New Ratrac-S owner

Sisu said:

I was very lucky on last Friday receiving a call from a friend. He told he's standing next to a Ratrac snowcat that can be bought very cheaply. It has wide tracks which I could be interested of.
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Looks like the Ratrac version of a Thiokol 2100.

The sheetmetal forward of the cab looks almost exactly like that of a Ford model 3000 farm tractor from the late sixties/seventies.

It looks like you got a steal!

Uh, haven't had much time for this project but tested the engine works... Guess I have to activate this topic and re-post the photos as I changed the photo hosting company some time ago.

If someone is interested, check youtube I never tested it works, but after two years of standing... what a great surprise!
[ame="http://www.youtube.com/watch?v=vSPLBx96qLA"]YouTube- 1967 Ratrac Sprite (Thiokol Spryte) snowcat first start[/ame]
[ame="http://www.youtube.com/watch?v=YiyCrkTsWHs"]YouTube- 1967 Ratrac Sprite (Thiokol Spryte) snowcat first start, testing the drive system[/ame]
(Sorry about the quality, I was rather interested to see it starts than making a great film

The spare snowcat (which looks like Thiokol 2100) is now disassembled to a state where I have to choose whether I rather build the Sprite on its chassis or move the stronger axle (OC12) and gearbox from 2100 to Sprite. The difference between the chassis is only about 1-2", but in the 2100 its in much better condition. Anyway, the outcome will be wide-track version

Ok guys - long time no see,
I want your expert opinions before I start cutting metal I've been playing a little bit with the CAD and I'm about to start the project seriously. I have finished almost all my other projects so time is right.

I'm going to rebuild the Sprite on the spare Ratrac ST -chassis I bought/showed previously. Unfortunately I have changed my photo storage provider so all the previous photos have vanished... Too bad it makes this thread look really bad, sorry about that.

On the spare chassis I will build a new body, due the dimensions of the Ratrac ST the "new" Sprite will be 22" longer, making it a total of 161,5" long. The new aluminium tracks from Ratrac ST are much wider than the originals, 57" per each, this will give a total width of 135,8" for the vehicle.

Bad news, I found a crack from the casting of the OC-12 right side drop box (goes around the part), so I've got to repair that one too or find a new one. I suspect the C-4 drop boxes are different, didn't measure yet.

But, I'm going to loose the open bed and instead fabricate a fully closed cabin. The extra lenght should give ample space for fishing gear etc. - my actual plan is to use the snowcat on ice fishing trips etc - so I'm driving on lakes. I played a little on the computer and I could actually widen the complete body about 8", the new chassis is couple of inches wider than the Sprites, so I could benefit of having little bit more space inside (for beers of course!).

THE QUESTION!
As the new tracks are 57" wide, do you think the vehicle has enough power on keeping reasonable speed in deep snow? The Ratrac ST is looking more like a tractor so can I expect similiar behaviour as the Sprite or is it too slow? I tried to find the ratio from the OC-12 but it must be hidden somewhere. Has anyone got any experience of driving Thiokol's with such tracks? I'm interested to learn the pro's and cons.

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Here are some photos showing what the tracks look like and the new basis for the Sprite (I loaned the photos from www.pistenraupe.de - an excellent website, please visit for more photos!):




In Ratrac ST the driver sits in the center, I have calculated that I should be able to convert the chassis quite easily for left hand driving.


And last, that's how my Ratrac looked during the summer, now you have to imagine those two snowcats welded together (Truck won't be included!)


Cheers!

Just to show what will be happening to my Sprite, here are some photos from previous projects that were completed during the time Sprite was waiting outside.

Only the chassis remained on the trucks, everything else was scratch build from new metal. The particular truck in these photos is going to be used for expeditions in Africa, the other one was build as original. Was a real pain to build them:

The start - after cutting most of the old truck away:




The beds:


The cabin was build in crew cab style, original was only 3-seater short cab:






And couple of months ago, metalwork finished - its finally gone. The owner is going to paint the truck in neutral white (as seen on the cabin) and furnish the camper (which has raisable roof), new motor is still waiting for a test run. The design looks crude, but thats made for purpose, nothing else. Too bad the new big wheels+tires were not fitted before the transport - they look awesome. The owner helped me to finish the metalwork, I almost had a burnout cutting and welding all that steel!:

I found a great link for all Ratrac owners - also should be interesting for Thiokol guys, I didn't notice before that the website has the full Ratrac brochure in PDF-format: http://www.unusuallocomotion.com/rubrique,two-tracks-rigid-vehicles-med,1183388.html

Here's the brochure: http://s4.e-monsite.com/2011/03/20/79846948ratrac-1970-pdf.pdf
Btw. Check from the brochure the last model "Juggernaut", never seen one but looks very impressive!

I get hardly anything done these days, my mother is in Intensive Care Unit at the nearby Hospital and I have lots of time but can get nothing started. I forced myself out for few hours to get my thoughts elsewhere. I'm well prepared to remove a 7.3D Ford IDI (diesel) from my F-250, but as this requires some planning and concentration I decided to start disassembling the tracks. If I find a way to fit the Ford diesel in the Ratrac, it will be a cool project. More about that later...

After a long standing was a good feeling to uncover the snowcat and do something - although almost nothing got done but its a start anyway


Here we can see how wide the new tracks will be! They are really enormous compared to the old ones! I'm just hoping not many of those cleats are missing - I heard these tracks cost 9000,- eur new (over $10k), although I can't verify that. The rubber would be usable but unfortunately the previous owner has intentionally cut the tracks before taking the machine to junkyard. Or perhaps someone made the cuts before and that was the reason for dumping the Ratrac ST. Anyway, they will look great with ST wide axles and Sprite bodywork (I hope):


Good point of having purchased a spare snowcat is having so many spare wheels and sprockets.


Ok, tomorrow I'll start working with the bolt gun and see how much progress I get! Simple work is good at sometimes

I see a lot of guys here are using hydraulic presses on creating the holes for the track belts - multiple holes at a time. I'm not sure my sheetmetal puncher is the best tool for the job, but I thought to give it a try. However, I can only punch one hole at a time. Its hydraulic and extremely powerful so I'm sure the hole itself won't be a problem, more that how big the task will be - punching one by one, each track has four belts and holes are in 3 rows on each belt!

Great thing about the puncher is the tool has a strong needle at the center which will help punching in the right place. Worst job must be getting those cut rubber pieces out from the tool!

Sisu,

With your shop and tools, and experiance, I am bettting on one really cool project....

Keep us up dated on our progress.

Sorry to hear about your mother, as life can give us some challenges for sure. Hope for the best for her, and you as well.

Thats a lot of track to get up to speed, but with the 7.3 it should have the torque, is it a tubo charged version?

Regards, Kirk

Sisu,

I see in another post you have a naturally asperated 7.3 Diesel....

Maybe this is better for the rear end, with less HP on tap. But IMHO it should have enough power for your application.

Regards, Kirk

Thanks for your nice words, Kirk.


Yes, its naturally aspirated diesel as you noticed, I have no intention of turbocharging the engine since the IDI (International) has an excellent reliability record but will get longevity problems with the turbo. Good point of having this old-generation engine is its really a simple tech diesel - no fancy electronics etc. I don't like an engine that eats battery power once its running, this might be a question of life and death in extreme conditions and having an alternator failure.


So, all electrics will be 24V. I like that since I've got so many unused truck parts that are 24V and I can just install the whole collection in this project


Regarding the tracks, I got started - only worked for an hour and got six cleats away, wow . Its not a difficult job, but its physically heavy - I didn't invent any trick to do it, especially alone - just old-fashioned one-by-one removal process. Compared to the old steel tracks these are peace of cake! Only one bolt was really stuck but the bolt gun is so powerful that it cuts them in half. The thing causing corrosion is the aluminium and steel forming a galvanic pair.

Although I will replace all the bolts, the cleats are in very good condition. Its surprising how light they are, being aluminium. These tracks were run with the same standard Ford straight-6 like the Ratrac Sprite (Thiokol Spryte). Certainly they generate more resistance on heavy snow, but they aren't that bad I guess. I'm still wondering if my OC-12 rear-axle from the Ratrac ST has lower gearing due the wide tracks, this might affect the top speed.


As both of the tracks have already been cut in half, they are in optimal size for disassembly. Every seventh cleat is slighty different in shape, but not higher:





The cleats can be taken into three parts. I would like to know who is the manufacturer of the tracks - I'm going to need couple of new cleats to finish the project:



Someone has broken few things while moving the tracks with a forklift - propably at the junkyard. I like that everything comes apart and parts are easily replaceable:


I found this photo from internet, showing tracks about the same width. It looks hmm... interesting Now just imagine the Sprite bodywork on top of the chassis.


Here's the donor F-250, its been standing over 10 years but has only 100k miles. I'm going to remove the engine as soon as I can:

Very slowly some progress I´ve been busy getting more space in my garage and doing some various other stuff - but finally I finished the disassembly of the tracks. Each cleat has 12 bolts and I must have opened 2000 of them, the secret of making the job fast is shamelessly using a friend as help Now I could do each track in 8 hours, using forklift, boltgun, HEX key and plastic hammer. Without a friend it takes four times longer... It first feels like a huge task, but after a while its almost fun! I have about 10-15 cleats that need some repair, but the rest were in excellent condition - also, I didn´t need to cut more than few bolts off. I´m sure making the new belts and assembly will take much longer... But that will be the last task after the rest of the cat is finished.

I have those cleats everywhere in the garage...






In total I got 1.5 buckets of bolts and nuts!

So finally I moved the spare Ratrac chassis in the garage - now this will be the chassis for the "hybrid". Unfortunately my plans with the Ford 7.3 Diesel went downhill since firstly it was way too big (that radiator is huge!) and secondly someone came and offered me good money for it... So, I´m going to keep the in-line six.

After an hour of cleaning all the spiderwebs with pressure washer...


There seems to be a problem with the gearbox. Its totally stuck which could be the reason why the whole snowcat was taken to junkyard and the tracks cut with knife in four parts. I made a theory the box broke somewhere in difficult place and they just cut the tracks off the get it away with a tractor or something. Have to open the box and see whats wrong, spare boxes aren´t that easy to find on this side of the pond...


Good thing about this motor is the hydraulic pump installation. I might do something with it... I will use the engine from the Ratrac Sprite as its in such a good condition. This one´s a Ford 200cid from 1970.




I will first build the chassis as the projects takes this way much less space than with the body installed.




The new width of the Ratrac will be quite exactly 12 foot with the wide tracks - must think how to transport this thing between places.



...More pics after the chassis is disassembled and the drivetrain removed... Going slowly but surely

tHE RATRACT IS THE EUROPEAN MODEL OF THE THIOKOL 2100 A. tHEY STARTED PRODUCTION OF THESE AROUND 1968. tHE TRANSMISSION SHOULD BE A NEW PROCESS 435.wHEN YOU APPLY THE DRIVESHAFT THE CAB WILL HAVE SOME SMOKE IN IT FROM THE HAND BRAKE SO YOU ARE BETTER TO USE THE STEERING LEVERS TO STOP.tHIS UNIT WAS BEFORE THE 2100B. i HAD ONE OF THE FIRST 10 UNITS OF THE 2100A PRODUCED AS WELL AS ONE OF THE FIRST 10 3700S PRODUCED AND AN IMP.
Ray Green

The motor in the ratrack should be the ford 300 vs the 200 in the spryte both using the 435 new process transmission unless the spryte is an automatic which were just being introduced then.
Ray Green

Ray, many thanks for the information. The motor is indeed Ford 300, but the transmission is OC12 in this example. Unfortunately the spare snowcat came to me without a type shield, so I can't confirm the build year. But the year you gave is likely right. The Sprite is 1967 and this spare snowcat (2100 as you say) seems to be from the same era. The upside is, I got lots of interchangeable parts now. I have scrapped the spare snowcat chassis as conversion was to be too much work - its easier to fabricate a new chassis.

Also, I have decided not to make this a wide-track version, I'm going to use the wide-track aluminium cleats but I will narrow them to the dimension of the standard track version. This is mainly because of the transport would be impossible with the tracks on, I mainly travel alone and moving those tracks would be too much of a hassle without a crane.

I have now moved the Ratrac inside my garage, been inspecting the C-4 and there are some problems to report. I will post some photos in near future to show where I am at the moment... Gladly the tracks are now fully disassembled, which was a 2 day project and lots of cold beer!!

Allright, a small info on the drive-axle donor Thiokol 2100 "look-a-like", I'm wondering how well the suspension works, since the wide-track axles are different type than ones under the Sprite. Notice the absence of the torsional springs and its seems I only way to disassemble it, is to cut the welds. Anyway, I wrote elsewhere about the cleat widths, and my target was recently to cut the cleat to the narrowest Thiokol offering. Unfortunately I calculated the work to narrow the OC-12 axle and all those cleats... Too much work! But I'm still wondering if this particular wide track suspension really works for the Sprite (different axle weight capability etc). I would like to see close-up photos of wide-track Sprites/Sprytes if they have the "springs" or not...



Have anyone else noticed how bad quality the factory welds have been on Thiokols/Ratracs? I've seen now many broken welds which were unacceptable quality.

Earlier I removed the drive-train from the donor ("2100"), they said the engine was running before the vehicle was destined scrapped.





Seems I can use the OC-12, the drive-shafts and the gearbox from the donor. Regarding the wider track, lets see...


Firstly, I decided to inspect the condition of the axle...


Inside, everything looking normal, some surface rust on contact surfaces of the gears from long standing (comes off without damage):


The left-side drop-box seemed ok..


Everything came off nicely:


Unfortunately the right-side drop box was cracked (as previously known) and came into pieces when unbolted... I'm going to need a new one. From the crack in the casting the water had entered inside the box making a big dirty mess inside:


Regarding cleaning; I'm really lucky to live in an area where are lots of companies specialicing in automotive industry contracting. My next door neighbour is a big company manufacturing parts for Audi, Volkswagen, Mercedes etc. and there are lots of good friends working at night shift who can help when I need some big machinery that is outside my resources. One example is the parts cleaning machine, what a great piece of engineering! It has saved endless nights of cleaning work and how many boxes of brake cleaner ! So, I'm getting all the parts cleaned there - shown are parts from another projects... They use some chemical which are unavailable for normal consumers so parts are really clean after the operation, and funnily smell like fresh apples


As the Ratrac is now in the garage (and not waiting outside "when I have time"), I decided to start the disassembly... Before:


The parts on front are not for this project..


After...:


This thing will need a total rebuild. I can see lots of shoddy field repairs... The basic metal is still in very good condition, if dirty.. but not rusty.


So next time we'll (hopefully) see how the donor parts and the new chassis come together! Thanks for looking, and sorry for wasting your time

Hi!
I have just bought an old Ratrac ST, 1971 model. I run a skilift i Norway, and this machine was the first one at the skilift. The ST has a V4 Ford engine, so i'm not sure your machine is a ST. Do you have the cabine from it? I need one... And if you decide to not use the aluminium tracks, i'm interested in them as well.

And by the way, I think the Thiokol 2100 looks more like a Ratrac Hydro Turbo?