Reply
 
Thread Tools Search this Thread Display Modes
 
Old 06-15-2013, 04:35 PM   #15
Rivet Master
 
SteveSueMac's Avatar

 
2012 27' Flying Cloud
W , New England
Join Date: Oct 2012
Posts: 5,412
Bob - thanks - FALR = front axle load restoration.


Here are the pics of the tix :laff: in the order I did them.

W/6" WD on the jacks:

Click image for larger version

Name:	image-991151898.jpg
Views:	366
Size:	684.5 KB
ID:	188312

With 5" on the jacks:

Click image for larger version

Name:	image-1324318580.jpg
Views:	1152
Size:	684.7 KB
ID:	188313

With 0" on the jacks: (and it bottomed out coming off the scales :dang:

Click image for larger version

Name:	image-1396998112.jpg
Views:	191
Size:	699.8 KB
ID:	188314

TT attached, 0" WD, only truck axles on a single portion of the scale:

Click image for larger version

Name:	image-3318254700.jpg
Views:	182
Size:	701.8 KB
ID:	188315

Disconnected TT and TV alone on drive and steer scales:

Click image for larger version

Name:	image-1613900040.jpg
Views:	216
Size:	686.1 KB
ID:	188316

Those are the numbers I put in the table earlier an I included a column for max allowed values for each axle and tongue weight.
__________________

__________________
SteveSueMac is offline   Reply With Quote
Old 06-15-2013, 05:05 PM   #16
CLOUDSPLITTER "Tahawas"
 
ROBERT CROSS's Avatar

 
2003 25' Classic
Zanadude Nebula , WNY
Join Date: Jun 2007
Posts: 11,153
Images: 1
Steve,

Any more left on the jacks?
It would be good to get at least another 100lbs to the front.

How did it tow?
Are you level?, especially the AS.

Bob
__________________

__________________
PFC.....

“After all these years the reason I continue to love Thanksgiving.....I still sit at the kids table.”
RLC

Sandra wanted to go to Cleveland on vacation,
but I’m the Husband, so we went to Cleveland.
RLC
ROBERT CROSS is offline   Reply With Quote
Old 06-15-2013, 06:25 PM   #17
Rivet Master
 
SteveSueMac's Avatar

 
2012 27' Flying Cloud
W , New England
Join Date: Oct 2012
Posts: 5,412
Bob - I think I can get to 7" on the jacks. I'm also thinking I REALLY should have followed Sean's advice and ordered the 1400# bars not the 1000. My AS manual said the TW shouldn't go above 1000 - or in any case - not to exceed the hitch manufacturer's limit (1500 in my case).

Towed well and the trailer is almost perfectly level at all 4 corners.
__________________
SteveSueMac is offline   Reply With Quote
Old 06-15-2013, 06:30 PM   #18
Rivet Master
 
Ridgerunner3's Avatar
 
2002 25' Safari
Fountain Inn , South Carolina
Join Date: Sep 2011
Posts: 659
Images: 11
I may not be calculating tongue weight correctly. I weigh the TV with each axle on a different pad. I then weight the TV and TT with no tension on the WD bars. I then sum the weight of the truck axles alone. Then I sum the truck axles with TT attached and no WD tension. I then subtract lone TV weight from the TV weight with TT w/o WD tension to calculate tongue weight. This would be 1080# for your rig by the method I use. I may be using the wrong process. I hope someone chimes in on my process for calculating tongue weight.

My rig (propride 2012 GM 2500 & 6300# 25 footer) is more comfortable to me when I do not return all of the front axle to the TV.
__________________
Bud
Ridgerunner3 is offline   Reply With Quote
Old 06-15-2013, 06:37 PM   #19
CLOUDSPLITTER "Tahawas"
 
ROBERT CROSS's Avatar

 
2003 25' Classic
Zanadude Nebula , WNY
Join Date: Jun 2007
Posts: 11,153
Images: 1
Thumbs up

Great Job!!

Try it at 7" first. You'll get a softer ride with them. I have 1000's on our 2500 Burb and they work fine. I can max them out and get that 100lbs forward, but the ride is better and and everything's level without.


Now about the possible water leak. Boy you'd think with it leaking that quickly there would be a LOT on the ground. I know when I drain the FW thru the pet-cock it takes a good long time to empty a full tank.

RR3,

1080 is my TW for Steve's rig also. That seems more in line with my 1200 for our Classic using the SL scale.

Bob
__________________
PFC.....

“After all these years the reason I continue to love Thanksgiving.....I still sit at the kids table.”
RLC

Sandra wanted to go to Cleveland on vacation,
but I’m the Husband, so we went to Cleveland.
RLC
ROBERT CROSS is offline   Reply With Quote
Old 06-16-2013, 12:05 PM   #20
4 Rivet Member
 
Livingston , Texas
Join Date: Dec 2007
Posts: 394
Quote:
Originally Posted by SteveSueMac View Post
---I get 8740 for the truck w/trailer connected but trailer not on scales, minus 7900 for truck by itself on scales for 840 tongue weight.
In one of the ticket captions, you mentioned dragging when coming off the scale. That indicates a down slope at the exit and, probably, an up slope at the entrance. If so, the TV would have been higher than the TT and the TT tires might have been on the up slope. This would make it difficult to make much sense of the TV weight of 8740#. I recommend we disregard that weighing to reduce the confusion.

Quote:
First question: is that static no matter how much WD I apply?
If the tongue weight is properly determined, it should remain constant unless the trailer loading is changed.

Quote:
Note: CGVW of TV and TT is 14740. That minus TV of 7900 suggests the TT weighs 6840. But even with 0 WD applied, the TT axle weighs in at 5760 (a difference of 1080# and 240# off from calculated tongue weight). The steer and drive axles of the TV weigh in at 8980 and the difference there is 1080 from the truck alone. So where does the 840 tongue calculation fit in??
As stated above, I think it would be good to disregard the "840 tongue calculation". IMO, the 1080# value is a better estimate, but I'll say more about that later.

Quote:
Second question: when calculating FALR, is the denominator 500# and the numerator the difference in lift of the steer axle from 500# or is the 4620 steer axle weight (truck alone) the denominator and the cat scale steer weights the numerator? I ask because in the former method, 6" gets me 56% FALR (280/500). In the latter method, I get 95% FALR (4400/4620).
FALR is the amount of load restored to the front axle via application of WD (4340-4120=220# for 5") divided by the amount of load removed when the TT was initially attached (4620-4120=500#). The FALR for 5" is 220/500 = 44%. The FALR for 6" is (4440-4120)/500 = 56%.

More later --

Ron
__________________
Ron Gratz is offline   Reply With Quote
Old 06-16-2013, 02:54 PM   #21
CLOUDSPLITTER "Tahawas"
 
ROBERT CROSS's Avatar

 
2003 25' Classic
Zanadude Nebula , WNY
Join Date: Jun 2007
Posts: 11,153
Images: 1
Question

KISS...just replace the front axle loading.

FALR....what's the point, what am I missing?

Oh wait....the rules have changed, now we are told that we can just replace a percentage of the weight and everything will be fine. A little for you, more for me and none for him.
No thanks' I prefer to make that determination by actually driving my rig, plus I'm rotten at werking my calculater while driving.

Bob
__________________
PFC.....

“After all these years the reason I continue to love Thanksgiving.....I still sit at the kids table.”
RLC

Sandra wanted to go to Cleveland on vacation,
but I’m the Husband, so we went to Cleveland.
RLC
ROBERT CROSS is offline   Reply With Quote
Old 06-16-2013, 07:17 PM   #22
Rivet Master
 
SteveSueMac's Avatar

 
2012 27' Flying Cloud
W , New England
Join Date: Oct 2012
Posts: 5,412
Ridgerunner3 - looks like your method would produce 1080 and that makes more sense to me than something in the 800s. The 1080/6840 would suggest a 15.7% TW...that seems ok to me.

Ron - thanks so much. It's so gracious of you to share your knowledge like this!

I'm seriously thinking about those 1400# bars. In an earlier attempt, I got to 100% FALR at 6" and now apparently I'm at 56% which makes no sense to me...much more noodling and testing to do. We'll get this right eventually. I will get you the measures you suggested in your PM.

Bob - thanks too for your encouragement and the practical advice. Unless WD on the PP works like decibels - one inch is going to get me 60-80 lbs so at 7, I'd be closer but still not where I want to be. I'm very confident I'm going to get this dialed in - really appreciate everyone's help. The ride still seems fine to me but this is my first rig. How would I know any better? :-)

I'm trying to KISS and feel like having a boatload of data is helping me understand more and more about it so I can get to something simpler that I know I can manage more intuitively having the background of the math behind it all. Math was definitely not a strong point for me! :-)
__________________
SteveSueMac is offline   Reply With Quote
Old 06-16-2013, 09:40 PM   #23
4 Rivet Member
 
Livingston , Texas
Join Date: Dec 2007
Posts: 394
When is Tongue Weight not Tongue Weight

Tongue weight usually is defined as the upward force against the ball coupler required to keep the trailer in a level attitude when it is sitting on a level surface.
When a trailer has independently suspended axles, the "level attitude" is especially important to get an accurate measure of tongue weight.

When a TT is attached to the TV with no WD applied, the "sag" at the rear of the TV usually will cause the TT to be in a "nose-down" attitude.
Is so, an independent suspension on the TT will cause net load to be added to the TT's axles (decrease on rear but larger increase on front) and the upward force against the ball coupler will be reduced.
This means the load which is added to the TV will be somewhat less than the actual tongue weight. And that means if you subtract the "TV ONLY" weight from the "TT HITCHED WITH NO WD APPLIED" weight, the result will be somewhat less than the actual tongue weight.

For Steve's data, the usual direct method of estimating tongue weight gives (4120+4860)-(4620+3280) = 1080#.
A second "direct" method using data for the TV on the scale, the TT off the scale, and no WD applied, gave an estimated tongue weight of 840#.
This probably was due to having the TT's tires partially or fully on the up slope to the scales -- likely causing a fairly large "nose down" attitude relative to the plane on which the tires were sitting.

An indirect method of estimating, using data for "WD APPLIED" along with TV and TT dimensions should get us closer to the actual tongue weight because, with WD applied, the TT should be closer to "level".
For Steve's 5" data this method gave an estimated tongue weight of 1169# with 149# transferred to the TT's axles.
For Steve's 6" data this method gave an estimated tongue weight of 1126# with 166# transferred to the TT's axles.

However, without knowing the attitude of the TT at 5" or 6", we cannot say if either the 5" or 6" data would give a more realistic estimate of TW.

Perhaps a more accurate method for estimating TW (if permitted by the scale operator) would be to position the TT with its axles on Pad 3 and its tongue jack over Pad 2. Then lower the jack and disconnect with the TT level. Next move the TV so both of its axles are on Pad 1.

The above method will give the load on the jack, which is not equal to the TW -- but a correction can be applied.
Measure the distance from the center of the jack to the midpoint between the TT's axles. Call this distance "d1".
Then measure the distance from the center of the jack to the middle of the ball coupler. Call this "d2".
The TW then is equal to jack load times d1 divided by d1+d2.
For example, with jack load = 1000#, d1=240", and d2=10", we would have TW = 1000*240/(240+10) = 960# (plus or minus the accuracy of the scales).

And, of course, with a PP or HA hitch, the drawbar should remain in the receiver for all weighings.

I'm sure this does not simplify matters for the OP, but it does point out factors which should be considered if one wants to get a really good estimate of tongue weight.

Ron
__________________
Ron Gratz is offline   Reply With Quote
Old 06-16-2013, 10:58 PM   #24
Rivet Master
 
2008 23' Safari FB SE
Boulder , Colorado
Join Date: Mar 2010
Posts: 510
Quote:
Originally Posted by SteveSueMac View Post
I don't have a Sherline scale and don't want to spend $150 on one, and I don't like the bathroom scale method (seems way too prone to variation). So I'm wondering if this would work:

1) pull TV on to cat scale with TT connected BUT trailer axle NOT on the platform.
2) track weight - let's say it's 6000 lbs
3) drive off the scale and disconnect the TT
4) weigh the TV on the cat scales alone - let's say it weighs 5000 lbs
5) tongue weight = step 2 (6000) - step 4 (5000) (or 1000 in this example)

Is this an accurate way to calculate tongue weight? Are there other ways to calculate it without a dedicated scale or bathroom scale/boards/pipes?

Thanks!

Edit - this is based on a recommendation I found on a web search - not an original idea on my part...
Would this approach for determining how much the tongue adds to the payload of the truck (taking measurement #1 with weight distribution bars removed) or would it be better to do measurement #1 with weight distribution bars?

I am trying to figure out how much my full TT adds to my truck's payload.

I weighed the truck today empty at the CAT scales and now want to figure out what the tongue adds to the payload...
__________________
bonginator is offline   Reply With Quote
Old 06-17-2013, 12:03 AM   #25
4 Rivet Member
 
Livingston , Texas
Join Date: Dec 2007
Posts: 394
Quote:
Originally Posted by bonginator View Post
I am trying to figure out how much my full TT adds to my truck's payload.

I weighed the truck today empty at the CAT scales and now want to figure out what the tongue adds to the payload...
Have the TV loaded the same as when you weighed it empty.

Hook up your full TT to the TV.
Hook up the weight distribution hitch for the amount of load distribution you want.

Weigh the TV with TT attached and weight distribution applied,
with steer axle on pad1, drive axle on pad2, and TT axles on pad3.

Your towing TV weight is the sum of the steer and drive axle loads.
Subtract the empty TV weight from the towing TV weight to get the amount added to the payload.

Ron
__________________
Ron Gratz is offline   Reply With Quote
Old 06-17-2013, 10:28 AM   #26
Rivet Master
 
2008 23' Safari FB SE
Boulder , Colorado
Join Date: Mar 2010
Posts: 510
Thanks, Ron.

Anyone have a good printed guide that instructs step by step how to do proper CAT scale weighings and record values and call results for a dual axle TT and TV? I had one before but can't seem to put my hands on it now...
__________________
bonginator is offline   Reply With Quote
Old 06-17-2013, 06:42 PM   #27
Rivet Master
 
SteveSueMac's Avatar

 
2012 27' Flying Cloud
W , New England
Join Date: Oct 2012
Posts: 5,412
Quote:
Originally Posted by bonginator
Thanks, Ron.

Anyone have a good printed guide that instructs step by step how to do proper CAT scale weighings and record values and call results for a dual axle TT and TV? I had one before but can't seem to put my hands on it now...
Hi. Try here: http://catscale.com/how-to-weigh


Now as it happens this was apparently my 499th post which means my next one makes me a Rivet Master - which can not mean what it sounds like as I'm not a master in this game by a long shot!

So - any recommendations or traditions I should know about for post 500??
__________________
SteveSueMac is offline   Reply With Quote
Old 06-17-2013, 08:40 PM   #28
Rivet Master
 
richinny's Avatar
 
2011 34' Classic
Westchester Cty.NY , / Miami FL
Join Date: Jul 2007
Posts: 3,122
i think you buy the forum a round of drinks!
__________________

__________________
Ricky
2012 F150 Super Crew 5-1/2' bed Ecoboost 4x4 3.73 elec. lock diff. Propride hitch
give life. kidney & pancreas transplant 9/9/06
Ingrid-my unofficial '"World's Oldest Streamer" 1909-2008 R.I.P.
richinny 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 05:36 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.