Trailer Build Planning

hube2 · Jul 15, 2021

In another discussion I was looking for a trailer. In the end I have decided that I would be better off if I just build it myself. I'm going to use a Harbor Freight 1720# frame. There are many examples of doing this out there so I have a lot of inspiration. Also a lot of tips on issues and things that need to be improved like the grounding issues.

Anyway, I am going to build railings using cedar because it is lighter weight than other materials but still sturdy, unless someone can tell me of something lighter I can use that will still be sturdy. The railings will be 32 inches high form the trailer bed because I am going to use plywood to enclose it when I need to haul something like stone. A single sheet of plywood will cut nicely to fit this height.

Here's the part where I am looking for ideas...

I would like to be able to easily and quickly attach and detach the plywood from the railings.

I'm not exactly sure how to accomplish this. I have some ideas on how this might be done but I want to see what others think. I could do it with carriage bolts but that would be a real pita if I wanted to take them off.

The panels would need to attach securely so that they could not come loose and should also be tight enough to help prevent any warping and yet be attached in a way that would let me "unhook" them easily. It would also be nice if it didn't look like crap.

I'm thinking of some kind of clamp or bracket but can't seem to find anything... more than likely because I'd need to know what it would be called to find it.

Any ideas?

jaxs · Jul 15, 2021

If that frame is 48"x96", 8" sides will hold all the rock,sand or dirt axles and springs can support. Tires may farthar reduce load capacity so look at those before getting too far along. Perhaps making bottom slat of 3 slat side shown above 8-10 inches tall can make plywood unneccessary when hauling rock. Wish you were close,I'd injoy helping you weld up a trailer that fit your need. For this I'd salvage a tandem axle boat trailer,cut it way down in leingth and build from there. That give's you wheels for 15 or 16 inch tires that easily carry 1k each on passenger tires and much more on LT truck tires. $500 to $800 ready for floor. Sorry about thread wander,what is the "grounding"issue you mentioned?

CoyPatton · Jul 16, 2021

My personal experience with one of these light duty trailers is that the 1720lbs of weight rating is over rated and based solely on what the tires are rated to handle at the prescribed psi!
I had one of these trailers. Carrying about 1500lbs on the trailer with the weight over the axle and forward of the axle, tires fully inflated, I bent the frame of the trailer, there was no weight in the back 2-2.5 ft of the trailer. Yet the frame bent from traveling on the highway at reduced speeds. Following this experience, I limited the load on the trailer to 1000lbs or less, typically less in the form of s small lawn mower. Upon purchase of a larger/heavier mower, a larger trailer was purchased.

newbury · Jul 16, 2021

For fastening Plywood to slats I've used flat ubolts. flat ubolt
And for assembly/disassembly I use an extra deep 7/16 socket on my DeWalt 20vMax drill.

hube2 · Jul 16, 2021

jaxs said:
If that frame is 48"x96", 8" sides will hold all the rock,sand or dirt axles and springs can support. Tires may farthar reduce load capacity so look at those before getting too far along. Perhaps making bottom slat of 3 slat side shown above 8-10 inches tall can make plywood unneccessary when hauling rock. Wish you were close,I'd injoy helping you weld up a trailer that fit your need. For this I'd salvage a tandem axle boat trailer,cut it way down in leingth and build from there. That give's you wheels for 15 or 16 inch tires that easily carry 1k each on passenger tires and much more on LT truck tires. $500 to $800 ready for floor. Sorry about thread wander,what is the "grounding"issue you mentioned?

Didn't actually think about the fact that I could not possible carry that much stone. I get it in 1000# loads and you're right, that's not much stone and I don't need 32 inches of depth on the sides. using an 8 or 10 inch wide board on the bottom may be the simplest solution.

hube2 · Jul 16, 2021

jaxs said:
Sorry about thread wander,what is the "grounding"issue you mentioned?

Sorry I missed your question.

the wiring that comes with these trailers does not run the ground wire to all of the lights. Instead you are supposed to connect the ground for each light directly to the frame near then light and you connect the ground at the front to the frame. The issue is that with all the paint and the fact the the frame connections are not solid so that it can fold the continuity is poor. The only real way to fix it is to get some additional wire to run all the way to the lights instead.

hube2 · Jul 16, 2021

Going to be honest here, the only reason I was going to make the sides 32 inches was because a 4x8 sheet of plywood would be extremely easy to cut up to fit the size of the trailer.

The comment by @jaxs really made me think about how deep this thing really needs to be. I seriously doubt that I will ever need that kind of depth. I can just make the sides a lot shorter. A single 1x12 board would give me plenty of depth to haul anything that I'm likely to haul. Means less materials and less weight reducing the load capacity of the trailer.

If I ever need something taller I can simply build a second set of rails.

This is why I posted my question, to get someone to make me think about things that I had not thought about.

WranglerX · Jul 16, 2021

A lot of people in "teardrop" trailer world use the HF Chinesium trailers for base, and many report a failure of where tongue attaches to bed to be a failure point... Secondary failure point is wheels and tires.... I would think for "farm" work where trailer is treated more roughly than on a "highway" that HF trailers is not going to be what you hoped it would be...

hube2 · Jul 16, 2021

DL Meisen said:
A lot of people in "teardrop" trailer world use the HF Chinesium trailers for base, and many report a failure of where tongue attaches to bed to be a failure point... Secondary failure point is wheels and tires.... I would think for "farm" work where trailer is treated more roughly than on a "highway" that HF trailers is not going to be what you hoped it would be...

I am not 100% decided on the frame, but it's what will suit my needs.

It's really not going to see much use and most of that use will get to haul things home. Yes, the small tires will limit my speed, but it's not like I'm going to be pulling this every time I pull out of my driveway.

I'm not going to build my own trailer completely from scratch (frame). What I need a frame like this that is already road worthy that I can have shipped to my door and all I need to do is put it together. Adding a plywood deck and some lumber sides is in my skill set. Building a trailer frame is not. Taring down some old trailer that started life as something else and getting it road worthy is also something likely beyond my capability to get done.

I'm willing to go with some other trailer frame kit in about the same size if anyone has suggestions, but I'm not finding anything that really any better than the one from HF.

nyone · Jul 17, 2021

hube2 said:
I am not 100% decided on the frame, but it's what will suit my needs.

It's really not going to see much use and most of that use will get to haul things home. Yes, the small tires will limit my speed, but it's not like I'm going to be pulling this every time I pull out of my driveway.

I'm not going to build my own trailer completely from scratch (frame). What I need a frame like this that is already road worthy that I can have shipped to my door and all I need to do is put it together. Adding a plywood deck and some lumber sides is in my skill set. Building a trailer frame is not. Taring down some old trailer that started life as something else and getting it road worthy is also something likely beyond my capability to get done.

I'm willing to go with some other trailer frame kit in about the same size if anyone has suggestions, but I'm not finding anything that really any better than the one from HF.

Any trailer that you can get shipped to your house and bolt together is going to be prety poor quality in part because if they can ship it to you in a box they can ship it from over sea in a bigger box.

mrmikey · Jul 17, 2021

I drew this up (attached) almost 12 years ago and made my own trailer from it. Only change from original is I changed the Torqueflex axles from 2000LB to 3500LB and added electric brakes as I haul a 1100L water tank as my daughters well goes dry in the summer. So weight of trailer 700lbs ±, water 2500lbs for a total of 3200lbs±.
I made a similar size trailer my SIN but he wanted a conventional lighter spring axle instead of the Torqueflex. After hauling his and mine, I'd never consider a leaf spring suspension if I had a choice. When empty, the Torqueflex hits a bump, bounces twice and stops, his is still bouncing 10 minutes later LOL.
Full, mine bounces once and stops........Mike

ArlyA · Jul 17, 2021

hube2 said:
Didn't actually think about the fact that I could not possible carry that much stone. I get it in 1000# loads and you're right, that's not much stone and I don't need 32 inches of depth on the sides. using an 8 or 10 inch wide board on the bottom may be the simplest solution.

Go bigger ak higher capacity, go better frame, is my suggestion.

jaxs · Jul 17, 2021

hube2 said:
Sorry I missed your question.

the wiring that comes with these trailers does not run the ground wire to all of the lights. Instead you are supposed to connect the ground for each light directly to the frame near then light and you connect the ground at the front to the frame. The issue is that with all the paint and the fact the the frame connections are not solid so that it can fold the continuity is poor. The only real way to fix it is to get some additional wire to run all the way to the lights instead.

Thanks,I wanted to know so as to best address your concern without detouring. You are correct,that is absolutly a poor way to ground when frame is bolted togeather instead of welded. Adding a dedicated ground wire that go's to all lights is simple and straightfoward. The conventional flat car to trailer plug already has the dedicated ground wire. Just make sure all connections are good and take time to route wires where weeds and brush can't grab wire and pull it loose. Through boxed frame members or tucked to an inside corner of angle or channel is a good idea. I think your best option is a used trailer such as this so that you get welded frame,heavier duty,larger tires and within budget.

CoyPatton · Jul 17, 2021

jaxs said:
Thanks,I wanted to know so as to best address your concern without detouring. You are correct,that is absolutly a poor way to ground when frame is bolted togeather instead of welded. Adding a dedicated ground wire that go's to all lights is simple and straightfoward. The conventional flat car to trailer plug already has the dedicated ground wire. Just make sure all connections are good and take time to route wires where weeds and brush can't grab wire and pull it loose. Through boxed frame members or tucked to an inside corner of angle or channel is a good idea. I think your best option is a used trailer so that you get welded frame,heavier duty,larger tires and within budget.

I have re-wired many many trailers. A few of the various folding trailers. Any bolt together trailers have a major issue with frame grounding—dissimilar metals of bolts wasters and these frames exposed to weather are a recipe for quickly compromised grounding through the frame. If you want the trailer to fold, as many do for compact storage, you have a built in problem area for wiring to be jerked out, as you must have slack for the wiring to not be damaged when folded.
One way to get 3 separate wires of slightly greater gauge is to use extension cord wire. You will have to determine what color you use for what purpose as you are limited to white, black and green.

WranglerX · Jul 18, 2021

CoyPatton said:
I have re-wired many many trailers. A few of the various folding trailers. Any bolt together trailers have a major issue with frame grounding—dissimilar metals of bolts wasters and these frames exposed to weather are a recipe for quickly compromised grounding through the frame. If you want the trailer to fold, as many do for compact storage, you have a built in problem area for wiring to be jerked out, as you must have slack for the wiring to not be damaged when folded.
One way to get 3 separate wires of slightly greater gauge is to use extension cord wire. You will have to determine what color you use for what purpose as you are limited to white, black and green.

https://www.etrailer.com/Accessories-and-Parts/Deka/DW04923-1.html

CoyPatton · Jul 19, 2021

DL Meisen said:
https://www.etrailer.com/Accessories-and-Parts/Deka/DW04923-1.html

$2.80 a foot
14 feet. Distance from rear bumper of pull vehicle to rear of trailer (allows for slack for turning and at fold point).
6 feet. Distance from one side light to other side light.
20 feet total at $3 per foot = $60 for a 4x8 framed trailer.
Compared to either salvaging a cord or using a damaged cord for wiring a trailer?
Your decision! But unless you plan well in advance you have some wait time also. With shipping these days from all carriers that could be a week or a month.

WranglerX · Jul 19, 2021

But do it once properly and it is good forever... Really hate rebuilding trailer wiring every few years using lesser quality stuff... Also it's kind of comforting to know when ever I hook up the lights will be working and not have to muck around with them ever time I want to use trailer....

But really my post was to only show that 4 wire cable was available for those who might need it for proper wiring job....

flyerdan · Jul 19, 2021

Using the frame for a ground is fine if everything is welded together so there aren't any continuity issues.
When we built a bobcat trailer at work (back in the 90's) it had 2x4 frame rails that the lights were integral to. While it was tacked together, I took measurements and strung pull wires, then prefabbed the wiring harness to live inside the tubes. When the welding was done, pulled the wiring in and drilled for the grounds. Cleaned and deburred the inside where the pop rivet would hold the terminal. I think there were five ground rivets for eight lights total.
Also had a junction box at the front to tie both sides to the plug wiring. If you have a shared trailer where employees may forget to unplug it before driving away, or grind it off on the highway, having a replaceable wiring lead can save a lot of headaches down the line.

jaxs · Jul 19, 2021

flyerdan said:
If you have a shared trailer where employees may forget to unplug it before driving away, or grind it off on the highway, having a replaceable wiring lead can save a lot of headaches down the line.

Do you mean to say people don't always stop then and there to put things back like they found them?.

hube2 · Jul 20, 2021

To be honest, I'd prefer not to have a folding trailer. The likelihood that I will ever fold it is small. More than likely I'm going to replace all the pins with bolts and be done with it.

Edited to add: I might be able to fold it in half, but it will never stand safely or be rolled around on those tiny stand wheels where I will be storing it.

I have looked for other similar trailers that are available but the capacities of what I have found are much less or the wheels are even smaller. On the other hand I wouldn't be able to store anything bigger. Nothing that I've seen that comes assembled will suit my needs and I'd just be buying something that would need even more work to make it suit those needs.

If I had the skill and the equipment I'd probably build my own or if I had the skill and ability I'd get something else and modify it. But I need to work within what I know that I am capable of doing or I'll just end up with a piece of crap sitting in my yard that never gets finished and I have to move around every time I have to mow.

What I really need is 2 trailers, one for the road and one to drag around my property with the tractor, but I just don't have the space to store unitaskers. When I say drag around the property, it's not going to get a work out off roading, we're talking lawn and flat (well hilly but smooth) field.

I appreciate the link to the wire actually. I just had a talk with my father in law who has one of these and he has had to to rewire it every spring due to rodents. Something with a jacket rather than loose wires would have a better chance of surviving storage. Yes, it costs more, but would it really cost more if I needed to replace wires every year?