The M - Chassis TOPIC

[Pylon80 3422]

On 4/16/2024 at 10:05 AM, Pylon80 said:

Right, I hadn't measured it then. So standby but be ready to source multiple sizes of music wire as I recall there were 4 different diameters in total. 

As for the material I would think any sort of steel will exhibit similar stiffness (Young's modulus) so I wouldn't hesitate to use music wires from the hobby store. They will rust just by looking at them wrong or if they hear you say "moisture!" so I would prime and paint. Stainless on the other hand wouldn't rust but will be much harder to source in the various diameters you want.

@Honza here goes: 

Front Soft/Black: 1.6mm

Front Hard/Silver: 2.0mm

Rear Soft/Black 1.3mm

Rear Hard/Silver 1.5mm

They all appear to be stainless, bare for the silver ones and painted for the black ones.

[Honza 1115]

@Pylon80 Thanks! Awesome and very helpful info. I'm surprised tbh, they appear thicker on photos.

 

[Pylon80 3422]

1 minute ago, Honza said:

@Pylon80 Thanks! Awesome and very helpful info. I'm surprised tbh, they appear thicker on photos.

 

I was surprised too, especially the rear ones!

[chris.alex 1077]

My worries about unbalanced proportions seem to be unfounded. The new Citroën DS body for m-chassi looks beautiful in this video:

 

[Pylon80 3422]

@Andreas W or anyone who might want to use Rush tires, I was able to glue the tires correctly using a thicker CA glue called Zap-A-Gap and used by the RC plane folks. It's tricky but it's possible and the result spins nice and round.

@chris.alex wow! A DS body, that's a nice surprise! A little bit old for me but I think there's a lot of older people in France who would find that irresistible as the DS was considered the most advanced and desirable car of it's time in the 60's. The French president rode in a DS 21 Palace at one point of I'm not mistaken!

 

[JimBear 859]

Aah ... well, perhaps +4 rims were a bit too wide? Need to get some others, let's see if the +1 will fit, otherwise I'll go back to Tamiya originals (these are Carten ones, on 60D)

[JimBear 859]

Does anyone know if the re-re Fiat Abarth body would fit on the M-06 chassis?

[Rinskie 860]

2 hours ago, JimBear said:

Does anyone know if the re-re Fiat Abarth body would fit on the M-06 chassis?

I understand the rear motor on the chassis interferes with the fake rear motor on the body. 

[Honza 1115]

3 minutes ago, Rinskie said:

I understand the rear motor on the chassis interferes with the fake rear motor on the body. 

What if the fake motor is cut out?

[Rinskie 860]

32 minutes ago, Honza said:

What if the fake motor is cut out?

Well if you go down that road, there is little that won't fit some way or another. 

[Honza 1115]

On 5/25/2024 at 10:05 PM, JimBear said:

Does anyone know if the re-re Fiat Abarth body would fit on the M-06 chassis?

Just saw this in a Facebook group:

And found some older photos from build:

As expected, some cuts have to be done.. but they can be masked by the engine model. 

[JimBear 859]

3 hours ago, Honza said:

Just saw this in a Facebook group:

As expected, some cuts have to be done.. but they can be masked by the engine model. 

Aha, thanks! Great to have some photos of what it would look like. I guess the M-02 was easier to fit, since the motor isn't as far back as the M-06.

[Rinskie 860]

I have been slowly trying to improve my M08 for a while now. The biggest issues with it as I see is the weird steering linkage that has a lot of slop and for some odd reason the car will not recenter after a turning either direction. I put off doing the direct steering mod because I wanted to keep the chassis as it was designed with the hopes of being able to use it in a TCS race. I decided I am a lover and not a fighter, so racing seemed to be out of the picture. After looking around for the sexiest solution, I ordered part #54120 Aluminum Horn for M Chassis. I could have used the plastic servo horn the kit came with but the blue balls sit lower on the blue part making the steering linkage parallel with the ground instead of angling down a bit as it did before. The results were better than I hoped for, the steering will recenter perfectly each and every time from either direction and it just looks cleaner. The coolest part is the travel is the same as it was with the weird linkage. 

 

 

 

[Alexei 718]

45 minutes ago, Rinskie said:

I have been slowly trying to improve my M08 for a while now. The biggest issues with it as I see is the weird steering linkage that has a lot of slop and for some odd reason the car will not recenter after a turning either direction. I put off doing the direct steering mod because I wanted to keep the chassis as it was designed with the hopes of being able to use it in a TCS race. I decided I am a lover and not a fighter, so racing seemed to be out of the picture. After looking around for the sexiest solution, I ordered part #54120 Aluminum Horn for M Chassis. I could have used the plastic servo horn the kit came with but the blue balls sit lower on the blue part making the steering linkage parallel with the ground instead of angling down a bit as it did before. The results were better than I hoped for, the steering will recenter perfectly each and every time from either direction and it just looks cleaner. The coolest part is the travel is the same as it was with the weird linkage. 

 

i like how it looks symmetrical. i have also been thinking about doing this with my M-08. but how does the steering feel when driving with this part? worse, similar or better than original?

[Kowalski86 4076]

2 hours ago, Rinskie said:

The results were better than I hoped for, the steering will recenter perfectly each and every time from either direction and it just looks cleaner. The coolest part is the travel is the same as it was with the weird linkage. 

That's really how it should have been done out of the factory, clean, simple, and elegant. My only guess is that the linkage was meant to reduce the bump steer that you get with direct to servo saver setups.

 

On 4/20/2024 at 1:21 AM, chris.alex said:

My worries about unbalanced proportions seem to be unfounded. The new Citroën DS body for m-chassi looks beautiful in this video:

 

It just needs super soft suspension to really replicate a DS. Old Citroëns felt like used clouds for shocks.

[Pylon80 3422]

39 minutes ago, Kowalski86 said:

That's really how it should have been done out of the factory, clean, simple, and elegant. My only guess is that the linkage was meant to reduce the bump steer that you get with direct to servo saver setups.

 

It just needs super soft suspension to really replicate a DS. Old Citroëns felt like used clouds for shocks.

They sort of did if I am not mistaken they were using a revolutionary for the time system of pneumatic suspension!

[Honza 1115]

4 hours ago, Pylon80 said:

They sort of did if I am not mistaken they were using a revolutionary for the time system of pneumatic suspension!

Hydropneumatic suspension. It was really cool system, instead of pumping gas into rubber springs, it used pressurised gas balls and pumped fluid around for ride regulation. The ride was so soft, because fluid would redistribute around the entire suspension when one wheel hit a bump. Guess one could replicate a similarly working system with mechanical linkages on an RC 😁

The only similar system was Hydrolastic/Hydragas used by British manufacturers (can't name a specific one, since British automotive indistry is a mess, but some Mini Cooper variants used it aswell). I played with an idea to try replicate this setup in an RC car, but it involves lot of weird shaped rubber parts.

One fun bit of trivia I found recently about the Citroen system is, how its engineers dealt with leaking of the hydraulic cylinders - they didn't 😁 They just collected leaked oil in a rubber boot and pumped it back to reservoir. This is why DS lays on its belly when it's not driven for a while.

[Rinskie 860]

13 hours ago, Alexei said:

i like how it looks symmetrical. i have also been thinking about doing this with my M-08. but how does the steering feel when driving with this part? worse, similar or better than original?

It's way more connected and left/right direction changes are much more precise. Honestly there are no downsides with the exception that it's no longer stock. I only changed the servo horn, I didn't use any shims or spacers. I just removed the bell crank, flipped the servo and added the longer horn and bolted it all back together. I hardly even had to adjust the tie rods as the steering balls were roughly in the same place as they were with the bell crank, only slightly lower. You can see how the tie rods now sit parallel to the ground as the mounting points on the horn drop down a couple mm's. 

 

[Kowalski86 4076]

7 hours ago, Honza said:

The only similar system was Hydrolastic/Hydragas used by British manufacturers (can't name a specific one, since British automotive indistry is a mess, but some Mini Cooper variants used it aswell). I played with an idea to try replicate this setup in an RC car, but it involves lot of weird shaped rubber parts.

Iirc the Morris 1100 and Austin America used a Hydrolastic setup, I think it could be done with an RC with enough work.

25 minutes ago, Rinskie said:

It's way more connected and left/right direction changes are much more precise. Honestly there are no downsides with the exception that it's no longer stock. 

Kind of makes you wonder why they didn't go with that setup from the get-go. Tamiya used a setup like that in a lot of their old designs and it worked fine, except maybe for some big wheel models.

[Busdriver 6281]

On 7/30/2024 at 6:55 AM, Honza said:

Hydropneumatic suspension. It was really cool system, instead of pumping gas into rubber springs, it used pressurised gas balls and pumped fluid around for ride regulation. The ride was so soft, because fluid would redistribute around the entire suspension when one wheel hit a bump. Guess one could replicate a similarly working system with mechanical linkages on an RC 😁

The only similar system was Hydrolastic/Hydragas used by British manufacturers (can't name a specific one, since British automotive indistry is a mess, but some Mini Cooper variants used it aswell). I played with an idea to try replicate this setup in an RC car, but it involves lot of weird shaped rubber parts.

One fun bit of trivia I found recently about the Citroen system is, how its engineers dealt with leaking of the hydraulic cylinders - they didn't 😁 They just collected leaked oil in a rubber boot and pumped it back to reservoir. This is why DS lays on its belly when it's not driven for a while.

You didn’t need a jack as you could use the suspension to lift the car and get the punctured wheel off the ground. I believe  it also allowed you to drive short distances  on 3 wheels?