90 ton 1/14 metal excavator scratch build w/embedded PC

[liftmys10]

Awesome job!! I love the fact that you provide a link to all these materials. That's a first that I've seen. Keep up the great work.
I used to have a 1/16 scale CAT 390D. So a 1/14 scale would do some serious digging. You can look mine up for ideas on here.

[RCTech9]

Looks like a great start.

[SteinHDan]

Thanks!

I bought the chain in a local shop, but I see that you can buy the same on Amazon by the meter:
- 1M 08B K1 attachments: http://amzn.to/1W71CaA


Stein :-)

[crusher]

Probably the best presentation of a build I have ever seen, also great work on the project, have you considered drawing up plans for your build and selling them? I for one would definitely be interested in purchase.
Terry

[SteinHDan]

Hi Crusher!

Thanks!

No, no plans to sell, but you can have it for free:
- http://d1t2tbzmskak12.cloudfront.net...e_4%20v122.f3d (5MB)

Just download the free Autodesk Fusion 360 and then upload this file into that program. Then you can export any part to STL (for 3D printing) or I've also added the CAM setup for CNC cuts of some of the parts. And you can export the parts to other formats.

See the Autodesk Fusion 360 tutorials on YouTube for more info on how to use the program.

Don't pay any attention to the parts above the undercarriage. They are just placeholders for now.


Stein :-)

[SteinHDan]

I wanted to create a very simple swing mechanism, but ended up with something not that simple. I tried various types of bearings, and I was very close to just stack 5 of these on top of each other, but it didn't roll very well:
- http://www.ebay.com/itm/262008651254
Also it would have had to be machined and the tolerance was very low.

So I ended up with two tapered bearings facing each other. It is very sturdy.

Here are the parts:



All of the milled parts are from 6mm aluminum. The slip ring is not the one I'm going to use, but the same size. There is also a slip ring mount printed in ABS (50% infill) that both hold the slip ring in position but also helps align everything before the different parts are bolted in place.

Ebay links:
- Slip ring that I will use: http://www.ebay.com/itm/141778017008
- Slip ring from picture: http://www.ebay.com/itm/371343809973
- Bearing: 30212 http://www.ebay.com/itm/160994544123

The bolts are countersunk M6 80mm and countersunk M4 50mm.
The M4 nuts are locking nuts.

First, the slip ring is mounted inside the slip ring mount:





It's important that the M6 bolts are countersunk, because they are rotating and the wires are not, and I don't want the bolt heads to catch or damage the wires when rotating.








The static part is made up of 6 rings. If I should do it again, I would make the two similar pieces above and below the bearing mount plate into just one piece each of 12mm aluminum instead of two pieces of 6mm aluminum.


















And then the previous assembly goes in from the bottom:




Underneath, the wires from the drive motor meet up with the slip ring wires:

[SteinHDan]

The swing drive consists of a drive motor, a milled bevel gear and a set screw:



The drive motor is a 12V 50RPM gear motor. The set screw is M4. I'm going to use one that is slightly longer in the final version (10mm long).

Ebay links:
- Motor: http://www.ebay.com/itm/321622024429

The gear is milled from a 12mm aluminum sheet, where 6mm is the gear and the other 6mm is the part where the set screw sits. The set screw hole was drilled with a 3.5 mm drill and the tapped to M4 thread.




I 3D printed a test plate to find the right fit for the gears before milling the real bottom plate of the excavator:

[SteinHDan]

Milling the main bevel gear:
- https://youtu.be/_9gfQj9GZf4

[crusher]

Thank you for your offer re plans, I have downloaded Autodesk Fusion 360, now have to figure out how to download your drawings, not very computer literate. The pictures of your turntable look great.
Terry

[SteinHDan]

Hi Crusher,

Just click on the link and then save to your computer. Then start fusion 360 and select Upload and select the file you downloaded.

To create a drawing from the design, you can do as in these tutorials:
- https://www.youtube.com/watch?v=d4SY7RaL3K4
- http://knowledge.autodesk.com/suppor...4E837-htm.html


Best regards,
Stein :-)

[crusher]

Thank you for your reply and help, I will give it another try. As I said earlier I am not good at using the computer so appreciate your help.
Terry

[Marquez81]

I consider the project whatyou doing, a spectacular job Stein !

I am monitoring the project these to show.

You will put the various phases of the project complete the excavator ?

Best regards!

[SteinHDan]

Hi Marquez81,


Thanks!

I'm not sure if I understood you correctly, but if you ask if I plan to do the same as this for the rest of the components of the excavator, then the answer is yes. (even if I'm in that phase of the project where it dawns on you just how much work that is left... ;-). Just got to make sure to have a little bit of progress every day, and it will get done eventually. )


Best regards,
Stein :-)

[SteinHDan]

I started work on the upper frame and base:



All the parts are milled from 6mm 6082 aluminum.

The base is 10 mm less wide on all sides than the finished base will be. I'm planning on 3D printing parts that will go down to the same depth as this base plate, to try to avoid having to paint so much.




The upper frame is put together with two middle parts perpendicular to each other and that slot into the sides. This gives the upper frame support in all directions. The sides bolt together with two 110 mm long M6 hex bolts (not shown in the pictures).












The uper frame then goes onto the base. It will be fixed in place with an 20 x 20 x 2 mm aluminum angle bar, 310 mm long (not shown in the pictures).

[SteinHDan]

Stepping back a few steps and mounting the new slip ring, adding PTFE protective tubing to the drive motor wires and mounting the angle bars that hold the upper structure in place.

The PTFE teflon tubing is this one:
- http://www.ebay.com/itm/111392849268

[SteinHDan]

Mounting the boom

I'm going to try to use electric gear motors first. If that doesn't work out, I'll make the excavator hydraulic instead.

I'm using some quite powerful gear motors for all of the joints.
Ebay link:
- http://www.ebay.com/itm/221515025957

These are 10 rpm 320 kg / cm stall torque motors. Two in parallel should produce 640 kg / cm.




The two motors mount to the upper structure with 8 M5 countersunk bolts.






The boom itself is constructed with two milled 6mm aluminum profiles. At the end, another gear motor is mounted with another 8 M5 countersunk bolts.

I bought the hubs on aliexpress:
- http://www.aliexpress.com/item/10mm-...922964248.html












I'm using gas springs where the hydraulic cylinders would normally go.
The gas springs functions in many interesting ways in this configuration:
- Equalize the weight of the arm, so that the gear motor only have to lift the payload
- Dampen sudden movements and protect the gear motor
- A sound that is similar to a hydraulic cylinder
- Visually resembles a hydraulic cylinder.




Item links:
- Gas springs: http://www.ebay.com/itm/181788326018
- Clevis: http://www.ebay.com/itm/161559757356
- Rod eyelet: http://www.ebay.com/itm/5mm-Female-T...-/181888111312

[SteinHDan]

The stick consists of these parts:
- Sides in 3mm aluminum
- Hubs in 12mm aluminum
- Gear motor (similar to the previous ones)



Again, the gear motor is mounted with 8 M5 countersunk bolts.






Mounting the stick onto the boom:

[SteinHDan]

The bucket linkage is milled from 12mm aluminum. The gear motor is driving the bucket through these links, so they need to be strong.

The pins are M8 x 80mm pins bought here:
- http://www.ebay.co.uk/itm/291511678072

[SteinHDan]

I've tried to construct a bucket without welding. It looks pretty ok and feels strong even if I've just printed it in ABS for now. I'll mill these parts in 10mm aluminum shortly. But I just had to print one to see how it fit. I think it's a little wide, so I believe I will make it a 5-teeth one instead of a 6-teeth one.

The construction uses a center slice that is tapped with M3 thread. All the other parts just have a 3.18mm hole in them.

10 M3 60mm long countersunk bolts are then inserted from each side, and bolt into the threaded center slice.

Bolts are added to odd-number holes on the one side and even-number holes on the other side.

The good thing about this approach, is that the width of the bucket can easily be changed. It would also be super simple to create a sifting bucket.

















Borrowing the cab from a Bruder CAT 320 1/14 to see how it will look with a cab on:

[Rakthi]

That will be one impressive machine once finished! Interesting/brilliant way of doing the bucket. Gives you the possibility to easily make various widths.

Personally, I do not think the bucket is too wide at all.