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Old 24th March 2011, 12:37   #1
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Default Thar Hardtop Design

Hey All,

Just completed the 1st stage of the design...

We are working on increasing the size of the panels and well as the window size while keeping the strength of the panels and frame and weight of the panels low.

As of now:
  • There are 5 removable panels
    • one for the front top, one for the rear top, one for the back, and 2 for the sides
  • The black band in the model is a part of the body of the Thar - the top will integrate around it
  • Panels will have to be placed from the outside and then locked from the inside. We have found latches similar to the ones used on the sides of suitcases
  • The idea is for all panels to be locked in 4 places except for the rear window panel which we need to still work out how to lock on the tailgate so that you can open the tailgate without having to worry if the panel is locked onto it
Any feedback and suggestions will be helpful.

Cheers,
Manas
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Thar Hardtop Design-1.jpg  

Thar Hardtop Design-2.jpg  

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Old 24th March 2011, 12:52   #2
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Default Re: Mahindra Thar : Test Drive & Review

Hi Manasm,

This is definitely a good start. I would suggest the following to improve visibility and hence safety.

1) Decrease the thickness of the D-Pillar
2) Increase the glass are of the sides and rear door.
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Old 24th March 2011, 13:03   #3
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Default Re: Mahindra Thar : Test Drive & Review

4x4addict: Already working on both those.

The challenge is to decrease the width of the D pillar without having to increase the thickness of fibre to keep strength - it has to support the roof. The "glass" areas have already been increased and will look much better. Just FYI - the "glass" will not be glass. It will be transparent plastic. This is both for safety and cost. The estimates already look like it will cost us about 1 lakh to make the top. Don't know how much people would be willing to pay for it.

But once I buy my Thar, I know that this is the top I will put on!

Plan to go sit with a Thar owner on Sunday to take photos and measure exact dimensions to look at mounting points for the roof etc...

Anyone in Bangalore volunteering their time and Thar on sunday?

We hope/plan to have the first prototype done by 15th Apr...

Manas


Quote:
Originally Posted by 4x4addict View Post
Hi Manasm,

This is definitely a good start. I would suggest the following to improve visibility and hence safety.

1) Decrease the thickness of the D-Pillar
2) Increase the glass are of the sides and rear door.
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Old 24th March 2011, 14:14   #4
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Default Re: Mahindra Thar : Test Drive & Review

a suggestion from my side :
try poly carbonate sheets instead of glass - lightweight as well as durable - dual advantages.
one lakh for the HT would be too high a price, but regular production might bring down the cost to 40k, i suppose.
another suggestion. manasm, pls contact eagle888 from SA, who has a thar, and try to get the dimensions from his HT. his HT is 2 piece, but worth the effort, if such a HT could be replicated here in india.
i am willing to do any help, in this project, manasm.
best regards.
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Old 24th March 2011, 14:34   #5
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Default Re: Mahindra Thar : Test Drive & Review

Thanks Shekaran - will look into poly carbonate.

If I get the top right - dont mind if it costs me 1lakh - but of course would be better if it was cheaper. The cost is basically due to the dies which have to be made for moulding. Other than that, there are also the fittings, the latches, the rubber for the beading to make the seals between the removable and fixed panels water proof - no point if there are leaks all over!

Have already been in touch with eagle888 in Jan - but he has been busy and so unable to take measurements.

I am not interested in a 2 piece HT and since this is primarily being designed as something I would use/buy for when I get a Thar, I want something where I can take the panels out and stow them in the cabin during a journey and put them back on when I reach a destination.

If you know anyone in Pondicherry who can manufacture the top and would be interested in quoting once we finalize the design, let me know their contact details.

Thanks,
Manas


Quote:
Originally Posted by shekaran View Post
a suggestion from my side :
try poly carbonate sheets instead of glass - lightweight as well as durable - dual advantages.
one lakh for the HT would be too high a price, but regular production might bring down the cost to 40k, i suppose.
another suggestion. manasm, pls contact eagle888 from SA, who has a thar, and try to get the dimensions from his HT. his HT is 2 piece, but worth the effort, if such a HT could be replicated here in india.
i am willing to do any help, in this project, manasm.
best regards.
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Old 24th March 2011, 15:32   #6
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Quote:
Originally Posted by manasm View Post
4x4addict: Already working on both those.

The challenge is to decrease the width of the D pillar without having to increase the thickness of fibre to keep strength - it has to support the roof. The "glass" areas have already been increased and will look much better. Just FYI - the "glass" will not be glass. It will be transparent plastic. This is both for safety and cost. The estimates already look like it will cost us about 1 lakh to make the top. Don't know how much people would be willing to pay for it.

But once I buy my Thar, I know that this is the top I will put on!

Plan to go sit with a Thar owner on Sunday to take photos and measure exact dimensions to look at mounting points for the roof etc...

Anyone in Bangalore volunteering their time and Thar on sunday?

We hope/plan to have the first prototype done by 15th Apr...

Manas
Manas, You can use my Thar to take all the measurements you want.

I hope you can make a close to production prototype without investing on the moulds.

Some things that came to my mind -

The Thar Soft-top makes squealing noises at all places in the front cabin when you hit a pot hole or uneven road. Please ensure your hardtop design does not generate any additional noise from joints or otherwise.

The standard soft-top has a frame inside to support the cloth. If the occupants are not careful in an uneven road, anyone above 5'10 "can bump their head on the frame and bruise themselves. please ensure there is a good balance between exterior looks of the hardtop and interior space and safety of the occupants in case they are thrown around.
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Old 24th March 2011, 16:15   #7
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Default Re: Mahindra Thar : Test Drive & Review

I Expected some thing like this .

Thar Hardtop Design-untitled.jpg
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Old 24th March 2011, 16:17   #8
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Default Re: Mahindra Thar : Test Drive & Review

dear manasm,
i too was in a similar work like you, talking with various FRP fabricators, who are willing to do the job. but all of them are yet to quote for the moulds.
i gave a simple 2 piece design - the front sits between the A and B pillars, the rear is a straight line cut 3 sided mould with a top hinged rear glass door design.
the original rear doors are to be not disturbed in anyway, but to open the rear hatch door, the rear door should be opened first.
best regards.
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Old 24th March 2011, 16:51   #9
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Default Re: Mahindra Thar : Test Drive & Review

Quote:
Originally Posted by sreejeshmp View Post
I Expected some thing like this .

Attachment 522451
@sreejeshmp: This definitely looks good. I like it. But I beleive, it would push costs up further since the moulds required for LHS and RHS would be different.
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Old 25th March 2011, 10:17   #10
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Default Re: Mahindra Thar : Test Drive & Review

Sreejesh:

Looked at the angular top, but did not work for me:

1. The backs of the rear bench seats stick out straight and unless you cut them or remove them, will not fit
2. Liked the looks of the straight back more than the angle
3. As mentioned by someone else, costs go up. With the straight back, the rear left and right panels can be the same mould if we use a straight back

Apart from that, we are increasing the window and panel size and decreasing the fixed frame size as much as possible.

Hope to post a better model next week, once we do our measurements on Sunday.

What I would really like is for people who would be interested in the top to let me know, so I can see what kind of demand there is and how much I can cut the cost by ordering in bulk.

Manas

Quote:
Originally Posted by sreejeshmp View Post
I Expected some thing like this .

Attachment 522451
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Old 25th March 2011, 15:39   #11
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Default Re: Mahindra Thar : Test Drive & Review

Like the angled look given by shreejeshmp more even if it increases the cost, The visibility also increases in that look.

Also would suggest that the top have the option of a transparent plastic moon / sun roof as well. It would aid the airy feel desired in the rear and also give better allround visibility.

For all practical purposes the fiber structure could be mounted on groved plates wielded on to a roll cage such that the frame for the structure serves a dual purpose and is not just additional metal weight without adding to safety.

The Soft top provided by M&M is good enough for the AC, so if one is adding a Hard Top it has to be Aid looks and also to secure the vehicle better. A Basic Fiber HT will not add to looks unless it is done with a bit of stylish flair.
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Old 25th March 2011, 16:14   #12
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Default Re: Mahindra Thar : Test Drive & Review

Quote:
Originally Posted by ACM View Post
so if one is adding a Hard Top it has to be Aid looks and also to secure the vehicle better. A Basic Fiber HT will not add to looks unless it is done with a bit of stylish flair.
I agree ^^

BTW, one needs to ensure the HT withstands a Rollover, especially with the power the THAR generates. A clever design will help the vehicle roll back onto its wheels .
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Old 25th March 2011, 21:10   #13
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Default Re: Mahindra Thar : Test Drive & Review

Quote:
Originally Posted by ACM View Post
Like the angled look given by shreejeshmp more even if it increases the cost, The visibility also increases in that look.

Also would suggest that the top have the option of a transparent plastic moon / sun roof as well. It would aid the airy feel desired in the rear and also give better allround visibility.

For all practical purposes the fiber structure could be mounted on groved plates wielded on to a roll cage such that the frame for the structure serves a dual purpose and is not just additional metal weight without adding to safety.

The Soft top provided by M&M is good enough for the AC, so if one is adding a Hard Top it has to be Aid looks and also to secure the vehicle better. A Basic Fiber HT will not add to looks unless it is done with a bit of stylish flair.
except the Sun/Moon roof should not be much radiating heat and sunlight. I completely agree on the aesthetics part and would love to resemble the following soft top model or the hard one. The side facing seats can be made to a front facing one, small sacrifice .
P.S - Headers, you are not permitted to drive my Thar .
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Last edited by drjones : 25th March 2011 at 21:13. Reason: wanted to add a sentence
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Old 26th March 2011, 02:36   #14
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Default Re: Mahindra Thar : Test Drive & Review

I would any day prefer this. With a sun-moon roof on the cockpit it will just look awesome. I think the rare piece is slide lock kind. I am also impressed with the roll cage work they have done on this
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Old 26th March 2011, 12:07   #15
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Default Re: Mahindra Thar : Test Drive & Review

The rear cage looks more like a design to keep the luggage from hitting the passengers when the hard top is on, too filmsy for a roll cage. Hard top is to die for, very good.
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