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90 ton 1/14 metal excavator scratch build w/embedded PC
I've always wanted to build an excavator, and now the time has come!
The main goal of this project is to build an excavator that can dig normal dirt like you'd find in your own back yard. Some subgoals: - Minimize work - Try to make a simple design (input wanted! :-)) - Minimize cost - Realistic sound - Realistic operation (smooth movements, etc) I'm trying to minimize work and cost by using off-the-shelf standard components like ball bearings and sprockets. I also try to design the parts so that the CNC cuts are simple and quick, and the same thing for the 3D-printed parts. But even so, the project is probably going to turn out to be a massive amount of work anyway.. ;-) I've selected the CAT 390 as the model for the project, but I'm not trying to make a scale replica. Rather, I just want a functioning machine with a simple design, and that will in many cases not be similar to the original CAT. http://d1t2tbzmskak12.cloudfront.net...r/IMAG0001.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0002.jpg The 90 tom CAT is large enough to dig some serious dirt while still at the 1/14 scale that will match my other construction RCs. For the controls, I want to use an embedded PC for this project too. It gives complete control of the controls, the movements, the sound and also video streaming (for first-person views from the driver's seat). I've made two projects previously with this approach, and I felt it worked our well: - Bruder MAN truck: http://www.scale4x4rc.org/forums/showthread.php?t=80393 - Bruder CAT delta loader: http://www.rcsparks.com/forum/thread...dded-pc.36063/ Here is the design for the undercarriage: http://d1t2tbzmskak12.cloudfront.net...r/IMAG0010.jpg Stein :-) |
Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
The two side rails (is that the right name?) are made of a aluminum + ABS sandwich construction. The outer sides are 3mm 6082 aluminum, which is easy to machine. The ABS in the middle is 3D printed black ABS (Verbatim), printed at 50% infill (very strong).
http://d1t2tbzmskak12.cloudfront.net...r/IMAG0651.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0652.jpg The motor mount for the drive motor is milled from 6mm 6082 aluminum. http://d1t2tbzmskak12.cloudfront.net...r/IMAG0653.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0654.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0655.jpg The bottom rollers are industrial ball bearings with a U-groove: - SG20 U Groove 6x24x11mm Sealed Ball Track Guide Bearing The bolts are standard hex socket cap M6 bolts 40mm long. I'm going to use black bolts when the undercarriage has been painted. The washers are 1mm thick. I use two in the middle to get the right width. http://d1t2tbzmskak12.cloudfront.net...r/IMAG0656.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0657.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0658.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0659.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0660.jpg |
Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
looks good
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Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
Off to a great start, this looks like it will be nice , heavy duty. Keeps the pics coming!!
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Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
The main frame is made very strong, as this component is the one that prevents twisting in the undercarriage.
It consists of a roof and a floor in 6mm aluminium and the vertical parts in 12mm aluminum. I've not mounted the floor yet, as I want to have some room to build the swing mechanism. http://d1t2tbzmskak12.cloudfront.net...r/IMAG0675.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0676.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0677.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0679.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0680.jpg The main frame attaches to the side rails with eight M4 40mm bolts. I'll use black bolts when the undercarriage has been painted. http://d1t2tbzmskak12.cloudfront.net...r/IMAG0681.jpg |
Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
I was thinking a lot about if a track tensioner is needed. It adds quite a lot to the complexity of the undercarriage, and one of the goals was to keep it simple. But after some testing, I found that I think it's needed. With the large weight and powerful motor, something has to give when for example rocks comes between the drive sprocket and the track, and it keeps the track tensioned so that it doesn't detach so easily.
I ended up with this: http://d1t2tbzmskak12.cloudfront.net...r/IMAG0685.jpg In this picture: - A milled idler mount in 12mm aluminum - An idler sprocket with a ball bearing, 4SR16 (16teeth, 08B) - Two springs - Two very long M6 bolts where I cut off the heads - 16mm steel tube, 18mm long, inner diameter 12mm - 12mm steel tube, 18mm long, inner diameter 8mm - 8mm steel tube, 18mm long, inner diameter 6mm - M6 40mm bolt - M6 spacer 4mm long The track I'm using is an industry standard roller chain, but it doesn't have much room for an idler wheel. That's why I'm using an idler sprocket. It helps to avoid derailing the track. The chain type is British Standard 08B roller chain, similar to the ANSI #40 roller chain (1/2" pitch). The springs are quite strong to give enough tension to the tracks. Currently they push 15kg - 18kg outwards on each track, depending on their position in the milled slot. This seems to be fine. It can't be to low, as the track would loosen when driving into something. Ebay links: - Idler sprocket: http://www.ebay.com/itm/British-Stan...-/191502712638 - Springs: http://www.ebay.com/itm/191650948305 - Steel tubes: http://www.ebay.com/itm/111668876683 http://d1t2tbzmskak12.cloudfront.net...r/IMAG0686.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0689.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0717.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0718.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0720.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0721.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0722.jpg Temporarily holding back the tensioner with a strip while securing it with a bolt: http://d1t2tbzmskak12.cloudfront.net...r/IMAG0723.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0724.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0726.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0728.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0729.jpg |
Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
:jaw::jaw::jaw: Very nice Work.
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Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
The drive motor drives the drive sprocket directly. A 12mm steel tube (inner diameter 8mm) matches the inner diameter of the drive sprocket and also extends the gear motor axle somewhat.
http://d1t2tbzmskak12.cloudfront.net...IMAG0730_a.jpg The gear motor is a very common GW31ZY 12V 14RPM 30Kg/cm. The drive sprocket is an industry standard 08B 16 teeth sprocket. The plastic part is just a part I used for finding the correct distance when drilling the holes. On this drive sprocket it currently serves to hold the pin (a M4 bolt cut to size) in place. On the other sprocket I opted to place the hole inside the sprocket and thus no extra part is needed to keep it in place. Ebay links for the parts: - Drive sprocket: http://www.ebay.com/itm/321308379034 - Gearmotor: http://www.ebay.com/itm/291536954105 - Gearmotor alt.: http://www.ebay.com/itm/301680855441 http://d1t2tbzmskak12.cloudfront.net...IMAG0730_b.jpg http://d1t2tbzmskak12.cloudfront.net...IMAG0730_c.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0732.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0733.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0734.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0735.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0737.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0738.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0740.jpg |
Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
Like it. Great Job.
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Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
The top rollers are similar to the bottom rollers, but a bit smaller.
The type is SG15 U Groove 5x17x8mm Sealed Ball Track Guide Bearing. Ebay link: - http://www.ebay.com/itm/400561381584 The top rollers use an M5 40mm bolt and two M5 4mm spacers on each side to get the right width and position (I've not received the spacers yet, so I just used some washers in these pictures). http://d1t2tbzmskak12.cloudfront.net...r/IMAG0741.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0745.jpg The mount is a bit different than the original CAT 390 (and most other excavators). Normally, the top rollers are only mounted on the inside. I guess this is to avoid rubble being stuck under the roller as it slides down on the tilted suface of the rail. But for this build, keeping it simple, I've just mounted it on both sides like the bottom rollers. |
Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
The tracks are made of an industry-standard roller chain and track pads. The roller chain I'm using is a British Standard 08B 1/2" pitch chain, similar to the ANSI #40 chain. I'm using this chain as it is one of the more commonly used types, and thus the price is lower. It is a bit too big for this model. The 1/2" pitch means that every track pad is 25.4 mm long, and it should really be something more like 15mm long.
http://d1t2tbzmskak12.cloudfront.net...r/IMAG0746.jpg The "ears" are called attachments and there are various standard types. These ones are name "k1 attachments". There are wider versions that also can be used called "wk1". They have two mounting holes on each side. Search for "roller chain k1 attachments" on google to get more info. - https://www.google.no/search?q=rolle...=lnms&tbm=isch - https://www.google.no/search?q=rolle...=lnms&tbm=isch I originally planned to mill all the track pads in aluminum. But then I though I just make some temporary ones on the 3D printer, and they became very tough, so now I'm thinking that I'll keep the plastic ones until they break (or maybe they won't break). It is also a benefit to be able to drive inside without scratching the floors. http://d1t2tbzmskak12.cloudfront.net...r/IMAG0749.jpg The pads attach to the chain with two M4 bolts 10mm long. I chose a slotted head, as I think it will be easier to unscrew than philips or hex when the tracks get full of mud. On the other side I use two M4 locking nuts with nyloc locking mechanism. Ebay links: - Screw: http://www.ebay.co.uk/itm/261605587451 - Nut: http://www.ebay.com/itm/321386920963 http://d1t2tbzmskak12.cloudfront.net...r/IMAG0751.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0754.jpg I also overdid the width on purpose, but now I regret it a bit. I like the wide-tracks look, but I guess this is a bit too much. The real model in scale would be something like 60mm wide tracks. Mine are currently 70mm wide. http://d1t2tbzmskak12.cloudfront.net...r/IMAG0757.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0758.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0761.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0762.jpg |
Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
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Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
Doing an excellent job, for an excavator I think you will be fine with the track pads you printed. abs is pretty durable stuff and by the sounds of it you probably printed them solid. I think they will hold up for you very well. Keep up the good work, can't wait to see what else you come up with. And it's nice you are sharing where you sourced your parts. Always good to know places to get things. :)
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Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
A top notch build and an excellent documented progress report - pure eye candy!
As Cooper already said, the links where you got the parts are an added bonus! Looks like you put in a lot of time to figure it all out. :) |
Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
Outstanding work. Thanks so much for posting the links where you got some of the parts used in this build. It'll surely help us when we want to start our own project.
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Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
Very nice job, great ideas and parts used, the motors seems perfect for this application, strong and fits perfect!
Well done! |
Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
Nice start on this build. It's just my opinion but the problem I see is in the next to last picture. The large gaps between the track pads is why I do not like roller chain but I understand why you went this way. It works perfect and is readily available.
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Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
Yes, I also don't like the large gaps. I think on this model it has mostly got to do with the track pad length being too long (25.4mm VS the 18mm it should have been if it were to scale) caused by me using a 1/2" pitch roller chain. I think with a 3/8" pitch roller chain (and the 7mm overlap of the pads that I already have) it would be almost no gap. But even the original model has some gap, though, visible in the very first picture in this thread.
So maybe I'll change the chain to a 06B (3/8" pitch) or ANSI #35 at some point. That said, after having fastened 38 x 2 pads with 2 screws each = 152 screws by hand, I don't really miss having more pads per track ;-) Stein :-) |
Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
Looks great! Very precise. :cool: Hasn't printing in 3d changed this hobby? Imagine where we'll be in a few more years!
Keep up the good work and keep posting pic's :) |
Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
On our scale the gap in track pads can't be big enough. If they are very close 1.5mm < they will arch up because of dirt/sand particles getting in between them. Not as bad on a crawler track but a pusher track is worse (dozer)
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Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
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. |
Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
Looks like a great start.
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Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
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 :-) |
Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
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 |
Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
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 :-) |
Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
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: http://d1t2tbzmskak12.cloudfront.net...r/IMAG0771.jpg 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: http://d1t2tbzmskak12.cloudfront.net...r/IMAG0773.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0778.jpg 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. http://d1t2tbzmskak12.cloudfront.net...r/IMAG0779.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0780.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0782.jpg 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. http://d1t2tbzmskak12.cloudfront.net...r/IMAG0783.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0784.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0785.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0786.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0787.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0788.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0789.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0791.jpg And then the previous assembly goes in from the bottom: http://d1t2tbzmskak12.cloudfront.net...r/IMAG0793.jpg Underneath, the wires from the drive motor meet up with the slip ring wires: http://d1t2tbzmskak12.cloudfront.net...r/IMAG0795.jpg |
Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
The swing drive consists of a drive motor, a milled bevel gear and a set screw:
http://d1t2tbzmskak12.cloudfront.net...r/IMAG0798.jpg 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. http://d1t2tbzmskak12.cloudfront.net...r/IMAG0802.jpg I 3D printed a test plate to find the right fit for the gears before milling the real bottom plate of the excavator: http://d1t2tbzmskak12.cloudfront.net...r/IMAG0804.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0806.jpg |
Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
Milling the main bevel gear:
- https://youtu.be/_9gfQj9GZf4 |
Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
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 |
Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
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 :-) |
Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
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 |
Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
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! |
Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
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 :-) |
Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
I started work on the upper frame and base:
http://d1t2tbzmskak12.cloudfront.net...r/IMAG0808.jpg 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. http://d1t2tbzmskak12.cloudfront.net...r/IMAG0809.jpg 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). http://d1t2tbzmskak12.cloudfront.net...r/IMAG0816.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0817.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0818.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0820.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0821.jpg 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). http://d1t2tbzmskak12.cloudfront.net...r/IMAG0822.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0828.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0829.jpg |
Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
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 http://d1t2tbzmskak12.cloudfront.net...r/IMAG0842.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0844.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0848.jpg |
Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
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. http://d1t2tbzmskak12.cloudfront.net...r/IMAG0849.jpg The two motors mount to the upper structure with 8 M5 countersunk bolts. http://d1t2tbzmskak12.cloudfront.net...r/IMAG0850.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0852.jpg 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 http://d1t2tbzmskak12.cloudfront.net...r/IMAG0853.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0856.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0858.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0859.jpg 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. http://d1t2tbzmskak12.cloudfront.net...r/IMAG0861.jpg 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 http://d1t2tbzmskak12.cloudfront.net...r/IMAG0863.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0864.jpg |
Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
The stick consists of these parts:
- Sides in 3mm aluminum - Hubs in 12mm aluminum - Gear motor (similar to the previous ones) http://d1t2tbzmskak12.cloudfront.net...r/IMAG0867.jpg Again, the gear motor is mounted with 8 M5 countersunk bolts. http://d1t2tbzmskak12.cloudfront.net...r/IMAG0882.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0883.jpg Mounting the stick onto the boom: http://d1t2tbzmskak12.cloudfront.net...r/IMAG0885.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0886.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0887.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0889.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0890.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0891.jpg |
Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
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 http://d1t2tbzmskak12.cloudfront.net...IMAG0891_1.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0892.jpg |
Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
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. http://d1t2tbzmskak12.cloudfront.net...IMAG0893_1.jpg http://d1t2tbzmskak12.cloudfront.net...IMAG0893_3.jpg http://d1t2tbzmskak12.cloudfront.net...IMAG0893_5.jpg http://d1t2tbzmskak12.cloudfront.net...IMAG0893_6.jpg http://d1t2tbzmskak12.cloudfront.net...IMAG0893_7.jpg http://d1t2tbzmskak12.cloudfront.net...IMAG0893_8.jpg http://d1t2tbzmskak12.cloudfront.net...IMAG0893_9.jpg Borrowing the cab from a Bruder CAT 320 1/14 to see how it will look with a cab on: http://d1t2tbzmskak12.cloudfront.net...r/IMAG0894.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0899.jpg http://d1t2tbzmskak12.cloudfront.net...r/IMAG0901.jpg |
Re: 90 ton 1/14 metal excavator scratch build w/embedded PC
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. |
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