KOMATSU KAC960E Dump Truck

[izzzul]

Hi guys, here i wanna share the build progress I've made. I did mentioned about it the another thread on my KOMATSU PC650 EXCAVATOR build that this will be my second build. Ideally I cannot copy similar 1:10 scale ratio as per my EXCAV, as it gonna be too big, thus, i scale it down to 1:20 scale, about 370mm in height, 780mm in length.

Here's the real one:


And mine just past few weeks after some scratch works and CAD..here's the blueprints:




Front axle..


Rear axle: using differential gears..customized



Additional spec will be: hyd lift bucket, custom-made tires..
(more pictures will be added in my blog: http://my-rc-page.blogspot.com/)

[Hemi1966]

Great looking CAD drawings , wish I could do draw like that too

[izzzul]

Blame the Olympic, etc, kindda busy with other stuffs, ramp up in PROD market (my real job in semicond)...

Now adding the workhorse/powerplant...it's a full hyd function, rotor motor
for the main drive and lift bucket...As seen in the CAD computer, yet to start fabrication, as to confirm real size and dimensions of the internal gadgets...(pumps, rotors, tanks, spool valves, servos, etc)

PS: kindda busy mastering the skill to operate my KOMATSU PC650 EXCAV, refer video here for latest 'skill' that I have...lol
http://www.youtube.com/watch?v=sPKtaNU2CpM
http://www.youtube.com/watch?v=1lTR0ilKT6M

[izzzul]

These are final CAD drawing, before sending to machine shops for metal cutting, then welding...assembling...should be fun..






Or refer here: http://my-rc-page.blogspot.com/

[D8R]

nice drawings, looking forward seeing it being built.
Question, why this little odd location on tipping cylinders? Looks like it will be hard to get the body up last part since cylinder is working almost straight with body.
Dan

[elliot330]

Originally Posted by D8R

nice drawings, looking forward seeing it being built.
Question, why this little odd location on tipping cylinders? Looks like it will be hard to get the body up last part since cylinder is working almost straight with body.
Dan

Yes, i thought the same. Looks very good, but aren't the cylinders normally vertical on these type of dumpers?

[Espeefan]

I never tire of viewing drawings like these. This looks like a very nice project. So if I read your post right, you're going to use a hydraulic motor to run the drivetrain?

Please add updates, as you get things built.

[izzzul]

Originally Posted by elliot330

Yes, i thought the same. Looks very good, but aren't the cylinders normally vertical on these type of dumpers?

Dan and Elliot,
You both have very sharp eyes, i thought i can run away with that.

The lift hyd cylinder shud be mounted vertically the main chassis, but i have
some small problem, i need to make space for two gigantic batteries as seen below..so i tried to mount the cylinder further to the rear end. On drawing, it should work, but of course i'll loose some lift power because of odd lifting angle. See pic below for the actual ones. I'll try to mod further during the assembly, plan to hide the cylinders better.

[izzzul]

Originally Posted by Espeefan

I never tire of viewing drawings like these. This looks like a very nice project. So if I read your post right, you're going to use a hydraulic motor to run the drivetrain?

Please add updates, as you get things built.

yes, i've found some hyd rotor for the drivetrain, now going to put this to test on this build, before i can convert my KOMATSU PC650 EXCAV to use similar hyd rotor for the tracks. The diff gears is custom-made, linked to planetary gearing.

Love to hear the hyd pump sounds + drivetrain, so realistic, unlike BL motors, i think. Wish me luck.

[Madda]

Redesign the lift cylinders for sure!

The lift angle is very-very bad. It pressurises other parts that shouldn't be involved in lifting + you lose so much lifting force. It seems that you have there some space


But I really like your CAD drawings and look forward to see that working!

[Supermario]

Originally Posted by Madda

Redesign the lift cylinders for sure!

The lift angle is very-very bad. It pressurises other parts that shouldn't be involved in lifting + you lose so much lifting force. It seems that you have there some space


But I really like your CAD drawings and look forward to see that working!

Mazda is correct, very bad lift angle.
This may sound crazy but how about mounting the cylinders on the back end of box and anchored to rear axle area? The cylinders would look like suspension cylinders.. Yes, that would be a 3rd class lever and not have as much lifting power but would be better than the horizontal position and cause less strain.
Some smaller CAT trucks have the hoist cylinders inside the frame rails, but if your going with Hyd drive, I doubt there's going to be any room in there either
Great looking pics, can't wait to see it come to life


Mario

[izzzul]

Originally Posted by Supermario

Mazda is correct, very bad lift angle.
This may sound crazy but how about mounting the cylinders on the back end of box and anchored to rear axle area? The cylinders would look like suspension cylinders.. Yes, that would be a 3rd class lever and not have as much lifting power but would be better than the horizontal position and cause less strain.
Some smaller CAT trucks have the hoist cylinders inside the frame rails, but if your going with Hyd drive, I doubt there's going to be any room in there either
Great looking pics, can't wait to see it come to life


Mario

Mario/Madda,
You're right, and that's the plan that i hv too, like mount it on side wall of the battery covers or somewhat. I cant touch the axle, because i make such it will have some travel play to coop with unflat-terrain..some kind of dampening motion or suspension function...plan to customize own cylinders, so it'll have big lift capacity...

I'll start cutting next week, hope to get good/quick progress here..

[speedy8305]

hey from looking at the design would you be able to move the battery box further outward and mount the cylinders in between the box and the frame?

[apfubar]

Originally Posted by speedy8305

hey from looking at the design would you be able to move the battery box further outward and mount the cylinders in between the box and the frame?

That sounds like a good idea! :-)

I would recommend sorting out the placement of the cylinders, before the placement of the batteries.

Cheers,
AP

[izzzul]

Originally Posted by speedy8305

hey from looking at the design would you be able to move the battery box further outward and mount the cylinders in between the box and the frame?

certainly great idea, will try to fit in my CAD drawing, that shud fit just nice I think, thx for the great ideas folks..

[Lil Giants]

I see from drawings that it looks like you're using a servo for steering?

The steering axle always seems way overloaded on these types of scale model trks that servos struggle to steer in soft ground. Would there be room for a third valve in your design for hyd steering?

[izzzul]

Originally Posted by Lil Giants

I see from drawings that it looks like you're using a servo for steering?

The steering axle always seems way overloaded on these types of scale model trks that servos struggle to steer in soft ground. Would there be room for a third valve in your design for hyd steering?

Last 2 week, i'd thinking the same thing, and my fren suggested to use 2 servos instead of 1 for the steering..certainly hyd steering will be the choice here, I think I can make some space for another valve and cylinder to steer this monster.

Thx Joe, another superb input, appreciate that!

[speedy8305]

looks like we all come up with some good ideas to help out a felow builder

[jack van]

where do you get the cad program and how much toi purchase ?

[jack van]

hi every 1 just got my membership approved hehe looking forward to this for years lol