Boat tail project based on a single wheel trailer...

[aerohead]

Beefy and 'cleaner'
Question,if the load is to the rearmost part of the trailer,does it improve the bucking at all?

[BamZipPow]

Originally Posted by aerohead

Beefy and 'cleaner'
Question,if the load is to the rearmost part of the trailer,does it improve the bucking at all?

I'll find out later tonight when I load up the trailer with some gear and secure it to the deck.

[BamZipPow]

Tonight's run was a bust. Guess I didn't ratchet the straps down tight enough and my "weights" (gear in a bag) broke free of the straps. I'll take another shot in the morning.

[aerohead]

Sometimes the road to success looks more like one of M.C.Escher's staircases
http://upload.wikimedia.org/wikipedi...Relativity.jpg

[BamZipPow]

This is sort of the setup I want to attempt at the hitch. This shock setup is fer a Toy-Tote single wheel trailer.


I did notice that it is an air shock setup fer adjusting to the load. I might want to look in that direction as well.

[BamZipPow]

Doing some more thinking...maybe attach the air shock absorber to the rear bumper using the available holes and building an adapter plate to bolt into there. The top of the shock will not be any higher than the top of the bumper so the tailgate won't end up hitting the shock absorber. This way there will be no welding required on the hitch! I would only have to build attachment points on the trailer and the truck bumper.

I did notice that the ballast weight in the trailer did okay but didn't do anything fer the road oscillations when I encountered those type of road conditions.

[BamZipPow]

Found some used replacement swivel wheels fer the front support legs on eBay. They should be here within a week. It will be nice to roll the trailer around again instead of picking up the front end to move it. Total cost was $17 shipped...not bad fer my initial boo boo.

I will be cutting the bottom of the support leg guides as well as the tops of the support legs back about an inch as I've noticed that the wheels have been scraping the driveway as I back in. The swivel wheel drops the back end of the trailer when backing up. This mod will allow me to raise the wheels up at least another inch to allow fer the clearance.

I will be building a mock up of the shock absorber from some PVC pipes and the connecting frame out of Coroplast so I can determine the range of motion and proper placement to allow fer clearance in the raised and lowered positions as well the physical requirements of the shock absorber. I could probably figure it out with math but I like playing with physical things. I will probably need to put the attachment points on swivels so it will allow fer slight rolling when the frame flexes.

I'm still thinking about cutting the front access doors back a few inches to allow fer better clearance from the back of the truck since they don't need to be as long since I have the clear gap covers attached to the truck/aero cap. It should fairly easy to revamp it since it's assembled with that capability in mind.

[aerohead]

I've been noodling numbers on the one-wheeler and it's pretty interesting:
*The T-100's road load is
----------------------- 6 hp @ 30 mph
---------------------- 20 hp @ 50 mph
---------------------- 47 hp @ 70 mph
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*If the load @ 70 is 47 hp
*With a driveline mechanical efficiency of 92%
*The engine is delivering 51.086 bhp @ 70 mph
--------------------------------------------------------------------------
*If mpg @70 is 21
*Then your using 3.333 gallons/hour
*And if gas is 6.2-lbs/gallon
*Then your burning 20.666 lbs/hour
--------------------------------------------------------------------------
*@ 20.666-lbs/51.086= 0.4045 lb/bhp-hr BSFC
--------------------------------------------------------------------------
*Since we know the original drag coefficient,Cd 0.44
*And we estimate frontal area @ 28.925 sq-ft
*We can calculate the original aero hp load at 70 mph @ 29.798 hp
*Subtracting,our remainder is our Rolling Resistance load @ 70-mph @ 17.201 hp.
*At an EPA test weight of 3,800 lbs we can calculate the R-R coefficient for the tires @ Cf= 0.0242 for the set of 4-tires.
--------------------------------------------------------------------------
*If the T-100 aero mods and trailer push the mpg up to 28
*Then we're down to 2.5-gallons per hour
*Or,15.5-lbs/hour
*Assuming a constant BSFC we get an engine load of 38.3189 bhp
*Allowing for the driveline losses we get a road load of 35.253 hp
*At say 4000-lbs,our new R-R load is 18.069 hp
*Subtracting that from our total load leaves 17.183 hp aero
*Solving for the new drag coefficient we get Cd 0.253.
*If at a future date we roll the sides in with tumblehome and give edge radii we're looking at Cd 0.232.
*If we 'basjoos' the front wheels we might be looking at Cd 0.192.
--------------------------------------------------------------------------
*We haven't added the R-R of the 5th-wheel of the trailer,so the drag coefficient should be adjusted down accordingly.

[BamZipPow]

Got my replacement wheels in today and installed. It sure is nice to roll the trailer around again.

Doing some more thinking, I think I need to have the high point on the air shock on the trailer side and the low point on the hitch side. This should allow dampening almost immediately as the trailer pitches up/down. With the trailer side low and the hitch side high, the trailer would be able to oscillate a few degrees before the shock would be able to engage it's dampening. That sound about right?

[BamZipPow]

...and now the trailer is black (except fer some of the top side of the lid).