[WIP] Greyhound - 4WD RC Buggy with BuWizz 2 - Redesigned wheel hubs

[AFOLegofan66]

A superior final build for sure...can’t wait to get mine going before the snow flies!!

[KD123]

Great update to an already amazing buggy.  It handles like it's on rails!  Keep perfecting please.  

[Didumos69]

Thanks!

Here are some final images:

[Didumos69]

Sorry, but as part of preparing for making instructions, I'm still improving things. I finally found a way to properly fix the steering links to the wheel hubs.

Before:

After:

Edited November 9, 2018 by Didumos69

[agrof]

Nice render!

Isn't the half blue pin connection inside of the  suspension arm illegal build though (no way to build or separate without stretching the part)? I liked the first solution better, which is stronger?

Edited November 9, 2018 by agrof

[Didumos69]

29 minutes ago, agrof said:

Nice render!

Isn't the half blue pin connection inside of the  suspension arm illegal build though (no way to build or separate without stretching the part)? I liked the first solution better, which is stronger?

The newer is much stronger. The plates of the old one disconnect sometimes when the front wheels hit something. Others have reported that as well. But the most important change is the way the steering link is mounted to the wheel hub. By using 8L axles with stop the connection is firmly locked. The pin with the hammer inserted was the weak link in the old version. This new connection could however still be combined with the plates approach.

About the blue half pins. Strictly taken, it is illegal, but practically spoken, installing the 2 5L thin levers with the half pins inserted can be done with the least of bending; the bottom side of the suspension arm already has some cutouts that make the installation easy. You should try. EDIT: I actually think the new steering arm would still be better, even without the blue half pins inserted. I will also try with the half pins inserted from outside, with the knob sticking out. If I find the legal version to be equally strong, then that would still be preferable over an illegal solution.

Edited November 9, 2018 by Didumos69

[AFOLegofan66]

This front upgrade is a fantastic solution. I have all my parts and new wheels ready. The final shots look great....beautiful MOC!!

[Ivan_M]

I like how the suspension arms are locked on the hub. By the way if you will ever need towball that is held in place much firmly try part below inside cross hole, it is esp. strong connection together with pin with axle hole

Edited November 9, 2018 by Ivan_M

[DugaldIC]

Oh man @Didumos69 you're the only one to reinvent the wheel! You always go all out, it's awesome to see 

 

[agrof]

@Didumos69 Thanks for the explanation, I used to use the flexibility of the parts and the system, it was just surprisingly "radical" from You.  Glad to see the improvements though, I do miss such a part, which allows proper going-through-connection in cases like this with the suspension arm.

One more hint: in Stud.io there is black rubber color, which gives for the tires more realistic appearance for Your awesome renders.

11 hours ago, Ivan_M said:

I like how the suspension arms are locked on the hub. By the way if you will ever need towball that is held in place much firmly try part below inside cross hole, it is esp. strong connection together with pin with axle hole

This is something, what we already tested in this very project, I put the post here, might be useful for some:

 

Edited November 10, 2018 by agrof

[Didumos69]

Thanks guys!

14 hours ago, Ivan_M said:

I like how the suspension arms are locked on the hub. By the way if you will ever need towball that is held in place much firmly try part below inside cross hole, it is esp. strong connection together with pin with axle hole

Thanks for thinking with me! I would have to insert the bar ends into half pins, which was tested by @agrof and turned out to be no good. And I can't figure out a way to change the structure to have axle holes instead of pin-holes for the tow-balls. The structure is very small and ties together the gearrack, a slider and the steering links. However, I added a static structure (suggested by @Lipko) to lock up the ball-joints. This actually makes for a self-healing setup: When it happens that the pins with tow balls are no longer fully inserted, steering will push them in again.

With the new steering links the model can take a serious frontal beating:

I think I'm ready for making instructions now... (At the end of the video one BuWizz is empty).

Edited November 10, 2018 by Didumos69

[Ivan_M]

1 hour ago, Didumos69 said:

Thanks guys!

Thanks for thinking with me! I would have to insert the bar ends into half pins, which was tested by @agrof and turned out to be no good. And I can't figure out a way to change the structure to have axle holes instead of pin-holes for the tow-balls. The structure is very small and ties together the gearrack, a slider and the steering links. However, I added a static structure (suggested by @Lipko) to lock up the ball-joints. This actually makes for a self-healing setup: When it happens that the pins with tow balls are no longer fully inserted, steering will push them in again.

I didn't mean to use the towball with shaft in your wheel hub, just a general tip, I was fidling with it and realized that it might be useful, sometimes the structure is very small so a pinhole "wasted" for towball is not good, ths part solves that

[agrof]

Wow, I did not expect that level of sturdiness of the construction! I am truly amazed by your commitment, and engineering, very inspiring. 

I am confident to say: this is the best developed and executed, while most capable Off-Road (or overall RC) Lego MOC, ever. Period.

[kbalage]

Your fantastic build is just getting better and better, I'm truly amazed! Can't wait longer to test it, can you please confirm if the files on bricksafe are updated with the latest changes? Starting to collect the pieces right now :)

[Didumos69]

2 hours ago, Ivan_M said:

I didn't mean to use the towball with shaft in your wheel hub, just a general tip, I was fidling with it and realized that it might be useful, sometimes the structure is very small so a pinhole "wasted" for towball is not good, ths part solves that

Aha, I get it. Indeed a useful tip ?!

2 hours ago, agrof said:

Wow, I did not expect that level of sturdiness of the construction! I am truly amazed by your commitment, and engineering, very inspiring. 

I am confident to say: this is the best developed and executed, while most capable Off-Road (or overall RC) Lego MOC, ever. Period.

Thanks! The fact that I couldn't finish this before the summer actually turns out fine. Making instructions triggered me to make it more worth the effort for end-users. I also made some changes that allow for a more easy building experience, but it will still be really challenging.

1 hour ago, kbalage said:

Your fantastic build is just getting better and better, I'm truly amazed! Can't wait longer to test it, can you please confirm if the files on bricksafe are updated with the latest changes? Starting to collect the pieces right now :)

Thanks and I would be honored if you build this. I'm sorry, but most files are out of date. The only file up to date is this one, but it does not include building steps. I don't expect much will change now though.

Edited November 10, 2018 by Didumos69

[AFOLegofan66]

I have to agree with @agrof this is the best MOC to date that I will build. I have been building Moc’s for 12 years now and this is the ONE I’ve been waiting for...and with buwizz...awesome!!

[Didumos69]

On 11/10/2018 at 7:56 AM, agrof said:

One more hint: in Stud.io there is black rubber color, which gives for the tires more realistic appearance for Your awesome renders.

Thanks for the hint!

More renders here. The latest digital files: Stud.io, LDD and LDraw (I removed the old files to avoid confusion). The LDraw-file can best be used as parts list, because it does not contain placeholders for the BuWizzes. I will only update things now, when I find inconsistencies while making the photo sequence instructions.

[technic_addict]

I had all the pieces ready a long time ago.  I am sure I have all the updated pieces when instructions are finally released.

I can't help to think what a 2 Buggy motor (or even 4 buggy motor) would be like!  I built the updated class one buggy with buggy motors and at higher speeds there are issues with it that this buggy seems like it would resolve.

[kbalage]

2 hours ago, technic_addict said:

I had all the pieces ready a long time ago.  I am sure I have all the updated pieces when instructions are finally released.

I can't help to think what a 2 Buggy motor (or even 4 buggy motor) would be like!  I built the updated class one buggy with buggy motors and at higher speeds there are issues with it that this buggy seems like it would resolve.

I was also playing with the idea but honestly this build is already very balanced with the L motors and it has a great performance. The motors are structural parts of the build so it'd need a major redesign to incorporate the buggy motors. Additionally I don't think 4 buggy motors would fit and the 2 BuWizz units could not handle them anyway at high/ludicrous speed on rough terrain. With 2 motors you either make it RWD which is again a completely different behavior either try to put them somewhere in the middle but then you need lots of additional axles/gears meaning a lot of potential weak points in the drivetrain.

Once I'll build this one I think I'll also rebuild the original sized buggy from @agrof with the 2 buggy motors to compare them, but I don't think there's too much difference in speed. The smaller one I currently have is much lighter so it can use better the power of the buggy motors.

[Didumos69]

I don't think I could have phrased it much better, thanks @kbalage ?. I also don't think this model will be faster than your remake with buggy motors of @agrof's class one buggy, the main difference will be the way it behaves. The way it tilts in turns, the way it responds to bumps and small curbs and the way it takes bigger obstacles.

Apart from pursuing performance, this model explores what's possible when it comes to robustness and durability. This has much to do with the fact that this is a 4WD model with 2 Buwizzes. A lot of power is sent to both the front an the rear wheels. That puts high demands on the strength of all kind of things; the steering, the suspension, the chassis, the bodywork. I had to think outside the beaten track on all these aspects, while holding on to requirements such as Ackermann geometry, small turning radius, extensive suspension travel and minimal slack in moving parts. But adding strength and coherence comes at the price of using more parts, which adds weight, which requires even more strength, etc. With this model I have tried to find a balance between performance, robustness and weight. A balance that fits the power of 2 Buwizzes and 4L motors on the one hand and a 4WD model built from LEGO on the other hand.

Edited November 14, 2018 by Didumos69

[Didumos69]

A final test before I take it apart.

And the final teaser.

[michald69]

WOW, truly amazing work... Hats off to @Didumos69! :)

[AFOLegofan66]

@Didumos69 that was some teaser...the tension is killing me!!

[kbalage]

Those renders OMG  I'm sure you mentioned already so sorry for asking again, you make the renders with Stud.io?

[pagicence]

On ‎11‎/‎13‎/‎2018 at 5:22 PM, Didumos69 said:

The latest digital files: Stud.io, LDD and LDraw (I removed the old files to avoid confusion).

@Didumos69 the link to Stud.io file is the LDraw password protected zip file.

Edited November 15, 2018 by pagicence