My Mruder (bruder cat320 something look alike)
 

This will be a quick and disorganized run down since i have about 400 things on the honey do list for today alone.. hard to find me time lately.

This is a pooper scooper. Its job is to go in the reptile cage and turn over the soil. Not as hardcore as digging a basement ( i love that thread!), but it allows me to get away with building it less than milspec tough. Besides its all red clay out where i live; you aren't digging through that regardless.

At first i thought about simply converting the bruder cat but the thing is a joke and so I opted to make a lot of my own parts, just using the body canopy at the end. I thought about extending this as well to make it into a 40 or 60ton but I dont want another super long project to drag on. So it will stay as a 20 ton with a custom long reach arm, which is what i really need.

Initially i extended the lower arm on the stock cat, but it was still too small and the geometry was wrong as far as cyllinder and bucket control angles. So i machined one out of reinforced plastic stock. Drilled and tapped with 6mm sleeves and the shafts are 3mm hardened ss stock.

There are 2 of those holding the bucket itself, the epoxy is there to help keep it all centered as i mounted it and what not. most if not all of that will be cut away. The range of motion is phenomenal with the 172mm cylinder and the longer than scale bucket oscilting links.

To give you a size idea of mine vs the stock lower arm:

http://i.imgur.com/LJ1R0.jpg

The long arm is custom extended bruder one (3 extensions to get the proper geometry). I could cut that too out of plastic stock but i already invested a lot in the stock extension. Pics of that later when im done prettying it up. I still might cut one, depending on how much power i get out of the system - that solid plastic is heavy!

Quick test of the tracks section. This is weighted with lead (epoxy is a good bonding agent for that, again that will be machined away, prettied up and painted and hidden with top attached) and it weighs as it stands at close to 5lbs. I can make it 10lbs easy if i ballast it all. So there is room to play with that if COG is off down the road. Right now i left it as is since i have a few lbs in the top floor ballast. Also there will be a battery in the lower body for the turn table motor (it gets it's own battery yes - fewer wires to run between the 2 sections this way)

The servos are factory modified robotic servo motors producing over 100oz of torque each at 6v. This test is with an almost dead 4.8v pack and the throttle didn't go over 20% even here. Of course, friction on the floor was pretty slim so im quite i'll use all of the 200+oz down the road. If i really wanted to i could have made it a quad sprocket for over 400oz of power, but that's an overkill.. Could have also gone with direct motor drive (have them here) but i just WANTED to play with these awesome servo blocks. As you can see quite easy to mount and adjust height and position to get the perfect mesh with track and ground level. The tracks have also been extended a few links over stock. Width is the same; see comments above about making the body scale bigger.


I have the base plate, the turntable main floor - all that ready -1/8 and 1/4 t6 alum plate that was interesting cutting to shape. Waiting for some hardware to attach the bottom floor to the main beams. Then it's time to tinker with the hydraulics. I decided to stay brushed for now, using a cool new motor over the stock 540 can. It's shorter to boot.

The drive section will not be as scale as other's but this isn't a conversion per say. I will opt for function over realism any day when it comes to something like that. I will probably lose the H pattern the tracks section has but it's ok.


http://www.youtube.com/watch?v=0fB9vQ8YkWk

Re: My Mruder (bruder cat320 something look alike)
 

Cleaning the reptile cage..? That should make for an interesting video.. titled Cat vs Snake should get you some views! :D

Red clay.. would that put you in the midwest somewhere between southern Kansas & Texas?

Re: My Mruder (bruder cat320 something look alike)
 

further down, southern red clay. slippery as ice when wet, hard as a rock when dry. there is a bit in between where it is mallable but our seasons have been either dry or monsoon the past few years.

took the cab out and i'll use that to store the electrics. The stock cab had no detail so no point in preserving it. I'll cut some lexan and make windows but that's about it.

http://i.imgur.com/Znf44.jpg

http://i.imgur.com/hhrRN.jpg

drilled the holes and mounted the main components. I have plenty of space for batteries and what not now. My valves came with the straight fittings and i ordered none first time around of the 90d ones. So i just put in another order for the swivel ones tonight. The good news is i can run the system with the straight ones so i can at least test it before the new ones arrive. Filter is hooked to the valve which is the shortest and weirdest connection i had to make so far. No kinks in the line or any real strain points.

The filter should be connected to the pressure line, right? P on pump > top of filter, bottom of filter to P on valve block?

Servos are in the mail. Ill try the 3153 futaba digital and see if that will fit. The HS55 is too short on the horn area and too long on the mount holes (which can be fixed). Futaba is slightly different sized, by a mm or so.

Next up, the boom.

Re: My Mruder (bruder cat320 something look alike)
 

the s3153 digital is a direct fit in the control valve! the 4 way default horn takes 30 seconds to cut and grind to size.

no reason to not use it over the 4.8v limited analog version.

mounted the turntable to the tracks today. still need to lower the rear sprockets about 1mm down to the ground.

http://i.imgur.com/tlkRI.jpg

http://i.imgur.com/rhCfz.jpg

Re: My Mruder (bruder cat320 something look alike)
 

Correct, filter the oil before entering the valve block.

Re: My Mruder (bruder cat320 something look alike)
 

Decided to test the rc4 cyllinders today since they are very stiff so i had some doubts about what it will take to get them to move. With your instructions from the other thread servo setup on the valve took less than 10 seconds, including remounting the horn. Thanks! So easy to zero it in i was surprised actually. Response is amazing with the digital unit. Not sure if the video shows it but i can feather the stick for instant response all along the range. I have mixes off but can turn those back on after the pump is broken in to further modulate the speed and power depending on stick pos.

http://www.youtube.com/watch?v=5wHPCyrJkvg

12bar stock on this pump @ 29% power on the motor (can go all the way to 125% if i want to). Tried to hand grab the bucket and no dice. it kept moving so power is awesome from what i can see so far. Took it easy as the pump is still new but from what i can tell, no leaks on the leimbach gear.

Going to go test the other cyllinders now but i expect no leaks there either. If you can live with the 6mm mounting holes and the sizes they are in, they seem a great unit that you can get stateside. So far.


Back to working on the main boom now.

Re: My Mruder (bruder cat320 something look alike)
 

Your conversion is coming along nicely! I have a bruder excavator i plan on doing as well i just havnt decided hydrolic or not yet

Re: My Mruder (bruder cat320 something look alike)
 

great work, i will be following this build!

Re: My Mruder (bruder cat320 something look alike)
 

Lower boom after its first primer. Lots of little things left to smooth out. I should have just cut it out of solid stock. There is now enough metal (alum angles, u channels, threaded rods) in it to say that weight savings are nil.

The only weak point i can think of are the mounting ears for the short section. If those break though (can't see why unless i push it) i can make the whole part out of 1/4 stock. But for now i'll just carry on with the reinforced bruder ears, which i still need to trim out to get max travel. If they break i'll make a new part. If they dont, less work for me.

http://i.imgur.com/sFC2e.jpg

started working on the boom to chassis mounts. then i wore out my blades. waiting on the new one to get in, should be in tomorrow. i really have no tools to cut stainless. even aluminum destroys what i have in no time. hmmm.

also ordered a new esc to handle the voltage. the one i was using was only up to 8.6v and it didn't like the heat. good brushed escs are hard to come by it seems. but china to the rescue. got one up to 18v with built in cooling so i should be covered.

Re: My Mruder (bruder cat320 something look alike)
 

2x12 sabertooth from robot market place or a 2x25 those are good up to 24 volt lol

Re: My Mruder (bruder cat320 something look alike)
 

too expensive, laughable amps.

Sabertooth 50HV Dual Motor

is nice but for that price i can go so many better routes. robotic escs are really way behind hobby ones for some reason.

they are still stuck in the 80s

Re: My Mruder (bruder cat320 something look alike)
 

Began working on mounting the main boom (which will use another detail over before the paint goes on)

http://i.imgur.com/3ALkU.jpg

had to chop up the cyllinders a bit at the base and replace a few 13mm orings. 1 due to my fault, the other chipped from the factory and leaking. anyhow, i couldnt mount the boom today because I decided to go with 5mm shaft vs the original 6mm. the outer collar for the 6mm is way too thick requiring too much material removal for my taste (less material = less strenght). 5mm i can go down to 8mm OD or 10mm OD vs 13mm OD for the 6mm shaft which is used for the cyllinders themselves.

parts are on order for that part. as soon as i mount the base of the boom i'll be able to begin cutting and bracing the little "ears" to shape and make them all pretty along with any other metal pieces i need to pretty up. i wont leave them square :)

in other news, the body is getting extended. why, you'll see later. simple version: its too small. but i'll cheat! i'll extend the upper canopy and just add solid material to the base plastic on the outside.

so much for a quick and fast build eh. you know, you double the boom and go with 14mm bore hydraulics, and expect to keep the stock bruder. im such a noob..

in other other news... leimbach uses 4mm holes on the pump and filter, 3mm on the valve and reservoir.

my last batch of 90d connectors only fit half the joints. but at ~7euros for 1 of the 4mm ones, i might just ignore them.

Re: My Mruder (bruder cat320 something look alike)
 

it was a busy night.

as soon as i mount the lower boom and machine the mounts to shape i'll be able to drop down the guts and begin wiring it up.

http://i.imgur.com/Qzv6X.jpg

i love the hitachi orange. never cared for the puke cat yellow.........

Re: My Mruder (bruder cat320 something look alike)
 

Gosh!! that's quite a reach.. you using a block of lead for a counterweight?

Re: My Mruder (bruder cat320 something look alike)
 

:eek: 1st thing I thought was an old 6644 Koehring .

Re: My Mruder (bruder cat320 something look alike)
 

Probably out reach my Volvo! It will be more fun to play with having a longer reach though IMO.

Re: My Mruder (bruder cat320 something look alike)
 

Oh there is lead.. and more can be added if needed. I didnt go overboard since the tracks are well.. plastic. But i figure with the batteries (3 of those) et al in there it should be more than enough.

I googled that. the boom is eerily similar. Thing is i still have to fiddle with the body since the twin cyllinders can't fit in the space of the stock clearance width wise. I might just make a new smaller cab for it. 1/2 the cab = 2x the tonnage. :D Will deal with this when i get there. It just might turn into a koehring by the time im done with the styrene.

big booms are bigger fun and imo just looks better.

And speaking of booms, i got it mounted tonight.

http://i.imgur.com/KsfAT.jpg

i think it can go higher, not sure if this was the max position when i took the photo. i took the turntable pinion out so im using a tool to hold it from spinning :o

http://i.imgur.com/SpcAn.jpg

sideways balances just fine. empty deck.

i was copying the geometry of this thing: http://www.youtube.com/watch?v=Rchz0ob8sAk

hopefully the angles arent too crazy for the model version and the boom doesn't stall. if it does, well i'll just have to recut new ears and remount in another position. we will know soon enough

Re: My Mruder (bruder cat320 something look alike)
 

bolted the hyds in and tested the tracks and turntable. tracks have loads of power and turntable could use a slower motor (i was trying to calculate it but i overshot a bit). instead of 27rpm final its more like 40. it works fine as long as you dont go all the way on the stick, but like i said, just a matter of swapping the motor unit for a lower rpm one. overal im very happy


now, initially i planned on using 1 battery in the chassis to power the turntable and feed the rest of wires between the 2 halves. that would of course give me a limit to the numbers of turns you can make before wires get twisted.

tonight after some beers i had the stupid idea of trying 2 receivers to 1 radio at the same time. lucky for me (hitec is my deity now!), that actually worked (some dont).

so i have optima 9 upper deck, optima 6 lower deck. 0 cables between body and chassis. i can spin it round for hours :D

lower receiver is channels 1 (track1),2(track2) and 6(turntable esc) and upper is 3 4 5 (valve block) 7 (pump esc). perfect. still have 8, 9 on the upper as spares for whatever i might add.

no videos etc as it is 4am and i just got out of bed to test that theory.

Re: My Mruder (bruder cat320 something look alike)
 

trying to see the best way to get it all in there. i ended up with more space than i thought would be. ignore my sloppy dremel grind marks. that's what the hood is for.

ordered the styrene and will fiddle with the canopy. as if i needed another styrene project, but it has to be done.

http://i.imgur.com/Y0qmL.jpg

Re: My Mruder (bruder cat320 something look alike)
 

mounted and wired everything up today, began working on the underside skirt (just to make things pretty on the undercarriage).

i have 1 leaking cyllinder.. could be my fault since when i took them apart i might have nicked the oring in the process.. the one i didnt replace. so new orings in that size are in order.

the good news is the geometry is perfect on everything and no other leaks.

got one air lock up the main boom due to not bleeding it properly but took care of that.

video after i fix my leak

Re: My Mruder (bruder cat320 something look alike)
 

Re: My Mruder (bruder cat320 something look alike)
 

Quite a wide range of movement! What's the reach @ ground level?

Pump sounds slower than it should be.. what the rpm of the motor you substituted? Batteries full charge?

Now for the vid in the snake tank w/the snake. :D

Re: My Mruder (bruder cat320 something look alike)
 

I was getting lots of leaks on the 210mm piston. seals kept getting cut and what not. ended up beveling all edges to prevent that upon assembly.

rpm is low as this is my bleeding speed. i need to turn it up. how could you tell tho lol

i'll measure the reach once im done with the tracks section canopy. i don't want to get anything dirty yet because im using the kitchen counters as a table now. all my machinery is on that floor of the house and im not running up and down to my usual RC bunker.

the small arm was designed to level almost horizontally on the pull, but after testing by hand the pull force seemed excessive to get it to that position, so i cut the mount for that cyllinder a little forward, so the arm bends more than it levels. makes sense? otherwise the space is there. i might rework it down the road.

Re: My Mruder (bruder cat320 something look alike)
 

A white lithium grease works well for lube on o rings & sharp edges, and it then dissolves in oil well too.

I've been listening to the whine of that pump for over a decade now, I know how it should sound when running at optium speed. ;) :D I'm curious to see what your cyl cycle speed is like when you do tune the pump to 6000rpm (est)? I've been thinking for awhile of installing a Leimbach pump & valves into this HK hoe I have with the oem cyls.

No need to get your hoe dirty to measure the ground level reach... while on the kitchen floor, measure from the center point of the house pivot to the very tip of your bucket with the arm fully stretched out along the floor... my 850 is 1400mm, as an example.

I understand what you're saying, and yes it does take alot of hyd power to nearly level the stick, especially with a bucket full of dirt.. it's a negative leverage. ;)

Your custom Mruder is taking shape nicely in just over a month.. your early pics of hacking & wacking & gobbs of expoxy widen my eyes with much WTFism!!! :eek: :D Now I'm looking forward to seeing it in motion. :cool: ..especially with the snake in the same area. :D

Re: My Mruder (bruder cat320 something look alike)
 

I meant dirty as in digging video

The reach is ~2.5ft up, down, across. 1400 comes to 4.5ft. that's insane. i cannot counterbalance that long of a boom on this thing anyway. after i beef up the top side to a scale body, i will be maxing the undercarriage to its "looks small" limit. and i even stretched that 1" over stock as is. i considered making a totally custom bottom out of robotics tracks and what not, but that would push into another realm of expensive and labor intensive

http://i.imgur.com/qGAwnL8.jpg


66% rpm
http://www.youtube.com/watch?v=7qxv4-eXdoY


82%
http://www.youtube.com/watch?v=iV4BSQLdaGc

I am getting a lot of foaming in the tank and it sometimes overflows when the main boom is lowered all the way down, then when it's raised, it runs low on fluid as you can hear/see. That leaking piston isn't helping any either im sure.

http://i.imgur.com/FbPs4VX.jpg

I need a bigger fluid tank. Any way i can jerry rig one on top of the stock without screwing up the venting system? All bigger capacity pump/tank combos were special order so i didn't go for them.

Epoxy i know.. i have never done that before honestly. Not on such large scale anyway. I have 0 access to CNC, or cad skills to even produce a model for 3rd party machining. The 2 companies in the area that do custom cnc produced a look of utter disbelief so this was a no go. So it's hand tools only and unorthodox approches to everything on this build it seems

Re: My Mruder (bruder cat320 something look alike)
 

ordered another 210mm one. this one i couldn't rescue. i resealed it so many times with all sizes of orings but still not good enough. issue is there is only 1 oring @ shaft and that one is supposed to both seal the shaft and the casing where the shaft goes. if you try to oversize it, it won't fit. if you go smaller to seal shaft tighter, the casing area leaks.

their quality control is pretty bad. 1/4 bit the dust. thats 25% failure rate? i know i know sample size too small to claim that but we will see if replacement is good

Re: My Mruder (bruder cat320 something look alike)
 

Well fixed my leaks and in my attempts to get the reservoir to not overflow (its just too small ) in a fit of brilliance i decided to plug both vent holes. half a second later i blew the cap out and am still mopping up fluid. what a nightmare. pump side seals should be fine. the cap just flew out (its held in by an oring apparently).

anyway doesn't matter because i will have to extend the reservoir. im thinking pipe/spacer stock and some creativity with jbweld. we shall see.

the big leim pump is NLA. id much rather buy the 480ml one with the big tank but what can you. unless somebody can point me where it is available?

Re: My Mruder (bruder cat320 something look alike)
 

Looking pretty good!!!

Re: My Mruder (bruder cat320 something look alike)
 

What does NLA mean?

I'd just put an extention on the exsisting tank, pretty simple lathe job to make a sleeve joint, then epoxy in place.

Those large cyls you have, similar to my 850, the piston rod is quite thick, probably less than half the volume of oil on rod side vs piston side.. greatest reason why the boom drops like rock! I have the EPA set to 70% to go down & even then it's rather sensitive, especially with screener.

Re: My Mruder (bruder cat320 something look alike)
 

No Longer Available.

picked up the perfect 6061 pipe stock i can sleeve over; 1.37id vs 1.36 od for the stock leimbach. jbweld should seal it well. im not even going to attempt to weld that! im glad i live an hour away from a mcmaster warehouse. lifesaver i tell you.

i set programming mixes now. pump idle is at 30 and it goes up to 60 with a single valve use (faster results in no higher speed that i can visually note). then when 2 are activated it runs at close to 90. 3 pushes 100. this gives me enough flow to move all cyllinders at once for short times without killing the pump or pulling massive battery amps constantly. i will likely tweak these down the road. but my experiment was cut short last night as i mentioned

began extending the body as well. more on that later down the road when i have something complete to show. i'll make a whole new canopy and cab, scaling it to at least a 60ton machine. no particular brand on model. i'll also double my counterbalance.

the rod is something like 7.5mm D (odd number i know) at first i thought they were 6mm but that is not the case. 14mm inside diameter of the tube. i am using digital servos @6v so control is more precise than my frame skipping camera shows. although there is grat momentum on the downward swing. i can rock the whole model if i stop the boom suddenly.

Re: My Mruder (bruder cat320 something look alike)
 

Pump is done, even kept the clear plastic cap so you can see the level. Managed to actually bleed the system properly and get no more foam/air/bubbles/goo in there. Capacity is now a little over twice stock, around 2.1 times stock due to the larger bore of the extension.

If i had the space i would run 2 pumps. 1 for the main boom and the other for the bucket and arm, but no space means it isn't happening in that build. I am loving the big bore of the cyls so i am not downgrading those to more leimbach friendly sizes (i guess nothing over 10mm).

I am drawing a lot of power, eatin up 3400mah or so in a few minutes. I will eventually check power draw and see if i have to go to a higher turn motor. I know that without the fan this one overheats... Likely a torque issue. I was trying to go brushless speeds on a brushed but seems i've overdone it a bit. But ive decided to go nuts on battery at 12800mah main and 2800mah for the undercarriage. so ultimately it doesnt matter i suppose......

Started working on the cab.. Got the new counterweight extension and base area completed. I can now scale up the body into at least a 60ton and add a few more lbs of counterweight.

Re: My Mruder (bruder cat320 something look alike)
 

The Leimbach excavator cyls are 14mm, the speed seems slow some times too.

The current draw is about 2.1 amps with no cyl movement, 1.1 amps with cyls moving.

My Stahl track hoe, I had one 2700mAh running just the pump & another 2700mAh to run the rest of the model. The pump batt lasted about 40mins & the other was hours. That's with the Johnson that comes with the pump.

Re: My Mruder (bruder cat320 something look alike)
 

I was drawing something like 5 amps if i am to trust my meter.. After reducing the speed i consumed 1400MAH every 15 minutes on the same motor. But getting the speed up by another 15% tripled the draw.

Got my new torquemaster 45turn in today, haven't tested it yet since i have the thing apart but im hoping to do that tomorrow after i paint the undercarriage. Speaking of that

http://i.imgur.com/iynCvbm.jpg

Some early stages of the cab. It is not supposed to look like anything real in particular. I was experimenting with front windshield angles and this one i liked best.

http://i.imgur.com/E8OTCvv.jpg

Here you can see the new scale of the machine. The new counterweight will allow me to add about 8lbs of ballast on top of what i already have (im still deciding how high i want to make it, hence as you see it is not really closed up yet). Side to side i've extended 1/4" each way; total of 1/2" (any bigger will look funny on the carriage after i add the walking ramps) Front is about 1/2" and about the same in the rear. So total about 1" of lenght added. Dimmensions are almost identical to a liebher 944 now.

http://i.imgur.com/HsOukKr.jpg

The undercarriage... 2 3s lipos for the drive servos (~250oz torque @ 6v), a full size ESC with active brakes forward and reverse, a 6ch receiver, the turntable and the BEC all fit in there. Want to finish trimming it up and pulling out the switches and charge plugs tonight so i can paint it tomorrow. It goes down all sides, not just on top.

It cannot look any more scale and support the weight and have the unlimited rotation of the body.. I planned it more scale but decided function over form. It is a small model :\ I have the entire beam support system around the sprocket servos, vs gluing them to the side like everybody else does. It will carry a lot of weight which was the point. Stock bruder buckled so there went that idea.

Turntable and bearing are rated at something stupid like 200lbs distributed weight but with the hollow shaft call it 100lbs. Plenty! I do have a solid shaft too but what's the point. This one ain't bending

Re: My Mruder (bruder cat320 something look alike)
 

Its raining buckets so no painting can take place. Instead if took the boom apart and inspected the joints. No stress damage so it was time to address something that has bugged me.

recut the stick and made a whole new mount to allow for full range of motion in both directions.

Also loving the new motor. Much quieter.

http://i.imgur.com/hAx9LWE.jpg

Re: My Mruder (bruder cat320 something look alike)
 

http://www.youtube.com/watch?v=pje467gi0GE

full functions test a success. I walked it out there under its own power (no way to film and operate it at the same time, will have to tripod later).

And found another problem. The incline getting down on the deck from the inside ran the hydro dry despite it being 3/4 full. so now i have to rebleed (hence my limited use of the pump in the video). unfortunately there is no way around that with the leim system. and that's why folks vario has a 50 gallon reservoir in there, to avoid things like that among others. i remember people saying how big theirs was.. well now i personally know why. inclines are bad :i

but that asides, im happy. now i can finish up the bodywork and maybe add some details and i am done.

i am already thinking of my next excavator with a true scale underbody and lots more metal (and a better pump! and maybe valves if i could find any)

Re: My Mruder (bruder cat320 something look alike)
 

Forgot to mention, current weight is 20.08LBs. I expect to top at 25 with the extra ballast. Right on my target of 20-30lbs final weight. :)

Re: My Mruder (bruder cat320 something look alike)
 

Styrene work last night and some earth box testing. none of that you can see here.

Today it was time to give it a real test

Keep in mind my yard is packed gravel and clay; Not natural earth by any means.. years down i still can't even get grass to grow despite me dumping topsoil and what not on there. Anyway learned a few things today.

I was awkward on the controls because my fingers were freezing and im still a noob as is.

dont care about the tracks..but it made me laugh; yes i was trying to turn it.... yes they are too loose, no i never made a working tensioner. no im not making one now. yes i have spare tracks.

because

new SCALE all metal undercarriage will be coming soon! this one is mainly to just screw around with. its the top side im concerned about and it performed flawlessly. numerous hydro stalls and nothing broke!

yes i remated and rebalanced the motor/pump connection last night. was off center or something resulting in scary sounds. didnt know it was even possible to kink that but i guess it is!

http://www.youtube.com/watch?v=2s6qQYe5w6A

Re: My Mruder (bruder cat320 something look alike)
 

Some better shots of the cab..

http://i.imgur.com/xI375WK.jpg

http://i.imgur.com/dyOmWzE.jpg

http://i.imgur.com/yiI31Fp.jpg

Haven't decided if the door will be a slider or a hinge.

As well as other details like window guards (super tedious to make). Interior.. not sure. the floor will be separate and the cab will slide atop the floor piece. Once i put the glass in and see how much visibility is there i'll decide if i will go for the full interior..

It's officially no longer a bruder look alike.. And will use 0 bruder components when im done with the new carriage. I'll change/get the topic changed once it's done. More on that soon enough. Also other things are in the works, such as exchangeable booms. Not buckets, booms. I really want a double articulated one like you can get on the liebherr, just much bigger. STC makes them in real scale

Re: My Mruder (bruder cat320 something look alike)
 

http://i.imgur.com/ZUuZ7qW.jpg

prototype 1 of the track carriers has been sent for milling. no holes for idler and sprocket yet as i'll add these manually (or calculate them later and send for remilling).

2 plates for each track..

and have made my choice. cabin door will be a hinge.

Re: My Mruder (bruder cat320 something look alike)
 

The snowball effect has now begun! :D