[WIP] Ultra4 Buggy + Black Edition

[offroadcreations]

Just now, Didumos69 said:

I know it doesn't need a grill, but maybe some small headlights to give it a little bit 'face'?

I did something like this in one of the earlier WIP stages, but forgot to put it back in. I like your idea a lot more, so I hope it's okay I changed it just a bit and applied it to my model:

49 minutes ago, Didumos69 said:

It doesn't need the stripe in the hood in my opinion. It somehow reminds me of one of my first sets, the 8845 Dune Buggy, but this one obviously is more advanced and looks better. It does make me want to see this with a black cabin / roof instead of LBG.

That links to a video about installing rubber bands, but I found the set and I agree. I will be making this in LDD, and plan to make renderings with many different color schemes, so I will try that. 

[offroadcreations]

Here's the video: 

 

[Leonardo da Bricki]

Good performance from this buggy. I second Didumos69, a black rollcage might look better, as it would provide some contrast. And I especially like the slow-motion crash!

[offroadcreations]

12 minutes ago, Leonardo da Bricki said:

Good performance from this buggy. I second Didumos69, a black rollcage might look better, as it would provide some contrast. And I especially like the slow-motion crash!

Thanks! Yes, it doesn't do as well as my Firestorm Truck (already at the right spot in the video):

 

Edited April 24, 2017 by Offroadcreat1ons

[Aventador2004]

Good speed but can't do a stair jump. Only thing I don't like is the negative caster.

[offroadcreations]

59 minutes ago, Aventador2004 said:

Good speed but can't do a stair jump. Only thing I don't like is the negative caster.

Do you mean the positive caster? Mine is tilted toward the back of the car like this picture, so it is positive.  

 

I do see how you might not like it because of the problems it causes because when it goes backward, you have to make more space for it when the suspension compresses. I like it because when I drive over bumps it makes it easier for the car to keep going.

I will be making the LDD file soon, and I have another trick up my sleeve to give this even better performance.  The new upgrade will also mean a new video.

Edited April 24, 2017 by Offroadcreat1ons

[Didumos69]

13 hours ago, Offroadcreat1ons said:

I did something like this in one of the earlier WIP stages, but forgot to put it back in. I like your idea a lot more, so I hope it's okay I changed it just a bit and applied it to my model:

Excellent!

13 hours ago, Offroadcreat1ons said:

That links to a video about installing rubber bands, but I found the set and I agree. I will be making this in LDD, and plan to make renderings with many different color schemes, so I will try that. 

Sorry for that. We're working on instructions for my rugged supercar, that's what the video was intended for.

[Aventador2004]

15 hours ago, Offroadcreat1ons said:

Do you mean the positive caster? Mine is tilted toward the back of the car like this picture, so it is positive.  

 

I do see how you might not like it because of the problems it causes because when it goes backward, you have to make more space for it when the suspension compresses. I like it because when I drive over bumps it makes it easier for the car to keep going.

I will be making the LDD file soon, and I have another trick up my sleeve to give this even better performance.  The new upgrade will also mean a new video.

Maybe I am seeing from the wrong angle but it looks like the outside wheel has positive caster when turned. This happens from negative caster. I do see it leans back but it seems during driving it isnt.

Edited April 24, 2017 by Aventador2004

[offroadcreations]

Here is the LDD: http://bricksafe.com/files/Offroadcreations/competition-buggy/Ultra.4.lxf Enjoy!

Maybe this picture from one of Sariel's videos can show you:

Compared to mine:

[muffinbrick]

Nice performance of the buggy! I think it's  too short to make stair jump, but other than that it's very agile. My suggestion is to reinforce rollcage, you should connect those free column ends to upper frame. In video it looked like the cage was damaged by that fall.

[offroadcreations]

@Didumos69@Leonardo da Bricki Here is that black roll cage you asked to see. I was pleasantly surprised at how good it looks.

5 hours ago, muffinbrick said:

Nice performance of the buggy! I think it's  too short to make stair jump, but other than that it's very agile. My suggestion is to reinforce rollcage, you should connect those free column ends to upper frame. In video it looked like the cage was damaged by that fall.

Thanks! I might be able to reinforce it.

[Leonardo da Bricki]

@Offroadcreat1ons Thanks for rendering our ideas! I think this is a great improvement, will you change the real model? Also, thanks for sharing the LDD.

[Didumos69]

6 hours ago, Offroadcreat1ons said:

@Didumos69@Leonardo da Bricki Here is that black roll cage you asked to see. I was pleasantly surprised at how good it looks.

Looking very nice with black top! Glad you tried. EDIT: I suppose some of the axles you painted black are hardly available in black. You could incorporate some black #2 connectors to get the same measures with even-length axles, which are widely available.

Btw, I have an easy way to make POV-Ray renders from LDD designs in a few steps:

1. Use LDD to export your model to LDraw-format (.ldr). To make this successful you need to download the LDraw.xml file here and replace the original as described in the same post.
2. Load the exported LDraw file in Stud.io and choose 'Render from the ribbon'. Stud.io comes with POV-Ray (some parts are not present, for instance the Porsche hubs, rims and tires are missing). In the Render-dialog you can rotate, zoom and pan the view and select quality, light position and image size.

Edited April 25, 2017 by Didumos69

[PorkyMonster]

When turned, I saw positive camber rather than positive caster (not sure if that's what @Aventador2004 meant) on outer wheel. This is normal for models without KPI, camber and anti-roll mechanism.

About the stair jumps - I think speed / weight ratio is the key factor here, more so than the length of a vehicle although a longer one with sufficient ground clearance will "appear to" jump better - simply because the steps are relatively smaller.

[Aventador2004]

2 hours ago, PorkyMonster said:

When turned, I saw positive camber rather than positive caster (not sure if that's what @Aventador2004 meant) on outer wheel. This is normal for models without KPI, camber and anti-roll mechanism.

this is exactly what i meant @PorkyMonster. i think due to the roll from the normal shocks cause it, maybe anti roll bars will fix the problem. 

edit: at 1:20 in the video you will see the positive camber @Offroadcreat1ons.

Edited April 25, 2017 by Aventador2004
typo

[offroadcreations]

16 hours ago, Didumos69 said:

Looking very nice with black top! Glad you tried. EDIT: I suppose some of the axles you painted black are hardly available in black. You could incorporate some black #2 connectors to get the same measures with even-length axles, which are widely available.

Btw, I have an easy way to make POV-Ray renders from LDD designs in a few steps:

1. Use LDD to export your model to LDraw-format (.ldr). To make this successful you need to download the LDraw.xml file here and replace the original as described in the same post.
2. Load the exported LDraw file in Stud.io and choose 'Render from the ribbon'. Stud.io comes with POV-Ray (some parts are not present, for instance the Porsche hubs, rims and tires are missing). In the Render-dialog you can rotate, zoom and pan the view and select quality, light position and image size.

Actually, everything I used is available IRL. I did use the connectors for some of the axles, but I will have to use them for all of the axles when I build it, since I don't have the long ones in black. Also, thank you for the tips on how to render it, I will check that out. Also, here is one more rendering I did.

EDIT: say you said "hardly," didn't see that the first time.

Edited April 25, 2017 by Offroadcreat1ons

[TechnicRCRacer]

It looks excellent! I always look forward to your models! Will it be posted on Rebrickable?

Edited April 25, 2017 by TechnicRCRacer

[Didumos69]

First of all I would like to emphasize - without any doubt - that this model incorporates positive caster by design, which is generally regarded as a good thing.

3 hours ago, Aventador2004 said:

this is exactly what i meant @PorkyMonster. i think due to the roll from the normal shocks cause it, maybe anti roll bars will fix the problem. 

edit: at 1:20 in the video you will see the positive caster @Offroadcreat1ons.

What you are referring to is not positive caster, but positive camber (just like what @PorkyMonster suggested), indeed caused by body roll of the car and slack in the parts. Anti roll bars would help, but when riding off-road you don't want too much leveling between the left and right compression. Another thing that helps - not that this should be added to this model, don't get me wrong - is to add active (or progressive) camber. This means that negative camber increases when the suspension is compressed and decreases when suspension is released. This can be obtained by having a shorter upper wishbone compared to the lower wishbone. Cars like Mercedes and BMW usually have highly active camber, which gives a lot of visually evident negative camber when the car carries a heavy load.

EDIT: See also this video to see the effects of caster and active camber.

3 hours ago, PorkyMonster said:

When turned, I saw positive camber rather than positive caster (not sure if that's what @Aventador2004 meant) on outer wheel. This is normal for models without KPI, camber and anti-roll mechanism.

Besides that, there is quite some slack in the parts, which will influence these angles, especially with all the forces that apply in turns. However, theoretically spoken, positive caster will give the wheel on the outside of a turn some negative camber and the wheel on the inside some positive camber, even without KPI. So the positive camber caused by body roll and slack in the video is already somewhat moderated by the positive caster. You can see the positive caster and its positive effect on negative camber in timestamp 0:23 of the video. EDIT: Added illustration:

 

Edited April 25, 2017 by Didumos69

[Aventador2004]

1 hour ago, Didumos69 said:

What you are referring to is not positive caster, but positive camber (just like what @PorkyMonster suggested), indeed caused by body roll of the car and slack in the

just realized i wrote caster when i meant camber.

[PorkyMonster]

2 hours ago, Didumos69 said:

@PorkyMonster

Besides that, there is quite some slack in the parts, which will influence these angles, especially with all the forces that apply in turns. However, theoretically spoken, positive caster will give the wheel on the outside of a turn some negative camber and the wheel on the inside some positive camber, even without KPI. So the positive camber caused by body roll and slack in the video is already somewhat moderated by the positive caster. You can see the positive caster and its positive effect on negative camber in timestamp 0:23 of the video. EDIT: Added illustration:

Unfortunately, this "negative camber" caused by "positive caster" effect is only apparent when the vehicle is reversing. The opposite camber effect happens when advancing and turning. The difference in camber behavior between advancing and reversing could be due to body roll. Slack in parts will aggravate the problem too due to lateral friction between tire and ground. This is probably best solved with progressive camber.

[offroadcreations]

@Didumos69 I was able to make a POV-Ray rendering, but I didn't understand how to convert the LDD file, so I had to just import it as-is. A lot of the parts were messed up, but I just deleted them, so here it is:

6 hours ago, PorkyMonster said:

Unfortunately, this "negative camber" caused by "positive caster" effect is only apparent when the vehicle is reversing. The opposite camber effect happens when advancing and turning. The difference in camber behavior between advancing and reversing could be due to body roll. Slack in parts will aggravate the problem too due to lateral friction between tire and ground. This is probably best solved with progressive camber.

To sum this up, there is caster on purpose, and camber because of slack in the parts.

Any help with converting the files would be appreciated.

[offroadcreations]

Oops, forgot to answer a few questions...

11 hours ago, TechnicRCRacer said:

It looks excellent! I always look forward to your models! Will it be posted on Rebrickable?

Thank you very much, and yes, it will be posted on Rebrickable.

On ‎4‎/‎24‎/‎2017 at 11:02 AM, muffinbrick said:

My suggestion is to reinforce rollcage, you should connect those free column ends to upper frame. In video it looked like the cage was damaged by that fall.

I was able to do that:

And here is the souped-up Black Edition

 

Featuring 3 L-Motors and a 3:1 gear ratio and then a differential.

[Aventador2004]

Looks good. I used that same gear idea on one of my earlier cars.

[PorkyMonster]

3 hours ago, Offroadcreat1ons said:

To sum this up, there is caster on purpose, and camber because of slack in the parts.

What a way to sum up .

But I guess most Lego models don't require much attention in this area for two simple reasons - they're (1) not fast enough, and (2) not run long enough, to see any serious effect.

[muffinbrick]

3 hours ago, Offroadcreat1ons said:

Oops, forgot to answer a few questions...

Thank you very much, and yes, it will be posted on Rebrickable.

I was able to do that:

And here is the souped-up Black Edition

Featuring 3 L-Motors and a 3:1 gear ratio and then a differential.

Now it looks way better and should save passengers rolling down the stairs :D