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  #1  
Old 10-12-2014, 02:55 AM
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Default Fumotec Komatsu 490 LC build

Got the kit end of June and took some pictures during the build.

This is my first functioning model, so basically a total noob at this. There are plenty of build threads on one of the German forums, so figured I will post this here.

For those who are really interested, you can download the .pdf of the manual at this link: http://www.fumotec.de/downloads/koma...tung-klein.pdf

The parts were sanded and painted by me using rattle cans, but no point showing that.

First a couple of pictures to give an impression of the size. All comparisons I have seen so far were with other excavators or trucks. Good if you know those models, but if you don't ... kind of pointless.

Bucket



Hydraulics



I started with the (for me) least intimidating part which was assembling the tracks using a piece of wood, drift pin and hammer. Assembled in lots of 10. There are 51 pieces to each track.



Turned out Frank had forgotten to include the 2 extra pieces to make up full tracks.



A quick email to Frank sorted it and he posted the missing pieces following business day (supposed to be 103 pieces of track so there is one spare)
Too bad I live in Malaysia so it took some time for the parts to arrive. No big deal, plenty of other stuff to keep me busy.

Next step ... the parts for the drive train -- manual, page 10 / step 1 (all parts come bagged and labeled per page)



Inserting the bearings. Was a tight fit.





Hard to see in the pictures, but first time around I had the shorter piece the wrong way round.





Getting to this state took way longer than I thought because I had to start all over again when I noticed I had the parts the wrong way round ...



As you can see, all parts very tightly machined and massive.

Took a break from the drive train and went on to page 8
Inserting the bushings in the lower rollers.



Again a very tight fit



Had to use a vise to get them in one by one



After that install them into the under carriage



Needed a bit of filing (due to paint mostly)



And to finish a good wack with the hammer and driftpin to seat the pins properly.



To be continued in next post

Cheers
Stephan
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  #2  
Old 10-12-2014, 03:14 AM
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Default Re: Fumotec Komatsu 490 LC build

Now back to page 10 for step 2









This assembled part then slides into the carrier. (page 11)





Of course, I got confused again and installed the right drive into the left carrier, so had to take it all apart again, turn motors around to get cables in the right place etc etc ... Live and learn.

Ended this session with installing the cover on the drive wheels. The little hex bolts are just glued in with UHU Endfest.



Since I had to take the drive bits apart again, noticed that the parts didn't really have a tight fit. A sharp 90° corner doesn't really fit 100% in a slight rounded one.



A bit of filing later ...



Perfect fit



And now properly installed.



Next up were the 4 upper rollers.



Those too needed sa bit of filing and sanding to fit properly as they are a very tight fit indeed.



Next up, page 12, the track tensioners.





Again some sanding required.



Plastic bushings installed with some force



install the 2 nuts on each bolt



I followed the drawing in the manual, but that didn't leave much room for tensioning ... so before I installed them and after some experimenting, they were more like this.

By now the missing pieces of track had arrived so I could finish the under carriage. In the red box you can see one of the pins used to assemble the track.



Before installing the tracks, I decided to install the bearings connecting upper and lower parts. Page 5 in the manual



Needed to file this little nub to be able to fit it in.



Top view:



Bottom view:



As you can see the machining is really tight. Had to put the metal holder in the sun (does get nice and hot here in the sub tropics) and the bearings in the freezer to be able to fit easily.



Installed (view underside)



Ready to install the tracks



ESC's of both drive motors squeezed in







To be continued when I find the time to size and upload the pictures.
Hope you have as much enjoyment out of looking at the pics as I got out of building it.

Cheers!

Stephan
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  #3  
Old 10-12-2014, 04:31 AM
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Default Re: Fumotec Komatsu 490 LC build

Next up is the slewing mechanism (Page 14)

Note: On this electrical motor one needs to solder the leads and the diodes to limit interference.





The axle is sitting too high.







Axle in correct position



Mechanism installed - tried installing the bushing for the excavator's arm. Bushing needs some adjustments as it is too wide.



While at it, installed the bushings for the hydraulic cylinders. Very tight they are. Ended up using 2 ice cream sticks and pressing the bushings in place by squeezing one in between them. (I knew there was a reason to keep those sticks around!)



Adjusted bushing for the excavator's arm



After being side tracked by this, installed the hydraulic pump

You will need a 10mm and 13mm wrench to install connectors to the pump.
The rubber dampers came installed on the pump. The spacers are installed with 6mm long M3 grubscrews half in the spacers and half in the rubber damper.



In position



Now we tackle the valve block (page 15)



All nipples installed with plenty of sealant. Note, there is an error in the manual, says to use one 4mm and one 6mm at the side of the pump, both should be 6mm. The right parts are with the kit however. (I substituted a 4mm for a 6mm in the picture above. - I had ordered some spares)



Trimmed the servo horns with scissors and filed the sharp bits smooth.



Installed and servo holder attached



Beautifully machined, so another picture.



Installing grubscrew to attach the spacers



And installed in position (already attached one of the oil lines because so close to the pump, easier this way)



Married top and bottom (had to remove the slewing mechanism)



Installed power/signal throughput to lower part (page 13)
It attaches with 2 screws and is held "floating" with 2 messing spacers.
It can be installed with the slewing mechanism in place but it is a bit of wiggling.





Yup ... had to do it all over again because I forgot the 3D printed cover ...

Power and signal through at the bottom and being connected to the ESCs.
To accommodate the 2 pos and 2 neg plugs, I soldered 2 female plugs to the wires and shrink wrapped them. Used 2mm plugs.



Put on blocks to test the electronics for the tracks and slewing.



very messy set up for testing ...





To be continued ...

Cheers
Stephan
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Old 10-12-2014, 05:06 AM
ddc333 ddc333 is offline
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Default Re: Fumotec Komatsu 490 LC build

Brilliant step by step look at how this goes together and the quality of what goes into building these models
Thanks for sharing
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  #5  
Old 10-12-2014, 08:41 AM
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Default Re: Fumotec Komatsu 490 LC build

Stephan,this is amazingly detailed posting. I'm sure its more detailed then original instructions.Thanks for taking the time to share with us your build.Can't wait to see it running.
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Old 10-12-2014, 10:33 AM
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Default Re: Fumotec Komatsu 490 LC build

Yes thanks for the detail. I appreciate being able to see how these models are engineered and some of the minor tweaks to make them as best as possible.
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Old 10-12-2014, 03:23 PM
liftmys10 liftmys10 is offline
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Default Re: Fumotec Komatsu 490 LC build

Thank you for taking time in posting step by step build. I always wondered what is involved in building it.
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Old 10-12-2014, 08:19 PM
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Default Re: Fumotec Komatsu 490 LC build

Quote:
Originally Posted by Rakthi View Post


Yup ... had to do it all over again because I forgot the 3D printed cover ...

Cheers
Stephan


I had a BOL (big ol laugh) at this knowing what a bytch it is to line up the bolts with the several series of different holes & the spacers in the bridge too, not an easy trick to accomplish with big fingers.

I'm about as far as you are now & will get back to building again shortly. I went with 5valves & that required some redrilling of the mounting plate to fit beside the pump, hopefully I can still fit a 4s lipo on the left... might have to do a little surgery on the cab.
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  #9  
Old 10-13-2014, 01:02 AM
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Default Re: Fumotec Komatsu 490 LC build

ddc333, kaptain Jack, Cooper and liftmys10, thanks for the compliments, glad you enjoy this thread!

Lil Giants, I understand the BOL! Although at the time expletives were all over the place. As for battery, I have a rather big 3S lipo that would never fit in the required space. Following the lead of some German owners I cut into the counter weight. Lots of room there and plenty of space now for the electronics.
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Old 10-13-2014, 02:00 AM
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Default Re: Fumotec Komatsu 490 LC build

Back to the build.

As you will have noticed there is the huge hole on the bottom where the ESC for the drive motors are installed. Taking my que from the German forum I decided to do a variation on making a cover for it.

Taped a piece of paper against the hole, scanned it in and cleaned it up in Illustrator. glued paper to a metal plate and cut the holes.





Now I only have to loosen the bolts a bit and will be able to take the plate out so I have easy access to the ESCs and wiring should I ever need it. Meanwhile no muck can get in.



That leaves the wires from the ESCs to the motors. A bit of fiddling with scissors and cardboard, transferring to 0.3 messing plate, some bending and double sided tape later that is sorted too. Better would have been to have drilled and threaded a hole and attach it with a small bolt. (The double sided tape only held for 1 week )





Before installing I inserted a piece of rubber in the slot to hold the cables in. The little red arrow points to one of the 3D printed covers of the drive system. I forgot to mention earlier that one needs to cut a couple of slots to accommodate the heads of the bolts holding the gears/motor to the carrier.





Now we get to the part that worried me the most ... the hydraulics ....

First install the messing tubing on the boom and upper arm. This covers a couple of pages in the manual.

I made a template for the upper arm so both would be in about the same position. I actually should have had them closer to the bucket ... I also cut the provided small screws in half. (this was suggested on the German forum because apparently they strip easily)





As you can see not much place between those tubes.



FYI, the parts are painted. Not enough yellow to be found on this island, only non-eye-hurting paints in large supply were Matt White and Honda Grey ... Also the painting was absolutely painful with long curing times and bad reactions between the primer and paint. Sadly enough no decent spray paint to be had here in Malaysia.

Actually did come out rather nice in the end (if I say so myself)

Next I ran a drill bit through the holes in the boom and upper arm. (need a 10mm, 8mm and 4mm)



Installed the quick release to the bottom of the upper arm. (had to slightly file out the provided openings in the 2 metal bits connecting arm to hydraulic piston)



Fit with the boom very thigh so some sanding of the hinge part required. (you can see a spot of yellow there from one of the failed painting attempts)

Connecting dipper to boom.



Boom to upper wagon



Installing the hydraulic tubing was easy peasy! Cut to size, stick on nipple and tighten the metal bit with needle nose pliers.



Trying on the unpainted bodywork for fit - the counter weight that is supposed to slide over the 2 metal bars in the back didn't quite fit. The openings need some filing - more about that later.







Too finish the installation of the hydraulic lines to the valves, needed to take of the servos. I messed up drilling holes in the oil tank - needs 3 10mm holes to fit the connectors. The middle one was not right. Ended up glueing all 3 connectors with UHU Endfest glue. You can see the oil tank sitting between bucket and carriage.



View from the other side. Hook up pressure regulator etc. To get the filters in the yellow tubing, the wife's hairdryer and a bit of silicone works wonders!



Ready for oil tank



Oil tank in, and hydraulics primed according to manual. It lives - and no leaks!
Operated the valves by hand for the priming.



After that, took it out in the garden for a bit of testing. Sadly enough our back garden in that area is mostly rocky and very hard soil ...





So all my fears of the hydraulics were for naught! Got all worried for nothing.

To be continued
Cheers
Stephan
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  #11  
Old 10-13-2014, 02:26 AM
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Default Re: Fumotec Komatsu 490 LC build

Now the modification of the counterweight.
Having seen this on a German forum, I figured I might try it too. Maybe not as professionally done, but it did work out.

Drilled a couple of holes to kind of mark out the area to be cut and loaded the Dremel with a plastic cutter.

You can also see the scratches in the primer from trying to fit it to the carriage. (the holes are not deep enough either so need drilling out)



Lots of room in there! I also bent a piece of metal to rest the battery on, and to tie the back to the front for strength.



Used Milliput for additional strength on top of the metal supports. Had made 2 extra pieces for metal for support, but they ended up not needed. (Yes looks hideous, but it works)



Slightly better looking when painted in primer



From here on it is finishing touches.

Painted in primer



Stickers applied



Windows and interior cabin installed. Towels in case of leaking oil (one never knows)





"Only" have to clean up the electronics and fine tune the settings on the RC



All the details like railings and mirrors are painted, but not installed because our cats are too interested in messing with them. Will do that once I have a storage box made.



Well that's where we are at as of today ... All in all a very satisfying model to build and just enough things to sort out to keep it interesting.

When I have time I'll see if I can get some action shots ... still have lots of training to do to get my coordination right and get the model to do what I want.

I better go looking for my soldering iron and shorten some of those wires.

Cheers!

Stephan
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Old 10-13-2014, 01:30 PM
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Default Re: Fumotec Komatsu 490 LC build

You not adding any ballast to the counterweight shell? A full bucket with the arm stretched out will the tip the model over, especially when swinging perpendicular to the tracks.
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  #13  
Old 10-13-2014, 07:00 PM
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Default Re: Fumotec Komatsu 490 LC build

I presumed the battery I have would be heavy enough. It just fits in the opening I cut and weighs in at about 400 grams. If that is not enough I can always source some lead to put in the bottom part of the counterweight at a later date.

The challenge at the moment is figuring out how to operate it smoothly .

Stephan
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Old 10-13-2014, 11:17 PM
liftmys10 liftmys10 is offline
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Default Re: Fumotec Komatsu 490 LC build

Cant wait to see some videos!
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Old 10-14-2014, 04:46 PM
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Default Re: Fumotec Komatsu 490 LC build

A very detailed and excellent build, thanks very much





I would change the layout of the hose here - having the t-piece like this and the gauge hanging of it might give you problems later on

Calum
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Old 10-14-2014, 07:54 PM
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Default Re: Fumotec Komatsu 490 LC build

Quote:
Originally Posted by liftmys10 View Post
Cant wait to see some videos!
I will see what I can do, living here on hill on an island in Malaysia with no landline, our internet is a slow 3G connection with limited bandwidth. So video not really an option at the moment. Maybe I can do it from the free WIFI in the airport.

Quote:
Originally Posted by calum_scania View Post
A very detailed and excellent build, thanks very much

I would change the layout of the hose here - having the t-piece like this and the gauge hanging of it might give you problems later on

Calum
Thanks for pointing that out! You are right, I cut the yellow hose at the bottom of the pressure regulator too short. Will replace it when I redo the electrics. The pressure gauge is on a quick disconnect, so normally not there. But that doesn't change the fact that I have to redo those connections. Going to be messy and oily ... have to wait till the wife is out.
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Old 10-15-2014, 11:28 PM
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Default Re: Fumotec Komatsu 490 LC build

Had some time this morning to test out the adjusted program on the RC.

On the way out, had to park it so I could open the door. Placed it at the first convenient spot and found out the foot print of the excavator is almost the exact same size as a flat of 24 cans!





Battery is a tight fit



Got the bucket full with gravel from the parking lot (also added some by hand as layer not deep enough), seems to be holding fine like this on a flat surface.



Cheers, Stephan
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Old 10-16-2014, 07:52 AM
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Default Re: Fumotec Komatsu 490 LC build

Very Nice pictures!! Looks to be a super fun build. Thanks for taking the time to post the pictures.

3G, that sucks.
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Old 10-16-2014, 12:06 PM
Azonic Azonic is offline
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Default Re: Fumotec Komatsu 490 LC build

Great pictures and overall thread!

Have fun with it!
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Old 06-09-2015, 10:57 AM
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Default Re: Fumotec Komatsu 490 LC build

After 8 months, time to check up on the 490 LC ... Been postponing sorting the electrics for too long. The thing worked without a hitch and you couldn't see the mess, so didn't feel the need ...

However when I checked under the hood a veritable mess was apparent. Bit embarrassing really.



Also noticed some chafing of the low pressure return lines.





First "fixed" the awkward fit of the pressure regulator and manometer hook up.
Didn't have to make an oily mess. Just repositioning and fixing it right took care of that.



Added an extra security to the T-connector with some wire to prevent it from moving sideways.



Tried to put the ESCs from the slewing mechanism and pump under the servos of the valves, but that didn't work out.



So just made a quick "box" to toss them in as a temporary solution.



Not really ideal at the moment, but had to sort something out.

Never even got around to shortening the wires. Will do that when I come up with a better tray for the ESCs and receiver. Receiver should be able to fit underneath. and then the antenna can go in a better place too.

Having the antenna sitting on the power connections and looping the + wire around the cable was not my brightest idea. Made for some funny interference.



The receiver and power connections are sitting on a ¼" thick piece of high density foam and some wood (don't ask - but it's teak ) for now until I come up with a better overal solution. Well at least it looks a bit better.

This will need a little more thought put in.

Hopefully this time it doesn't take another 8 months.

Stephan
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