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This is the trailer cart I made for my dog Thunder.
It's a folding bike trailer, I made a harness and rigging for him to pull it places.

Aside from the trailer and green dog harness, which I already had, I spent $18 total to make this rig. 

A lot of engineering went into this project. If loaded correctly this produces as little as 1kg of downward force on my dog. The poles are only for weight and steering. The upper leads pull the cart slightly forward and move the centre of gravity for propulsion. My dog also has breaks connecting underneath his body which allow him to stop the cart. Finally thanks to Archimedes; Even a completely unbalanced load of 10 pounds will only exert 4 pounds of force spread over a harness with over 3 ft square relative weight distribution contact in the rigging.

Step 1: The Supplies

You'll Need:

- Folding Bike Trailer. I originally purchased mine for groceries and laundry.

- Dog Harness. Originally purchased to roller blade together. Most any decent harness will do. On mine, I added a metal loop to the bottom (for brake lines), and a pad to the top, and that's it.

- 2 poles. These serve two purposes; 1) They transfer weight to the animal, 2) They help the dog steer the cart and provide a "zone". The poles must be strong enough to transfer the weight, but light enough to not affect total mass. I chose 2" bamboo stalks.

- 8 leashes thick enough to be useful.

- 6 collars of the same size as leashes, to be used for their adjusting hardware.

- 2 eye screws, I chose PVC coated for comfort. The key to these is not just the size, they need a flange at the base of the hook

- Electrical / PVC tape

- matching yarn, Acrylic is best.

- liquid fabric glue

- Cheeky Licence Vanity Plate

- Finally, a happy dog.

Step 2: The Extender Poles

This area took the longest to figure out.

I needed something entirely removable and yet strong enough to do the task. First I tried broom sticks and bungee cords, just to see if my dog would take to it at all. Turns out, he loved it a lot. I tightened everything up and secured the broomsticks with electrical tape so I could sort out the harness. If you choose broomsticks, I reccomend plastic ones, the metal ones seem to kink easily and become useless. Plastic will just bend. Plus most broomsticks today come with swiveling holes in the handles, making things easier to dream and hook up. 

They just look like broomsticks. Remember the more professional you make your rig look, the less likely you'll be interpreted as being cruel.

Tape a grip pattern into the base of the poles, this will help secure them with a lashing later.


Step 3: The Trailer Brake

You'll need a secure mounting point for the eye screws so once stopped, the trailer won't roll into the dog. It will be stopped by the Brake Straps.

This method I thought of while thinking about wicker furniture. It's like a fiberglass binding
I pre-drilled and sunk the screws into the bamboo about 4" from the top of the pole. I then applied glue liberally to the last few threads and finally again all over the base flange of the screw and tighten flush. Now wrap the flange to the bamboo with the matching yarn. Wrap liberally and sink into the glue pool. Once a nice wet mound of thread binds the eye screw, wrap the bamboo evenly for aesthetic and tie off the end. Cap each side of the wrap in a neat layer of PVC tape for finish and security.

At this time wrap the end nob of the bamboo in PVC tape to prevent scraping and increase comfort levels.

Step 4: Mounting the Extender Poles

- Slide the poles through the frame and into the basket weave of straps holding the shell and seat to the frame.
        **- Make sure to use the frame for the shell to create tension.

- Loop a strap around the grip you made before reinserting it.

- Once the poles are even, tighten the seat straps, and your poles are securely mounted.

Step 5: Making the Hardware.

Take out those leashes and collars you picked out earlier.

Take a pair of sisoros and cut the adjusting hardware off the collars.

Then remove the hand loop from two leashes. Connect them to the shell frame with a set of hardware. These become the Pulling Leads.

Cut 2 different hand loops off at about 2 ft. Then cut the clips at the ends of scrap off. Use sets of collar hardware and clips to make your adjustable Load Straps with clip ends Make 2 loops out of scrap just big enough to fit over the end. These help lock onto the bar by sliding up and down.

Cut 2 leashes at about 1ft, then cut off the clips from the remaining 2 leashes. Use collar hardware to make double ended straps for the Brake Straps.


REFERENCE: In hanging picture: Hanging L-R: Load Strap, Brake Strap, Pull Strap, Pull Strap, Brake Strap, Load Strap.

Step 6: Hook Up Your Pup.

First hook up the load loops on the side to the top harness ring. Then the Pull Straps to the top ring.

Finally connect the Brake straps to the lower harness ring and the other end to the pole mounting point.
    - Use care here. Adjust your straps so that the harware doesn't hit your dog's legs every step, but short enough to pull to a brake.

Step 7: Make a Final Statement

Pick something funny for the back of your cart. A joke, or a play on words really keeps people thinking about you positively.

Congratulations, Now you have a professional looking trailer for your doggie, and still have a usable bike trailer as well.

Keep loads light and spirits high. Remember there's a thin line between well trained and abused animals.




Keep checking in for updates, modifications and the big ALL SEASONS CONVERSION.

Step 8: MODIFICATIONS & UPDATES

Truth be told, this design won't be considered final until next summer (2012). Some will be mods because of dog growth, Some will be for practicality and general improvements. The biggest mod upcoming will be the ALL SEASONS CONVERSION.

Updates & Mods in Planning:

- Upgraded Weight Belt (and raincoat from scraps)
- Frame Mod - Center Wheels
- Bigger Wheels, same hubs
- 4 SEASON CONVERSION

Step 9: Optional Frame Mod - Metalwork Skills Required

I did this step while still in the design phase. I don't have many pictures of it, but I'll do my best to show you what I did.
Basically take the hanging axle bracket and raise the axles to go through the frame.

PROS: Lower center of gravity. Easier load distribution, Better overall handling.

CONS: Frame is lower to the ground making obstructions and grass harder to traverse. Requires future body painting.
                  (can all be solved by installation of a bigger wheel, future MOD)

First
- Strip your trailer down to it's basic frame. (remember where everything goes, take pictures if unsure)
- Remove wheels.
- cut the 4 welds securing the bracket in place.
- Measure and mark the centre of the frame.
- Temporarily mount the bracket and mark out the new axle holes.
- Remove bracket and drill 5/16 hole for axles.
- Pre-drill and rivet in place. I used 16 rivets per bracket. It should be stronger than before.
- Replace wheels. grinding holes for fit and finish.
- Reassemble the trailer, You're Done.

poor dog
<p>Dogs are happiest when they have a job! They love having a task to do. My dog is happiest when he has a job! I'm looking at plans to build him something similar to this to pull our younger kids around while we take him on walks.. plus a sled for winter. If you have a dog and you are not giving him a job, you are not helping him meet his full potential!</p>
<p>You should be more aware of the physical and intellectual needs of ananimal.</p><p>It is a pitty people make this assumption.</p><p>Do some Google'ng adn get yourself informed.</p>
<p>Hello! I love your rig!!! </p><p>I just purchased a kids wagon and I'm thinking to have my dog pull it with my son in it (she's a 77lb newfie/collie mix, I'm sure sure she'll love it!). There are some adjustments I will have to do for the 4 wheel wagon but the one step I didn't really understood is the brake part. Can you post more picture of the brake system or explain how it works a little better?</p>
<p>For me. I used a few ways to be certain.</p><p>There was a strap made between the poles. It connected to the white eye screws. I just had a loop in the harness where I could thread it through on the bottom. It used the harness to stop. Not the best way. But it's a good fail-safe. Simply because it tends to push the dog forward before the cart can collide with it. Its a little cruel, but dreadfully efficient.</p><p>Because of that; I also had only a certain length on the weight straps. I also had a collar to bring down on the weight strap when looped amount the pole.. that way the strap would grab the poles as they move forward and only allow a certain amount of forward travel before the cart stops.</p><p>Either way, I used both. The main key is to allow enough clearance between the dog and the cart. You never want it to be painful.</p>
<p>Thank everybody for their supportive comments. Unfortunately, about two years later, the bicycle trailer frame rotted through. Its no longer safe for use. :( </p><p>Some advice, don't skimp on the trailer frame. give it an extra coat of rust paint before assembly. It was very frustrating to spend so much time on this project, just to have a weld rot through.</p><p>I'm currently working on a 4 wheel wagon. It will allow for more weight and steadier loads. </p><p>It has pneumatic turf tires and can hold 12 cu'ft of cargo. </p>
There is a video available on the Intro page.<br><br>It is a U-turn followed by a &quot;wait&quot; position.
Your dog looks soooo cute!!!!
He's gonna get a little bigger before he can pull any real weight. But this winter, my nephew and him will both be big enough for this to be interesting.<br><br>That will be cute.
That is one nice rig! Your pup looks well pleased with it too. I would really love to see a youtube video of it in action. I know a few rotties that would love the get a work out with one of these. Very well thought out and nicely made.
<p>What a great idea. I already had backpack strap so I didn't buy leashes or collars. The PVC pipe was cheap so I'm not sure how long it will last. I also needed to be able to adjust according to the pulling harness I have ordered so left the straps long and just used electrical tape to keep them out of the way.nd </p>
<p>My dogs kurgo harness has a hook in the front so I could use the front strap as the brake. The metal circle helped was great to attach the straps so that I only needed to hook one carribeaner on the harness, making it quick and simple to hook up.</p>
Poor black dog
<p>no the dog is thinking. comere soos i can lick u now. aww why cant i get to the kids.</p>
oh how i wish i had a dog...
A friend of mine is expecting twins and just got a labrador. Looks like the perfect project.
I'm sure he's willing, but do you think a Border Collie could do this? He's 43lbs and 22.5&quot;. I'd like him to eventually pull ME.
You're looking for something called a 'sulky'.<br>There are many out there to Google. <br>Just remember, your dog should never be subject to more than three times it's own weight. <br>eg: 40lbs dog = 120 lbs max load and trailer weight.<br><br>You'll probably want two dogs for such a thing. It can be done with one,, Look into Scooter Mushing
Is that humane?
yes it is if you do not go overboard with it (too much weight for the dog, etc)<br><br>Most dogs are happy to have a job. If you have a puppy or dog that is destructive, it is usually because they are bored. If you give them a &quot;job&quot; something to do, it usually corrects the problem.<br><br>I have a service dog and he ears a backpack right now to help me carry groceries and my books at school. Soon he will have a cool new trailer for other jobs as well.<br>
A service dog will take to this sort of thing very nicely. PM me and I'll help you make a single harness, minimal hookup for your ease. The Mk 1 I posed here was very much 'Stupid Puppy Proofed' and over designed. I'm in the process of fabricating an all in one harness / weight pad for sledding and carting.<br><br>Otherwise, just remember, it'll take about 12 months of training before you introduce anything weighing more than 5 pounds.<br><br>Your pooch needs to learn about how to deal with obstacles, poles and hangups without the burden of carrying weight. A dog in panic mode strapped to a trailer with weight is just no fun for either party to deal with.
Yes, it is a doggy, not a kid... y'know... now that I think about it.. this might be good for driving the extra energy off of 3-6 year olds as well...
LOL. Only one difference between kids and dogs. <br><br>Dogs Listen!
Believe it or not, there is actually a sport dedicated and sanctioned by the Kennel Clubs world wide.<br><br>Abuse or inhumane would be going for weight records..<br>He has the energy to pull me on rollerblades for 20 miles, so why not 4 with a small cart?
How long do the :<br>Bamboo pieces<br>Leashes<br>need to be?
All final measurements won't be known until all your major parts are assembled.<br><br>RULE OF THUMB FORMULAS:<br> Pole Length = (mounting length) + (dog length chest to tail tip) + 4 inches<br> I really just bought 2 6ft canes, $2 ea then cut to suit, keeping in mind that basic formula when measuring.<br><br> Leashes? Well they're all adjustable so make them as long as you think they need to be, then add 6 inches. All my hardware had long scrap tails until i cut them for the camera. <br> <br> Well there's two answers; 1) Hardware, 1M (3ft) leashes will do fine, you're just cutting them up. All mine are sacrificed 1M leashes. A big chain dollar store ususally stocks it pet section with the same supplier across the board, so fining sacrificial hardware collars is very easy. 2) Tow Straps, these might need to be longer than you think depending on how easily a pulling point can be found on your trailer.<br><br>IT IS VERY IMPORTANT that the load straps bear the weight, and the tow straps pull. It's all about weight transfer and animal health.<br><br>Today I did make a neck bridal out of some more dollar store items. for $3.75 I bought a chihuahua harness and two 20ft 'training&quot; leashes. I turned the harness for use at his neck level. I'm going to begin teaching him directional commands and need to control his movement from behind.<br><br>
for the directional control try using a gentle leader. as this works the same as a horse bridal but without the bit<br>
Thanks for the info.I have a Min-Pin about10 lbs.,and needs a job. As I'm not very good with formulas could you please help me with designing a cart for her?I would appreciate your help, and so would Dee-Oh- Gee. <br> Thanks,Wayne
Ok, so. 10lb dog = 30 lb MAX weight, ever.<br><br>for you I recommended cutting apart a folding metal grocery buggy. it's light and about the right size. Strip it down to the wheels and handle frame. Zip tie a milk crate to it and your basically done. just make it look pretty.
Thank you very much for this information and for being so creative. I love this!
That's cool. I hope your dog enjoys it!
Nicely done! I've got a handicapped dog that frequently rides in a trailer. I could get a second dog to tow him around, if not for my city's pet limits.
I've seen such things on my readings over the past while. You could buy a good wagon, spend $20 in PVC pipe and have something much more suited to you.<br><br>Dogs of all sizes have pulled things, the wagon should just be of appropriate size so it doesn't offend people.
Nice! Love the tag. :)
Nice work! <br><br>I made a harness for my dog for when we go on extended hikes. It's made to fit two canteens and a water dish, so she packs her own water. She's kind of hyper, but having a &quot;job&quot; really helps her focus and calm down. I guess she feels important.<br>

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