Custom Chassis For a 4x10x4 1/2

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Postby aggie79 » Mon Nov 22, 2010 7:09 pm

DMcCam wrote:
Here are the current specs: Flexiride 2,000lb axle derated to 1,400lbs for a 56" frame width with a 5 bolt hub. The wheel size is 205/75 R14 with a 2mm offset (I want the wheels to be tucked in pretty tight).

A few questions.
Are these specifications correct?
Are there better or more common specs (would 4 bolt be better)?
What size electric brake assembly would we need?
What would you recommend for a good brake controller for a Honda Element?


Hi Guys, I would really appreciate your feed back on these specs. The fellow building my frame wants to get it done before the years end!!! :o


Hi Dave,

I've been checking your specs. For my comments below, please keep in mind that I'm a well-wishing amateur. Hopefully the experts will chime in.

These are my thoughts:

1. In your frame drawing, there is a conflict for the dimensions of the frame width. On the right side, the o/o dimension is 56". On the left, the individual dimensions total 57". By your axle spec, the 56" dimension appears to be what you are wanting to do.

2. There seems to be one axle spec that is missing. That is the hub face to hub face dimension. From what I found on the flexiride spec, the overhang distance from outside of frame to hub face can vary from 6.12" minimum to 10.25 maximum. I "clipped" the drawing below from the flexiride website.

Image

Your tire section width will vary somewhat depending upon what width wheel that you use. From a chart I found online, a P205 tire on a 6" wide wheel has a section width of 8.23".

Assuming you spec the minimum overhang of 6.12", with a tire section width of 8.23" and a wheel offset of 2 mm, I come up with the inner edge of the tire being about 2" from the outer edge of the frame. (clearance = 6.12" - 8.23"/2 + 2mm/25.4mm/inch = ~2.0")

The 2" clearance will leave room for your sidewalls to extend below the frame if that is what you intend to do.

3. The distance from frame to outside edge of tire is 10.23 inches. You may want to want to think how these dimensions affects your fender width. Assuming you use 11" wide fenders, the fenders are flush-mounted to the sidewalls, and the sidewalls extend beyond the frame by 3/4", then the clearance between the fender and outside tire edge would be about 1.5" less the thickness of the fender.

Please double and triple check my numbers. From what I understand from other posts about the flexiride axle, you can provide them with your dimensions and they will spec out the axle.

Sincerely,
Tom
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Postby DMcCam » Mon Nov 22, 2010 11:03 pm

Thanks for all your help Guys.

De-rated axle and 5 bolts are good to go. Check

I'll check the Honda Element forum too for the best controller. I've heard you're better off with the factory wiring though. Check

So the 7.25" brake assembly would be fine for this light weight tear, but if I can go bigger do it. Check.

Numbers, why'd it have to be numbers... You know, you think you checked all the totals then bang, an inch off. :oops: Yeah, she's supposed to be 56" wide! Now I'd better call tomorrow and check to see what they did weld!?

Tom, your math looks about right to me but I think I have another error. After shopping around the trailer suppliers, most all trailer wheels have 0 offset! So, I would think the best I can do is order the axle with the minimum overhang of 6.12". This would give me just less than an inch of clearance between tire and fender on the outside. Is that enough clearance?

Thanks again guys,
Dave
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Postby aggie79 » Tue Nov 23, 2010 3:24 pm

DMcCam wrote:This would give me just less than an inch of clearance between tire and fender on the outside. Is that enough clearance?


David,

The inside clearance on my teardrop is a little more than 3/4". I have seen several schools of thought on the forum on clearance, but it seems that a torsion axle can get away with less clearance than a leaf-spung axle. My guess is that this is because a torsion axle limits the wheel/tire movement along just one axis. I guess time will tell.

On a related note, I thought I'd offer one of my learning experiences/work-arounds that you may encounter. My axle is a Dexter torsion axle that, unlike the Flexiride, has a fixed torsion arm start angle. I wanted a low-slung teardrop so I ordered the axle with a 10 degree up start angle. I thought I had done my math but I did not take into account the clearance between the torsion arm and the sidewall extending over the frame.

Image

As you can see in the picture, I had to "notch" my sidewalls to allow for movement of the torsion arm.

On your frame drawing, you show the torsion arm parallel with the frame - a zero-degree start angle. The torsion arm will rotate with the weight of the teardrop - about 1" for the Dexter - and with suspension travel. With the Flexiride, you can adjust the start angle; however, depending upon your desired ride height, you may need to notch your sidewalls.

Sincerely,
Tom
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Postby DMcCam » Tue Nov 23, 2010 8:11 pm

Hi Tom,

Man I really appreciate your help and guidance. I'll have a little more room but not much.

Image

Download large jpeg image here:
http://www.vulcaniavolunteers.com/TEARDROP/wheels.jpg

It looks like the torsion arm will be very close. I probably won't know that clearance until I get the axle mounted. :worship: What are you doing for brakes?

Gratefully,

Dave
Last edited by DMcCam on Fri Mar 23, 2012 4:39 pm, edited 1 time in total.
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Postby aggie79 » Wed Nov 24, 2010 9:32 am

DMcCam wrote:Hi Tom,

Man I really appreciate your help and guidance. I'll have a little more room but not much.

Image

Download large jpeg image here:
http://www.davidmccamant.com/TEARDROP/wheels.jpg

It looks like the torsion arm will be very close. I probably won't know that clearance until I get the axle mounted. :worship: What are you doing for brakes?

Gratefully,

Dave


Dave,

You're graphics are incredible! I think you'll be fine on the clearance.

As far as brakes, I did not order them with the axle. (I did order the axle with brake flanges in case I decide to add them later.) My tow vehicle is a 2007 Honda CR-V. I have towed my HF utility trailer with a 800+ pound loads (plus the 200 pound weight of the trailer) several times. The CR-V handles the trailer and loads very well. I did have to allow greater stopping distance and on inclines the CR-V would downshift to 3rd. Other than that, I don't notice the trailer. It will be interesting to see how it does with our teardrop.

Take care, Tom
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Postby DMcCam » Wed Nov 24, 2010 11:18 am

Hi Tom,

Thanks again for checking the oil on this. We're going to be towing with a Honda Element so the weights are a real concern. Element's are rated at 1,500 lbs with a 150 lbs tongue weight. I figure the added help of the brakes will be worth doing for our mountain camping areas. The grades around the Sierra Nevada range are significant for our little 'E'.

All the best, Dave
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Postby teardrop_focus » Wed Nov 24, 2010 2:43 pm

I was just out in the garage and measured the distance between my trailer's sidewall and the tire; it's 1 - 3/4 inches. I can take a pic later if you like (camera batt's charging).

Remember, however, that as rubber torsion axles get older, the weight of the trailer can cause semi-permanent deflection of the rubber encapsulation and the steel torsion axis will deviate - especially with a Dexter because there's no delrin bushing as there is on the outside of a Flexiride housing - where the wheel's camber angle can change slightly towards negative... meaning that the top of the tire may tilt inwards over time, athough I'd think that would take years and/or a very heavy trailer.

:thinking:
.
Image

"There is something about these little trailers that brings out the best in people." - BigAl, Scotland, 2010

"Climb the mountains and get their good tidings. Nature's peace will flow into you as sunshine flows into the trees...
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Postby DMcCam » Wed Nov 24, 2010 4:36 pm

Hi Chris, Do you have a Flexiride then? I love to see pics of your rig. It sounds like I'll have about the same clearance as you. Sounds good.

Best, Dave
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Postby teardrop_focus » Mon Nov 29, 2010 1:12 am

Here are a couple of pics not posted in my album... took them just for you.

:R

Yes, it's a Flexiride... but two half-axles. Some chassis pics are in my T&TTT Album linked below.


Image

Image
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Image

"There is something about these little trailers that brings out the best in people." - BigAl, Scotland, 2010

"Climb the mountains and get their good tidings. Nature's peace will flow into you as sunshine flows into the trees...
The winds will blow their own freshness into you and the storms their energy, while cares will drop away like autumn leaves..." - John Muir, 1898


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Postby DMcCam » Mon Nov 29, 2010 10:36 am

Hi Chris, those images are excellent! I can really see the space I'll be working with now. Thank you very much for taking the time to take them for me sir.

The nice thing about Flexiride full axles is they are bolted on. If deflection happens in the future, I can just swap it out for a new one. :thumbsup:

Thanks again, Dave
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Postby DMcCam » Sat Apr 09, 2011 7:07 pm

Here's the completed chassis, it was delivered this afternoon!

Image

Image

Image

Image

Image

I'll be starting the build tomorrow. I wish to thank everyone who generously offered their invaluable expertise and experience to me. It turned out wonderfully.

Gratefully yours,

Dave
Last edited by DMcCam on Fri Mar 23, 2012 4:40 pm, edited 1 time in total.
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Postby angib » Sun Apr 10, 2011 4:40 am

There are lots of interesting, and clever, details on that chassis that I think anyone would be wise to copy:
- nice A-frame to single tongue transition - strong and simple
- triangular offcuts of square tube used as body hold-down brackets
- angle used for all the intermediate cross-members
- clever use of two angles to support the rear jacks
- built-in spare tire mount

More detailed photos of some of those parts would be good - OK, I see that your build thread has those detail photos already!
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Postby DMcCam » Wed Apr 13, 2011 12:15 pm

Thank you for your post Andrew sir. Here are a few more detail pictures because you just can't have to many.

Image

Image

Image

Image

Image

Cheers,

Dave
Last edited by DMcCam on Fri Mar 23, 2012 4:41 pm, edited 1 time in total.
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Postby teardrop_focus » Sat Apr 16, 2011 10:37 am

Nice chassis!

MOAR pics! We want build pics!!!

:lol: :thumbsup:
.
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"There is something about these little trailers that brings out the best in people." - BigAl, Scotland, 2010

"Climb the mountains and get their good tidings. Nature's peace will flow into you as sunshine flows into the trees...
The winds will blow their own freshness into you and the storms their energy, while cares will drop away like autumn leaves..." - John Muir, 1898


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Re: Custom Chassis For a 4x10x4 1/2

Postby zimbar » Thu Jul 23, 2015 9:13 am

Hi Folks,
Just wondering why 2x2 tube steel was used instead of 2x1 structural C-channel? 1 foot of 2x2(.125 thick wall) weighs in at 3.05 lbs/ft, where as 2"x1" structural C weighs in at 1.59lbs/ft. I'm in the very early stages of doing a teardrop of my own, and like Dave, want to limit the weight as much as possible. I've got an '09 Dodge Charger that can haul 1,000lb trailer with no problem.

Thanks,
Patrick
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