14 replies to this topic

[freedomtrac]

I have designed and built a tracked mobility device based on the track system of a catterpillar. The entire unit is built from HDPE (High density polyethylene) and is completely hand built. Unlike other tracked chairs, the user sits between the tracks instead of above the tracks which makes it extremely stable.
The pricing on this would be around 10k for the electrical, and 8k for the manual. I am looking for some feedback on this, so please let me know if there is any interest.

Steve

[xxm]

Pictures ?

[freedomtrac]

freedomtrac, on 25 August 2010 - 12:47 PM, said:

I have designed and built a tracked mobility device based on the track system of a catterpillar. The entire unit is built from HDPE (High density polyethylene) and is completely hand built. Unlike other tracked chairs, the user sits between the tracks instead of above the tracks which makes it extremely stable.
The pricing on this would be around 10k for the electrical, and 8k for the manual. I am looking for some feedback on this, so please let me know if there is any interest.

Steve

[freedomtrac]

I have photos and some video, but they are both to large to post here. If you email me at sstaley67@yahoo.com I will gladly send you some pics as well as a small video shot with my phone. The proper videos I have are all over 40mgb and I don't know how to resize..



Admin Note: Photo Added.

[allis53ca]

feedback : um, its wider than my van..BIG prob..and looks like it'd be louder than a bulldozer on hard surfaces

[4wheelz]

saw one the other day for $6k. it was electric, i believe.

[freedomtrac]

The unit is 48" wide, and there is not much I can do about the width without increasing ground pressure. Yes it's pretty noisy on hard surfaces, I will try bonding a polimer to the grouser pads, but being a skid steer device I'm not sure how long it will last. On the upside it will climb a 35 degree angle as well as traverse a 35 degree side slope with no difficulty or danger of tipping.

4wheelz,

Can you tell me where I can find the model you are refering too please.

[sh1wn]

I am wondering why you went with a high track configuration instead of normal flat tracks?
Thanks
Shawn

[freedomtrac]

Shawn,

In the beginning it was to shorten the overall length. But as I tested and found problems and redesigned, I liked the idea of having 12" of ground clearance. Also I built the track assembly from hand using HDPE (plastic), and to make the links strong enough I had to make them a little larger than I would have liked. This required a larger diameter sdrive sprocket and idler wheels to deal with the bend of the chain as it conforms to the curve. Also the high track allows me to mount the motors and controller 2' above ground level allowing better access to mud, snow, and water.
As a side note the original high track design was built for dozers that worked in iron ore applications and was designed to keep the drive sprocket up and out of the ground material, adding life due to less material causing friction wear.

Steve

[allis53ca]

track pads too big...creates too big of gap where track meets surface..will grab rocks/veg like plastic fist

[freedomtrac]

Allis53ca,

I appreciate your feedback, the distance between the pads was to large. I have closed the gap to 1/4" between pads and it still grips material but not so that it affects the performance. The pads are 10" x 5.5" and with the amount of track on the ground and a 250lb person riding the unit the ground pressure is 1.75PSI, which is pretty lite. Skid steer machines have always had this issue, and Case got around it by building the Quadtrac which is a 57,000lbs machine that has 4 tracks and articulates in the center to steer. This design is much easier on the environment, but just not practicle for my application. Why don't you give me an email so I can send you some vids, keep in mind that this is the original prototype, and that the finished unit is still 3-4 weeks away.

Steve

[sh1wn]

I see, are you planing on selling the completed chair, or plans or maybe kits? That would be cool.

[freedomtrac]

Shawn,

I will probably start by selling the complete unit here in Thailand for beach and jungle applications until I can figure out import and export duties. At the moment to build in the states the machining that is required would make the unit to expensive. I am looking at injection molding which would help both with weight and cost, also would like to incorporate carbon fiber intop the design but the initial cost is enormous. I am hoping that once I get the bugs worked out to where I have a unit that is durable and rugged enough to do what going offroad is all about, that there will be some kind of leniency on export and import duties where I can make it available worldwide.

Steve

[allis53ca]

email me thru my profile ..... thx

[WC_Sage]

Regarding

Quote

I have photos and some video, but they are both to large to post here.

Could some or all of the video be placed on YouTube or Vimeo and then referenced here via a link?