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1/12th Pan-M from h2e

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1/12th Pan-M from h2e

Old 11-20-2022, 05:31 AM
  #16  
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I know that every Mini race I've been to would clarify the rules as soon as anyone turned up with a pan car running rubber tyres. Completely different class of car.

It may not be explicit in the rules, but everyone "knows" that an M-chassis has 4-wheel independent suspension.

We've had plenty of experience in the past with people running "outlaw" minis in M-chassis classes (conversions or cars like the Xpress), cars that are much faster than the Tamiya alternatives.

All that happens is that the class gets split and eventually the "outlaw" cars fall out of favour because of costs and parts availability. Tamiya chassis always survive.

So by all means play around with your idea (rubber tyred pan cars are not new), but as soon as you outperform a true M-chassis I guarantee you will be asked to stop running in the class.
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Old 11-20-2022, 05:43 AM
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Originally Posted by h2e View Post
That's exactly what I am aiming at. but don't tell anyone.
Unfortunately it's going to cost dearly to mod a 1/12 car, as the front wheels need to fit a 12mm hex. So I will need to use 1/10th steering knuckles, and so a full blown front suspension. So weight wise I might go to 900g.
Or just use the suspension from the TCR-M.
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Old 11-20-2022, 07:42 AM
  #18  
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The good thing about this outlaw is that there's no danger I might outperform the locals. A) I train way less, B) for much fewer years than the others. So it just might be for being closer to them than otherwise...

Last edited by h2e; 11-27-2022 at 11:44 PM.
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Old 11-21-2022, 08:29 AM
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Originally Posted by h2e View Post
Well the TCR-M may definitely be a plan B if my already purchased base car plus my mods show to be slow.
I want it rear mid motor as my Bodies will be rwd cars. Don't want to spoil it all too much this time...

The rear pod on pan cars seems to create way too much anti squat (typical >200%, my M-class prototype: 166%), so I am thinking of making a 3 link rear pod attachment like the "Pantoura" that can be found on rctech too, to create less anti squat.

typical anti squat geometry on pan cars (centre ball and two side links).

Where I am unsure is what front wheel suspension I should choose, and where the rollcenters should be lying. Many rollcenter decisions on pan cars seem to exist just to counteract other weird effects (foam tyres hooking suddenly etc.). As I will run M chassis rubbers the starting point may as well be completely different.

What book is this? I would like to get a copy?
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Old 11-21-2022, 12:46 PM
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German book
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Old 11-22-2022, 08:02 AM
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Originally Posted by h2e View Post
Thank you!
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Old 11-25-2022, 01:13 PM
  #22  
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Thinking of V-link vs. 4-link rear pod suspension:


4-Link suspension (Panhard + 3 Links) for rear pod. The rear link has to be rather long or angled to reach 100% anti-squat (CG is inside transverse battery).

So far it looks like the 4-link system will be rather restricting for the dimensions of an M-class car, as the link above the battery needs to be large. Any suggestions how to reach roughly 100% anti squat with a pan car style rear pod? How would you suspend the rear pod for this design? Would one rather try to reach less than 100% anti-squat to get a stable rear under acceleration/braking?



Hatzenbach V-link rear suspension with angled-in longitudinal links to reduce the rear roll centre height.
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Old 11-26-2022, 08:09 AM
  #23  
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Default CAD Update


Top View (Longitudinal Battery Arrangement)



Steering link and 3rd link quite angled.

Short chassis and panhard bar

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Last edited by h2e; 12-10-2022 at 12:09 PM.
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Old 11-30-2022, 01:10 PM
  #24  
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Default Front Wheelhubs - own design?

As I was planning on using my Schumacher Mi8 wheelhubs for the front to allow the attachment of M-Wheels, I realized that there is rather little space for the ball joints - let alone the lower A-Arm:


Wheelhubs with 4mm balls. The lower balljoint almost rubs the wheel. Ball to ball distance: 30mm

So I came up with an own hub design, that uses 2 screws on top and on the bottom of the wheel axle to fix carbon plates. The lower one is the steering arm, and the upper one is the bracket to hold the upper ball joint in place.


Wheelhub concept with 5x8x2.5 bearings and 2x 2.5 mm carbon plates. The lower one is the steering arm + lower ball head holder, the upper one bridges the ball head. Ball to ball distance: 23mm.

The new concept would allow me to use fixed-length A-arms upper and lower (even the same ones), and adjust camber just with e.g. the upper small cross plate on the hub, which would have an offset.

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Old 12-10-2022, 01:12 PM
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Default updated...

Originally Posted by h2e View Post

Top View (Longitudinal Battery Arrangement)



Steering link and 3rd link quite angled.

Short chassis and panhard bar
updated...
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Old 12-15-2022, 06:17 AM
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Is there enough room to turn the servo 90deg so that you can have a more favorable geometry for the servo arm?

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Old 12-15-2022, 11:50 AM
  #27  
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Originally Posted by simple View Post
Is there enough room to turn the servo 90deg so that you can have a more favorable geometry for the servo arm?
Thanks for your remark,
The reason for the rather strange position of the servo is two-fold:
a) to be able to use the rear brace (where the side springs attach) as a servo-holder
b) to be able to rotate the battery with no change to electronics at all. So I can change the weight distribution in no time

If at least b) can be reached with another servo position, I am up for it.
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Old 12-15-2022, 12:04 PM
  #28  
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It looks rather complex.

Sometimes brutal simplicity is easier, more durable and more consistent.

Also you don't need anti-squat, pan cars have built in anti-squat as the motor tries to 'climb' the spur gear when under power, lifting the pivot and middle of the car.
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Old 12-15-2022, 01:04 PM
  #29  
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What do you think I can simplify?
I am trying to replicate a double wishbone suspension in the front, but only with two leaf springs and a heave damper (no roll damping).
In the rear, the two longitudinal links are accompanied with leaf springs to suspend the rear pod. So I can adjust the stiffness very easily. The panhard rear suspension is a no-discuss (had a phone call with an experienced guy who said it was giving much more grip than V-link or Pivot, with the caveat that you have to find your own springs/dampers, as the selection is limited).

Also, I try to have a very low rear body mount (hooks on the side wall of the body, instead of top), and some crash protection for the rear axle (so to not bend it)

Other than that, all seems rather typical of 1/12th pan cars? Enlighten me?
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Old 12-15-2022, 01:10 PM
  #30  
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Battery Corridor layout? How would I attach the rear chassis cross beam @Simple ?


Battery Corridor layout. Note weight bias range that can be achieved with 50mm battery shift range.
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Last edited by h2e; 12-15-2022 at 01:39 PM.
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