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481a5ed97c742288faa19436031147b4?s=80&d=mm&r=g
(@oyvind)
Eminent Member Customer
Joined: 3 years ago
Posts: 34
19/04/2018 7:49 am  

Have started planning my robot (waiting for the controller and other parts)
I plan to use 120 mm wheels
https://www.ebay.com/itm/4pcs-AUSTAR-5020-5-120mm-1-9in-Rim-Rubber-Tyre-Wheel-Set-for-Axial-SCX10-J7G7/142744287865?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

+

https://www.ebay.com/itm/1pcs-HUB-12mm-HEX-5mm-internal-diameter-30mm-length-with-screw/182760011913?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

Any point using Shock Absorber Stepper Motor Vibration Damper to reduce vibrations from the stepper motors?

https://www.banggood.com/Shock-Absorber-Stepper-Vibration-Damper-for-Nema17-Stepper-Motor-p-1188070.html?cur_warehouse=CN

I plan to use 3S LiPo battery on mine

Started my design (using Fusion360) – is there a electronic brain shield v3.1 3d model (step format..?)

3469=291 30232571 10214633125082336 1005012672 o


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93dd108e8288522c69ed87b154778bae?s=80&d=mm&r=g
(@dcpowered)
Eminent Member Customer
Joined: 3 years ago
Posts: 40
20/04/2018 11:35 pm  

Wow! Upload a video or link a youtube video. We really want to see it rolling!

I plan to upload a good video when i have my tripod so i can film it properly. 😀

I’m also working on a new chassis idea where the cables for the motor are no longer visible on the side of the robot. So, the robot can have a cleaner look with the cables going straight up from the motors through holes in the top plate to connect to the shield.

Also, i’m thinking of swapping the current 6 AA flat battery holder for a more compact one which can fit in the empty space between the stepper motors – this could make the robot even shorter in height or fit more layers/components within the same height.

3475=292 6 AA Battery holder


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350a26dd49eb55d3494500240423a207?s=80&d=mm&r=g
(@robotn1)
Honorable Member Admin
Joined: 5 years ago
Posts: 687
23/04/2018 6:09 pm  

Well, lowering the center of gravity will make the B-robot even faster. Keep us updated!


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127b7bfe9e1e74a5737be21327a956f4?s=80&d=mm&r=g
(@nikola-wan)
Active Member Moderator
Joined: 3 years ago
Posts: 13
08/05/2018 4:30 am  

I just got my latest EVO2 Off-Road MEGA 2560 working tonight.

I wanted more I/O and program space – so replaced the Arduino Leonardo in the kit with an Arduino Mega 2560.

Since the Mega 2560 is over an inch longer – I used Meshmixer to cut the Stealth files and Simplify3d to stretch and merge the pieces to extend the width of the chassis to 130mm.

I had to modify the Leonardo program files for several things that are different in the Mega 2560:
– Mega i2c pins are outside the EVO2 shield – so I plugged two long header pins into the Mega i2c pins and plugged in the i2c CLK and DATA pins from the Gyro cable into the Mega.
– Mega Serial0 (console) is on pins 0 and 1, so I bent the shield pins 0 and 1 out and jumpered the pins to Mega TX1 and RX1.
– I changed the servo code to use the SoftwareServo library. The Servo library conflicted with the Wire library. Then I changed the servo code to make library calls. If I was more proficient at Arduino timer code – I might have been able to not use the softwareservo library and initialize the Mega timers.
– I changed the PORT and bit from Leonardo to Mega 2560 to get the stepper motor code to work with the Mega.

Here is a photo of the front and back of my Off-Road EVO2 MEGA. I’ll get someone else to make a video later – as TouchOSC on my phone stops the robot when I stop touching the screen.

3549=311 Off Road EVO2 MEGA front

3549=312 Off Road EVO2 MEGA rear

I ordered the same wheels Vaygr posted – and although I love the brass coupler to the servo shaft – I don’t like this size wheel as much as my bigger wheel.
I’ll have to make a 17mm hex to 12mm hex adapter – and bolt the bigger wheels to the brass couplers. I found the bigger wheels were easier to drive on carpet.

Monty


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93dd108e8288522c69ed87b154778bae?s=80&d=mm&r=g
(@dcpowered)
Eminent Member Customer
Joined: 3 years ago
Posts: 40
08/05/2018 8:15 am  

I just got my latest EVO2 Off-Road MEGA 2560 working tonight.

I wanted more I/O and program space – so replaced the Arduino Leonardo in the kit with an Arduino Mega 2560.

Since the Mega 2560 is over an inch longer – I used Meshmixer to cut the Stealth files and Simplify3d to stretch and merge the pieces to extend the width of the chassis to 130mm.

I had to modify the Leonardo program files for several things that are different in the Mega 2560:
– Mega i2c pins are outside the EVO2 shield – so I plugged two long header pins into the Mega i2c pins and plugged in the i2c CLK and DATA pins from the Gyro cable into the Mega.
– Mega Serial0 (console) is on pins 0 and 1, so I bent the shield pins 0 and 1 out and jumpered the pins to Mega TX1 and RX1.
– I changed the servo code to use the SoftwareServo library. The Servo library conflicted with the Wire library. Then I changed the servo code to make library calls. If I was more proficient at Arduino timer code – I might have been able to not use the softwareservo library and initialize the Mega timers.
– I changed the PORT and bit from Leonardo to Mega 2560 to get the stepper motor code to work with the Mega.

Here is a photo of the front and back of my Off-Road EVO2 MEGA. I’ll get someone else to make a video later – as TouchOSC on my phone stops the robot when I stop touching the screen.

I ordered the same wheels Vaygr posted – and although I love the brass coupler to the servo shaft – I don’t like this size wheel as much as my bigger wheel.
I’ll have to make a 17mm hex to 12mm hex adapter – and bolt the bigger wheels to the brass couplers. I found the bigger wheels were easier to drive on carpet.

Monty

Great work, Monty! You’ve done quite a lot of modifications. The extra pins of the MEGA can always come in handy to connect more components, such as additional servos, etc. For example, it would be cool to attach a small/simple robot arm on top of the B-Robot to pick up stuff. Could you post some close-ups of the wiring on your MEGA or maybe some schematic if you made one? Maybe you could even consider sharing your work on GitHub. 😀

What is the diameter of your bigger size wheel? I also realized that the 83 mm wheels didn’t leave much space between the bottom of the chassis and the ground surface, especially for off-road. I ordered some new wheels: https://www.aliexpress.com/item/2pcs-Wild-Monster-Truck-Tires-Rim-Wheel-For-1-10-Hex-Hubs-12mm-Scale-RC-Car/32832060975.html?spm=a2g0s.9042311.0.0.US6LXX
Diameter 125mm
Width 70mm
Hexagon adapter 12mm
Brand: GWOLVES (since it’s branded, i’m hoping that the quality will be better)
I’ll post some pictures and video of my upgraded B-Robot setup when i receive the new wheels in a few weeks.
I also have some larger wheels but with 17 mm hex and i just ordered these adapters (although you can design and 3D print your own): https://www.aliexpress.com/item/12-17mm-Alum-Hex-Adapters-12MM-conversion-17MM-Aluminum-combines/32746040979.html

P.S. I see that the automated anti-spam forum system banned you (undoubtedly, for editing and submitting several times and too quickly – it happened to me too) but i don’t have the forum privileges to unban you, so let’s wait for the admins. 🙁


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127b7bfe9e1e74a5737be21327a956f4?s=80&d=mm&r=g
(@nikola-wan)
Active Member Moderator
Joined: 3 years ago
Posts: 13
16/05/2018 3:08 am  

I just got my latest EVO2 Off-Road MEGA 2560 working tonight.

Great work, Monty! You’ve done quite a lot of modifications. The extra pins of the MEGA can always come in handy to connect more components, such as additional servos, etc. For example, it would be cool to attach a small/simple robot arm on top of the B-Robot to pick up stuff. Could you post some close-ups of the wiring on your MEGA or maybe some schematic if you made one? Maybe you could even consider sharing your work on GitHub. 😀

What is the diameter of your bigger size wheel? I also realized that the 83 mm wheels didn’t leave much space between the bottom of the chassis and the ground surface, especially for off-road. I ordered some new wheels: https://www.aliexpress.com/item/2pcs-Wild-Monster-Truck-Tires-Rim-Wheel-For-1-10-Hex-Hubs-12mm-Scale-RC-Car/32832060975.html?spm=a2g0s.9042311.0.0.US6LXX
Diameter 125mm
Width 70mm
Hexagon adapter 12mm
Brand: GWOLVES (since it’s branded, i’m hoping that the quality will be better)
I’ll post some pictures and video of my upgraded B-Robot setup when i receive the new wheels in a few weeks.
I also have some larger wheels but with 17 mm hex and i just ordered these adapters (although you can design and 3D print your own): https://www.aliexpress.com/item/12-17mm-Alum-Hex-Adapters-12MM-conversion-17MM-Aluminum-combines/32746040979.html

Vaygr,

Thanks for the kind comments.

I have now posted my modifications to the EVO2 Arduino code on github:
https://github.com/mmcgraw74/BROBOT_EVO2_MEGA_2560
I have included my TOUCHOSC file. My mods include getting the PID sliders to report the adjusted PID values, plus a working battery voltage and battery percentage display with a background RED LED that lights below the low battery threshold.

The secret to getting the EVO2 telemetry back to the TOUCHOSC application was only sending one message – immediately after the TOUCHOSC app pings the EVO2 Wifi. There is a short window where TOUCHOSC listens, then closes its connection to the Wifi.

I reworked my first attempt – bending the shield serial pins out made the shield too sensitive and it would pop off if the robot fell over. My suggestion to JJROBOTs- if they are redesigning the shield would be to put jumper headers for the Wifi serial to the shield pins 0 and 1. This would have allowed me to remove the jumpers and connect the Mega serial1 pins to the Wifi – bypassing the shield pins.

My rework was to unsolder pins 0 and 1 from the shield and resolder them to the top side of the shield – making sure the pins did NOT make contact with the arduino pins 0 and 1 when the shield was plugged in.

I also decided to change out the inline 6x AA battery box and created a 2 row 3x AA battery box by cutting off a larger 2 row AA box. This allowed me to put the batteries between the two stepper motors to further reduce the EVO2 MEGA center of gravity.

I’ve got several photos of my latest modifications – I’ll post those in separate messages in this thread to keep from being banned again.

Monty


Vaygr,

My tire info is in post #9:
http://forums.jjrobots.com/thread-887-post-3180.html#pid3180

My github site also includes my stretched “Stealth” EVO2 front and back bumpers, stretched electronics platform and stretched stepper motor platform. The platforms are now 130mm long – just enough to bolt the Arduino MEGA and fit inside the side panels.

Monty


Here are some photos:

First the relocated Serial pins to the top of the shield:

3578=319 MovedSerialPinsToTop

MEGA Serial1 to shield Serial1

3578=320 IMG 6646

Gyro i2c cabling

3578=321 GyroCabling2

New battery box between stepper motors

3578=322 Battery box between stepper motors

I added an external power switch on the side

3578=323 Added external power switch


I soldered red wire to the +9V terminal on the battery pack – but didn’t check which wire was center conductor (plus) to the Arduino. So I reversed the power leads from the Arduino – now I’m switching on/off the ground lead.


Vaygr,

I took your suggestion and purchased a 17mm to 12mm metal hex adapter on Amazon – I didn’t want to wait for the shipment from China 🙂

I did have to use my grinding wheel to shave off some of the adapter so the washer would fit flush with my big wheels. I also cut off the captive washer on the bolt that came with the brass coupler and smaller wheels – otherwise I would have had to find longer bolts to attach the big wheels to the coupler.


I forgot to post a photo of my EVO2 MEGA Off-Road 🙂

3578=324 My EVO2 MEGA


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481a5ed97c742288faa19436031147b4?s=80&d=mm&r=g
(@oyvind)
Eminent Member Customer
Joined: 3 years ago
Posts: 34
16/05/2018 8:04 am  

Great work 🙂

I`m building my own “Off road” version – how does it handle obstacles (not flat surface) when you have a low center of gravity? Does it not need to lean forward and use a top weight when trying to “climb” angled surface..?


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127b7bfe9e1e74a5737be21327a956f4?s=80&d=mm&r=g
(@nikola-wan)
Active Member Moderator
Joined: 3 years ago
Posts: 13
16/05/2018 1:13 pm  

Great work 🙂

I`m building my own “Off road” version – how does it handle obstacles (not flat surface) when you have a low center of gravity? Does it not need to lean forward and use a top weight when trying to “climb” angled surface..?

Great question!

I have tile and throw rugs in my house. I found the original wheels with an O-ring had difficulty transitioning to the throw rugs from the tile.

The larger 1:8 scale wheels can easily handle the transition.

I am using the “Pro” mode which has more aggressive ‘angles’. I have found that I can easily turn the MEGA Off-Road in either direction on a fairly deep pile carpet – but if stopped on the carpet – I need to drive backwards to get off. Sometimes with ‘shag’ pile carpet I need to jog the robot forward and then back to begin to move. I believe the backwards angle in the code is larger than the forward angle – has something to do with that.

I haven’t tried driving outside on any surface other than concrete. I think the aggressive off-road treads will help here.

I’m still experimenting with changing the PIDs – although I’ve found that reducing the Stability P to 0.200 helps a lot with the changed center of gravity.

Monty


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413ae9dd0f8f4129708e88ce91d4f0d3?s=80&d=mm&r=g
(@mrobot)
New Member Guest
Joined: 12 months ago
Posts: 1
06/12/2019 5:29 pm  

Do you have a discount for him?


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d50b8e4a058a34c8db7e017a7956f7e6?s=80&d=mm&r=g
(@antitesto)
New Member
Joined: 3 months ago
Posts: 1
19/08/2020 9:54 pm  

Neat, I look forward to trying it. subscribed.
These AKA wheels from the link above measure as:
83.4mm (3.28 in) hub diameter
112.4mm (4.42 in) tire diameter

I’m using the six AA holder that came with the robot and I use NIMH.
Only changes are a GoPro mount (no GoPro while testing), USB cable (easier to program) and some tiewraps.

ดูหนัง netflix


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