[dhawcash]

greetings to everyone at team-bhp

[note to moderators- this article is about a 4x2 sandrail with offroading credentials. please move to appropriate forum if im doing it in wrong
place ]

I am an engineering student (b tech. automobile) and was faced with a decision in the month of august, 2010. A decision regarding what to make to fulfill my university's requirement of a major project.it was a toughie, my wild mind overflowing with many variations of the following ideas:
1. A 4x4 quad bike (rejected as almost every one ends up makin one...wud be too common)
2.A Low profile go cart (rejected: because of limited scope of use)
3.A Drag bike (rejected for same reason above)
4. a 4x4 go anywhere bug (kind of rejected due to expenses involved)

The last one , however, stuck. i could drive it anywhere i wanted, would be useful, and fun. needed some idea fine tuning keeping in mind the limited budget.

So it was decided that i'd design n fabricate a vehicle fulfilling the following requirements:
1: Fast, Light and fun to drive
2: Go Anywhere capability (Rugged) [NOTE: did not intend to beat HUMMERS, but cabaple of a bit more than softroading]
3: acceptable handling and safety
4: Reliability
5: Acceptable running and building costs
6: 2 seater + space for luggage
7: Scope for easy upgrades to drivetrain and suspension
8: a four month building time, shuffling between classes and event management and home errands.
to meet the above requirements, the basic idea of what the vehicle would be like was as follows:
- Rear engined, rear wheel drive.
- long and low (with a 12 inch ground clearance to meet offroading demands)
-Tubular spaceframe, acting as rollcage
-all go, no show building attitude. if something did not help with the required goals, it wasn't added.
- A function oriented look. dont care if the chicks don't dig it

so, started off with a mid-lecture-back-of-notebook design session, making drawings of possible layouts, and where all the working parts would be placed.
next step was to do a research on what parts were available at what prices at the local junkyard.
as it was a budget build, i decided on ditching the long travel suspension plans, and zeroed on to maruti esteem's mcpherson setup (for all four corners) . Gave a thought to a Double wishbone setup, but cost, parts, and concern of reliability made me go against it.Mc pherson was Nothing too glamorous, but turned out wasn't a bad decision.
The mcphersons had the added advantage of having a tough build (have seen esteems in rally action), reliability, biggie discs, and a hub which can accomodate maruti 800's driveshaft splines. this was an important decision as it made the drivetrain bulletproof (theoretically)by use of tried and tested parts .

As the layout was decided initially[ rear-mid engine, rearwheel drive, with two passengers at front] it was time to design a frame with space and mounting points for the passengers, engine and suspension.
Dimensions for passenger space and ergonomics were taken, along with other hardware, and designed the frame using Pro- Engineer software. This virtual design was a big help during the actual fabrication.
Note that i did not make the whole thing virtually (excluded engine mounts, suspension mounts, and exact locations of where everything goes), as that would have been kind of boring. i do what i do for happiness, and designing the whole thing virtually and assembling later on seemed a bit soul less and unpassionate to me. plus i planned it to be a one off, so wont need the virtual data for mass production. {i quiet enjoyed playing lego as a kid, and this project reminds me of the countless hours i spent making stuff with it }

At this point, i'd like to add a picture of the finished vehicle to keep the story interesting.


Have a lot more to tell, my next post coming shortly

[jeepster]

congrats brother!!
GREAT WORK .

IMO just needs a windshield (at least a frame) & A pillars to be joined with B pillar.

also get some tall tyres at front & rear for high Ground Clearance.

& best of luck for your next project.

EDIT: please post some WIP pictures.

[maddy42]

Amazing man. That is some project you have there. How many members were in your team and hows the performance of it? Any videos?

And the last picture for the future project had me go eyes wide open. Hope you try that out

[Mr.Boss]

Congrats dude and all the very best for any further upgrades on her.
BTW here is my graduation project, Concept of Zero Turning Radius.
Sorry for using your thread, could not resist me doing this
I am the one sitting on the vehicle and the other is my Professor and Project guide

[fazalaliadil]

Originally Posted by dhawcash

this article is about a 4x2 sandrail
Have a lot more to tell, my next post coming shortly

Dawcash,

Intresting. The propotions have come out good.

Though it my not have a problem on flats, my apprehension is, will the tubular chassis take the off road stress and not warp and bend?

A reinforced 'C' section welded and bolted frame under the existing tubular, is required you think?

What is the engine that powers it?
Regards,

[dhawcash]

Originally Posted by jeepster

congrats brother!!
GREAT WORK .

IMO just needs a windshield (at least a frame) & A pillars to be joined with B pillar.

also get some tall tyres at front & rear for high Ground

Thank you! Glad you like it.

yes, you are right about the A- pillar and a windscreen frame. would unveil why i didn't incorporate them as the story rolls forward

And as per the tyres, I chose them after a lot of research on the engine and transmission possibilities. with the present transmission, bigger tyres will make the gearing too tall, and did not have the resources or time to mod the gearbox.
But it's performing quiet well, will post more pics and videos soon.

[dhawcash]

Originally Posted by fazalaliadil

Dawcash,

Intresting. The propotions have come out good.

Though it my not have a problem on flats, my apprehension is, will the tubular chassis take the off road stress and not warp and bend?

A reinforced 'C' section welded and bolted frame under the existing tubular, is required you think?

What is the engine that powers it?
Regards,

Thank you sir.
The tubular chassis has been made out of 1.5 inch (inner dia) 1/8 inch wall thickness mild steel tubing, and welded via conventional arc welding. I have used plenty of triangulations, and only two members in the frame are prone to bending stress. plus the fact that she weighs in at 480 KGs, the frame is quiet upto whatever i plan to throw on to it. Also, have done torsional and bending tests on FEA software Ansys. (unfortunately my harddisk crashed, so cannot show the test results to you.)
Also, during the testing phase, we had an unintentional 'crash test', where a team mate slammed into a tree at more than 50 kmph. the car survived well, with minimal damage. the front still bears a dent as a souviner

It is powered by a 1994 maruti 800's engine.

Originally Posted by Mr.Boss

Congrats dude and all the very best for any further upgrades on her.
BTW here is my graduation project, Concept of Zero Turning Radius.
Sorry for using your thread, could not resist me doing this
I am the one sitting on the vehicle and the other is my Professor and Project guide

Thank you

Originally Posted by maddy42

Amazing man. That is some project you have there. How many members were in your team and hows the performance of it? Any videos?

And the last picture for the future project had me go eyes wide open. Hope you try that out

Thank you! well, i led a team of ten members.
Performance is quiet peppy, as it weighs in at 480 KGs. it can cross 120 kmph wit ease (provided you are brave enough). will elaborate on performance specs and post some in action videos soon

And the sandrail bug has bitten me hard now. itching for the day i have the resources to build something like that ( have even better ideas in store

[dhawcash]

Here's a picture of the dent i was talking about.
the impact was pretty hard, and damages included a dislodged streeing column, a busted radiator, and a ripped rubber engine mount (and hence an unfunctional gearshift linkage).

[Sutripta]

Hi,
Are the rear tyres from a power tiller?

A tie from what would be the base of the A pillar to the corresponding point in the back would have done wonders for rigidity. (You young people should be able to jump in and out over the bar.)

What is the front/ rear weight distribution like with driver?

Regards
Sutripta

[dhawcash]

story continued:

till now, i mentioned how the idea came, and how the basic layout of the vehicle was decided.

Here is the virtual model.


This was a great help, as i could calculate the amount of tubing required, and cut and sort them for profiling and welding.



profiling the pipes was the most time consuming phase of the build, and we ground and ground till all dimensions were the way they were supposed to be.

In this picture, members are placed in proper positions to ensure dimensional accuracy.The floor was marked to ensure parallel sections and angles came out correct.Used old school techniques most of the time. Welding had its own set of issues, distortion due to thermal contraction making us redo many sections.


Used makeshift jigs, like this peice of plywood for various sections.


kept going, and created this mess [ will have better workshop management for my next project]

moved the frame around over the engine, as its quiet heavy, and did not have an engine lift.



jigs for rear suspension A-arm mounts.


And after a month long wait, she's standing on her own wheels! this was an emotional moment for us..seeing our baby stand up without support of jackstands



At this point, had to take her to college for a practical viva. made this makeshift towhook to tow it there.


never make tow hooks out of angles, no matter how strong they seem, the can't resist bending stress.


signing off now, more details on the line. stay tuned

[dhawcash]

Originally Posted by Sutripta

Hi,
Are the rear tyres from a power tiller?

A tie from what would be the base of the A pillar to the corresponding point in the back would have done wonders for rigidity. (You young people should be able to jump in and out over the bar.)

What is the front/ rear weight distribution like with driver?

Regards
Sutripta

Yes sir, they are from a power tiller.

Yes you are right about the tie, and had similar plans, but my dad and senior faculties opposed the idea. and had a hard time trying to convince them, but they were too keen on ergonomics. The present layout is working fine and gave acceptable results in the Finite Element Analysis [ capable of withstanding corrosponding forces of a 60 kmph head on impact and 1 metre high jumps without exceeding yield stress and maximum deformation of 4.8 mm.] And i have taken 2 feet high jumps and (accidently)crash tested it without any worries

with two 60 kg passengers, the weight distribution is almost 35:65 .

[fazalaliadil]

Originally Posted by dhawcash

Also, have done torsional and bending tests on FEA software Ansys...
a team mate slammed into a tree at more than 50 kmph.

dhawcash,
I am convinced, but still would not volunteer to be replacing a test dummy speeding at over 50kmph into a tree. Team mate in more than the truest sense.
Regards,

[jeepster]

Originally Posted by dhawcash

Here is the virtual model.

This was a great help, as i could calculate the amount of tubing required, and cut and sort them for profiling and welding.

profiling the pipes was the most time consuming phase of the build, and we ground and ground till all dimensions were the way they were supposed to be.

In this picture, members are placed in proper positions to ensure dimensional accuracy.The floor was marked to ensure parallel sections and angles came out correct.Used old school techniques most of the time. Welding had its own set of issues, distortion due to thermal contraction making us redo many sections.

Used makeshift jigs, like this peice of plywood for various sections.
kept going, and created this mess [ will have better workshop management for my next project]

And after a month long wait, she's standing on her own wheels! this was an emotional moment for us..seeing our baby stand up without support of jackstands

never make tow hooks out of angles, no matter how strong they seem, the can't resist bending stress.
signing off now, more details on the line. stay tuned

thanks for the pictures.
any points for overcoming the distortion due to thermal contraction? (will be help full for my project)

what equipments were used for the build? (welder, grinder ect.)

how did you notched the tubes? with Multi-Cutter Saw?

i am also buying some tools & equipments for my DIY workshop.

please go through Team-BHP - Announcements in Forum : 4x4 & Off-Roading
because Smilie usage is restricted to TWO per post only.

[ashphil]

Dhawcash, you are indeed a genius. Imagine building a four wheeler with locally available parts and your own makeshift jigs. Par excellence!
@Mr. Boss- Please take the trouble of posting a thread on the building of your Zero turning radius vehicle. I am sure it will generate a lot of interest with our fellow members
Regards,
Ashok

[Savin_Shetty]

Really amazing...congrats dude... an all time four drive.....we are waiting for that