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Old 02-16-2013, 06:39 AM   #31
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No, I didn't. What advantages will I have from the use of two servos that will react in the same way?[/QUOTE]

Not sure any advantages performance wise. Maybe it would cause less changes to the original TC6 design.

Just a thought. Very nice work on yours !!
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Old 02-16-2013, 08:19 AM   #32
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^ using 2 servos would allow u to use a radio with servo mixing to adjust steering duel rates for both front and rear independently . And if u used 2 servos I would think u could use mini servos (with good torque).
That would also help with ur turnbuckle angles (to keep the both linear L&R)
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Old 02-16-2013, 10:22 AM   #33
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Thanks for the ideas, guys!

Right now there are no problems with the turnbuckle angles as you can see on the video there is no visible angle change:
http://www.youtube.com/watch?v=GEUVX...ature=youtu.be


I think the two servo idea offers a lot of potential. And as it should be no problem to do so I will sure try it sooner or later. I would need only a second servo which would be taped to the place it normally resides. The complicated thing is the servo mixing (for me) as I never did that. Do you know if a Sanwa MT4 is able to do that?
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Old 02-16-2013, 02:48 PM   #34
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Yes it will I love that radio I have 2
The turnbuckle angle I'm referring to is the relationship between the servo long link front bell crank. When u turn full left it almost makes a strait line between the pivot points and when ur turn hard right it doesn't . I wish I could explain this better . Take a look at ur EPA adjustments for left and right if they r close in # then I'm wrong but if one is set to 60-70 and the other is set to 80-90 that's a big difference and would think it would show when u set ur turning radius L&R
To descripe this differently . Look at ur rear short link and the angles between the turnbuckel and the servo .. when its strait they r both just about 90deg with the pivot points . Now look at the front . They r no where near 90deg . The servo is (just guessing) 60deg and bell crank is about 120deg when lining up wheels strait . This is what lm referring to. U have a great setup here I love all the tooling u have done to build this car . Its awesome . Thanks for reading my thoughts
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Old 02-16-2013, 03:35 PM   #35
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Thanks for the ideas, guys!

Right now there are no problems with the turnbuckle angles as you can see on the video there is no visible angle change:
http://www.youtube.com/watch?v=GEUVX...ature=youtu.be


I think the two servo idea offers a lot of potential. And as it should be no problem to do so I will sure try it sooner or later. I would need only a second servo which would be taped to the place it normally resides. The complicated thing is the servo mixing (for me) as I never did that. Do you know if a Sanwa MT4 is able to do that?
The way I had done it was without servo mixing....just a servo female type ''2 into 1'' wire so when the receiver gave the command,both servos operated. Much like a Y connection.
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Old 02-17-2013, 07:38 AM   #36
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wtcc ... when you have your finished model, please post a video of it on a track. thanks !!
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Old 02-17-2013, 07:51 AM   #37
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wtcc ... when you have your finished model, please post a video of it on a track. thanks !!
I will! Promise!


Today I ordered some cfk and prepared the 3D-data for my miller. This is how it looks:

All the prototype parts with their location on the car...


...and separated.


He wants Auto Cad drawing files (.dwg) as 2D and 3D version. So I give him the lines, drill holes and drill hole length plus the 3D drawing of every part to avoid misunderstanding. Here a detailed view of the right spurgear bulkhead:


If someone needs prototype parts to bring his ideas to life he can visit his website: http://shop.alza-racing.com/
Of course this adress will only make sense for europeans or if you have to much money for your mailservice
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Old 02-17-2013, 11:05 PM   #38
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Such a crazy idea you've got here, haha! A fun project to follow.

How long did it take you to model your car in Rhino? Have you tried to model a touring car body shell? I'm studying Industrial Design in University right now and we are learning to use Rhino this year. I have been thinking about modelling my Xray T3, but of with so many projects for my classes I don't have time for such fun asides. I barely have time to even read this thread! So, it is cool for me to see someone who has already done the modelling. You should post Renders next time. Throw some materials onto those parts and everyone will be blown away by how good the car looks!

If you did goto a rear servo there are a few advantages that could be gained:
1. The ability to control the rear wheel motion completely independent from front wheel motion.
2. More freedom of servo positioning. You could easily get away with a mini or micro servo to steer the rear wheels because the amount of deflection required is so small you can use a short servo horn to get a better mechanical advantage to the steering bellcrank.
3. Possible variable rear geometry. By varying the angle at which the rear servo linkage meets with the steering bellcrank you might be able to achieve different level of linear to non-linear motion (servo output to wheel movement relationship). Similar to the way that the shock rate varies as the suspension moves through its travel due to the angle at which the shock is mounted, or similar to the way that the ackermann effect is achieve in the steering rack.

Now, if you really have a lot of time on your hands (and I can't imagine anyone would have time to do this...) you could link the rear servo to an accelerometer and maybe write some code that would interpret the acceleration of the car in the x-y plane, and consider that against the position of throttle input and map different levels of rear steering output for different levels of x-y acceleration and throttle positions. Then you would just need to add independent braking at each rear wheel to achieve torque vectoring and you'd have yourself a 1/10th Nissan GTR.

Maybe this summer I will build some RC stuff in Rhino and get some things cut with a CNC for fun....hmmm
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Old 02-18-2013, 08:56 AM   #39
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Thanks Wheelnut! Nice to hear from an actual industrialdesign student! I studied the same here in Germany at the university of Duisburg/Essen

We learned Rhino, too. After that I never found another program that is as fast and clearly arranged in modelling as this one. I was truly addicted to it in the first years.
I already did some renderings of my RC-ideas some three years ago with Vray like this one for example:



I am not sure if I can find my old files with the studio I build for the stage lightning. If I can find it will only took some minutes, because the materials will be there, too. Anyway, that is a nice idea! I check that out later.

The servo project seems to be something everybody wants me to do, but I sure will not write a code for it.

If you build your own car just don't underestimate the costs. Since your university sure has a milling maschine you can at least save some bucks there


Edit: I just found some old stuff on an old harddisk.













Not the level of today, but wasn't bad six years ago. At least some of my professors had a hard time to differentiate between photo and rendering...
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Old 02-18-2013, 09:14 AM   #40
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Thanks Wheelnut! Nice to hear from an actual industrialdesign student! I studied the same here in Germany at the university of Duisburg/Essen

We learned Rhino, too. After that I never found another program that is as fast and clearly arranged in modelling as this one. I was truly addicted to it in the first years.
I already did some renderings of my RC-ideas some three years ago with Vray like this one for example:



I am not sure if I can find my old files with the studio I build for the stage lightning. If I can find it will only took some minutes, because the materials will be there, too. Anyway, that is a nice idea! I check that out later.

The servo project seems to be something everybody wants me to do, but I sure will not write a code for it.

If you build your own car just don't underestimate the costs. Since your university sure has a milling maschine you can at least save some bucks there

I work as a professional 3D Graphic Artist, Mainly with Architectural designs, I use 3Dstudio and Vray among many other things and would happily knock you up some renderings.
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Old 02-18-2013, 09:48 AM   #41
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I work as a professional 3D Graphic Artist, Mainly with Architectural designs, I use 3Dstudio and Vray among many other things and would happily knock you up some renderings.
Of course! Give us a taste of your skills!
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Old 02-18-2013, 05:08 PM   #42
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Of course! Give us a taste of your skills!
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Old 02-20-2013, 10:41 AM   #43
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It's cool to finally see an industrial designer on RC Tech!
Yeah, getting custom stuff might be expensive. Our CNC at school doesn't cut metal Oh well, I'll find a way!
I like the 3-in-1 LRP unit you've designed. Very clean. It would be awfully nice to get rid of the mess of wiring provided by standard electronics.
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Old 02-23-2013, 01:28 PM   #44
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Default 4WS comparison with W.C.

I just came home from my clubtrack in Senden.
As I my 4WS is waiting for new parts (the cfk arrived today and I sent it to my miller), I used the day to compare my prototype with Team Associateds TC6 W.C.. The W.C. is my usual racecar and has already clinched several podium places this season. So I thought it would be the perfect candidate to compare laptimes with my 4WS.

I equipped it with the same motor, esc and tires (esc an tires are the same I use for the races) and did my first laps since a month with a "normal" TC. The first run wasn't easy at all. I had my hands full to keep it on track. The car showed in comparison a lot of understeer and didn't want to turn in. The laptimes showed that this car needed some tweaks. The car usually runs in a 17.5t-class so it is clear that I have to do something to make the car better for the installed 10.5t motor. So I did what I had to do and made the car better from run to run. At the end of the day the car was nice to drive and well adjusted.
Still I couldn't beat my laptime driven with the 4 WS. I was always one tenth behind...


The spotted differences are:
1. The corner entry with the 4WS is easier and faster.
2. To carry the speed through the corner is easier with rear steering, because there is no breaking effect from the turned front tires.
3. The corner exit is quicker as the rear steering allows you to accelerate earlier, because the rear tires provide extra steering (the car weight shifts to the rear tires while accelerating).
4. Today I also took a special look at the tires: The front right tire of the W.C. got much more worn then it was the case with the 4WS. In the end I can say that the rear steering takes away the pressure on the front outside tires on every corner realizing a reduced and/or equated tire wear.

I was surprised myself to have found so many positive aspects today. As you can see they "only" made one tenth difference a lap, but on track it feels much different. Now I am very excited how the 4WS will perform with the new parts as I believe I could find another two tenth a lap with the added adjustment possibilities!
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Old 03-14-2013, 06:57 AM   #45
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Finally the new parts arrived today. Can't wait to put them in the car
I'll post pictures of the optimized 4WS later!
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