Power functions IR-receiver help for a new member.

[lamaii]

So about 6 months ago I got my first technic set 42078 Mack truck, and since then I’ve been hooked and got another 7 sets. One of the sets I got was the “42070 All Terrain Tow Truck” I wanted a set which had the IR controls, as I wanted to see it all working on a model. So, another kit I got was the 42069 Extreme Adventure, and looking to make this motroised, so far I have fitted 2x L-motor (one powering each axle) and here is the problem!

If I run the motors directly off the AA battery box (so no control) it moves fine in both forward & reverse, however if I try and control it by using the Lego V1 IR receiver the model only moves a few mm then stops. I read a few posts about the IR receiver and from what I understand this is the source of the issue, and even if I found a V2 IR receiver it won’t resolve my problem 100%. 

So I guess my questions, are there any hacks to the V1 receive to allow extra power to get to the motor, as I read about the hack to the battery box or should I give up on the Lego IR receiver.

Would the Sbrick device solve the problem, are there any restrictions and would you go for the plus version over the standard.

Are there any other possible controller only solutions, as I have looked at BuWizz device but just cannot justify the costs as I have 7 other models I what to convert to power functions, and don’t have a spare £700 as I still need to get a lot of motors, parts & new 2019 sets when released.
 

Edited November 11, 2018 by lamaii

[MxWinters]

Welcome to Eurobricks Iamaii and welcome to the LEGO community.

As far as I know, the version 1 IR receiver isn't able to provide the huge amount of current that the L and XL motors can draw causing the receiver to cut the power to prevent it from burning itself out. I do believe that this was fixed with version 2. That said, when powering anything with the LEGO Power Functions system, make sure you reduce friction as much as possible (friction is evil with LEGO and should be avoided like the plague), make your vehicle as light as possible and avoid going forward-back-forward-back in quick succession.

Personally I have never had any issues with the IR receivers, I have 2 version 1 receivers on the cab unit of my artic lorry powering 2 XL motors for drive (both XL's hooked to a single channel) and it still runs great. A lot of people don't like to IR system, partly due to the issue you talked about plus most claim that IR doesn't work in strong sunshine, a myth I have well and truely busted. The Sbrick and BuWizz units are ok up to a point but be prepared for a ridiculously short battery life and having to constantly charge both them and your phone, Bluetooth is massivly power hungry compared to IR.
 

3 hours ago, lamaii said:

So I guess my questions, are there any hacks to the V1 receive to allow extra power to get to the motor, as I read about the hack to the battery box or should I give up on the Lego IR receiver.

Avoid modifying your LEGO, us purests hate it, modified LEGO simply INS'T LEGO. Be creative and engineer a solution around the problem, if you can't find a solution, you ain't tried hard enough (I mean that in the nicest and politest way possible).

[doug72]

A V1 PF receiver should be a Lego run two. L motors  OK, I have done without problem.

Sounds as if there is either too much friction in the drive train or the wrong gear ratios is being used & overloading the motors.

Try L motors on seperate red  & blue out puts NOT both on red or blue.

 

Edited November 12, 2018 by Doug72

[mocbuild101]

On 11/12/2018 at 9:21 AM, lamaii said:

1. If I run the motors directly off the AA battery box (so no control) it moves fine in both forward & reverse, however if I try and control it by using the Lego V1 IR receiver the model only moves a few mm then stops. I read a few posts about the IR receiver and from what I understand this is the source of the issue, and even if I found a V2 IR receiver it won’t resolve my problem 100%. 
2. are there any hacks to the V1 receive to allow extra power to get to the motor
3. Would the Sbrick device solve the problem, are there any restrictions and would you go for the plus version over the standard.
4. Are there any other possible controller only solutions, as I have looked at BuWizz device but just cannot justify the costs

1. The V2 receiver probably would help quite a bit, but then the power bottleneck would move to the current limiter in the battery box (as shown in this video) - and the only way to get around that would be to modify it (which is also shown in the video).
2. Not that I know of, aside from just using 2 receivers powering 1 L-motor each.
3. Not really, it probably wouldn't be much better than a V2 receiver in this case, as it would have the same battery box bottleneck. The plus version only adds some extra functions, it still has the same power limits as the standard version.
4. Well there is this, but I'm not really sure if it would have any significant difference in terms of power.

17 hours ago, Doug72 said:

Sounds as if there is either too much friction in the drive train or the wrong gear ratios is being used & overloading the motors.

+1, maybe try loosening the gears and axles in the drive train and see if that makes any difference.

[lamaii]

Thanks for the reply's.

The issue was trying to run two L motors on the one connector of the IR receiver. So now the model now runs fine with both red & blue connected to a single motor. I now just need an additional receiver for the steering and winch 

I understand what you are saying about the friction, but the changes I have made are simple enough and don't cause any extra friction. I think the tracks are one of the biggest causes of friction compared to running wheels.

I will post a picture of 2x L-motor modifications, I'm happy with how the rear motor is mounted but the front motor mounting needs a little (lot) work.