile in percent, 70%, and the wheel diameter in Inches!
So for the example of 235/70/16, it’s (235*.70*2)/25.4 + 16 = 28.95″ in outside diameter. This is actually pretty close to what I need, as the inside of the tire diameter is what I actually want. This is dependent on the thickness of the rubber of the tire, so hard to know exactly. I will probably have to measure a few tires to find the actual one that works. Fortunately, junk tires are quite plentiful!!!!
I replaced tires on my truck this fall (Dec 2015), and those tires are 265/75/16 tires, which equates to a 31.65″ outside diameter. That works out to a outer circumference of 99.43″. Since these tires were off, I decided to measure the inside diameter to see what that was, and that came out to roughly 95″. So these tires are a strong contender and would lead to a slightly longer track, which would be just fine. I also have an older set of 245/75/16 tires that could also be used. Since they are truck tires, they also have a fairly aggressive tread pattern that would be good in snow.