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Speedy's CR-01 Build Thread

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They look complex but if you have ever driven a Land Rover then you can just jump into one of these and it all comes naturally . The tilt cab is good feature because as you can see it makes cleaning and servicing a easy task . IMO they really are the worlds best factory built 4x4 . German engineering is hard to beat .

The only thing that ever breaks is the IMO overly complex transfer box . Its just over engineered and a real swine to repair . Many owners replace it with the simpler and more reliable Land Rover unit .

if you get the impression that I love the Uni and have driven quite a few then your right :D .

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I would pick out the elements you like such as a soft top and mesh bed and just create what you feel is right . There really is no right or wrong with these because owners adapt them to their own needs . One thing you never see in Africa is a clean one though :lol:

I think I've zeroed in on what I want to do with this model to finish it out... Stay tuned for part 2 of this build...

Adopted Features

- Metallic red cab

- Black fenders

- Black rubber window trim

- Chrome grill logo

- Full interior

- Chrome fuel tanks

- Black air tanks

- Stained wood bed with black edge capping

- Bed tilting mechanism

- Head lights

- Parking lights

- Tail lights

- Driving lights

- Rear bed light

- Snorkel

- Vertical exhaust

- Air horn

- Rear hitch

- Winch

- Tow hooks

- Shovel

- Chains

- Spare tire (maybe)

- Tire iron

- Air ratchet & hose & fittings

- Jack

- Tool box

Transmitter Channel Assignments

1 - Front steering - right stick

2 - Throttle - left stick

3 - Rear steering - left stick

4 - Parking lights and tail lights - 2-way switch

5 - Head lights and driving lights - 2-way switch

6 - Rear bed light - 2-way switch

7 - Bed tilt control - analog knob

8 - Winch control - 3-way switch

Dropped Features

- Tilting cab

- Soft top

- Painted corner indentations

- Two-tone paint

- Front bush guards

- Corner marker sticks

- Side steps

- Rear metal mud flaps

- Lower tail pipe

- Stainless steel bed

- Mesh rear bed

- Rotating beacon

- Roof mounted spot lights

- Chevron tires

- PTO

- Rear winch

- Grapple attachment

- Back hoe

- Front end loader

- Trailers

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If the attention to detail and quality of work that has gone into the chassis is anything to go by then the body is going to be epic .

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A friend of mine had a unimog 406.

He used it for forestry work.

It had an escape hatch in the roof

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I started looking at the body and electronics tonight to think through a plan.

The body's wheelbase does not match the chassis' wheelbase at all. When lining up the body post holes with the chassis post locations, it looks like the front cab is set too far back by maybe an inch or so.

IMG_1410.JPG

The first feeling in my stomach isn't that good, but then I start thinking about how I need to separate the bed from the cab and fill in the rear cab wall. It also strikes me that I need to come up with some sort of access to the battery tray, and maybe the front bumper needs to go away to show more of the shell's front bumper. I need a better winch attachment point. I also want the fender arches to line up with the tires better to allow for the maximum articulation and steering possible.

So, I think what I'm going to try is:

- Trim the shell

- Separate the bed from the cab

- Reconstruct the missing rear cab wall

- Build an interior floor

- Remove the front bumper from the chassis

- Position the wheel arches over the tires correctly

- Construct a custom hinge on the chassis to pivot the cab forward for battery access, lock the cab down for normal running, and provide a new winch mounting location

- Build the interior

With the cab moved forward I will fabricate a new bed that is longer than scale to compensate. Planning the bed, fuel tank, and air tanks will come later and will be easy compared to the front cab.

Tonight was the first time I pulled all the electronics together.

IMG_1412.JPG

I already have a HPI Saturn 35T brushed motor installed in the chassis along with two servos, so this setup was temporary only so I could program the radio and test all the channels. The equipment list:

- Turnigy 9X 8-channel transmitter. I was attracted to this radio and receiver for the initial price (about $60) as well as the open source firmware that was available. I hacked the radio by soldering a programming connector to the main board and used the Atmel AVRisp MkII programmer to burn in the new firmware about a year ago. The "open9x" firmware provides a flexible environment for configuring the radio. instead of being stuck with airplane and helicopter profiles, "open9x" has a bank of programmable mixers that can accept any of the sticks, switches, buttons, and potentiometers as inputs, and the outputs from the mixers can be assigned to any of the channels freely. Trims, offsets, expos, custom curves, custom switches/functions, etc. are all possible with this firmware as well. I don't need to program all sorts of custom functionality, but I did want more channels of control than the usual pistol radio. With some basic setup I was able to implement the channel assignments listed above.

- Turnigy 9X8CV2 8-channel receiver. This comes with the transmitter, and additional receivers are available for about $9-10 each. Binding the receiver to the transmitter is straightforward. Just install the binding plug, turn on the transmitter while holding the bind button on the transmitter module, then apply power to the receiver. The red blinking LED on the receiver will stop blinking and show steadily once the binding is complete. Then power everything off, remove the binding plug, turn on the transmitter again, turn on the receiver, and any of the channels assigned in the radio to sticks, switches, potentiometers, etc. should come through on the receiver.

- Channel 1 on the receiver is assigned to the front steering on the chassis. I used a similar spare servo for testing. On the radio channel 1 is assigned to the aileron; this is the right-left axis of the right stick since I am using the radio in mode 2 configuration. Mode 1/mode 2 configuration refers to which stick is used for throttle/rudder, and which stick is used for elevon/aileron. Mode 1 has the throttle on the right stick; mode 2 has the throttle on the left stick. I'm used to mode 2 more since I'm more familiar with the throttle on the left.

- Channel 2 on the receiver is assigned to the ESC for motor control. Believe it or not, I'm actually using a TEU-104BK in this case. Tamiya USA's web page for the CR-01 strongly suggests not using a TEU-104BK ESC, but I'm thinking I can get away with it for a few reasons -- 1) I'm running a higher turn motor, 2) I will be running on flatter ground and not doing extreme crawling, and 3) I will be swapping out the kit 20T pinion for a 15T steel pinion in the near future to run the model even more slowly and with lighter motor load. I wanted to use the TEU-104BK because it does not include a BEC. Normally that would be a bad thing for some receivers and maybe some servos, but in this case I wanted to run an external BEC to handle all the load the steering servos and bed servo will throw at it. Most internal BECs are rated for 1A or 1.5A, and this is not enough for a pair of digital higher torque servos. On the radio channel 2 is assigned to the throttle; this is the up-down axis of the left stick.

- Channel 3 on the receiver is assigned to the rear steering servo. Again I had a similar servo for testing. Channel 3 is assigned to the rudder on the radio, which is the left-right axis on the left stick.

- Channels 4, 5, and 6 are parking lights, headlights/driving lights, and bed light respectively. These are basic on/off channels that control Turnigy Receiver Controlled ON/OFF Switches. These are roughly $4-5 each, plug into receiver channels, and switch battery power to downstream loads. Each switch can handle up to 10A of current, which is way more than any of the lighting will draw from the main battery. For testing the radio channels I just used a servo to confirm signaling. In the photo I have the receiver controlled switches shown. Channel 4, parking lights, is assigned to the throttle cut 2-position switch. Channel 5, headlights/driving lights, is assigned to the elevon dual rate switch. Channel 6, bed light, is assigned to the aileron dual rate switch.

- Channel 7 is for bed tilt control. I want to use a servo with a linkage to make the rear bed tilt and also incorporate the same ball/pin features as the real vehicle so the bed can tilt in any of three different directions. Analog potentiometer #2, normally a helicopter hover throttle setting, is assigned to the servo that will push the bed upwards.

- Channel 8 is for winch control. 3Racing has a winch with controller available for about $20. The control board has a pushbutton on it that will cycle the winch between stopped and different rotation directions. Also, the control board has a receiver connection such that a 3-way switch can control the winch. On the radio I have the 3-position flight mode switch assigned to channel 8.

In tinkering and testing I found some open issues to address:

- Need a power distribution setup to get battery power to the ESC, winch, and receiver controller switches all at the same time. Most of the loads are pretty light, so smaller connectors would be nice to save space.

- Need a better BEC. The Integy 5V/3A UBEC fed by the TEU-104BK drops out when cycling the steering servos back and forth rapidly. There seem to be some transients that overload the BEC and then cause the receiver to drop out. A glitch buster cap didn't help. I'm thinking of trying a 5A BEC instead.

- Excess wiring could be a pain to hide. I normally don't like to cut wiring short as I might move the electronics somewhere else in the future, but I also need space in the rear mechanism deck for the receiver, ESC, and bed tilt servo.

I get the sense a lot of these challenges (cab, bed, and electronics) will all have to be worked simultaneously so that compromises in packaging and mechanical design can be made. It wouldn't be any good to have the perfect cab or rear bed, and find it impossible to package the electronics cleanly. Or, installing all the electronics now might limit what can be done mechanically on the body and bed...

More to come...

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Any updates?

I've just read the whole thread and now I'm left hanging!

I'd also be interested to know if it is actually possible to "economically"* build a CR01 *without* purchasing a kit - it would seem possible based on what you've done - very few stock parts used, and even those you have they are either very cheap (plastic bumpers) or possible to get aftermarket as well (ball ends etc)

* when I say economical, I mean the cost of the kit parts you need to buy separate is less than a kit!

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Any updates?

I've just read the whole thread and now I'm left hanging!

I'd also be interested to know if it is actually possible to "economically"* build a CR01 *without* purchasing a kit - it would seem possible based on what you've done - very few stock parts used, and even those you have they are either very cheap (plastic bumpers) or possible to get aftermarket as well (ball ends etc)

* when I say economical, I mean the cost of the kit parts you need to buy separate is less than a kit!

Man, I'm really sorry to leave you (and probably a few others) hanging with this build. I've been busy adjusting to a new job role, taking my daughter to visit potential universities, and taking my son to the local blacksmith club so he can enjoy his own hobby.

With respect to this chassis it's sitting on the shelf at the moment. I sometimes think about whether it would be easier to cut the lexan shell and fill in the back wall with styrene (hard to get a good match in the corners), or just fabricate an entirely new shell out of styrene from scratch (time consuming). The rear bed will be scratch-built for sure. I still have high hopes for the electronics, body, and interior on this model -- it's just not convenient right now.

I'm hoping for some time this winter to really dig in. Thanks for asking!

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I'd also be interested to know if it is actually possible to "economically"* build a CR01 *without* purchasing a kit - it would seem possible based on what you've done - very few stock parts used, and even those you have they are either very cheap (plastic bumpers) or possible to get aftermarket as well (ball ends etc)

* when I say economical, I mean the cost of the kit parts you need to buy separate is less than a kit!

Simple answer is its not economical at all.

Whilst my build is nothing like as 'non kit' as Paul's, I still have quite a few bit left over parts (wheels, shocks, chassis sides, steering rods, propshafts, axles, hubs, servo beds etc).

You'd think that was a good start for a second (stock) chassis, but when you look at the cost of axle cases, electronics tray, and all the small parts it soon adds up - the tubes that go through the upper links for instance will set you back ca AUS$35 for instance. You could forego the cantilever suspension which would save some money (and improve crawling performance).

I've bought a few 'unused' parts from bjorklos build left overs (chassis rails, link tubes, driveshafts) but I'm still looking at another GBP £100 worth of extra parts, after shopping around for the best deal (Seidel in Germany), to complete a second kit chassis. I only paid GBP £195 for a brand new kit (after shipping and duties), with motor, and body/decals included. By the time I buy another body I'm going to be back at the cost of a new kit - not out of pocket, no, but I've only bought 80% of a kit as parts. If I'd bought it all as parts it'd be at least GBP £300 (metal parts bag A is £70 even from jr-rc an another exanple!) after sourcing from the cheapest suppliers.

Is it worth me building the second chassis ? - probably not, even as a freshly built chassis its sale value is only £150 ?

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Sorry, I think I confused you.

I meant build one as much as you could from hop up or aftermarket parts.

And then the parts not available as hop up/3rd party, if you bought them new from tamiya would they amount to more than a kit.

I built a TA06 (over time) where the only things i used from the kit were camber and steering links, belts, bearings, shocks, suspension shafts and gears in the gearbox. Borderline costs of these vs kit.

It looks like speedy has used about $50 - $100 worth (at replacement) of a $150 kit.... :D

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Sorry, I think I confused you.

I meant build one as much as you could from hop up or aftermarket parts.

And then the parts not available as hop up/3rd party, if you bought them new from tamiya would they amount to more than a kit.

It looks like speedy has used about $50 - $100 worth (at replacement) of a $150 kit.... :D

If you went all out on improved parts then yes you wouldn't need much from the kit at all - $50-100 worth if you went with alternative wheels/tyres but kit body . You would then be spending $700 on hop ups/aftermarket parts.

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It would be an interesting project to do. Start with no kit and finish with a car!

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An update one year later...

I never made the time to pursue all the ambitions I had for the body shell, but I grew tired of the chassis sitting bare on the shelf. Finally I just used the kit shell and sprayed it anodized aluminum silver to go along with the bling of the chassis. I don't plan to add much more to this thread, so here's a picture to close it out...

IMG_1966.JPG

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Great build speedy. Where did you get this alloy beadlock wheels from? They look amazing, as does the rest of the build.

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Great build, thread and pics. Really informative. I quite fancied a CR01 but now you've put me right off, seeing what is available for it, I know I'd be broke all over lol!!

Good job, love the sheer amount of metal components you've used, nearly as much as a Bruiser!

Enjoy!

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Great build, thread and pics. Really informative. I quite fancied a CR01 but now you've put me right off, seeing what is available for it, I know I'd be broke all over lol!!

Good job, love the sheer amount of metal components you've used, nearly as much as a Bruiser!

Enjoy!

Yes I think it's an amazing build but probably expensive too. I found the wheels and just those alone were $139 which is nearly £90. I was going to get some for my project. I might just put the wallet back for the moment.

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The wheels are from Gearhead RC (http://www.gearheadrc.com/22wheels.htm), and I bought them from RPP Hobby (http://www.rpphobby.com/Default.asp).

I'm not sure what to say about expense. Emotion more than logic dictated how it played out. I think the stock kit is very good on its own with the exception of the center gearbox prop shafts (they're plastic) and the cantilevered dampers (need the zip tie mod or some center links like I did). Other than those two items, I'd build another in a heartbeat in stock form and drive it all over with no guilt. You can add lead weight to the plastic wheels, cut the stock tire foams in a star pattern, fabricate some simple skid plates, make extended links, etc. There are many homebrew mods to be done for very little or no money -- there's no need to spend a lot on this model.

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Glad to see you found some time to finish off the build Paul. Plenty of time in the future to mod and detail this or another body to meet your original expectations.

As you say there is no real need to add loads of extras and hop ups but it's so very tempting. I wasn't quite as extreme as yourself with my first build but I enjoyed it immensely and had enough kit parts left over to build another chassis; poor unimog body has been waiting for paint for 10 months so your update may well inspire me to get my butt in gear !

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Percymon, where have you been? It's like a small reunion today with beefmuffin in the Monster Beetle thread and now you in this thread... :D

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Percymon, where have you been? It's like a small reunion today with beefmuffin in the Monster Beetle thread and now you in this thread... :D

Hey Paul

I still occasionally pop in for a browse but I still have this thread tagged fit notifications so it sparked my interest.

Not done much RC this year, too many unfinished projects burnt me out and family life took precedence. Have tinkered with a few projects to move them along but nothing significant. I have finally collected the two cars from my mates house though, I couldn't leave them in his cupboard any longer lol!

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The wheels are from Gearhead RC (http://www.gearheadrc.com/22wheels.htm), and I bought them from RPP Hobby (http://www.rpphobby.com/Default.asp).

I'm not sure what to say about expense. Emotion more than logic dictated how it played out.

Thanks for the link speedy. They're such a nice set of wheels.

Hope you didn't take offence when I said when I said it looks expensive. We do things for the love of doing them and you can see the care and attention you've put into the build. When I said about expense it was a warning to myself. I'm spending so much lately I could hear my wallet screaming, here we go again, another build! :lol:

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I've just stumbled on this build as I'm bidding on a CR-01 and wanted to know what they are all about - I'm now afraid to win the auction as the amount of awesomeness that can be achieved is frightening!

Hats off to you on the attention to detail an comittment on the build - has anything more been done since? It would be great to see the tipping cab and various workhorse attachments added to your Mog.

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Thanks for the compliments.  Nope, not much has happened since last year.  I installed some electronics and made it usable, then shot some pictures and created a showroom entry on the main site:  http://www.tamiyaclub.com/showroom_model.asp?cid=129479&sid=37537

I jumped into a F103GT Nismo build:  http://www.tamiyaclub.com/forum/index.php?/topic/77212-speedys-f103gt-nissan-gtr-lm-nismo-build-thread/

Then got into a GF01 Heavy Dump Truck build:  http://www.tamiyaclub.com/forum/index.php?/topic/79254-speedys-gf01-heavy-dump-truck-build-thread/

I lost a lot of momentum once summer arrived, and since then I've just been taking pictures and adding showroom entries on the main site:  http://www.tamiyaclub.com/showroom.asp?id=37537

I'm treading water right now and am not sure when I'll make any real progress on open projects...

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Erector_Set.jpg

looking for axle housings for the CR-01 and this pops up. Speed you have been holding out on me.

oh! my!! Bubbles and pixies, & unicorns are flying through my head:wub:😍

That is a prize for prizes.

Hide it,

i'm flying to N. Carolina HA!

i had to close my eyes when the trains scrolled up.

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