Watch speed "tables" not bumps

[honda03842]

Stress seems to concentrate at the sharp edges of the reinforcements, the reason for adding the fish tails.

People have had structural failures at both edges of Scamp's frame reinforcements near where the frame goes under the trailer.

Flex issues are much larger on rough roads then parked. I believe the side jack produces no problems.

The jack I added at the front of the trailer is close to the door opening and reduces trailer motion when parked. It wasn't added to reduce stress but to reduce motion.

Sent from my SCH-I545 using Fiberglass RV mobile app

[Bob Miller]

Originally Posted by honda03842

Bob,
Our swing jack is on the left (driver's side) frame rail and we have not experienced any cracks in this area (after 24 years).

c.

I was referring to the frame cracks and breaks that have occurred on 16' Scamps right near the front of the trailer, not at the jack attachment point itself.
Didn't you have one like that recently? If my memory is incorrect, please let me know.

But, as I said, it was just a thought as to a possible contributing cause, especially when there are two full size adults in the front bed and additional stabilizers are not used in the front.

[redbarron55]

I doubt that the stress on the side mount is that high. The tongue weight might be 300 lbs and assume with two adults might go as high as 450. this should be relatively small loading compared to the dynamic loads while traveling.
Again stress concentrations and the differential bending moments are more likely to be the culprits here.
Norm is correct that the squared off reinforcements add to the problem along with the fact that there is no beam carrying the force spreading and contracting the frame at the bends. He is correct in that a tapered fishplate over the bends as reinforcement would be preferred.
In my modification I added the beam between the bends and the tapered reinforcements as well.I also reinforced the pass under tubes and added a cross beam in front of the door between the frame members to add stiffness and also make the aft door threshold to the bath/shower.
I did install the Ultimate jack on the Bulldog hitch I also installed.
I added a fair amount of weight, but I think that the reinforced frame will hold up pretty well in practice. I also bonded the floor and internal walls to the shell to make it a stiffer unit overall. The cabinets are also bonded to the shell along with the framing for the twin beds. I feel that this will produce a stiff unit. There are also no rivets, but rather screws with washers into the plywood/oak framing along with the epoxy bonding and glass.

[floyd]

Originally Posted by Bob Miller

Yep, as noted, that flat plate is a "Foot Pad" not a "Skid Pad", and leaving it on will further reduce your tongue jacks clearance.

But, rather than trying to fabricate a skid plate that will reduce clearance in itself, why not just remove the jack itself, either with one of the retractable jacks or a quick removal mount?

I have a skid plate just at the shell on the frame. It primarily protects the plumbing. The foot plate on the jack has adequate clearance when left installed since Scamp supplies one with the bolt plate mounted lower which allows it to retract closer to the frame than the one supplied for the 16.
The skid plate extends only as far as necessary to do its job and actually does not decrease clearance due to angle of approach consideration, it is located even with the sheet metal stone guard which was factory installed.

[redbarron55]

Do you have more pictures of the skidplate? I still need to design and build one.


Sent from my SCH-I605 using Fiberglass RV mobile app

[honda03842]

Originally Posted by Bob Miller

I was referring to the frame cracks and breaks that have occurred on 16' Scamps right near the front of the trailer, not at the jack attachment point itself. Didn't you have one like that recently? If my memory is incorrect, please let me know.

But, as I said, it was just a thought as to a possible contributing cause, especially when there are two full size adults in the front bed and additional stabilizers are not used in the front.

Bob,

We did have breaks at the point where Scamp bends the frame members to form the 'A', well under the trailer. Scamp's process of bending the frame kinks the beams and unfortunately they do not reinforce this now weak spot.

When I reported this failure a couple of people mentioned a failure forward on the 'A' frame just before Scamp's reinforcement. Where these people had failures I reinforced the beam with fish tails to reduce concentrated stress created by Scamp's reinforcement. Minimally if fish tails are not added to Scamp's reinforcement, a weld bead should be added along the unwelded leading and trailing edges of Scamp's reinforcement..

We do not have a front bed.

RedBarron55,

The tongue weight for our Scamp 16 is about 200 lbs. Since we've began RVing I've lost 60 pounds and reaching for 180lbs.

[redbarron55]

Norm,
I meant to indicate the weight on the jack with two adults in the front and not while towing.
I am shooting for that 200 lbs. when ready to tow. The rated hitch weight is 206 lbs.
I have been doing some research on this weight and I think it is rated with full fuel and two passengers (of some standard weight) in the rear seats. Also I think that there is some luggage included in the back of the wagon as well. I found reference on the Volvo site as the the reduction in hitch weight as payload is added ending with the ~ 200 lbs for the V70 with full load.
I believe that the rating is determined with the loading at the rear axle load rating and the front same with the gross within limits. More research is necessary.

[floyd]

Originally Posted by redbarron55

Do you have more pictures of the skidplate? I still need to design and build one.


Sent from my SCH-I605 using Fiberglass RV mobile app

Mine was installed on a whim when the trailer was new. It is made from a simple piece of black iron pipe and a scrap of flat stock. It has proven useful on several occasions (mostly gas station driveways).
I have been meaning to build a better and prettier one but find that I am overcome with sloth at those times when I am giving such a notion consideration.

[floyd]

Originally Posted by redbarron55

My guess the cracking on the left side is caused by the built in weakness in the right side from the drop frame at the door.
The flexing of the right causes cracking in the stiffer left side.
There is often cracking on the ends of the pass under tubes in front of the door.
While there are two 3" X 1 1/2" square tubes on each side the left are welded one on top of the other giving a box 6" high while the left is the same tow boxes laid flat and have a height of 1 1/2".
The 1 1/2" vertical section is very much more flexible than the 6" on the left.
The stress seems to be concentrated at the point where the frame kicks in to form the VEE snout.
I doubt that the placement of the tilt jack makes any significant difference compared to the above.

The connection between tilt jacks and cracks in the frame is likely only that the tilt jacks were supplied at a time when Scamp used a lighter gauge tubing and a smaller axle on the 16.

[honda03842]

Originally Posted by floyd

The connection between tilt jacks and cracks in the frame is likely only that the tilt jacks were supplied at a time when Scamp used a lighter gauge tubing and a smaller axle on the 16.

What year did they go to a larger axle and heavier gauge steel?

[redbarron55]

How much ground clearance do you have with the guard?
The 1986 16' at least had the 2500 lb ALKO axle and thin wall rectangular tubing.
The front of mine now has 11 gauge (1/8") square tubing and reinforcements.
Here are some shots of the front (poorly repaired)


Some reinforcements.

[floyd]

Originally Posted by honda03842

What year did they go to a larger axle and heavier gauge steel?

Not sure exactly, early to mid-nineties.
I'm pretty sure that's when they went to the 3500pound axle and switched to a vertical jack which won't fit on an 1-7/8" hitch.

[Steve in NY]

All this talk of Jacks leads me to tell of my 1988 dilema and it's resolution. My jack was I believe like Norm and Ginny's. A swing away. The "hub" is welded to the frame. The jack had been severely abused and the handle grip gone. It turned hard and I was sure I would need to have someone re-weld one on. One day I was walking around in Harbor Freight and I noticed a Jack that looked awful familiar. I bought it and took it home. It turns out to be an exact replacement and all I had to do was pop off the big snap ring on both jacks and swap guts. Easy Peasy and priced right. Here is the item if you need it.

Heavy Duty 2000 Lb. Capacity Top Wind Trailer Jack

Take Care,
Steve

[honda03842]

Originally Posted by floyd

Not sure exactly, early to mid-nineties.
I'm pretty sure that's when they went to the 3500pound axle and switched to a vertical jack which won't fit on an 1-7/8" hitch.

Floyd,

I have a 1991 Scamp. I have no idea what kind of axle I have, even after crawling under and looking for a stamped name. Does the following information provide a hint?

My axle has a square axle tube. The tube has rounded corners, probably a 3/4 inch radius on the corners.

Thank you

[floyd]

Originally Posted by honda03842

Floyd,

I have a 1991 Scamp. I have no idea what kind of axle I have, even after crawling under and looking for a stamped name. Does the following information provide a hint?

My axle has a square axle tube. The tube has rounded corners, probably a 3/4 inch radius on the corners.

Thank you

You have a Dexter axle, both tubes might look the same but be different sizes depending on capacity.
If it has straight spindles it is the smaller axle.
Probably not definitive, but do you have 10" brakes and a 2" hitch?

If it has an 1-7/8" hitch and 7" brakes, that would be a good indicator.
Otherwise MICing the tubing might be the only way to tell.

[honda03842]

Thanks Floyd. What's the capacity of the smaller axle?

I will measure the brake diameter in the morning though in my mind they're 10 inch.

What do you mean by straight spindles?

[redbarron55]

The earlier Scamps had 2400 lb rated axles with 7" brakes.
My trailer had a 2" hitch which I think was stock, but the frame has been modified to reinforce it.
I believe you could measure the square tubing behind the hitch since I believe that it is open there.
The Flexiride unit installed is rated 3500 lbs, but I had it made custom rated to 3000 so that it would not be too stiff. I think that the length of the rubber in the tubs makes the difference in the spring rates. The metal parts are the same.

[floyd]

Originally Posted by honda03842

Thanks Floyd. What's the capacity of the smaller axle?

I will measure the brake diameter in the morning though in my mind they're 10 inch.

What do you mean by straight spindles?

The early Scamps used a 1200 pound axle on the 13 and a 2200 pound axle on the sixteen. Later the 13 was upgraded to a 2200 pound axle and the 16 was upgraded to a 3500 pound axle. Through the years they switchedfrom Dexter to various axles such as Al-KO and Lippert. AFAIK they are now using Lippert axles and they are all bolt-on.

A glance will tell you the brake size since the 7" brakes look tiny.

A straight spindle is just as described, both inner and outer bearings are the same size. On a 3500# axle the inner bearing is much larger than the outer one and the spindle is stepped up to accommodate it.

[honda03842]

I guess it's time to find out what kind of axle.

When we bought the trailer it had a stepped 1 7/8th inch ball the Scamp replaced with a 2" ball and straight A frame in 2011.

Our trailer is now 24 years old and it's certainly possible that the axle was replaced. I'll have to look closer. I imagine the replacement would be visible though I regularly crawl under the trailer to check it out..

The performance of the existing axle seems fine, nothing seems too 'jouncy', good technical word. We have traveled on some tremendously rough roads over the last four years.

I'm sure my brake diameter is 10 inches, I can't even conceive of 7 inch brakes.

[Joy A]

I couldn't wait to get rid of the side jack. I always thought it tweaked the frame a little and it just didn't feel stable to me.

But most of all I needed it out of my way so I could reconfigure the 3 items on the tongue and built my generator/propane box.

I was happy as a clam when visiting the Factory in 2008 finding that Scamp had found a center jack for the 13 footers where the shaft and pad tuck up high under the tongue frame. I had looked at jacks all over the place and had never found one that would work on the 13 footer. Our trailers sit a lot lower than the 16 footers. Oh, and the hatch on the back of the Jeep just clears the jack.

My Scamp doesn't seem to move sideways as much when unhitching as it used to with the side jack.