CAT 14M Motor Grader

[Ultrashort]

Complete crazy !

Well done !

[Car5858]

love this kind of build

[9W Monighan]

Beautiful work. Making the slots in the grill;was that very hard to keep the previous row from bending outward from chips building up?

[Hemi1966]

Originally Posted by 9W Monighan

Beautiful work. Making the slots in the grill;was that very hard to keep the previous row from bending outward from chips building up?

I was afraid that it might do that, but surprisingly the previous row did not get damaged. I did broke a few end mills when trying to take too much one one cut
Those grooves are only 1,5 mm wide.

Today I made the blade circle side plates

[Hemi1966]

Got something done today

[rc_farmer]

Ari, U continue to do an amazing job. Your metal working skills are off the chain!

[D8R]

Very nice work, hope to see the model in real when finished.
Dan

[Hemi1966]

Here is a couple of pictures of the blade rotation drive, and also a video of blade circle rotating

[tc1cat]

This model just gets better and better every time you update the build Wish there was a way to see it in person when completed

[9W Monighan]

Very nice work as expected from you. On the mounting holes for the blade; On my antique Cat graders they had a tapered hole in the arms and a tapered bushing on the mold board to take up any play and overall made it much stronger. Here are some photos from my restoration in the works of a grader:
Circle with some other pieces ready for primer. The design of the circle sure hasn't changed much since 1930. I am amazed at how well the angles are bent. Cat must have employed some of the finest blacksmiths in the day


Closeup of the arm end. See how they mount from one direction.


RUST! Detail of the cone on the moldboard. Not sure if I want to restore this or make new again

[Snochaser]

Your build and skill still continue to amaze me!!!! Great Job!

Ben

[JensR]

I had exactly that motor in my 1:14 grader circle rotation, connected to a 1:60 worm reduction and found it too weak. Swapped it for a Maxon motor I had lying around. This works well.
Not sure what your ratio is, probably a bit higher, so should have more oomph.

Just for giggles, here's mine

[modelman]

Hemi1966-this is a great model and your machine work is amazing! I have a question. Is this going to be a working model? If so, is the motor on the rotator circle strong enough to handle the digging forces of the blade or do you have a way to lock the rotating circle in position? Looking forward to more pictures.

[JensR]

The gearbox to which the gearmotor is attached is a worm drive, which cannot be back-driven, so the circle will stay in position.

For the full-scale machines a powerful circle rotation is a major selling point, ideally you want to be able to rotate it with a full blade.

I, too, wonder whether this motor will be strong enough, after my own negative experience as a circle drive, but Hemi has a higher reduction, as far as I can see, so while slower, it should have some grunt.

[modelman]

JensR-I know nothing about scrapers but have had some experience with gears. I see in your pic that you are using plastic gears and worm gears. I think that spells disaster. The plastic might last but worm gears are notorious for causing heat and friction. Heat and plastic gears are a bad combination in my mind. If you are not planning on working it hard it may live, but if you rotate a few times with a full load I think the plastic gears will be toast.Just my opinion!

[JensR]

It's a grader, not a scraper

Thanks for your concerns.
The speed is very slow, already before the worm drive, so heat is not an issue.
The white gear is high quality PA. Sadly, the red worm is relatively low grade plastic. As the transmission is currently pretty exposed, dirt can enter the area and that together with the rather high surface pressure between gear teeth and worm will damage the worm over time. So far it has held up very well, though and as it is much cheaper and much smaller than any alternative worm I could find, I'll simply replace it once it wears out. I am currently still in the prototyping and testing phase and will look into doing a shield to keep dirt out.
Without a lathe or mill, I had to simplify the design, but this is not an area I am worried about.

Anyway, as this is Hemi's thread, I'd suggest that if you want to discuss this further, we do that in the thread I opened about my grader. I posted my picture for Hemi to see what I was comparing and I am fully aware that Hemi's grader is in a totally different ball park. But as sizes are comparable between our machines, so should the necessary power and that's why I posted a shot of my low-tech solution.

Cheers
Jens

[Stuff]

wow its looking good!

[Hemi1966]

I managed to make the blade and the side shift rails.
Here is a few pictures of making it:

[Hemi1966]

And to relieve your doubts of the blade turn forces I made this video. In the video the aluminium block weighs 1,2 kilos
Also about the blade hold forces with worm gear are no problem, you cannot turn the blade by hands. As JensR also explains earlier.

[JensR]

I really like how you did the blade.

I had massive problems getting mine done. I tried to bend it into shape with a vice and wood blocks :-/
I thought about using a tube, but I am not sure I could cut it clean enough with my jigsaw Might have to build a guide for the saw? That could work...
What diameter does the tube for the blade have?
I thought something in the 100mm region would look fine, but yours seem a bit smaller? This would make it a bit cheaper...

How do you mount the blade to the rails?
I have the silly(?) problem that my screw heads are sticking out of the rounded blade surface. It seems you are mounting from the backside with tapped/threaded holes in the the blade. You'll then grind/file/cut the protruding screws to sit flush with the blade?
I've thought about doing something like that when I take apart, paint and reassemble my grader. Not sure I can do this well enough with my tools, willing to try, though =)

The outer black dots in your photo look as if they are screw heads, what are you going to do about that?

Also, your sliding mechanism seems to be aluminium on aluminium - have you thought about brass or teflon/PTFE glide shoes?

What gearing to you have on your circle rotation (excluding the motor gearbox itself)? It seems slower than my first variant, but more torque, so I'd guess around 1:120?
Your video is impressive - although we do not know the fiction coefficient of the metal/polished wood surface

Sorry for all these questions!

Cheers
Jens