Reflection 220RK 6K Axle Upgrade Discussion - and help

[Yoda]

Tube properties are the easy one.

https://www.engineeringtoolbox.com/c...ta-d_1496.html (For Rob and our Northern friends).

https://www.engineeringtoolbox.com/s...ions-d_43.html

Let me help with the relief of the headache. https://www2.engineering.com/calculators/beams.htm Looks like only 1 load not 2 still looking

Thanks for the charts, but tubes are high strength steel of some sort.

[Jlawles2]

The chart are more for the structural properties.

Also if you look at the deflection calculations, none of the strength properties are used. The only ksi used is the modulus of elasticity of steel 29,000ksi. So it does not make a difference if the tube is 32ksi, 36ksi,42ksi, 46ksi, 50ksi, etc. deflection will be the same at the same load.

[Jlawles2]

I only dabble in the design stuff a bit.


note axle camber is based on full load not what you think will be on it.


I have a different program I can put it into, but that one is all metric so I would have to do the conversions.

[Yoda]

I only dabble in the design stuff a bit.

I have a different program I can put it into, but that one is all metric so I would have to do the conversions.

Good Grief - WOW!
You must enjoy a challenge. I am blown away, and my head hurts - been a long time sense i worked with calculations like this.. So it appears the 3" HW 5/16" tube will fit my needs. Do you agree or is .221" deflection going to cause tire wear issues? The 3.5" tube would probably be overkill, correct?

I was thinking you might want to do the metric one so Rob Cate&Rob understands..................................just kidding

Dexter Warrantee is helping get things straightened out by contacting the distributor on what is available - the 3" by 5/16 wall can be had. However I think they are recommending the wrong springs, 26" free arch verses the 25.25" I have. I think they are too long and will bind up the EZ-fles center hanger I have.

Thanks Joseph for doing this. A good dinner is on me when we meet up someday.

Keith

[Jlawles2]

Keith, I not very good with metric. No "feel" for it.

And I just sat down and took a little knowledge in a program called MATHCAD to type the equations just like they look in the steel manual. It took me just as long to get the screen shots as it does to regurgitate the equations that are printed into the program. It took me even longer to find your post with the dims so I could plug them in.

I can change any of the parameters and get new answers in as long as it take to press the enter key. If you have a question, let me know and I can change the variables and get you a new number.

Looking at the full load numbers:

The deflection from the center of the tire to the center of the hanger is about 1/8". Again at the 6k rated load. Axles should be designed around either full load or some percentage of full load.
Can you measure your current between spring perch camber loaded and unloaded? If so, then I can run the numbers again and see what load they are running for the camber calc.

[Yoda]

Keith, I not very good with metric. No "feel" for it.

And I just sat down and took a little knowledge in a program called MATHCAD to type the equations just like they look in the steel manual. It took me just as long to get the screen shots as it does to regurgitate the equations that are printed into the program. It took me even longer to find your post with the dims so I could plug them in.

I can change any of the parameters and get new answers in as long as it take to press the enter key. If you have a question, let me know and I can change the variables and get you a new number.

Looking at the full load numbers:

The deflection from the center of the tire to the center of the hanger is about 1/8". Again at the 6k rated load. Axles should be designed around either full load or some percentage of full load.
Can you measure your current between spring perch camber loaded and unloaded? If so, then I can run the numbers again and see what load they are running for the camber calc.

No way to measure what I have that I know of as the axle tubes are bent. Can you run the 3.5" tube 0.5" wall - just for grins?

Dexter warranty gave me the contact information for a senior management person that actually knew what I was trying to do and admitted thier folks at the distribution centers ordering are limited in what they know or have access to, so he understood what I was running into. He gave me a Colorado dealer, (Iron Bear Trailer), to talk with. Currently in discussion with them and so far I believe I found the supplier I need that understands what I am up to. Initial pricing is good to. Looks like the 3.5" tube and 3500lb springs will do what I want. The upgrade to the 3.5" tube is only about $300 each axle. the 3" HW were running about $820. They can ship fully assembled with springs attached. Their price beats a Dexter quote I got for just the axle by about $600 per axle. Shipping prices are about the same possibly slightly cheaper.
Anyone know anything about Iron Bear Trailer? https://ironbeartrailer.com

Thanks and more to come.

Keith

[Jlawles2]

Keith, the tubes are bent beyond the spring perch, correct? If between the perches is not bent, then string from U-bolt to U-bolt and measure up to the tube subtracting the measurement at the U-bolt.
3.5" X 0.5" (1/2")



Now 3.5"X5/16" makes more sense.

[Yoda]

Keith, the tubes are bent beyond the spring perch, correct? If between the perches is not bent, then string from U-bolt to U-bolt and measure up to the tube subtracting the measurement at the U-bolt.
3.5" X 0.5" (1/2")

You know this indicates with the 3.5" HW 0.5" tube no camber (arch) is really needed. Am I reading correctly?

The bigwig at Dexter and my previous trailer place both indicated no arch was needed. I'm still trying to wrap my head around this - Maybe I want some, say 10-15% of normal?

Thanks
Keith

[Cate&Rob]

0.5” tube wall . You will be significantly increasing the unsprung weight. This will change the handling of the trailer.

Rob

[Yoda]

0.5” tube wall . You will be significantly increasing the unsprung weight. This will change the handling of the trailer.

Rob

Interesting thought. The axles will be about 75lbs -100lbs heavier each and the weight will be well below the center of gravity. Would that not help stability? However with the stiffer frame I know there will probably be more hanger stress which is why there I will be installing 3 X-Factor cross braces (spring ends and center EZ flex). I have them sitting on the floor withe my Morryde HD shackle set and new wet bolts waiting for install. Am I missing something? I do plan to have the sumo springs in place to act as bumper stops again as you recommended earlier.
or
Go with the 3" HW 5/16" tube?

Keith

[Jlawles2]

What are the options for 3" tube wall thickness? Remember my calc are based on the capacity of the axle not your loadings.

I can go back and run the check based on your loads, but I would plan on the capacity just in case (because engineers never ever plan for what if).

[Cate&Rob]

Yoda

Unsprung weight is a big deal in automotive suspension where lighter is always more responsive and thus better at keeping the tires in proper contact with the road. Heavier unsprung weight means that the moving components of the suspension have more inertia. They get moving more slowly and stop moving more slowly. I really have no idea whether the concept of “lighter is better” applies to trailer suspension or not . . .

Rob

[Yoda]

What are the options for 3" tube wall thickness? Remember my calc are based on the capacity of the axle not your loadings.

I can go back and run the check based on your loads, but I would plan on the capacity just in case (because engineers never ever plan for what if).

in the 3 inch ; Light wall 0.16, what failed, std is 0.25", and the HW is 5/16. Given the 300$ price jump I am reconsidering if I wan to go to the 3.5 tube. Going to sleep on it.

Keith

[Yoda]

Our internet was down most of the day as well as power for a few hours, and now dealing with a house furnace issue - good thing I have the wood stove and a stack of wood

Anyway wanted to post some new information on Dexter springs. Dexter is now specifying specific springs models in weight ratings based if the springs are overslung (springs mounted over axles) or underslung (springs under the axles). I did not know that and only found out by double checking part numbers against the catalogs and asking questions of Dexter management and a vendor. The spring part number they recommended was not in the catalog I had, and the web information was lacking. This information is not widely available from what I can tell, so ask

So I an going with Dexter 3500lb 6 leaf (overslung model) (for the lift) I am also pretty sure I am going to go with the 3.5" tube, unless....... well.

I can finding nothing that says the extra 150 lb weight will cause issues.

BTW I found upgrading to bronze bushings is only a 1$ up charge over the stock plastic. Going the bronze option.

Well tine to stock the wood stove again so the house does not freeze tonight. - 60 MPH gusts in a blizzard today and 17 degrees tonight with more snow - what fun

Ill post all the parts numbers once the order is set.

Keith

[acoleman43]

Our internet was down most of the day as well as power for a few hours, and now dealing with a house furnace issue - good thing I have the wood stove and a stack of wood

Anyway wanted to post some new information on Dexter springs. Dexter is now specifying specific springs models in weight ratings based if the springs are overslung (springs mounted over axles) or underslung (springs under the axles). I did not know that and only found out by double checking part numbers against the catalogs and asking questions of Dexter management and a vendor. The spring part number they recommended was not in the catalog I had, and the web information was lacking. This information is not widely available from what I can tell, so ask

So I an going with Dexter 3500lb 6 leaf (overslung model) (for the lift) I am also pretty sure I am going to go with the 3.5" tube, unless....... well.

I can finding nothing that says the extra 150 lb weight will cause issues.

BTW I found upgrading to bronze bushings is only a 1$ up charge over the stock plastic. Going the bronze option.

Well tine to stock the wood stove again so the house does not freeze tonight. - 60 MPH gusts in a blizzard today and 17 degrees tonight with more snow - what fun

Ill post all the parts numbers once the order is set.

Keith

Following this saga intently., Great information

We were at a cozy 90 degrees today.....had to run the AC for a few hours. Temp drops to 83 tomorrow, I might need a jacket.