Flatbed Trailer

[farmersamm]

This will probably be the last bit of work for at least a week, there's real bad weather forecast for the next 7 days

The tongue framing layout is complete.



All the angle cuts were done with a razor wheel, extremely accurate for a nice fitup. It allows you to mark the ACTUAL angle, then cut it, instead of relying on measured angles



A good tight fit helps control distortion when the final welding is done. While it's possible to fill gaps in fitup, it causes the metal to pull badly when the bead shrinks in the void.



I've started sizing plate for the fishplates. Very convenient with the plasma cutter. Nice accurate straight cuts. 3/8" plate with the machine set at 55amps.





And that's about it until the weather allows me back into the "shop"

[TSCGG13]

Samm what sizes of channel are you using for the outside, and the crossmembers?

[farmersamm]

Latest progress through the weekend. AND PROBABLY FOR THE NEXT 7+ DAYS



Suppose it was time to get this weather, it's hit all the rest of the country so now it's our turn.

[Stick-man]

That sucks samm. I have been out in the cold and plowed so much this year, I really don't even feel it unless it's in the single digits. Stay warm, my friend!!!

[Dualie]

had some friends driving down I-40, said it was a real shat show with ice last night. good luck sam, hope you and the little lady stocked up and beer and firewood

[Tsanchez]

Good job.

[farmersamm]

Weather finally broke, and we're in the 30's today

After sizing the 3/8" UM plate for the fishplates, it's time to finish them out.



A straightedge, offset to compensate for the standoff guide, works good.



You see the cut marks? These are the result of cutting by hand. The travel speed can't be perfect, and you will get some marks along the cut edge. The important thing is that the pencil edge, and the reverse side, are perfect. This is 50amps, and air at 75psi.

If you can cut to your lines the way you want them, it's GAME ON



The points are trimmed, you don't want any sharp corners to create stress raisers, and they're ready to go to the LWS for bending. These have to be cold bent in order to preserve the metal's qualities. Remember that these are to reinforce an area that's been heat worked, and the metal damaged by heat working.



A note on slag (or dross if you prefer). This is about average for a non machine cut, and it's easily removed with a piece of scrap by scraping it.

[farmersamm]

I heard from somebody that I work too slow

Well, this is about near on 1.75 hours work. Dragging the machines out, setting them up, layout work, setup time for each cut, and actual cutting

I can do it faster, but I'd probably be unhappy with the outcome I have a thing for getting it right

[Canner]

I heard from somebody that I work too slow

Well, this is about near on 1.75 hours work. Dragging the machines out, setting them up, layout work, setup time for each cut, and actual cutting

I can do it faster, but I'd probably be unhappy with the outcome I have a thing for getting it right

I think you are doing it just right, if you wanted to work in a production shop you would but instead you have chosen to live on a farm and work for yourself. It is a completely different program and you are doing it. When you work for yourself there are lots of different jobs that have to be balanced not just the one that you are posting here.

By the way I have always enjoyed reading your posts and what you share, you have a knack for teaching and connecting with people that is rare. Which is not to say that I always agree with everything you say but enjoy it anyways.

[rdbrnr]

going to be a nice trailer Sam

[farmersamm]

I got very lucky today, they were able to get me in and do the press brake work

Very nice machine



First the piece is squared up, and lined up with my bend mark that I made.



Then the doood does the bend. He likes to sit off to the side while looking down the length of the machine bed, this gives him an accurate view of just how much bend he's putting on the metal.



Quite a machine, bends it like butter I took my machinists protractor with me, and it checked out to exactly 19 degrees with just one re-bend. This guy is good!!



The cost was very reasonable ($8.00). I'm lucky to have a one-stop supplier. Welding supplies, welding equipment, steel, and machine work, all under the same roof. Makes life pretty easy compared to other areas.

So now the fishplates are 100% complete.

[TSCGG13]

Good work! Lets see more! What are you doing for a deck?

[camjeep3]

we had the same machine where I used to work, Trailer is coming along nicely. Its hard to beat a well build custom trailer

[farmersamm]

The frame is complete, with the fishplated section done last.

The fishplates have absorbed a HUGE amount of time, much more than I thought they would.

Each plate has 42" of weld, and each set of cover plates has 18" of weld. Combined, that's 156" of weld

Working from side to side, preheating, moving crap, etc....................It's a whopper of a time killer

Preheat was 400 degrees, welds along a portion of the plate done, then repeated in the identical location on the opposite side of the trailer in order to balance the heat input, and hopefully keep everything relatively square.

The large fishplate was done with the little crackerbox running wide open at 125amps (Although I don't really feel that it was ever a full advertised output). The coverplates were done with the Ranger in the upper end of the 130amp range, and the welds were much nicer, and more to my liking.



You can see the difference in the heat input if you look carefully. The upper welds on the cover plate are very uniform, and a bit wider, due to the availability of more amperage. The ones on the fishplate, while still ok, are a bit narrow due to having to concentrate the available amperage from the transformer welder in a tighter bead.



I would not attempt this with anything other than a very beefy welder capable of a decent output. The reinforcement plates are 3/8", and the flange along the outside of the channel is close to 1/2" at it's thickest point.



Somebody will chime in, and say it's possible to use smaller equipment with a good preheat No it ain't Running the 1/8 rod at the upper limit, with 400 degrees already in the metal(verified with IR thermometer), is just about the limit for this size rod. It would be easier with larger 5/32 rod, but my weld lands are less than or just about 3/8", so the smaller rod had to be used.

All this time today, and I still gotta finish the underside coverplates That's another long session I guess. And I still haven't gotten around to even chipping slag off of the rest of the welds on the trailer, I'm fighting windy weather, and have narrow windows to work. GEEZ. But on the upside, it's all downhill from here.

[ThorsHammer]

looking good Sam, Can't wait to see the finished product. You painting it yourself or having it powder coated?

[Boostinjdm]

Somebody will chime in, and say it's possible to use smaller equipment with a good preheat No it ain't

I'll take it a step further and say it can be done without preheat.

[Gravel]

Hey Farmersamm,
make mine 7 x 20 and bumper pull, please!

[tanglediver]

It's a rare axle u-bolt that will come off any better than that. I don't even try anymore, just torch them and get new ones.

Now we need to start a best practices thread about proper wiring of trailers now.

This ought to settle the torque tube argument.

All that for a golf cart?

I heard from somebody that I work too slow

Well, this is about near on 1.75 hours work. Dragging the machines out, setting them up, layout work, setup time for each cut, and actual cutting

I can do it faster, but I'd probably be unhappy with the outcome I have a thing for getting it right

I get that at work too, I always wonder how much time they save when the work comes back for a second go-round.

Hey Farmersamm,
make mine 7 x 20 and bumper pull, please!

I can just hear Shemp Howard say, "7 x 20 bumper pull, coming right uuuuuuup! Ibibibibibibib!"

[jlames]

I heard from somebody that I work too slow

Well, this is about near on 1.75 hours work. Dragging the machines out, setting them up, layout work, setup time for each cut, and actual cutting

I can do it faster, but I'd probably be unhappy with the outcome I have a thing for getting it right

Last I checked, as with anything you love to do, for me anyway, it really "isn't the destination but rather the journey".

[farmersamm]

I'll take it a step further and say it can be done without preheat.

You would probably have something that looked good on the surface, but just might be less than adequate below the surface. The only way you'd find out is when the weld pulls out due to lack of penetration.

Here at least, the preheat serves three purposes. First to increase penetration, second to relieve stress, and third to moderate thermal upset (distortion). At least that was my attempt.

It's a given, and we all know it, that preheat will stretch the penetration potential of your particular combination of equipment, consumable type, and steel thickness.

Of greatest concern to me, in this situation, is "upset". A fancy word for the effect of heating metal, causing it to expand, then allowing it to cool in a restrained state. The cooling causes shrinkage in the area which borders the thermal zones (heated metal, and unheated metal). Because the cool metal acts as a restraint, it will move when the heated metal shrinks. It actually alters the structural shape of what you've welded. Heating a small portion of a structure, and allowing it to cool, will move the entire structure to some degree. (Conversely, if the entire structure were heated uniformly to the same temperature there would be no upset, and the entire structure would cool uniformly, and retain its original shape) (This phenomena has had some real detrimental effects in automotive technology ie. the marriage of cast iron engine blocks with aluminum heads....different cooling rates of the two metals has caused some problems)

Anyhow I get to rambling....... If you preheat the area it will slow cooling when the weld is completed, and also put some heat further away from the actual weld, sort of a buffer between the 2500 degree puddle, and the cool metal. The surrounding area becomes less of a big heat sink.

Slowing cooling relieves stress. And it helps to relieve stress cracks when welding heavier plate or heavier masses. The stress cracks can begin immediately after the weld is made, and show up later when the surrounding area cracks with fatigue cycles. Most failures are generally adjacent to the weld, the weld itself seldom fails.

There's other ways to relieve stress, but they're way beyond my ability to accomplish. Shot peening, and normalizing, are the two ways that immediately come to mind.

And by relieving stress to some extent, we've also helped to prevent distortion to some degree. Not entirely, but at least to some degree. There's always distortion.

Here's a pretty good example............Weld something, and listen to it cool. You hear a distinctive ticking sound. That's contraction in a restrained state. The metal is moving.

Now preheat the area adjacent to the weld to between 400-600 degrees, weld it, and step back and listen. You won't hear that ticking sound, or at least hear less ticking. It's because the metal is moving slower, and somewhat to a lesser degree.

The reinforced area here is full of locked up stress, I MEAN MONDO FULL By my way of thinking ANY form of stress relief has to be beneficial. There's a ton of weld piled on top of weld.

I mean, nothing here is an absolute solution, but I feel it's a step towards remediating the problem.

[farmersamm]

"remediating" Stupid stupid stupid......... Actually a lousy word for what I'm saying, probably should be remedying. Get fancy, and you fall on your nose

[Brand X]

Sam,
time to find a Metalmuncher with a brake attachment. Farming this stuff out, is like buying a factory built trailer...

[farmersamm]

Today is floor day

To cut waste, and leave longer useable drops, I'm cutting all the floor supports out of full sticks.



To save weight, the supports are 24" O.C. This would be too wide for a wood floor, but will be ok for a steel floor



Like my ladder elbow rest?? It's nice for bracing your hands/body when welding in this crappy high wind we've been getting

FLAT AS A SCHOOL MARM

A good tip for those who haven't had to build something that has to be absolutely flat.............Crown your materials. Look down the length of all the steel pieces you're using, and orient them with the crown up. This makes for a uniform floor etc. Old carpenters trick.

The supports will only be tacked for now (after I clean them up....been sitting in the stock pile for over 5yrs). After tacking, I'll place the axle assembly underneath the trailer. Then, I'll load all the remaining steel required for the floor, the steel required for other stuff, and then balance the axles. All the stuff will be piled where it will actually go when the trailer is complete. This is so I can get an exact weight distribution for setting the final axle position.

After that, the crap will be taken off, and then the trailer will be completed by WELDING IT ALL BACK ON

[leaguedude]

Great job so far Samm. It's coming along nicely. Thanks for sharing your project and cant wait to see the finished product.

[Canadian Welding]

Holy smokes. That looks really good.