Go Back   iRV2 Forums > MOTORHOME FORUMS > Toads and Motorhome Related Towing
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
 
Thread Tools Search this Thread Display Modes
 
Old 08-11-2012, 12:32 PM   #29
Senior Member
 
Join Date: May 2004
Location: Auburn, CA, Havasu, AZ & Mulege, BCS
Posts: 5,217
Phogg- the reason the un-reinforced angle, used in the attitude shown in your post#12, photo2, causes brain strain is that all tension & braking resistance will tend to cause bending across the thickness of the metal. The point of contact is on a cantilevered leg where the only transfer of stress is thru the haunch of the angle, by bending it. Gussets on both ends would create a relief for that weaker transfer, namely by flowing the stress into the horizontal leg along both edges. This type of shear transfer is easily handled by welds, and the transfer is in compression/tension in the gussets instead of bending in the haunch. Steel is waaaay strong in compression & tension, way less so in bending especially in vibration type ("stress reversal") conditions. The gussets are a good idea IMO.
__________________

__________________
Baja-tested '08 2-slide 36'
Alpine: The Ultimate DIY'er Project
EngineerMike is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 08-11-2012, 03:35 PM   #30
Senior Member
 
Join Date: Feb 2011
Location: Snowbird - Waterford Mi and Citrus Springs Fl.
Posts: 3,609
I knew that. Just didn't want to write it all out.....


__________________

__________________
1997 37' HR Endeavor, 275hp Cat, Freightliner
03 CR-V Blue Ox, Ready Brake
ahicks is offline   Reply With Quote
Old 08-11-2012, 07:59 PM   #31
Member
 
Phoggberg's Avatar
 
Newmar Owners Club
Join Date: Feb 2012
Location: Apple Valley, MN
Posts: 45
Quote:
Originally Posted by EngineerMike View Post
Phogg- the reason the un-reinforced angle, used in the attitude shown in your post#12, photo2, causes brain strain is that all tension & braking resistance will tend to cause bending across the thickness of the metal. The point of contact is on a cantilevered leg where the only transfer of stress is thru the haunch of the angle, by bending it. Gussets on both ends would create a relief for that weaker transfer, namely by flowing the stress into the horizontal leg along both edges. This type of shear transfer is easily handled by welds, and the transfer is in compression/tension in the gussets instead of bending in the haunch. Steel is waaaay strong in compression & tension, way less so in bending especially in vibration type ("stress reversal") conditions. The gussets are a good idea IMO.
I will have the welder add the gussets, should be no big deal. Should they be the full 5" across the angle or can the be added to the side legs? The lower one is no problem, however the upper does not give me much clearance to the backside of the bumper. how thick a plate should the gussets be. I am thinking that maybe 1/8" or 1/16 inch steel should be adequate but I am gessing here. It was easy for the mounts I had room for atleast 3/8 and even 1/4 would be more than adequate according to an engineer I know. The gussets are out of my range of experience.
__________________
Phoggberg is offline   Reply With Quote
Old 08-11-2012, 08:05 PM   #32
Senior Member
 
kalynzoo's Avatar
 
Join Date: Mar 2007
Location: Northridge, Ca
Posts: 751
Such a special beautiful car. I'd tow it in a box. Really.
I tow my Saturn Vue with a bib-cover over the hood and windshield. I still get plenty of road grime across the uncovered areas, and it smells hot every time I first start it up, I'm told it is because of the road grit which is pulled up into the underbody from being kept so close to the MH. But it works for me because I know the car is just meant to be my toad.
__________________
kalynzoo is offline   Reply With Quote
Old 08-11-2012, 09:01 PM   #33
Senior Member
 
Join Date: Feb 2011
Location: Snowbird - Waterford Mi and Citrus Springs Fl.
Posts: 3,609
In a perfect world the gussets would be of the same material/thickness as what you are gusseting.

In a not so perfect world (pinch) anything is better than nothing.
__________________
1997 37' HR Endeavor, 275hp Cat, Freightliner
03 CR-V Blue Ox, Ready Brake
ahicks is offline   Reply With Quote
Old 08-13-2012, 10:27 AM   #34
Member
 
Phoggberg's Avatar
 
Newmar Owners Club
Join Date: Feb 2012
Location: Apple Valley, MN
Posts: 45
About Gusseting

EngMike & Ahicks,

I have been thinking, you know living dangerously . Refering to the modified enclosed diagram:
  1. there really seem to be 4 points of bending moment (A,B,C,D) points B & C formed by welding the tow angles together
  2. Getting a gusset at point D is easy, Point a not so easy
  3. I have ordered the ReadyBrake and breakaway kit, as they seem more than adequate, and will still leave the car in original driving trim sort of. and still leave braking progressive and proportional. If I need to I will add an auxilliary vacuum pump to increase braking pressure
  4. the Surge braking moment will add additional compression force to the baseplate which I didn't think was an issue, but now realize it is

I propose adding a gusset I am not sure of the width but can easily be 5/16" steel bar or angle to one or both sides of the mount and welding it to he frame sides. We will have to see ground and mechanical clearance for the angle and length, but that should transfer all bending moment to the gusset thereby protecting the base plate. Or am I better off just welding a plate or piece of angle at point A & D? Opinions?
Attached Thumbnails
Click image for larger version

Name:	MG Base Plate.jpg
Views:	55
Size:	57.0 KB
ID:	24822  
Attached Files
File Type: pdf MG Base Plate.pdf (98.7 KB, 20 views)
__________________
Phoggberg is offline   Reply With Quote
Old 08-13-2012, 06:27 PM   #35
Senior Member
 
Join Date: Feb 2011
Location: Snowbird - Waterford Mi and Citrus Springs Fl.
Posts: 3,609
Sounds like you have a handle on what we were thinking now. That should work fine. Actually, probably better than the individual gussets would have worked, less stress involved. You could use that same angle iron material your brackets are made of pretty easily usually.

Regarding the Ready Brake, doubt seriously you'll need any aux. assist for it. It works fine on it's own.
__________________
1997 37' HR Endeavor, 275hp Cat, Freightliner
03 CR-V Blue Ox, Ready Brake
ahicks is offline   Reply With Quote
Old 08-13-2012, 07:44 PM   #36
Member
 
Join Date: Nov 2010
Posts: 34
I you change the angle of the gussett just a bit so it can be tack welded to near the points at D and C it would be even stronger
__________________
landtrv is offline   Reply With Quote
Old 08-13-2012, 11:25 PM   #37
Member
 
Phoggberg's Avatar
 
Newmar Owners Club
Join Date: Feb 2012
Location: Apple Valley, MN
Posts: 45
Another thought, could I use only one Gusset plate, or a rod that goes back. If I can do that I will not have to butcher up the Air dam any further.

I am hoping to leave the Air Dam intact, as I am theorizing that it will keep the road grime and diesel exhaust out from under the car because of ground effect. Also it may stabilize the car by adding some down force to the tires rather than lift. I would Ideally like to keep the entire car inside the the MH's draft.
__________________
Phoggberg is offline   Reply With Quote
Old 08-14-2012, 07:11 AM   #38
Senior Member
 
Join Date: Feb 2011
Location: Snowbird - Waterford Mi and Citrus Springs Fl.
Posts: 3,609
One gusset would need to be centered on the loading. If it were off to one side it might allow the brackets to twist enough to get you into the same problems the gusset is there to prevent?

I believe you might be over thinking your concerns about the airstream over/around the car while it's being towed. That's just me though.... -Al
__________________
1997 37' HR Endeavor, 275hp Cat, Freightliner
03 CR-V Blue Ox, Ready Brake
ahicks is offline   Reply With Quote
Old 09-03-2012, 07:23 PM   #39
Member
 
Phoggberg's Avatar
 
Newmar Owners Club
Join Date: Feb 2012
Location: Apple Valley, MN
Posts: 45
Just thought I would update the thread to current progress. The surge break came in and was installed with almost no challenges. The Breakaway brake unit also went in no problem. I had to turn the hitch up side down so the 1 inch rise became about a 1 in drop, and you can see from the photos below the tow bar is almost level. I put a six pin female connector in the front to the left of the radiator, and using split loom ran the three wires to the brake light /tail light in the rear. The running lights (i.e. parking lights and side marker lights were hooked to the 4th wire, and they all work off the MH 7 blade connector. The umbilical was re-wired to put the center pin to the battery so the MH will charge the MG's battery as we roll down the road. All attachments to the MG's wiring system used diode packs to isolate the voltage from the MH from the MG System. The hook up is easy and clean from the motor home, but easier if I raise the hood to plug it in.

The brackets and mount with the covers on look like a 1970s bumper riders and are not very noticeable if you look at the front end photo with the tow bar removed. A Demco sentry was installed to protect the MG from rocks coming under the MH, I don't anticipate anything coming from the roof. We will still have to run a highway test with yarn tufts to see where the winds will be hitting the little car, and see if maybe a deflector or two is in order.

When I had the brackets fabricated I did not take photos as I had a window of opportunity for the MH to be at the house so I could measure things up conveniently. So in the haste to test fit everything I did not take photos of them. They are enclosed below. They are currently being fitted with one gusset on each side running from about 1 inch above the upper bend to the bottom of the lower flange. I should get them back next week. They will be sand blasted and then powder coated to protect the steel from road abuse. There is very little clearance at the bumper for the upper angle, and so the gusset was modified to provide some support. Both my welder, my machinist, and a structural engineer all question even the need for the gussets as the car is so light that the A36 Steel should be able to handle the relatively light load of the car -- 2400 Lbs GVW. Combined with the supplemental braking the bending load on the haunches should be minimal.

I was going to weld the brackets to the frame, but again my local advisory committee said that bolting it on should be more than adequate, and therefore they are removable. I checked with Fastenal about getting longer studs (3/8's fine thread 2-1/2 inches long. They quoted me $41 each. I went with 3/8" 2-1/2 " fine threaded grade 8 bolts to the bumper with sufficient grade 8 fender washers and lock nuts (Cost abt $12). I will use red locktite to keep everything in place and torque to 36 pounds. My structural engineer wants to look at the mounts on the end of the frame, two pieces of 16 Gauge steel (abt 0.12" thick) to see if that is sufficient. If not the one more brace welded to the frame bottom to the back of the bracket will provide sufficient bracing. probably more than overkill.
Attached Thumbnails
Click image for larger version

Name:	MG B Toad Project - 31.jpg
Views:	43
Size:	449.7 KB
ID:	25628   Click image for larger version

Name:	MG B Toad Project - 32.jpg
Views:	56
Size:	408.0 KB
ID:	25629  

Click image for larger version

Name:	MG B Toad Project - 33.jpg
Views:	44
Size:	475.6 KB
ID:	25630   Click image for larger version

Name:	MG B Toad Project - 35.jpg
Views:	49
Size:	357.7 KB
ID:	25632  

Click image for larger version

Name:	MG B Toad Project - 37.jpg
Views:	39
Size:	315.9 KB
ID:	25634   Click image for larger version

Name:	MG B Toad Project - 38.jpg
Views:	41
Size:	388.6 KB
ID:	25635  

Click image for larger version

Name:	MG B Toad Project - 39.jpg
Views:	34
Size:	373.0 KB
ID:	25636   Click image for larger version

Name:	MG B Toad Project - 40.jpg
Views:	36
Size:	360.4 KB
ID:	25637  

Click image for larger version

Name:	MG B Toad Project - 41.jpg
Views:	37
Size:	320.3 KB
ID:	25638   Click image for larger version

Name:	Signature Photo.jpg
Views:	40
Size:	132.7 KB
ID:	25639  

__________________
2002 Dutchstar DPSP & 1978 MG B to push start it
Phoggberg is offline   Reply With Quote
Old 09-03-2012, 07:38 PM   #40
Senior Member
 
Join Date: Feb 2011
Location: Snowbird - Waterford Mi and Citrus Springs Fl.
Posts: 3,609
Nice lookin rig. Bet you have a blast with it! -Al
__________________
1997 37' HR Endeavor, 275hp Cat, Freightliner
03 CR-V Blue Ox, Ready Brake
ahicks is offline   Reply With Quote
Old 09-04-2012, 08:17 AM   #41
Member
 
Phoggberg's Avatar
 
Newmar Owners Club
Join Date: Feb 2012
Location: Apple Valley, MN
Posts: 45
Thanks Al, And for your advice and support and from all the posters through out this project... I will post the pictures when the brackets get back from the welding shop. I hope they will provide enough rigidity. That and what ever final comments will at least document setting up an MG B as a Toad.

I timed the hookup of the car -- about 20 minutes to hook the MG up to the motorhome + 9 Minutes to jack the car up at the back end, and skittle under and pull the 4 bolts from the drive shaft to the differential, and put the rear wheels on the ground. Another two minutes to stow everything in the basement. It would be nice to have a creeper, but right now I don't want to stow it in the basement.

A friend said I should work up a tow bar out of Aircraft Grade cable, and hook the creeper to the MG as it's toad. But with the MG on the length from stem to stern is already about 60 feet and then there is the problem of mounting tail lights on the creeper and installing an umbilical etc...
__________________
2002 Dutchstar DPSP & 1978 MG B to push start it
Phoggberg is offline   Reply With Quote
Old 09-04-2012, 03:30 PM   #42
Senior Member
 
Join Date: Feb 2011
Location: Snowbird - Waterford Mi and Citrus Springs Fl.
Posts: 3,609
You're disconnecting the drive shaft? Why?
__________________

__________________
1997 37' HR Endeavor, 275hp Cat, Freightliner
03 CR-V Blue Ox, Ready Brake
ahicks is offline   Reply With Quote
Reply



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Virginia Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 08:59 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.