Truggy Rearend

[rdc]

Looking at the rear end, from the transmission, with a 3 link.. With approx. 32" of travel, when one wheel goes all the way up and the other down, how much does the pinion swivel from left to right? Its top fulcrum will be the 3 link mounting point. Our frame that we are building only has a couple extra inches total room for the drive shaft. Is there a way to figure out how much the drive shaft will move left to right?
Jason

 

[fishd00d]

Here is a picture of their rear end:

Go Big Or Go Home

 

[rdc]

My question isnt about looks, I'd like to find out how much the driveshaft moves left and right so i can make sure i have enough clearance between the framerails. Im using a 4" diameter driveshaft and only have 1" plus clearance on each side looking from the transmission. I want to know if that is enough room, when the rear end "duck walks" is the driveshaft going to move that much to hit the frame?
Jason

 

[Bob_Sheaves]

Hi Jason,

There are 2 easy ways to get what you want....

1 Calculate the resultant using trig.

2. Use a 3D design program to cycle the suspension and measure the result.

Best as always,

Bob Sheaves

 

[Bob_Sheaves]

an ADDENDUM...

see attachment for an idea of what a 3D program can do for you....

Best as always,

Bob Sheaves

 

[DPpatrol]

Hey Bob,

what program is that and what can it do besides make a real pretty picture with lots of cool colors?

jason

 

[Bob_Sheaves]

Hi jason,

The program is called CATIA-I described it a while back on this board. The program is a design/engineering analysis/manufacturing tool I use in my business of designing vehicles.

Best as always,

Bob Sheaves

PS- Each of those "cool colors" means something very specific to the program about the part and how it is made, it's mechanical properties, etc....
<P ID="edit"><FONT SIZE=-1>Edited by Bob_Sheaves on 03/04/02 10:58 PM (server time).</FONT></P>

 

[rdc]

That fine and dandy Bob, but who one this board cam afford or have access to Catia.

 

[Bob_Sheaves]

Hi Goat1,

If you look in the phone book in the LA area, you will find several companies like INCAT and others that are in business to sell design time on CATIA. I am not saying that it's not expensive, but all you have to do is some basic thinking. Of course, you have to be able to explain what you need to have done....

As far as whom can afford it? I can.....and I'm retired! It all depends on how badly you want to be the best.

Best regards,

Bob Sheaves

 

[FABRICATOR]

There is a third way guaranteed to provide you with more useful information...Go the the hardware store and buy something rigid like emt conduit, etc., and make a mock up of the system you have in mind. You can get it all for probably around $15.00 or so. Stores like Orchards have low grade rod ends for $3 to about $7. A nut welded on the end of conduit works great for this and the rod end can screw right in. Size of the rod end is irrelevant. Unless you are into body building, take the time to mock-up the rear end too. This can be done with a big cardboard or ABS tube. Make things fairly accurate so you can rely on their dimensions later.

This will not only show you EXACTLY how everything will fit and move, but will also open your eyes to additional possibilities. Staring at a computer screen will not do this. You must think beyond just the part you are working on, so the project can progress intelligently. You can check the fit of other components at that same time also.

<font color=orange>The best ideas are the ones that look obvious to the casual observer.</font color=orange>

 

[BIG_FAT_LOSER]

take off the coils and cycle it.

<font color=red>PAT KAPKO</font color=red>
<font color=yellow>Fab by travolta</font color=yellow>

 

[AaronDixon]

Bob - That's an interesting suspension set-up. What is that designed for??? A TTB with an A-arm for alignment!!!

Aaron

 

[Bob_Sheaves]

Hi Aaron,

What is shown is part of a job I did recently for a foriegn customer of mine. Several parts that are unique to this design are not shown at customer request. Currently 2 mule vehicles are running high speed and durability testing in Africa. This design is capable of 6.2 inches jounce travel with 8.2 inches of rebound travel (roughly 14 inches of total travel, plus or minus a bit), with all it's components, on a 68 inch track width. Coupled with a similar design in the rear and a single speed, torque proportioning differential in the transfer case (another custom piece with both outputs on the left side of the vehicle, as on an old Dana 18, as I remember), the projected life is in excess of 80,000 miles MTBF (Mean Time Between Failures). At this time, the 2 trucks are a bit more than halfway through the test cycle and have had no failures, as predicted.


The basis of what is shown, is a derivative of a 1962 Jeep IFS offered on the first Wagoneers (along with the Hotchkiss design). While more durable than the Hotchkiss, this design was dropped after one year in production due to manufacturing costs and customer choice of the less expensive Hotchkiss design. The IFS was an option of some $150.00 per vehicle extra (remember this was when the vehicle cost approximately $3000.00 base price- so $150.00 was a BIG chunk of change).

Best regards,

Bob Sheaves

 

[DPpatrol]

Does that program you used calculate the MTBF or is that calculated some other way?

jason

 

[Bob_Sheaves]

MBTF is determined from the results of the Finite Element analysis on a component (this gives you the "strength" of the part or assembly in question) being used as input to an assembly duty cycle analysis with MBTF as the output from the duty cycle analysis. This process is common in the military aircraft and tactical/combat vehicle industry.

All that being said, yes, CATIA, being modular software, has the capability, through it's various modules, to give me the results I need to make such a prediction.

Best regards,

Bob Sheaves

 

[vwguy]

duh of course i thought everybody knew that

how ironic is it that most people slow down for speed bumps yet almost all of us here im sure pin it