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Erich_870
01-21-2006, 04:08 PM
(Also posted on yotatech.com http://www.yotatech.com/showthread.php?t=76849 )

I'm working on building a cart to haul a load of 250lbs max. I'm going to use two of these cart wheels form Northern Tool (#145124) rated for 125# each.

http://i7.photobucket.com/albums/y261/Erich_870/145124_lg.jpg

I need to construct an axle with 1/2" shafts for the wheels. My thought is to use 1" square aluminum tubing with a wall thickness of 1/4" This way I can fit 1/2" solid round bar stock inside the tubing and have it welded on the ends.

My dimensions right now are 21" of square tubing with two 7" round bar stock (1/2" OD) inserted 3" into the tubing, i.e. 4" sticking out both ends, which the wheels will sit on. The wheels have 3" hubs, so the extra inch is for the welds on the end and a cotter pin or castle nut/pin connection to keep the wheels on.

On to the questions! "BRILLIANT!!" :drink:

1. Any thoughts on overall strength? Does this sound strong enough?

2. Any estimates or educated guesses on how much a fabricator would charge to build this for me?

I stopped in at the local metal distributor/fabricator and they quoted roughly $60 bucks. They figured 1/2 hr of shop time ($75 per hr.) plus materials. They pretty much pulled that number out of their :booty: and I didn't get it in writing so I'm half expecting a new number when I head back with drawings. :chair:

Anyone out there want to build it for less than $59.99? :)

Thanks for the help.

Erich

Cebby
01-21-2006, 06:18 PM
Erich - sorry, I moved it... ;)

What is this for? Sounds like a two wheel cart for O/A tanks or something else that is upright? Almost like a large wheeled appliance dolly?

If you are using aluminum, this cart will get expensive (both materials and fabrication). Does it need to be lightweight? Corrosion resistant?

If you have a post a sketch, that would help. We can help you with the design - which would have a large bearing on the weight capacity. Materials alone won't dictate capacity. If you can't scan/generate dwg electronically, let me know - you can fax it to me (my faxes get converted to PDFs since I use Webfax) and I'll post it up.

Erich_870
01-22-2006, 02:30 AM
Erich - sorry, I moved it... ;)

What is this for? Sounds like a two wheel cart for O/A tanks or something else that is upright? Almost like a large wheeled appliance dolly?

If you are using aluminum, this cart will get expensive (both materials and fabrication). Does it need to be lightweight? Corrosion resistant?

If you have a post a sketch, that would help. We can help you with the design - which would have a large bearing on the weight capacity. Materials alone won't dictate capacity. If you can't scan/generate dwg electronically, let me know - you can fax it to me (my faxes get converted to PDFs since I use Webfax) and I'll post it up.

No problem on moving it. I thought it might go in this section, but since it's not a finished project I didn't know for sure if this was the right spot.

Close but no cigar on the O/A tanks cart. The cart does need to be both light weight and resistant to corrosion. It's not for shop use, but for outdoor purposes. Is that vague enough? :bricks: Basically this is the first phase in a yard cart with an attitude that won't stay in the yard :fun_84:

Here's a sketch

http://i7.photobucket.com/albums/y261/Erich_870/axle2.jpg




I guess I should get off my butt and dust off the strengths of materials text book and see if I can put some edumication to use :talkingn:

Erich

MXtras
01-22-2006, 04:34 AM
I have not run any numbers but at first glance, it seems a bit on the hairy edge to hold more than maybe 150 pounds. I would suggest stainless or going just a tab larger with the axle diameter - 1/2" alum rod is not going to hold more than about 75 at 3"-4". It seems a bit small to me.

Again - these are shooting from the hip.

Scott

Cebby
01-22-2006, 09:33 AM
What if you did 1/2" stainless rod inside your alum tube. Instead of welding it, run the rod the whole way through (rod=29" or so). You can drill a hole in the middle of the rod (and tap it) and a slightly larger one in the aluminum tube so you can run a bolt into the rod to keep it from skating around.

When I asked for a drawing, I meant of the whole cart. Is there going to something overtop of the full length of the alum tube (like a box of some sort)? The reason I ask, is that if you concentrate all the weight in the center of the unsupported tube, it may also fail (not as much if sleeved like I've suggested tho)

Erich_870
01-24-2006, 03:57 PM
What if you did 1/2" stainless rod inside your alum tube. Instead of welding it, run the rod the whole way through (rod=29" or so). You can drill a hole in the middle of the rod (and tap it) and a slightly larger one in the aluminum tube so you can run a bolt into the rod to keep it from skating around.

When I asked for a drawing, I meant of the whole cart. Is there going to something overtop of the full length of the alum tube (like a box of some sort)? The reason I ask, is that if you concentrate all the weight in the center of the unsupported tube, it may also fail (not as much if sleeved like I've suggested tho)

I don't have the rest of the cart drawn up. I have an idea, but I'm still chewing on it. The loads onto the axle, from the cart, can be considered two point loads 2" in from both ends of the square tubing (125lbs each).

I think I'm going to make my life easier and sign up for a membership at Efunda.com to use thier calculators.

I'll look into the stainless steel. A solid rod all the way thru would increase strength, no doubt, I just don't know if the added strength is required yet :fun_84:

Erich

MXtras
01-24-2006, 05:14 PM
Two things I have learned -

1) you almost never regret going big.
2) you almost always need something bigger.

Scott

Cebby
04-02-2006, 12:33 PM
Any updates Erich?

Erich_870
06-10-2006, 04:11 AM
Any updates Erich?

Opps, been away for a while. I had the first prototype built for $53 IIRC out of plain carbine steel to keep the cost down, etc, and who ever fab'ed it got a little excited with the grinder. He left it totally FUBAR'ed :wtf:

I'll post a pic to explain, but the 1/2" rod is not round any more. I gave them a very straight forward drawing that said nothing of finished grinding so, I'm not sure why this unknown welder went to such lengths to mess it up :rolleyes:

Then the wheels I purchased last minute off eBay were described as made for a 1/2" axle but are really 5/8". So I have nothing that works at this point. :bricks:

It's okay though. I'm going to try it again with a much better set of tires from Northern Tools that need a 3/4" axle. I also plan to keep the overzealous grinder away from my second axle.:boxing_sm

Erich

Erich_870
09-06-2006, 03:30 AM
Well here's another update.

I said I was going to share some pics of the first axle that never worked out.

Here it is.
http://i7.photobucket.com/albums/y261/Erich_870/Projects046.jpg

You can see the neck I was talking about
http://i7.photobucket.com/albums/y261/Erich_870/Projects051.jpg

And it's not round anymore. If I put a washer on it it's obvious it isn't 1/2" diameter either.
http://i7.photobucket.com/albums/y261/Erich_870/Projects050.jpg

Here is a pic of my new set up. I was talking with my parents neighbor who does fab work as a part time job and he welded a 3/4" alum rod in 1" channel for me as a wedding gift:biggrinan . It works great and even has a little camber thanks to some extra heat :talkingn:
http://i7.photobucket.com/albums/y261/Erich_870/Projects035.jpg

I'm finally making some progress since duck season is here and this cart will play a pivotal roll in my hunting plans. :bricks:

More pics to come! :40:

Erich

Erich_870
09-07-2006, 03:20 AM
This cart is going to have a suspension so I've been working on making some spring perches. The springs are 10" and the wheels are 20" dia so I need to get some room to flex. I haven't decided if I need a block on top and bottom yet.

Here's the first one.
http://i7.photobucket.com/albums/y261/Erich_870/Projects028.jpg


http://i7.photobucket.com/albums/y261/Erich_870/Projects030.jpg

I found these "U" bolts from cable clamps. They work pretty well, but it was trial and error to find where they need to be to match the spring.


http://i7.photobucket.com/albums/y261/Erich_870/Projects031.jpg


http://i7.photobucket.com/albums/y261/Erich_870/Projects033.jpg


Here's some more material for the trailer
http://i7.photobucket.com/albums/y261/Erich_870/Projects039.jpg

Cebby
09-07-2006, 12:55 PM
Those are some L-O-N-G springs! This is a cool build!

MXtras
09-07-2006, 01:01 PM
I have this image in my head and an accompanying noise - the noise sounds like 'boing, boing, boing'.....

Should be interesting to see the result!

Scott

Erich_870
09-07-2006, 11:12 PM
Work is killing me right now so it looks like I'll only have time to work on it one day a week (Sundays). We'll see how long this pace keeps up. :coffee:

Erich

Erich_870
11-16-2006, 01:20 AM
Well after almost 6 straight weeks of work, we are finally slowing down for the winter. :fun_84:

I've made quite a bit of progress since last time I posted. I have probably 2 evenings of work left and I can take it on a trail run. 2 feet of snow might delay that though.

I have added some new tools to my garage to help speed things up and ease my perfectionist nature. :rolleyes:

Here's some pics.

Here I'm tapping the axle to attach the bottom spring perch.
http://i7.photobucket.com/albums/y261/Erich_870/pics001.jpg

This is the first rivet for the frame structure.
http://i7.photobucket.com/albums/y261/Erich_870/Project004.jpg

This is one of the perches for the suspension links.
http://i7.photobucket.com/albums/y261/Erich_870/Project010.jpg

The frame laid out for inspection by my supervisor
http://i7.photobucket.com/albums/y261/Erich_870/Project001.jpg

The frame all riveted together, upside down with the springs and axle set on in place to see how it looks.
http://i7.photobucket.com/albums/y261/Erich_870/Project012.jpg

A close up of the suspension. You can see the two perches. The one on the upper right of the pic has a heim joint in it. the other heim joint is on the rod at the bottom middle of the pic. I was getting an idea of the length of rod I need. I still need to drill and tap the bottom perch.
http://i7.photobucket.com/albums/y261/Erich_870/Project013.jpg

This pic was actually taken before I started the frame, but it shows the basic design for my trailer. There are no suspension links yet.
http://i7.photobucket.com/albums/y261/Erich_870/P1020038.jpg

Let me know if you see something wrong with my suspension set up. It's nothing fancy, but I don't want any surprises when I test it.

Erich

Cebby
11-16-2006, 03:43 AM
I'll be interested to see your link layout. I'll bet it's LIGHT!!!

Driven2xs
11-16-2006, 10:05 AM
Erich,
I don't understand something. It appears in the pic that you are doing a panhard bar. That will allow the rear end to travel upwards, but on a arc that will push the axle out to one side. I assume you are also using trailing arms to limit fore/aft travel? Will you be using shocks to dampen the travel? Otherwise, that cart will be jumping off the road, as the stored kinetic energy is released by the relaxing of the compressed spring.


If you wanted to keep the axle under the cart, and still allow vertical motion, you may want to use what is called a "track Bar" instead of the panhard bar. A track bar would mount from the left front (frame) pivot to the right rear (axle) pivot position. You would mount these right on the trailing arms, as close to the pivot points. It will keep the axle centered throughout the travel.

Driven2xs
11-16-2006, 10:22 AM
Lets see if I can make a picture....

http://swracecars.com/gif/c10-300.gif



See that bar that mounts to the left front??
That will hold a 7 second car @ 200 mph, so I think the cart should be fine ! :rofl:

Erich_870
11-16-2006, 11:38 AM
Erich,
I don't understand something. It appears in the pic that you are doing a panhard bar. That will allow the rear end to travel upwards, but on a arc that will push the axle out to one side. I assume you are also using trailing arms to limit fore/aft travel? Will you be using shocks to dampen the travel? Otherwise, that cart will be jumping off the road, as the stored kinetic energy is released by the relaxing of the compressed spring.

That's correct. I've found some small shocks that I'll get if the trailer is TOO squirly, but I was thinking of lawn and garden trailers and boat trailers, most do not have shocks. I plan to pull this behind my Mt. bike, or walk along with it. I know I won't need shocks when I walk with it, we'll see about behind the bike.



If you wanted to keep the axle under the cart, and still allow vertical motion, you may want to use what is called a "track Bar" instead of the panhard bar. A track bar would mount from the left front (frame) pivot to the right rear (axle) pivot position. You would mount these right on the trailing arms, as close to the pivot points. It will keep the axle centered throughout the travel.

I'm open to any ideas, I just don't know how I would attach a track bar with the right geometry since my frame is flat. I don't have the arch in the back like the muscle car frame in your illustration (which I appreciate you for showing, as I'm a very visual learner:biggrinan )

Erich

garrett1478
07-05-2007, 03:19 PM
any updates? was this ever finished?

Erich_870
07-05-2007, 03:45 PM
It's pretty close. I need to take it to a welder in town and have it finished off. The riveted scab plates just aren't tight enough for my liking.

I need redesign the links a bit as I have too much axle wrap. I'm planning on ladder bars of sorts to just get it to work.

I was looking at a independent suspension set up that I may switch to at some point. At my current rate, that would happen about 2 years from now :fun_84:

I'll post up some pics when I get it welded.

Erich

Erich_870
09-17-2007, 06:21 PM
Well, I got it welded up and took it out for a test run this weekend. Me and the pup hiked into some ponds to look for some ducks. It was mostly a shake down and exploration trip. I didn't take a camera with me, but I got some pics before we left.

http://i7.photobucket.com/albums/y261/Erich_870/P1030232.jpg

http://i7.photobucket.com/albums/y261/Erich_870/P1030233.jpg

I still need to redo the control arms, but the side movement wasn't too bad. It was easier to push the trailer and I could keep an eye on everything.

Erich

Erich_870
10-11-2007, 07:15 PM
I got my axle back from the welder and just need to finish the links.

I want to make a hitch system like the lock n roll (http://www.locknroll.com/) but it works just fine as a hand trailer at this point.

I'll snap some more pics soon.

Any responses? :coffee:

Erich

Glenn
10-11-2007, 09:25 PM
Looks like it turned out well. What are you planning to tow it with? The reason I ask is because I have an old Popular Mech magazine that has a bike trailer (made of PVC pipe), anyway, the hitch was made from 2 eye bolts (looped through each other) and then it used an air compressor fitting for the "latch." This would allow it to pivot in all the directions like the lock n roll. :) HTH.

Cebby
10-11-2007, 10:19 PM
I think it turned out great - I want to see some pics of it in action with the kayak on it!

Erich_870
10-12-2007, 02:24 AM
Here's the only pics I have so far. It was dark when we finally hiked out from hunting some old dredge ponds near the glaicer. The beavers have free reign of the place so a bunch of the trail was flooded

http://i7.photobucket.com/albums/y261/Erich_870/DSC02737.jpg

http://i7.photobucket.com/albums/y261/Erich_870/DSC02739.jpg

Here's one of my pup and the trailer
http://i7.photobucket.com/albums/y261/Erich_870/DSC02740.jpg

I ran with the trialer for a little bit to see how it did. The dog thought it was a blast! :rofl: It seemed to handle pretty well considering it had no lateral support for the springs. Luckly I had them secured and wasn't trying to use a spring pocket set up.

Here's a pic of the axle. I had the hoop added for the upper links.
http://i7.photobucket.com/albums/y261/Erich_870/P1030271.jpg

Erich

Erich_870
10-12-2007, 02:54 AM
Looks like it turned out well. What are you planning to tow it with? The reason I ask is because I have an old Popular Mech magazine that has a bike trailer (made of PVC pipe), anyway, the hitch was made from 2 eye bolts (looped through each other) and then it used an air compressor fitting for the "latch." This would allow it to pivot in all the directions like the lock n roll. :) HTH.

Thanks :)

I'm going to tow it behind my mt. bike. There are several duck hunting areas that are hike in only, but they have very good trail access. I actually built a PVC prototype in college that I used until it finally broke one morning and it took me all day to get back to my rig :bricks:

Anyway, I've seen several options where people have used rope or plastic coated cable to loop the bike's seat post. Eventually I want a system like the lock n roll that is tight and doesn't rattle or feel sloppy.

Erich

Cebby
10-12-2007, 09:00 AM
Instead of 4 link + panhard, you might want to consider a wishbone upper link and forego the panhard.

Erich_870
10-12-2007, 12:03 PM
Instead of 4 link + panhard, you might want to consider a wishbone upper link and forego the panhard.

That's the plan, sort of. I'm going for a triangulated 4 link. I think I know what you mean about a wishbone upper link, but I'm going to run with two individual links on top mostly because I don't have a way to bend or weld the tubing I'm using for the links. I'll get some close ups of the the welds on the trailer, but the welder I've been using does not have the touch to weld light guage tubing.

Erich

Glenn
10-13-2007, 09:25 AM
Thanks :)

I'm going to tow it behind my mt. bike. There are several duck hunting areas that are hike in only, but they have very good trail access. I actually built a PVC prototype in college that I used until it finally broke one morning and it took me all day to get back to my rig :bricks:

Anyway, I've seen several options where people have used rope or plastic coated cable to loop the bike's seat post. Eventually I want a system like the lock n roll that is tight and doesn't rattle or feel sloppy.

Erich

If I can dig up the article I will scan it for you. If I recall, it was a decent design and would allow you to hook and unhook it from the bike using the air compression coupler.

Erich_870
10-14-2007, 03:10 AM
If I can dig up the article I will scan it for you. If I recall, it was a decent design and would allow you to hook and unhook it from the bike using the air compression coupler.

That would be great!

Cebby,

Here's some pics of my duck hunting kayak I built the trailer for.

The pup in front of the Marshrat
http://i7.photobucket.com/albums/y261/Erich_870/P1030273.jpg


My helper.
http://i7.photobucket.com/albums/y261/Erich_870/P1030277.jpg


I made a quick set of guides to keep the Marshrat from moving.
http://i7.photobucket.com/albums/y261/Erich_870/P1030276.jpg


I put to original links back on to get some more measurements at sprung weight.
http://i7.photobucket.com/albums/y261/Erich_870/P1030275.jpg


A view from the front.
http://i7.photobucket.com/albums/y261/Erich_870/P1030278.jpg

I'm playing around with the suspension geometry on ExcelCAD v2.1 - Multi-link Suspension Design program I found on Offroad Fabrication Network.

Right now I have an anti-squat of 147%, a roll axis slope of 0.31, and a roll axis angle of 17.21deg. This is probably the best I can do since my frame is flat. I'd have to make an inverted hoop that hangs off the bottom of the frame to get the links parallel. :rolleyes:

My shed construction took priority today since it stopped raining, so I haven't made the new links yet.

Erich

Glenn
10-21-2007, 09:33 PM
OK, here is a scan of the article. (It was in a 1984 issue!) Hope it is clear enough and I hope it helps. My cousin built this little cart as seen in the article. If I recall correctly, it all worked pretty well.

(I did not have permission to copy this article, however it is copyright Popular Mechanics.)

Erich_870
10-22-2007, 12:31 PM
That's pretty cool! I'll have to give the hitch system a try. Especially since the materials are all listed. :)

Thanks for digging up your copy and scanning it :goodpost:

Erich

Glenn
10-22-2007, 09:27 PM
My pleasure.

Erich_870
12-09-2008, 07:24 PM
Here's a bunch of updated pics.

I still haven't towed it behind my bike becuase it still has some bugs to be worked out, but I've walked with it 3 or 4 times this year.

http://i7.photobucket.com/albums/y261/Erich_870/Waterfowl%20Hunting/Marsh%20Rat%20Trailer/P1030992.jpg

http://i7.photobucket.com/albums/y261/Erich_870/Waterfowl%20Hunting/Marsh%20Rat%20Trailer/P1030995.jpg

http://i7.photobucket.com/albums/y261/Erich_870/Waterfowl%20Hunting/Marsh%20Rat%20Trailer/P1030997.jpg

http://i7.photobucket.com/albums/y261/Erich_870/Waterfowl%20Hunting/Marsh%20Rat%20Trailer/P1030999.jpg

I've decided I'm moving away from the triangulated 4-link as it has too many parts and doesn't match my needs for this project.

I'm working on Phase III right now :drink:

Erich

MXtras
12-10-2008, 09:30 AM
Very interesting. Keep us posted as you proceed!

Scott

Erich_870
02-16-2011, 01:41 AM
Update: My poorly constructed swing arm attachment points failed at the end of the 2009 season so I didn't even use it for 2010, but I have a design borrowed from the off-road trailer crew. I'm going to weld on some tabs and use a trailing arm design. I have all the components, just need the weather to warm up.

Erich