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Home Built Baja 5T-PTV (Personal Tracked Vehicle)

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Old 02-12-2010, 07:54 PM
  #1
brice_arnold
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Default Home Built Baja 5T-PTV (Personal Tracked Vehicle)

Here is my latest home-built project. This is something that I have wanted to do for a couple of years now. I finally have some time to play around with itl. Essentially I wanted to take an HPI baja and convert it to a Personel Tracked Vehicle. I started modeling this a couple of years ago and kind of lost steam on the project. Now I am at it again.

The project will be broken down into three main categories.

1. Track Assembly:
This is critical and I have been fussing over the design for awhile. I feel like I have come up with something that will work. I wanted a track that would basically be able to handle any kind of terrain that I could throw at it. I also wanted the track to basically be an assembly in of it self independent from the Baja chassis

2. Engine and Drivetrain Assembly:
I haven't quit decided on the motor yet. I would like to have something with a little more power than what out there maybe a 46 or 60cc. I would like it to be about the same size as the stock motor so I don't have to shuffle too many things around

The transmission will be 100% custom. To control the vehicle I will basically need to be able to shift the left and right track assembly from forward to reverse independently from each other. I have a design on paper but still need to model it to see if everything is going to fit.

3. Suspension:
The suspension should be fairly simple, at least on paper. With each track assembly a rigid member and independent from the chassis I will simply need to link it to the chassis with some kind of a four link system.

Here are the first images from this project. For almost everything that I do I first start on scratch paper. One I have whittled out the concepts that I will use in a design I usually default to AutoCAD to do all my layout work. From AutoCAD I then create my models in either SolidWorks or Pro-Engineer.

This is the layout workspace
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Here are the individual components of the track sprockets and link layed-out
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Here is the roughly finished track assembly. I still need to work out the track tensioners.
The over all length of the track will be about 30" by 10" high by 3" wide.
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Here is the model of the track representing the AutoCAD layout.
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And here are the tracks mocked up on a Baja 5T
Name:  TankSuspensionLayoutModel.jpg
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Thats it. If I can stay focused I will start machining track parts this weekend. I will try to keep this thread up to date with postings and photos.
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Old 02-12-2010, 08:00 PM
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Default RE: Home Built Baja 5T-PTV (Personal Tracked Vehicle)

So this was started a couple of weeks ago and there has been some progess. I started machining parts last weekend.

1. Each track link is comprised of three machined parts, and some hardware. There are a total of 45 links per track and 90 links for the entire vehicle. Two of the three parts are machined. I will get some photos up.

2. The track assembly design is finished with a series of idle rockers along the lower track and two tension rollers along the top of the track.

3. I am in the middle of designing the transmission. The concept is finished and I am working on the layout in CAD. Each track with be engaged to forward or reverse with servo actuated clutches. This will hopefully allow proportional engagement of the tracks and should help with the controllability of the vehicle.
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Old 02-12-2010, 09:00 PM
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Default RE: Home Built Baja 5T-PTV (Personal Tracked Vehicle)

That thing is absolutely amazing. I cant wait for the real deal.
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Old 02-12-2010, 10:03 PM
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Default RE: Home Built Baja 5T-PTV (Personal Tracked Vehicle)

Subscribed Thats a very interesting project!

Will you reuse some 5T components ? (are you actually taking a 5T apart to build it?) Do you plan to machine all the track pieces too?

The multilink suspension between chassis and track assemblies is interesting too, can't wait to see pics of the machined parts!

How do you plan to transfer the power from the chassis to the track assemblies ?
Fred
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Old 02-12-2010, 10:26 PM
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Default RE: Home Built Baja 5T-PTV (Personal Tracked Vehicle)

Man that's gotta be the coolest thing I've seen in a while.
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Old 02-13-2010, 02:56 AM
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Default RE: Home Built Baja 5T-PTV (Personal Tracked Vehicle)

I like it very much .I am keep watching .
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Old 02-13-2010, 05:43 AM
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Default RE: Home Built Baja 5T-PTV (Personal Tracked Vehicle)

Quote:
ORIGINAL: Frederik_b

Subscribed Thats a very interesting project!

Will you reuse some 5T components ? (are you actually taking a 5T apart to build it?) Do you plan to machine all the track pieces too ?

The multilink suspension between chassis and track assemblies is interesting too, can't wait to see pics of the machined parts!

How do you plan to transfer the power from the chassis to the track assemblies ?
Fred
-I will not be taking a 5T apart for this project. I though about it but there are very few parts from the 5T/5B that I will be using and it does not warrant tearing aport one of my bajas. Off the top of my head stock parts that will carry over from the baja to this tank include the chassis, front bulkheads, front 5T bumper, roll cage, and shocks. Thats about it. Most of these parts I already have as spares lying around with the exception of a couple of plastic parts.

-Yes, I plan on machining everything in my shop. All of the track links are almost finished. I am waiting on some material (Delrin) for the top plates so I can start to make those. The link base and tread are essentially finished.

-The suspension, I think will be pretty trick. To simplify things I will be making suspension links from welded cromoly tubing.

- Power will be transferred via telescoping CVD's. Very similar to what I did in a previous project except a little more beefier.

Here is a photo from a previous project of the CVD's
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Old 02-13-2010, 05:43 AM
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Default RE: Home Built Baja 5T-PTV (Personal Tracked Vehicle)

wow...

i like where this is going.tracks = cool

man cant wait to see the finished or near completed project..
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Old 02-13-2010, 05:53 AM
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Default RE: Home Built Baja 5T-PTV (Personal Tracked Vehicle)

Just got home from the shop. I spent the night doing post opps on the track links and finished the large track sprockets. Everything seems to be moving along.

Here I am drilling hinge pin holes on the the manual mill.


These are the finished tread plates. They just need a once over with the random orbital sander, a bath in the ultrasonic cleaner and they are off to the anodizer.


Here is the large sprocket running on the CNC


A finished large sprocket


Eight large sprockets for two tracks. Two sprocket per wheel. I will spend the weekend making spool pieces for the wheels.


Here is a section of track assembled. This is only the links. There is also a Delrin top plate and a tread plat that get bolted onto each link


Here is a mock up of the track section and the large sprocket wheel. To get a feel for size the Large sprocket is 5.75" in diameter.


This is a modified HPI baja front shock that will be used to tension the track. There will be two of these per track assembly


That's it for now. Tomorrow I will machine the small sprockets. A total of 32.
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Old 02-13-2010, 08:59 AM
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Default RE: Home Built Baja 5T-PTV (Personal Tracked Vehicle)

Awesome man.... Can´t wait to see more...
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Old 02-13-2010, 09:15 PM
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Default RE: Home Built Baja 5T-PTV (Personal Tracked Vehicle)


Quote:
ORIGINAL: brice_arnold

Quote:
ORIGINAL: Frederik_b

Subscribed Thats a very interesting project!

Will you reuse some 5T components ? (are you actually taking a 5T apart to build it?) Do you plan to machine all the track pieces too?

The multilink suspension between chassis and track assemblies is interesting too, can't wait to see pics of the machined parts!

How do you plan to transfer the power from the chassis to the track assemblies ?
Fred
-I will not be taking a 5T apart for this project. I though about it but there are very few parts from the 5T/5B that I will be using and it does not warrant tearing aport one of my bajas. Off the top of my head stock parts that will carry over from the baja to this tank include the chassis, front bulkheads, front 5T bumper, roll cage, and shocks. Thats about it. Most of these parts I already have as spares lying around with the exception of a couple of plastic parts.

-Yes, I plan on machining everything in my shop. All of the track links are almost finished. I am waiting on some material (Delrin) for the top plates so I can start to make those. The link base and tread are essentially finished.

-The suspension, I think will be pretty trick. To simplify things I will be making suspension links from welded cromoly tubing.

- Power will be transferred via telescoping CVD's. Very similar to what I did in a previous project except a little more beefier.

Here is a photo from a previous project of the CVD's


Wow man at first I did'nt realize that you were the builder of that insane baja!That is some seriously nice machining ! That is some dedication on the track links ! I really like the track section mock up pic. How much does the track assembly weight ? looks like its pretty light considering its size.

What range of speed do you plan to run? Tank like more torque oriented or more a fast machine ?

Fred
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Old 02-14-2010, 02:17 AM
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Default RE: Home Built Baja 5T-PTV (Personal Tracked Vehicle)

Dang man, you are actually making metal tracks... that's pretty darn awesome. Definitely one of the best projects I've seen for 1/5 scale.
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Old 02-14-2010, 05:00 AM
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Default RE: Home Built Baja 5T-PTV (Personal Tracked Vehicle)

Awesome!

Not sure about the Baja body though...... [&:]







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Old 02-14-2010, 11:57 AM
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Default RE: Home Built Baja 5T-PTV (Personal Tracked Vehicle)

yet again you amaze me, i am truly jealous of your machine shop...why can't i win the lottery so i can have one too[&o].
awesome project Brice...looking forward to seeing this evolve
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Old 02-14-2010, 09:52 PM
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Default RE: Home Built Baja 5T-PTV (Personal Tracked Vehicle)

Cool stuff Brice! Love to finally see a tracked vehicle!!
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Old 02-15-2010, 12:00 AM
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Default RE: Home Built Baja 5T-PTV (Personal Tracked Vehicle)

wow this looks pretty cool ive always liked the idea of a rc tracker....
a chap that comes to our 1/5 scale bashes built one by hand....

http://s9.photobucket.com/albums/a60...tankthingy.flv

not the fastest machine but very impressive
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Old 02-15-2010, 12:47 AM
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Default RE: Home Built Baja 5T-PTV (Personal Tracked Vehicle)


Quote:
ORIGINAL: da mad maori

wow this looks pretty cool ive always liked the idea of a rc tracker....
a chap that comes to our 1/5 scale bashes built one by hand....

http://s9.photobucket.com/albums/a60...tankthingy.flv

not the fastest machine but very impressive
That was really cool. Thanks for the link. Is that a chainsaw motor? It sounded like there was much room for tuning on the motor. How did they manage the steering?
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Old 02-15-2010, 01:17 AM
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Default RE: Home Built Baja 5T-PTV (Personal Tracked Vehicle)

its a stock 15cc week wacker motor lol i dont think these much more in it

the engine goes into a grinder head for a 90deg then into a 5b diff, then he made these "sort of" drum brakes on each side so its differential/brake steering..

heres another vid of it......

http://www.youtube.com/watch?v=9amT7YvKhIU

the owner is on this site but hangs out in the boat section as he make jet units too...

if your looking for ideas on transmissions and steering check this one out... he builds driveable scale tanks with no machine shop just a clever use of other tools

http://www.youtube.com/watch?v=BWHAf...eature=related

http://www.youtube.com/user/Gizmo4t#p/u/32/TbnMndCuVE4

maybe you could replace the belts and pulley with the clutches you were talking about??
just a thought...

cant wait to se your progress
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Old 02-15-2010, 02:45 AM
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Default RE: Home Built Baja 5T-PTV (Personal Tracked Vehicle)

WOW! Amazing. Here I've been trying to find solutions to come up with for a track... I don't know why it didn't occur to me to start from scratch... would have saved a lot of time and opened up some avenues.

Good job! Subscribed and in for updates. [sm=thumbup.gif][sm=thumbup.gif][sm=thumbup.gif][sm=thumbup.gif][sm=thumbup.gif]
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Old 02-15-2010, 03:03 AM
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Default RE: Home Built Baja 5T-PTV (Personal Tracked Vehicle)

OMG, what a build!
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Old 02-16-2010, 03:16 PM
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Default RE: Home Built Baja 5T-PTV (Personal Tracked Vehicle)

Spent Sunday on the computer hashing out the design. I started on the smaller sprockets. I need a total of 32 for the project. these small guys are taking longer than expected because they carry a bearing.





I also started working on the spools for the larger sprockets. These are machined on a manual lathe. I started with 3" round stock.





I am pushing to have the track assemblies finished this weekend. I am going to fire up my CNC router to machine the plastic track link top plates so that I can multitask. It should be interesting to have three to four machines running under one man. Too many parts and not enough time.

Total Machined Parts To Date: 211
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Old 02-19-2010, 02:31 AM
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Default RE: Home Built Baja 5T-PTV (Personal Tracked Vehicle)

OK guys good news on the motor. We are going with a KRD/SkoPod 62cc kit. in this project though I am rotating the motor 90 degrees with the outdrive facing the rear of the vehicle. This should be interesting.

I have been very busy this week. I finally finished the small sprockets. They took way to long to machine. but they are done

my goal is to a finished track assemblies by the end of the weekend. It's a big push but I think I can pull it off.

The spools for the larger sprockets are basically finished. They need some small finishing touches but not much.





I also started in on the track top plates as the material finally showed up today. Another batch of 100 pieces to run through the machine. Here is a finished section of track.







And here it is mocked up on the large sprocket





That's about it for tonight. Part count is up to 248 pieces. I will probably hit 400 by the end of the weekend.
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Old 02-19-2010, 09:12 AM
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Default RE: Home Built Baja 5T-PTV (Personal Tracked Vehicle)

Wow, thats very cool [X(]
I can't wait to see more!

What sort of speed do you think this machine will be capable of? If those skopod engines with stock internals and a pipe can easily push a go-ped to 40mph, I can only imagine
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Old 02-21-2010, 06:13 AM
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Default RE: Home Built Baja 5T-PTV (Personal Tracked Vehicle)

Thanks for the compliments guys. Glad you like the project.

Today was a long one but I got a lot done. I clocked in 17 hrs at the shop today. I am almost done with the track assemblies. I finished all the side plates. I need to work on the axles for the idlers. I also need to CNC the tensioner assy and the rockers.

Each side plate is made up of three individual plates. The main reason for doing this was the size of the plat and working with it on the CNC. In the end though there were some additional benefits that I might explore down the road. For the complete set of side plates there are seven different parts (seven different set-ups and CNC programs). This project is starting to get tedious.

Here are the side plates



Here is an assembled side plate. This is the inside right side plate



Here is a set of side plates to complete a track assembly



And here is a milestone for the project. A mock-up of track assembly with track.





And here is a perspective with the body for this project.



That's it for tonight. Hopefully I will be able to finish up what's needed for tomorrow. This week I will finalize the gearbox and begin machining the parts towards the end.
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Old 02-21-2010, 06:16 AM
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Default RE: Home Built Baja 5T-PTV (Personal Tracked Vehicle)

looks great....
very impressive


NOW GO GET SOME SLEEP!!!!!!
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