5x10 Bowfront, Raindrop on 5x8 frame?? or 5x10

[Gunguy05]

I think we have the design narrowed down to a 5x10, bow front (i.e. camp-inn raindrop inspired). Just working on the trailer type/source for the most part right now. Would like to buy used, but most of the used in this area are over priced, unless they are junk. I want too start out on the right foot, and having a crappy trailer isn't the way to do it.

Question is this when looking for trailers, since that seems like the obvious starting point.

Can we use a 5x8 northern tool trailer since they are easier to come by than a 5x10? I want to try and fit the front box on, AND have room for a propane cylinder.

My thought is to buy the 5x8 northern tool and then get 2ft more welded on the back (seem's pretty simple, and cheap), then slide the axle/springs rearward to the 35/40% distance from the rear. This will leave the stock distance from frame to tongue on the front, enough for box and propane.

Also how are the stock hubs, we want to have 14 or 15" wheels on it? Can the stock wheels be easiliy changed out to 14 or 15" rims?

[bobhenry]

No need to add to the frame I have a two 5 x 10 trailers on 8 foot frames. Just let the walls and floor cantilever out over the frame.

If you are getting the single tongue trailer you will want to reinforce the tongue My barn is built on a very similar namco 5x8 cargo trailer and the thing had been overloaded and bent the second crossmember down where the tongue ends.

[Gunguy05]

I think there new ones that they are selling now have the A frame to tongue, but I will check that thanks.

Do it need to have extra /modified framing in the cantilevered floor section or will the standard 1 x under the 3/4 plywood be enough?

Thanks for the help,
Brian

[bobhenry]

To create a bow front you need to run your above frame furring front to rear so your under floor framing will not run side to side.

With a teardrop profile there is no significant weight in the last or the first couple feet of the build. Oh maybe a cooler in the rear or a couple pieces of cast iron but no human weight.

You simply cut your round nosed profile and cut your furring to the edge of the nose.

[Gunguy05]

To create a bow front you need to run your above frame furring front to rear so your under floor framing will not run side to side.

With a teardrop profile there is no significant weight in the last or the first couple feet of the build. Oh maybe a cooler in the rear or a couple pieces of cast iron but no human weight.

You simply cut your round nosed profile and cut your furring to the edge of the nose.

Gotcha. That makes sense. Just a lot to think about, and like I said. Starting with the trailer is the post important part IMHO.

Thanks,
Brian

[KCStudly]

The front floor framing can run longitudinally, as Bob pointed out, but you can header this into a floor xmbr back at the second trailer frame xmbr (or so) and then the sub floor structure in the rear can run athwart ships (crosswise) if preferred. Remember that the walls are your strongest members and they will be what is holding up the floor where it cantilevers at the rear (if that is where you decide the extra 2 feet need to go). Unless you plan on having a short bulkhead or structural roll pan at the very back of the galley for full length longitudinal floor stringers to tie into at the back, I would change up and have the rear floor structure run across wise. Of course this assumes that you will have a floor sub structural at all.

That makes me think of Zach's X2; I think he dropped the galley floor down lower because he didn't need storage under that area. You could maybe do something similar, having the last 2 feet hanging level to the bottom of the trailer frame(???).

That said, you will really need to start at the beginning and look hard at your weight balance and frame clearance to the ground on transitions before you decide to stick a full two feet off the rear. Don't be too concerned about moving the axle if you need to. Even if it is outside of your personal skill set, that is not a good enough reason to start off with an iffy design that you may always regret (dragging tail at the slightest hint of a slope, or nasty sway going down the road due to a poorly balanced load). If you need a longer tongue to add a tongue box, and you need the axle further back to get your balance right, and/or avoid bottoming out, then that is what it is and there are ways to get it done. Don't compromise the design just to make it easy to build; design it to work the way you want it to, then find the easiest way to build it that way.

[Gunguy05]

Humm... Just a very rough sketch of things, but how to deal with the squared off frame?

I'm thinking have it cut/welded to the angle so that it is just under the cab.

I know there is no floor yet. Just trying to get the shape figured out.

Bow Front Plan.jpg (176.79 KiB) Viewed 1207 times

Thanks,
Brian

[bobhenry]

You really need to cantilever off of the nose of the trailer not the rear. As drawn you have a swaying nightmare.
Total body length as you have designed is 120" 60 percent of this need to be forward of the axle (72")
and 40 percent to the rear (48") Actually 65 / 35 weight distribution is even better if tongue weight is no problem to the towing vehicle. Rather than mess with the axle location simply extend the tongue enough to allow you to encroach the 2 foot forward. Inserting a square tube in the center of the a frame tongue simply adds extra strength. Moving the body forward also negates the need to alter the square corner at the front of the frame.

[Gunguy05]

You really need to cantilever off of the nose of the trailer not the rear. As drawn you have a swaying nightmare.
Total body length as you have designed is 120" 60 percent of this need to be forward of the axle (72")
and 40 percent to the rear (48") Actually 65 / 35 weight distribution is even better if tongue weight is no problem to the towing vehicle. Rather than mess with the axle location simply extend the tongue enough to allow you to encroach the 2 foot forward. Inserting a square tube in the center of the a frame tongue simply adds extra strength.

I wasn't sure about extending the tongue. I thought that moving the axle would be easier, but with the squared off frame, and the balance issue, if that is better then I will look into that.

I hadn't moved the axle in the drawing, but was going to if needed. But like I said if the above fixes both...

Thanks
Brian

[Cary Winch]

Brian,

If you trimmed off the square corners of the frame your frame would look a lot like our Raindrop frame then. That is how we do it, the side rails of the frame simply turn at the angle. We do add reinforcements under this however to "girder" it up for the needed tongue strength on a Raindrop.

Indeed your axle need to move back significantly. For a trailer not to sway you need at least 10% of the trailer's total weight on the tongue. We target 12.5% on our 8' models to allow the customer loading flexibility and to account for a two bike bike rack on the hitch option in back. On a Raindrop however we actually put more weight on,close to 15%. Since the heaviest area of your trailer is the galley a good share of the trailer weight is behind the axle. On a shorter 8' model the axle ends up under some of the galley and load variances in the galley (cooler, pots, pans, food, etc) have a smaller effect on the tongue weight. But, with a 10' teardrop the axle ends up further forward a bit and this shifts the axle a bit forward of the heaviest load items in the galley. This means loads in the galley have a more pronounced effect on tongue weight due to increased moment arm. To account for this we actually leave the axle rearward a tad making the tongue heavier when empty. But, as you load the trailer in the galley the trailer's tongue will get a lighter. A really fully loaded Raindrop will have a tongue weight of about 10%. There is a much more interesting challenge to figuring out axle location on a 10' teardrop. 8" teardrops are relatively simple.

One idea looking at your drawing. Maybe you could make your axle movable? Drill a series of mounting holes at 1" increments or something. Try loading (full cooler, water in tank, pots, pans and other weight) it up and moving the axle around until you get a happy tongue weight. Then mount the fenders, once you are good on tongue weight.

Another thing to point out I have not mentioned on this forum in a long time. When measuring tongue weight, make absolutely sure the frame is level. Common mistake people make is to unhook the trailer and drop the coupler down on a bathroom scale to get a tongue weight reading. Tipping the nose down makes it heavier, tipping it up makes it lighter. So, they measure the tongue weight with the coupler down on the bathroom scale and the tongue weight is adequate. Then when they connect it up to the two vehicle the tongue weight is far too light and the trailer sways. Drives everyone nuts trying to figure out the trailer sway because the builder swears he has enough tongue weight, weighed it and everything. So, put some blocking on top of the bathroom scale at tongue height, zero the scale with the blocking on it and then weigh the tongue on top of the blocking. This one we see happen sometime too with improper "drop" on ball mounts. The person has a big 4x4 pickup and a little 2" drop ball mount. They hook up the trailer and the nose is of the trailer looks like it is getting ready for a moon launch. The trailer can sway like crazy because the tongue weight goes away when that far off level.

Cary

[Gunguy05]

Brian,

If you trimmed off the square corners of the frame your frame would look a lot like our Raindrop frame then. That is how we do it, the side rails of the frame simply turn at the angle. We do add reinforcements under this however to "girder" it up for the needed tongue strength on a Raindrop.

Indeed your axle need to move back significantly. For a trailer not to sway you need at least 10% of the trailer's total weight on the tongue. We target 12.5% on our 8' models to allow the customer loading flexibility and to account for a two bike bike rack on the hitch option in back. On a Raindrop however we actually put more weight on,close to 15%. Since the heaviest area of your trailer is the galley a good share of the trailer weight is behind the axle. On a shorter 8' model the axle ends up under some of the galley and load variances in the galley (cooler, pots, pans, food, etc) have a smaller effect on the tongue weight. But, with a 10' teardrop the axle ends up further forward a bit and this shifts the axle a bit forward of the heaviest load items in the galley. This means loads in the galley have a more pronounced effect on tongue weight due to increased moment arm. To account for this we actually leave the axle rearward a tad making the tongue heavier when empty. But, as you load the trailer in the galley the trailer's tongue will get a lighter. A really fully loaded Raindrop will have a tongue weight of about 10%. There is a much more interesting challenge to figuring out axle location on a 10' teardrop. 8" teardrops are relatively simple.

One idea looking at your drawing. Maybe you could make your axle movable? Drill a series of mounting holes at 1" increments or something. Try loading (full cooler, water in tank, pots, pans and other weight) it up and moving the axle around until you get a happy tongue weight. Then mount the fenders, once you are good on tongue weight.

Another thing to point out I have not mentioned on this forum in a long time. When measuring tongue weight, make absolutely sure the frame is level. Common mistake people make is to unhook the trailer and drop the coupler down on a bathroom scale to get a tongue weight reading. Tipping the nose down makes it heavier, tipping it up makes it lighter. So, they measure the tongue weight with the coupler down on the bathroom scale and the tongue weight is adequate. Then when they connect it up to the two vehicle the tongue weight is far too light and the trailer sways. Drives everyone nuts trying to figure out the trailer sway because the builder swears he has enough tongue weight, weighed it and everything. So, put some blocking on top of the bathroom scale at tongue height, zero the scale with the blocking on it and then weigh the tongue on top of the blocking. This one we see happen sometime too with improper "drop" on ball mounts. The person has a big 4x4 pickup and a little 2" drop ball mount. They hook up the trailer and the nose is of the trailer looks like it is getting ready for a moon launch. The trailer can sway like crazy because the tongue weight goes away when that far off level.

Cary

Sounds like great information, and I sincerely hope that I am not stepping on any toes of the person who designed this originally. I just really like your design, but I like the challenge, and the $$ saving aspect of building it myself (with Dad). I truly appreciate the input.

I will play with the design some more. I am just picking up on how to work within sketchup, so I am battling that, along with my lack of creative streak to make this all come together. I do have a little physics in my background, so this all makes sense as you explain it in "teardrop talk" and how it applies to the trailer load and how it pulls rolling down the road. I do appreciate all the wealth of info that is contained with the forums here. I know that I wouldn't have made it this far without it.

The main thing that I am looking to do at this point is:

1. Find the right trailer to buy, and it looks like I have figured that out. I don't want to purchase something that doesn't fit what I want to build, or cannot be adapted i.e. with one of the above changes

2. Continue to develop the design and how it fits within the guideline of what we want to build... these discussions help with that greatly. Using what has been discussed here, I will keep the tongue wt, and the rear clearance on bump, hills, etc in mind.

Thanks again for all the help.

Brian