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Looking for 60's or early to mid 70's Wanderlodge
08-18-2021, 10:55
Post: #11
RE: Looking for 60's or early to mid 70's Wanderlodge
There's one problem (ha, like there's only one Wink ) with your thinking. The truck transmission will fail at the halfway point, not when you get home. Then you'll have not one emergency tow, but two. Now you've got way more than the first single tow would have been. You seriously need to rethink flat towing an rv of this size with what you've got.

John Mace
06 450LXi bigger bird
living in the wild hinterlands of the north
free to roam without the man getting me down
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08-19-2021, 02:58
Post: #12
RE: Looking for 60's or early to mid 70's Wanderlodge
I know you're looking after me and I am not being unappreciative(don't take this the wrong way I'm not being argumentative just for the sake of it. I want to emphasize that because sometimes it's hard to tell where people are coming from just reading text.) but I do dispute that it is a act of ultimate emanate peril to tow a bluebird with a F-350 and I think I can prove it.

If you are going slow, the strain on the truck on relatively flat ground is not that high. I'm not in any way saying it's ideal. I also not in any way saying this is good practice for an all the time tow where you are expected to be perfectly safe in all conditions. That's what most tow bars are set for. My perspective is I have a very good chance of making it with extreme care. I have towed a massive amount with this truck before. I towed a trailer with like 5 foot high of telephone poles. I have no idea the weight but it was a lot. It was no problem. The key is to not accelerate fast and stop slow. The actual pulling weight if you go slow is only slightly higher than the weight needed to overcome the force that the tires use because they flex and use energy doing so.

So let's use a high weight for the RV(30000lbs). The actual is more like 24,000lbs


Figures from above link.
Table of rolling resistance coefficient examples: [4]

Crr=0.0045 to 0.0080[28] Large truck (Semi) tires (use the higher number 0.0080)

(An example on the link above)
For example, in earth gravity, a car of 1000 kg on asphalt will need a force of around 100 newtons for rolling (1000 kg × 9.81 m/s2 × 0.01 = 98.1 N).

So (13607.77kg x 9.81 m/s2 × 0.0080 = 1,068N=240.09595123 lb. force

It's not some serious drastic number. That number above is just what it takes to overcome rolling resistance of the tires on the RV at a high Weight on flat ground. Now the slower you accelerate the less the extra force added to the tow bar and the truck.

And let's just look at some really rough numbers on max weight going up hills.

"...Maximum grade: The maximum permissible vertical angle, or grade, along the highway is determined from terrain and design speed,[4] with up to 6% generally allowed in mountainous areas, 5% in rolling terrain, and 4% on level terrain. An additional 1% is allowed in urban areas..."

So if you lift the RV straight up in the air it's, at the highest weight, 30,000 lbs. but since the grade is a max. 6%, and I assure you it's much less where I'm talking about moving stuff, but let's go with the 6%. It's not an actual 6% or 30,000 x .06= 1,800 lbs. force but it not tremendously that far off either. When you start looking at these sorts of numbers, and maybe I'm wrong, but they don't look so frightening. I was planning on 2" square tube 1/4 inch thick with lots of braces welded on the side. 3" if I could get it reasonably.

For normal towing all the time in all conditions you're going to need a much higher strength and a bigger truck but for slow methodical not up any big hills what I have will be fine. As long as I noted someone doesn't pull right out in front of me and slam on the brakes. That would be a problem but it would be a problem anyways even with a better truck.

While I'm at it I'll tell you what I figured for the tow bar. The steel would be not the best so looking around the average steel should be eletro welded square tube, round is stronger but less useful to construct with so I'll use square.

So a 2" square 1/4" thick has what strength.

SteamKing,"...The most common (and probably cheapest) square structural tubing is made from A36 carbon steel with a maximum yield stress of 36,000 psi..."

SteamKing,"...A36 steel has a minimum yield stress of 36000 psi

Your design should have a safety factor so that maximum tensile stress in bending is less than 21,600 psi (same for axial loading)

Max shear stress should be kept below 14,400 psi..."

So if you use So a 2" square 1/4" thick and ad up the area. It will be
four rectangles x (2"-.25") x .25 = 1.75 sq. inches
1.75 sq. inches x 36000 = 37,800

So the 2" would be good enough but a bit marginal. 3" would be better

One thing about steel if you get a real high tensile strength you may think you're coming out better but it loses bend ability and can snap easier. So if you use a less tensile strength it will be more likely to bend and stretch before it breaks. So the best is not always better. We're of course talking about regular steel some supper alloys may be different.
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08-19-2021, 09:44
Post: #13
RE: Looking for 60's or early to mid 70's Wanderlodge
I'm sure your truck is able to tow it, I'm concerned about the stopping part.
When I was in the air force, I worked on B-52's. One night, I got a wild hair up my a** . With a little liquid courage and the rest of the ground crew egging me on, I got a tow bar and a tractor. it took a little bit of power, but I got the plane to move, once it started, it was easy. Then came the hard part, stopping! I tried to stop, only to slide the wheels for a bit. Now I had to back it up to it's original spot. At this point wiser heads prevailed, and someone got in the cockpit and worked the brakes.

If you do tow the bird, maybe someone in the drivers seat, could help work the brakes. This is from an older and wiser one who has seen this and done that.

Steve Gureasko
90 WBSA "Jus Chillin"
Ponchatoula, La.
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08-20-2021, 19:55
Post: #14
RE: Looking for 60's or early to mid 70's Wanderlodge
Oh no B-52's. I was at Nellis AFB, (I worked on F-4's and A-10's Inertial Nav.), and one time got requisitioned to help set up a static display of all kinds of planes so some foreign dignitaries could drive by them and view them. Of course the B52 was covered in hydraulic fluid from leaks so we had to wipe the whole bottom of the thing off with paper towels and some sort of spray cleaner. Arrrgh.

You're right about stopping it. I don't know if I would have really been able to do this, eventually I could but not right away. If you have a remote brake tied to the brake circuit that is normally used for trailer brakes and could push on the normal brake pedal that would work. I probably would be able to do this in time. It is possible. I have seen these where you can buy them I think they are wi-fi.

There's this super cheap really extrodinarily useful micro-controller they have out now or for a while. The ESP32. You can get these on various type development boards for $9 or so on average. You can get them with a built in camera for really cheap. Here's a pack of 5 of them for $32.99.

These things are really extrodinary. They have wi-fi built into them with internet so you can log onto them and control or get feedback to-from a control unit. The things you do with these boggle the mind and there's lots of tutorials on line on how to use them. Add to these the new cheap $0.50 MOSFET's that can drive well over 10 amps of current with which you can turn on and off with these cheap $9 or less wi-fi controller and think of what you could do with these. Lots of possiblities.

look at all the stuff on these things. It's really amazing what kind of power you can get on these for next to nothing.

Features of the ESP32 include the following:[3]

CPU: Xtensa dual-core (or single-core) 32-bit LX6 microprocessor, operating at 160 or 240 MHz and performing at up to 600 DMIPS
Ultra low power (ULP) co-processor
Memory: 320 KiB RAM, 448 KiB ROM
Wireless connectivity:
Wi-Fi: 802.11 b/g/n
Bluetooth: v4.2 BR/EDR and BLE (shares the radio with Wi-Fi)
Peripheral interfaces:
34 × programmable GPIOs
12-bit SAR ADC up to 18 channels
2 × 8-bit DACs
10 × touch sensors (capacitive sensing GPIOs)
4 × SPI
2 × I²S interfaces
2 × I²C interfaces
3 × UART
SD/SDIO/CE-ATA/MMC/eMMC host controller
SDIO/SPI slave controller
Ethernet MAC interface with dedicated DMA and IEEE 1588 Precision Time Protocol support
CAN bus 2.0
Infrared remote controller (TX/RX, up to 8 channels)
Motor PWM
LED PWM (up to 16 channels)
Hall effect sensor
Ultra low power analog pre-amplifier
IEEE 802.11 standard security features all supported, including WPA, WPA2, WPA3 (depending on version)[4] and WAPI
Secure boot
Flash encryption
1024-bit OTP, up to 768-bit for customers
Cryptographic hardware acceleration: AES, SHA-2, RSA, elliptic curve cryptography (ECC), random number generator (RNG)
Power management:
Internal low-dropout regulator
Individual power domain for RTC
5 μA deep sleep current
Wake up from GPIO interrupt, timer, ADC measurements, capacitive touch sensor interrupt
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