The Enforcer Recharged: CUUSOO Project

[crazy_1993]

The Enforcer is back and better than ever before!

Support on CUUSOO!

Introduction

The Enforcer is a fully motorised remote control Technic off road vehicle. The vehicle has a police theme and is loosely based on the Hummer H2 but many subtle changes have been made to obey copyright restrictions. Here are some examples of the inspiration for my design:

The Enforcer was originally an entry for the ‘You Design It, We Make It’ competition but ended up coming in second place to rm88’s ‘Boss’ crawler. However I do not think that it is the end of the road for the Enforcer.

The Enforcer Recharged is a massive overhaul of the original Enforcer. Firstly, as this is CUUSOO, the original 9398 chassis could not be used anymore, so the chassis has undergone a massive redesign to adapt it specially to the Enforcer’s needs. The winch has now been motorised and all lights are now power functions. The battery box has now been changed to a 8878 rechargeable battery box which reduces weight massively (by about 160g) and is more convenient. There is now no need to remove the battery box so this allowed major part optimisations to be made. The result is this, The Enforcer Recharged:

Note: LDD does not contain certain power functions elements so in some images the following elements will be represented as shown:

Chassis

The Enforcer now uses a redesigned chassis and not the 9398 chassis.:

The new chassis does not have 4 wheel steering like the 9398 as I did not think that it was needed on a model of this theme. The 88004 servo motor for steering is now located in the front suspension module. The chassis is powered by one central 8882 extra large motor transmitting power to all wheels through the power joint system, unlike the 9398 which had one 88003 large motor for drive above each axle. Below is a diagram of the drive-train and gearing:

I have now changed the design of the drivetrain to prevent breakages of the gears in and driving the centre differential. The older style non-bevelled differential is now used and the gearing converts the torque from the XL motor to RPM before reaching the centre differential. Further gear reduction has been added after the two axle differentials to maintain an overall gear ratio of 1 : 6.72. The gearing results in 0.44 times the original torque on the centre differential. That's 40.2 mNm with an RPM of 495. I am just finishing the casing for the new rear axle module.

I am also thinking of working on an alternate setup which is the 9398 chassis with the battery box changed for the rechargeable version so that the bodywork can still be directly attached.

Here are some comparisons between the 9398 crawler chassis and the Enforcer chassis to show how the gear ratios were decided. These stats have yet to be updated for the new drivetrain:

Because the extra large motor does not deliver quite as much total power as the two large motors, two gear configurations are available for speed focused or torque focused performance. This is shown in the drivetrain diagram above the table.

Although the 8878 rechargeable battery box only outputs 7.2V which is less than the 9V from the 8881 AA battery box, this voltage is more consistent because the voltage from a Lithium polymer battery remains constant until the charge is depleted, whereas the voltage from AA batteries drops significantly throughout use.

Note that unlike the 9398 chassis, the front and rear differentials need to be facing in opposite directions as shown, otherwise the wheels will not rotate in the same direction:

On the Enforcer chassis, the space above the rear axle in the rear suspension module is occupied by an 8878 rechargeable battery box which is much lighter and more convenient than the regular 8881 battery box. More importantly, this means that the battery box does not need to be removed to change the batteries, it can just be plugged into the charger without being removed. This allowed the bodywork to be built directly on to the chassis, saving parts.

Another main feature of the chassis is the dual shock absorbers above each wheel. This is to help prevent the easy rolling behaviour which is common in Technic off-road vehicles with a heavier bodywork and to scale the suspension stiffness more appropriately to the weight of the model. Softer suspension such as using only one shock absorber per wheel results in the bodywork leaning away from the chassis on lateral inclines, causing premature tipping so the new design helps prevent this:

Care had to be taken to allow each shock absorber joint to rotate on two axes to allow the front and rear axles to move freely with the suspension. The main image shows the shock absorbers functioning.

Different Forms

The model with the most features has a very high part count so I have decided to make multiple versions of the model simplified to various degrees for different and slightly more practical part counts. The features of each version are shown below:

Features on all models

All models feature 4 opening doors, an opening tailgate and an opening bonnet. The doors feature compound hinges to allow the doors to fit into their frames properly. Each door also has a rotary handle to secure the door shut with:

The tailgate has a sliding handle which locks it in place when closed:

All models also feature power functions headlights and taillights which can be switched on or off while driving:

All models except the Enforcer Rapid Response have a rear roof section which can be removed for an alternate form.

Charging can be done easily by opening the rear door:

The Enforcer Elite

The Enforcer Elite features power functions flashing police lights. The flashing is performed by a mechanism containing a medium motor and 2 control switches:

The same motor is also linked to a piston engine in the bonnet:

The gear ratios mean that the piston engine will run at 127rpm and the light flashing system will be driven at 26.4rpm which will result in the police lights performing one on/off cycle every 1.14 seconds.

The Enforcer Elite contains a front mounted winch powered by a medium motor which is shown on the left in the above diagram. The gear ratio for this winch is the same as the gear ratio for the winch on the Unimog U400 (1 : 24 gear ratio, 15.8rpm winch speed, 40mNm torque). The winch would also contains a clutch gear to avoid damage in the event of a string jam or when the winch is fully reeled in. This is replaced by one of the white 24 teeth gears in the render as LDD does not contain the clutch gear.

The Enforcer Elite will be controlled with 2 8885 IR controllers.

The power functions wiring layout needed to make the functions run correctly is shown below along with the physical locations of the PF elements:

The Enforcer Standard Issue

The Enforcer Standard Issue shares largely the same bodywork as the Elite version but does not contain the winch, flashing police lights or piston engine to reduce the part count and number of power functions elements required. The bonnet has been modified to accommodate the removal of the piston engine.

The power functions lights are now turned on and off by a control switch in the boot which can be accessed by removing the rear roof section. The switch can be secured on with the red push bolt.

The power functions wiring and layout for this model are shown below:

The Enforcer Rapid Response

The Enforcer Rapid Response shares the same functions as the Enforcer Standard Issue but has the entire roof removed for a whole new look and a lighter and faster feel along with a further reduced part count.

Possible Stickers

The Enforcer has potential for a great sticker set to emphasize the police theme. Below is an example of a possible sticker set:

SUPPORT NOW ON CUUSOO!!!

Thank you for taking your time to read this, all support is greatly appreciated!

Edited February 14, 2013 by crazy_1993

[Edwin Korstanje]

You put a lot off work in the redesgin of it

[DLuders]

@ crazy_1993: OMG! You certainly have done your "research and development"! Your models are superb! :thumbup: They've got so many great features. What is the link to your LEGO CUUSOO page, so that we may "support" it?

[Interceptor]

WOW, you get my support, fantastic redesign!

[rm8]

Huge work was done! Very impressive. I am going to vote for it!

P.s. Can I critisize it?

Edited February 12, 2013 by rm8

[crazy_1993]

The model is still in CUUSOO moderation and the result will

@ crazy_1993: OMG! You certainly have done your "research and development"! Your models are superb! :thumbup: They've got so many great features. What is the link to your LEGO CUUSOO page, so that we may "support" it?

The model is still in CUUSOO moderation the result will be known within 72 hours (too long!). If it passes moderation (I really hope it does), I will immediately add the link! Thanks everyone for such immediate intrest.

Huge work was done! Very impressive. I am going to vote for it!

P.s. Can I critisize it?

I am glad you like my new versions of the model. Constructive criticism is fine but plain hating on the model is not.

[dvsntt]

Wow, that is awesome.

[shadowhearth]

Its nice, a lot better with its own suspension, not the 4x4 crawlers one.

Though even if it will Win, there is 99.99% they wont make it. Cuusoo is looking for iconic small/ish sets, which are not expensive and easy to flog. This thing would cost A LOT more then original crawler. It is not profitable for Cuusoo. Lovely set, but it wont become official set.

[jadedomg]

Much better model now, where the original enforcer was just for appearance, this one has a lot of nice things going on underneath. Much much better. It would be great to see one brickbuilt. Unfortunately I don't think cuusoo will make this set due to the way it has gone for models, and we have not seen a single technic model so far and its high part count. I love the chasis and it shows a lot of care in the way you built it.

[Porty]

Wow! I love it.... Did Blakbird help you with those renders or are you just that awesome???

EDIT: RIGHT CLICK, SET AS DESKTOP BACKGROUND

Edited February 12, 2013 by Porty

[MarkusOSX]

@crazy

Your redesign is awesome, i like it very much.

But there is one thing that won´t work.

You´ve split the transmission with three differentials. This will cause the total loose of torque at least. Hard for me to explain it in english, but i´ve tried the same for my 8x8 and it failed.

The problem will be; if one wheel looses contact to the ground, all of the torque was at this wheel.

You will see it, if you build it in real.

Greetz

Markus

[Zerobricks]

@crazy

Your redesign is awesome, i like it very much.

But there is one thing that won´t work.

You´ve split the transmission with three differentials. This will cause the total loose of torque at least. Hard for me to explain it in english, but i´ve tried the same for my 8x8 and it failed.

The problem will be; if one wheel looses contact to the ground, all of the torque was at this wheel.

You will see it, if you build it in real.

Greetz

Markus

Exactly, by the original 9398 if one left the ground, the other axle still worked, because they were indpendent. Here if only on wheel lifts the ground, all the power will go to it, spinning it 4x faster, but not doing actually anything.

All other ideas are great, especially the blinking lights.

[MarkusOSX]

Just remove the middle differential and use a rigid drive instead, that should solve this problem.

Greetz

Markus

Edited February 12, 2013 by MarkusOSX

[Meatman]

Have you actually built this, or is it just in CAD? Because I can not see that bevel gear from the XL motor properly driving that center differential without some serious slippage from all of the weight of the vehicle combined with the torque.

Edited February 12, 2013 by Meatman

[PsyKater]

Great presentation!

[timslegos]

the new version looks fantastic! I liek all teh features and I would lovet to see a real version.

tim

[z3_2drive]

agree with above statements about differentials...but one other thing is that by moving the shocks to the outside may increase stability, but it GREATLY reduces suspension travel, I can tell you that, but I guess it's ok because this model has so many other features great job :thumbup:

[Blakbird]

Amazingly thorough presentation of a marvelous model. I hope that I am able to build one whether it makes it through the Cuusoo process or not.

Question: have you actually built it or is it just an LDD model at this point? It looks amazing in CAD, but there is nothing like a field test to prove the design.

[Kronos]

Amazingly thorough presentation of a marvelous model. I hope that I am able to build one whether it makes it through the Cuusoo process or not.

I have to agree. I can't wait to build it.

[crazy_1993]

@crazy

Your redesign is awesome, i like it very much.

But there is one thing that won´t work.

You´ve split the transmission with three differentials. This will cause the total loose of torque at least. Hard for me to explain it in english, but i´ve tried the same for my 8x8 and it failed.

The problem will be; if one wheel looses contact to the ground, all of the torque was at this wheel.

You will see it, if you build it in real.

Greetz

Markus

This is exactly what I thought would happen, I was originally going to have no centre differential but I researched this and apparently with 2 wheel steering, the front wheels are on different arcs to the back wheels so leaving it out would be bad for the transmission. This is not the case with 4 wheel steering like on the 9398 chassis.

Seriously, is everyone sure that removing the centre differential would not put strain too much strain on the transmission when steering? Removing it is dead easy to do so it doesn't really matter either way but it is good to get these things sorted out.

Have you actually built this, or is it just in CAD? Because I can not see that bevel gear from the XL motor properly driving that center differential without some serious slippage from all of the weight of the vehicle combined with the torque.

Yes it is just an LDD render because I have a nowhere near good enough LEGO collection to create something of this magnitude in real life, a CAD model gives me much more freedom.

Also. the Unimog model uses a centre differential which was one of my main reasons for including it.

Wow! I love it.... Did Blakbird help you with those renders or are you just that awesome???

EDIT: RIGHT CLICK, SET AS DESKTOP BACKGROUND

I just used the LEGO to POV Ray converter and MANY hours of running POV Ray on my laptop to do all of this.

[Jim]

Your designs look really cool. You put a lot of work in it.

[Soluzar]

Obviously it looks impressive, and I'm sure that any technical issues can be resolved. I'm just wondering whether the TLC would be interested in doing yet another 4x4 RC off-road vehicle so soon after the original 4x4 Crawler and with the "Boss Crawler" already in the pipeline. Don't get me wrong though, I'd love to see this released. I think the "Boss Crawler" is a nice, stylish new body design for 9398 but this is every bit as stylish and with a different chassis design to boot.

[crazy_1993]

I am not going to lie, I think that the chances of LEGO developing this are extremely slim which is annoying because they were semi prepared to produce it at one point because they picked for the top 10 in the contest, but that was before the Boss won.

[PsyKater]

Well, the Boss Crawler will be sold out early enough. And if the Enforcer will hit the 10'000 votes, TLG might see the market potential this thing has. It has at least already support from fans and is well-known by the contest.

[DLuders]

@ crazy_1993: Don't be discouraged by the Lego Cuusoo prospects -- your model will gain EXTRA EXPOSURE there and possibly inspire others to delve into Lego Technic!