My Trailer Build Plan W/Questions (1 Viewer)

[ntsqd]

Don't limit yourself to Jeep products. There's a whole range of leaf sprung vehicles out there to choose from. For instance, those off the rear of Ford Ranger are 57" long and then there are the iconic "GM 63's" rear leaves off of the 1/2t & 3/4t GM pick-ups. S-10 rear leaves are shorter and may work better for a small trailer. Then there's the whole range of import mini-trucks. Mazda rear springs were a popular swap into crawler yota mini's for a while. Go for a walk thru the JY with a tape measure.

 

[greentruck]

Yeah, Isuzu put some pretty good springs under the back ends of my Trooper II and Rodeo. Never had a problem with either. I don't recall any exact dimensions, but they're are in the ballpark of what you're looking for. I would think with most minitrucks and similar, the capacity is probably close to what you're looking for without the need to take leaves out.

 

[LFD2037]

Don't limit yourself to Jeep products. There's a whole range of leaf sprung vehicles out there to choose from. For instance, those off the rear of Ford Ranger are 57" long and then there are the iconic "GM 63's" rear leaves off of the 1/2t & 3/4t GM pick-ups. S-10 rear leaves are shorter and may work better for a small trailer. Then there's the whole range of import mini-trucks. Mazda rear springs were a popular swap into crawler yota mini's for a while. Go for a walk thru the JY with a tape measure.

I'm familiar w/many of leaf springs, especially GM 63", but they are way too long for this application. The YJ's are 44" & I feel that's pushing it a bit. I was also thinking mini trucks, especially Yota mini's. I need to do what you said, hit the JY w/a tape & pic a decent set.

 

[LFD2037]

I should be buying all my metal beginning of next week. I'm kind of glad I've waited on buying the metal because it has allowed me to brainstorm a bit more about exactly what I want to do. I still haven't figured out how I'll do the lid or the tailgate (or do I even need a tailgate?). After our trip to Yellowstone last month I realized I really need a fully closed, lockable trailer. We had to stay in a hotel on the drive there & back (almost 1,400 miles each way). I worried all night about all our gear sitting exposed (well, in big Husky plastic job boxes) and if someone would mess w/it. Any unique & simple ideas for the lid & tailgate? Anybody regret NOT having a tailgate?
Also, I changed my mind, I think, on the uprights for the box. I'm thinking 1"x2" (instead of 2"sq. tubing) and placing them on the outside edge of the frame, leaving a 1" lip along the frame on the whole interior. This way I can put a marine grade piece of plywood (coated w/a waterproofer) on the bottom & it'll have a 1" lip all the way around that it'll catch on the frame plus the cross braces of the frame. Any problem w/this idea?

 

[greentruck]

A number of folks have made lids for the M101 CDN based on a design by a Canadian fellow who owns a metal shop of some kind. There are examples documented here. I have a copy of the basic plan illustration, but I think there is a more detailed plan around somewhere. Would be glad to forward it to you if you send an email address to me in a PM. It's designed as aluminum, but could be done in plywood to the same basic design.

I should be noted that a few people have observed what they believe are variances in the dimensions of the upper lip of the bed on the M101 CDN, so double check how everything interfaces together if you do build a lid to any plan said to be for a particular model trailer. Nothing like finding out you're a 1/2" off AFTER the darn thing is finished and ready to mate with the trailer...

 

[LFD2037]

A number of folks have made lids for the M101 CDN based on a design by a Canadian fellow who owns a metal shop of some kind. There are examples documented here. I have a copy of the basic plan illustration, but I think there is a more detailed plan around somewhere. Would be glad to forward it to you if you send an email address to me in a PM. It's designed as aluminum, but could be done in plywood to the same basic design.

I should be noted that a few people have observed what they believe are variances in the dimensions of the upper lip of the bed on the M101 CDN, so double check how everything interfaces together if you do build a lid to any plan said to be for a particular model trailer. Nothing like finding out you're a 1/2" off AFTER the darn thing is finished and ready to mate with the trailer...

Does your trailer have a tailgate? If not, do you really wish it did?

 

[greentruck]

No, it doesn't. I'm glad it doesn't, as it's tub is much stronger for it. I've seen enough butcher jobs to have come to the conclusion I'm better off without a tailgate.

I have seen good quality ones done. These typically retain a bar that goes across the top of the opening to tie the two sides together and devote a lot of attention to good hinges and latches, plus sealing against water and dust. Usually, the top bar is removable, in case you need to load large objects, but I've seen a few that retained a piece of the tub across the top of the rear of the tub and instead had something more like a door below that for access. This suits well if you have a RTT on top and want to reach in to grab stuff without tilting the RTT out of the way.

Which is not to say you can't design in tailgate and not have it come out OK. The mil-spec 1/4 ton trailers just weren't designed for a tailgate.

 

[LFD2037]

Yeah, the more I think about it the more I dislike having a tailgate. I really don't see a true NEED for one.

 

[greentruck]

With a bed the size of a 1/4 ton, you can reach in easily to get things over the side (unless you're really short or the tires on the trailer are a very large diameter.) A lid tends to restrict this some. But there is little need for a tailgate unless you regularly haul heavy items best slid off the rear. And there's another way to deal with that. My back grew worse over the last few years, so am thinking of installing one of those small winch/cranes they sell for pickup beds to sling my chuckbox in and out of the bed.

 

[LFD2037]

Got the majority of the steel today. Got all the frame and uprights cut. Grinded the mill scale off all the spots I'll be welding on the frame corners. Laid it out and am taking a break. I'll weld most of the frame later today.

 

[LFD2037]

Got the main frame welded today. Started on the tongue and realized I need 4' more of the 2.5"x3/16 for part of the A. I layed the taped and level where I'll be putting the A beams. Can't find my angle tool so have to go buy another one and more flap discs. I'll continue in the morning and post more progress tomorrow.

 

[LFD2037]

Got bored so I went into the garage. Realized I can't make the A-frame the way I planned (should've been obvious before now!). Since I'm not using the standard 20" trailer springs, the rear most part of the 'A' beams will be inside the frame & the spring. Doh'! About the only way I can do it similar to how I was going to will have the A beams only 31" long, ending about 6" down the frame side beam & at a 45* angle as opposed to 48" long, ~30* angle & tying into the frame side beam &/@ the 2nd cross-member. The center tongue section w/be welded to the 1st & 2nd crossmembers. The A beams with be welded to the center tongue, 1st cross-member and each frame side. Will this be okay? I know it'll be stronger than all the trailers, < 8' long, that I saw @ Tractor Supply today as they have only the single center tongue going back to the 2nd cross-member w/no other tongue support. I think it'll be perfectly fine but I'd like some honest input before I weld the tongue on. Thanks!

 

[LandCruiserPhil]

Got bored so I went into the garage. Realized I can't make the A-frame the way I planned (should've been obvious before now!). Since I'm not using the standard 20" trailer springs, the rear most part of the 'A' beams will be inside the frame & the spring. Doh'! About the only way I can do it similar to how I was going to will have the A beams only 31" long, ending about 6" down the frame side beam & at a 45* angle as opposed to 48" long, ~30* angle & tying into the frame side beam &/@ the 2nd cross-member. The center tongue section w/be welded to the 1st & 2nd crossmembers. The A beams with be welded to the center tongue, 1st cross-member and each frame side. Will this be okay? I know it'll be stronger than all the trailers, < 8' long, that I saw @ Tractor Supply today as they have only the single center tongue going back to the 2nd cross-member w/no other tongue support. I think it'll be perfectly fine but I'd like some honest input before I weld the tongue on. Thanks!

A single tongue is a huge advantage in maneuverability and designed correctly is plenty strong.

 

[Billyfj7312ht]

How do the new angles work out with your turning circle/jackknife situation?

 

[LFD2037]

How do the new angles work out with your turning circle/jackknife situation?

I measured before I cut the main tongue. I needed 36" to clear the bumper w/a full jacknife. I added 20" because my Pelican cooler will be on the tongue 24/7. The A beams will work in either the original plan or the new plan.

A single tongue is a huge advantage in maneuverability and designed correctly is plenty strong.

Do you think this will be designed correctly?

Thanks.

 

[greentruck]

Got bored so I went into the garage. Realized I can't make the A-frame the way I planned (should've been obvious before now!). Since I'm not using the standard 20" trailer springs, the rear most part of the 'A' beams will be inside the frame & the spring. Doh'! SNIP
Thanks!

You're actually real close to how my M101 CDN frame and suspension are set up. The A beams run back to the crossmember that is also at the location of the front spring perch and weld just inside the spring perch. The spring perch sits on the side rail of the frame and is welded to it. Seems to have been plenty strong enough for the Canadians, who largely copied the Americans while making some marked improvements. Here's a side view that helps locate the positioning of things relative to each other.

The perches also raise the body above the springs, leaving plenty of travel room for the axle that is located atop the springs. The stock set-up will handle up to 33" tires without modification so long as your fender lips clear.

 

[LFD2037]

Looks like I'm going to hold off on doing the tongue until I get some springs. Then I can dial everything in properly. I'll finish building the box today, hopefully.

 

[greentruck]

BTW, the spring perches on the M101 CDN are nothing fancy. You can see the front one is divided. Basically, the upper part is a piece of channel that fits up over the frame rail and is welded to it. The lower one is the same channel size, cut differently and turned down, welded to the upper one there in the middle where you see the seam. The front spring pin goes through to retain the spring by the eye.

The rears are a little more complex, sorta a sideways version of the front, but with a gusset on the inside to reinforce the rear portion. That's right above where the upper eye for the rear shackle is welded underneath. I can take better pics, if you'd like, but this really isn't rocket engineering here.

You may want to think about axle placement. The military had a good compromise, putting about 60% of the trailer ahead of the axle, so tongue weight tends towards correct with an evenly distributed load. For our purposes, you might put heavy stuff in front that stays there and tanks, where the weight varies, above the axle. That would leave you more tailgate area for the lighter, bulkier things, depending on your use, but might have to be more attentive to the urge to over load an bigger rear are past the axle.

 

[LandCruiserPhil]

Do you think this will be designed correctly?

Thanks.

From my experience to design the tongue correctly you need to know the weight you are dealing with and the desired length of the tongue. There are formulas for correct tongue design if you are using single bar or V supported. Rather than go with a bigger and heavier WAG building design I wanted the lightest design but plenty strong for my needs.
What are you using for a design guide?

I had no interest in dealing with this ▲▲

 

[LFD2037]

I'm using several different design guides, from the Internet. One is from the same guys you posted above. They have a calculator for tongue weight/design but not for a hybrid version like I'll now be using. The original tongue design I was using from another group of trailer people. It was way plenty strong for my plans, as I'm thinking the new way will as well. Got all of the box and frame welded today. I might put some 45* braces on the back wall but not sure it needs it. I managed to keep the whole box/frame 100% level and squared by welding opposing sides/ends, going to other end of trailer, doing the same thing, over and over again. Took extra time but I felt it was worth it. Probably won't be doing much else for a week or 2. I'll post back when I have more progress or questions. Thanks!

And a couple pics of my welds because somebody always wants to see the welds.