My 3DOF project is born!

Aldoz!
Hope u get it working..qouse I have ordered 2 jrk to and vill soon start on my project seat-mower :hi:

just for info El here my unit, seat mover using jrks must update video, moves alot better after pid sorted finially driving at 100% duty.

servo-driven-2dof-t2869.html#p28559

Hello, here my new vids. These vids shows the last mechanical stress tests using X-SIM test plugin.

this is the list of the changes of the platform since the last time.
1) Damper and iron legs height reduced of 9cm (now the platform is lower, 9cm are not too many but for me it's really hard to cut over the damper for now. I have not in my home the right tools to cut Iron propely ( I will reduce again the height in these weeks)

2) The spring was not cut because I wanted to get the spring more compressed (so dumper reduced using the same spring that obviously now is more compressed)

3) Damper modified for avoid the oscillation (drift effect).

4) Left and Right pots now are mounted in a different way. No more the pots are mounted with the rc hely gear. I lost 1 turn and over (so I lost some precision) but now the pots are mounted much safer than the other way.
Before could happen that the rc hely gear came out from the junction with the motor gear with bad consequences. Using max duty cycle the rc hely gear turned very quickly and it could happen that the union lost the motor gear.

However I am thinking to order some other rc hely gears and to use 2 of these joined together (2 hely gears that serve as one)and connected as now with the motor gear (sure I'll get less chanches to loose the connection between rc hely gearS and the motor gear.

5) the stern pot is the same as before because the stern winch motor is different than the other two winches so I can't to mount the pot as the left and right pots method.

6) No relay method used for this test. Using max duty cycle and half accelleration I get some times the over currency jrk error because I was more than 12 amperes draws (lucky the Jrk hold good with 30amps peaks!.

7)I am studyng about the optimization about leg position so small changes have been made about.

This last test result:
Main mechanical movement can be done! Tomorrow I will mount the seat and I will start to use rFactor ingame variables to obtain my platform move.

here the vids of today:
http://www.youtube.com/watch?v=-brXBLs9R0c
http://www.youtube.com/watch?v=v3GnFYBlbcs

You can notice the extreme force of the motors looking how the under dais is moving..
Sure one of the next steps will be to change this dais in another much solid heavy and resistant.

@eaorobbie :
Please can you explain how you mounted the heatsink+fan above the Jrk? And how many temperature you can cut using these heatskin and fan?
Until I don't to use the relay I would to avoid hot to my little Jrk!

ah look alot better mate well done. Well i found a small heatsink at my local elec shop, measuring 20x20x6mm and stuck it to the md03a chip then housed both card in a 65mmx130mm enclosure with two little 12v fans from an old pc cpu cooler, now at 100% everything set in the jrk now then dont get any hotter than 40 deg C, before un heatsinked they use to reach 75 deg C therefore dropping in amps supplied to motor, and motion started to lag.
Just keep in mind these cards were designed for battle robots and not what we are using them for, pololu says we are taking them to their extremes.

At the moment building the h bridge featured on this site to do a comparitive test which will be run by my k8055 board which i already had running with a dual motor driver on and yes it work but nowhere as smooth as the jrks. If H bridge is no better than the dual carrier then time to suck it up and build the amc board. And see how much better or worse is it than the jrks.

nice job so far. :yes:

@kubing : thx dude, I am trying to not get mad building this thing!!

@EL-CORAZON : No problem, you're making a good choice but look at your motor specs before buy a Jrk!!!

@eaorobbie : thx mate, I will try to build a box where to put the 3 jrk12v12 with a good heatskin and fan. I need to cut down temperature before I will have my little and weak jrk melted! :

Yesterday and today all the time trying to find the correct center of mass. Hard and very long work!! many drill and manual work.
If all will finish right so tomorrow I will have my seat correctly positioned and my platform ready to do first in game test with a person sit above!!

Stay tuned! :

He he...already ordered..jrk ..viper i have.planing using heatsink on jrk

Hello all!
The work continue days after days and now I can show you the new pictures (really a lot of manual work.. really really.. I am near to become total mad.. :cnotb:

Monitor mounted, wheels and pedal mounted, the 3 pots system is changed (no more the rc hely gears), center of mass changed and many little modifications from mechanical to force-profile configuration (rFactor)..

Things to be done:
1) Optimization of force profile
2) Add 2cm of motor height
3) Reduce the platform total height (4 cm)
3) Reduce 2cm the legs lenght + 4 cm of reduced total height
4) change the wood dais in an iron dais
5) paint the platform
6) make the envelope in which the pilot will stay indoors (no visual reference of the outside world)
7) many little iron modifications
8) Make a box in which the 3 jrk will stay whit heatskin and fans
9) Make a decent wiring..
10) tests tests tests...
11) :toohot:













Soon the in-game vids! ;D

great job AldoZ, I can not wait to see him in action!!!

regards
micma80

great job there, look forward to seeing it in action! :hi:

Thx dudes! ;D

Hi all and finally some in game footage! :uups:

* duty cycle = 5/6
* accelleration =2/6
* my friend is not in his better racing day.... :? lucky this mean I could see the platform as well behaved in the out of track situations.. :brows:


http://www.youtube.com/watch?v=AT1bxYjRC2Q
First minuteof vid so driving the car really slow, later the things get better!

http://www.youtube.com/watch?v=sYgjO2wEZ7k&feature=youtube_gdata


http://www.youtube.com/watch?v=NowQrGVRzNc&feature=youtube_gdata
here some goods out of track moments... vertical force working good! :yes: (just skip the first 40 secs)




Tomorrow I will to set a really major vertical movement (I am doing many x-sim training with the profiler and test after test I am improving my affinity with the edit tools)
I want to make the driver can feel a major up and down movement, however the actual vertical force is already good (considering barcellona is not full of on-track holes or jumps!)

I am notice that the 3 jrk get hot more slowly than I was thinking but more than one time I get my motors going over the max height pot limit.
I am trying to understand if is a question like the one in the loss motion thread or just I have to change PID settings.

However the global result for these tests is really over what I was hoping!

Next things to do:
1)Increase the legs travel. Now is more or less 12/14 cm, I would reach 20cm for all axis.
2)to Increase the vertical force travel (but I was looking the force-dynamics videos and the force-dynamics have not a too big vertical travel. I would to avoid to obtain a not realistic movement. Better less vertical movement than not realistic more vertical movement.
3) to change the stern motor. The clutch is different than the left and right motors and this make the motor forced to slightly change its position when other motors are moving. It's hard to teach you about but this problem but lucky it'is a problem related only to the stern winch. (the stern motor is what makes that loud and high noise, other 2 winches are really more quieter)

What do you think? How can I improve the realism in the motion? Please, tell me all you think about!

Looks good, you are really doing a good job there.
Perhaps take a video of it with the video on a solid base like a tripod so the motion can be better looked at would help.
As for the motors, is the power connected to the high speed setting, if the motors have that?
The motion is good, you will need to fiddle with the figures in the force-math settings by creating your own set of numbers and changing them. Thats what I did anyway. I have different settings for the four games I have currently. Grid, Dirt2, Rfactor and Gtr evolution.
Frakk wrote this Profile Making 101: When you have automatic maximum adjustment enabled, it will do just that. As soon as you crash the car, your maximum values will shoot up to 10G+, under normal circumstances 2-3G is the effective range of most cars. Increasing the maximum value effectively scales down the movement.

Proper way to do it: Drive the car around the track once without crashing, auto max enabled and find maximum g-force for car. Disable auto max and increase maximum by 10-20%, then adjust intensity with sliders.
Try that as well.
And refer to the thread motion-loss-issue-t3157-10.html
Can anyone else suggest anything?
:

my wipers make no noise, are you using a wench motor? that would drive me crazy and my wife as well, is it really that loud?

all that noise coming from the rear winch motor. Both the right and left winches motor are really more quieter but the rear winch is different than other 2.

The rear winch has 2 major problems related to the clutch:
1) clutch it's really noisy.
2) and clutch does not BLOCK the arm position as the other 2 winches.
This cause that when the frontal winches (left and right) are moving down (example) so the rear winch tends to change it's real position going to up and making it trying to back immediately to the real pot position. (changing continuosly the position :thbd: ).

When I will have the new winch (equal to the other two) so all these problems will be resolved with a real less noisy too!

Sure wiper motors are really less noisy due to the less of gearings and clutch but less power. (I was thinking about the use of wipers but my calculations told me : you will not have enough power for a 3dof! :no: )

Wiper motors would probably do a 3dof, depending on design.

Yes, sure it's possible to make a 3dof with wipers but the design you need to obtain a 3dof it's really much more difficulty to find than classical design like mine.

Sure you need to use a system based to pulleys and it's not an easy choice.
My mechanical experience is already at limits using winches motors (thx to the winches power you get less difficulty to design a 3dof system capable to lift easly a man + platform)

With puley system many other issues enters in the matter (mechanical issues) but sure you are right, with a good design and with some good puleys you can do a 3dof! but sure the building difficulty raise.

bravo !!!
very good project, I also see quite robust,

regards
micma80

Grazie micma80, non sai quanto mi siano tornati utili i tuoi PDF del tuo 2dof!

Thx micma80, your pdf documents about your 2DOF have been really helpful! :

yes pid values need refining for no 3 mate.will fix overshoot and ocilations finding positions.
my setting only a base
:clap: ya shown me what these little buggers can do. :thbup: