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Construction Equipment If it digs, pushes, hauls dirt "off road" post it here. |
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#61
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Re: CAT330D-L full hydraulic
The tubing is very pliable but you can also immerse it in hot water and then bend it and once it cools it will hold it's shape a lot better.
Erik79, When you say open center valve do you mean that when the valve is closed the fluid is allowed to circulate through the system so that the pump runs more efficiently?
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Youtube username iamaman27 |
#62
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Re: CAT330D-L full hydraulic
Thanks, I meant to say NOT kink, and I should have also indicated the copper and aluminum tubing. I did a lot of aluminum tubing when I built my RV6 but it was all quite a bit bigger diameter than the stuff on the excavator and I was not going for the tight radius that I see here, and even that was trouble in a few spots.
Jim |
#63
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Re: CAT330D-L full hydraulic
@avel, yes, exactly. In the video you can see when the valve is in the center position system pressure and current drain drastically decrease. In this condition the pump does not wear and produce the minimum of the heat, nevertheless the overall efficiency increase and so the autonomy become longer. In the center position with the MiMh 10 cells battery i have chosen the system can run hours and hours.
@rvjimd, the brass and copper tubes are not much simple to bend, but with some tools it's possible. I use some little metal wheels with the radial section of the same radius of the tube you have to bend. Next time i show you some photos. Enrico. |
#64
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Re: CAT330D-L full hydraulic
Hi everyone!
Recently i'm working to design and build the cabin of the model. Some pictures from CAD... See you... |
#65
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Re: CAT330D-L full hydraulic
This is a great project) I see the advantage of milling the undercarrige from one piece, as one save quite much hours compared to build it the traditional way with plates. Gets a bit more heavy to carry around, but the machine will sit more stable, so I guess it is mostly an advantage. Eletric motors for the tracks are quite more efficient than hydraulic ones, but I guess you like to experiment to see if it is possible to make hydraulic motors work on a model excavator) From an technical point of view, it is more interesting and challanging to install hydraulic motors, I agree to that Look forward to see the finished machine, keep on the good work)
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#66
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Re: CAT330D-L full hydraulic
Wow this is an amazing project, please keep the pictures and videos coming, keep up the great work.
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#67
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Re: CAT330D-L full hydraulic
Hi verybody!
@Rimrock: many thanks, i think you have perfectly understood my philosophy, agree with you on all the points. @Themonty73: thanks, i try my best to show you something new as soon as possible... Enrico |
#68
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Re: CAT330D-L full hydraulic
Hi guys,
Now i have to show you some parts of the cabin, still under construction... The console on the side of the seat, The armrests, And the joysticks, Pretty soon the seat and the bellows on the bottom. See you... |
#69
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Re: CAT330D-L full hydraulic
Hy all,
I send you the first short video of the hydraulic motor running and, for who has not noticed the previous link, the open center valve video. http://www.youtube.com/watch?v=8Bh3Zmr4MxM http://www.youtube.com/watch?v=6rOSZWjEAQ Bye... Enrico |
#70
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Re: CAT330D-L full hydraulic
well this is a buetifull build your skill and attention to detail is amazing keep up pics wow
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#71
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Re: CAT330D-L full hydraulic
Absolutely incredible. Any updates?
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#72
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Re: CAT330D-L full hydraulic
Many thanks to Jack Van and Snowman, hope to have some new things soon.
For now i am still developing the internal of the cabin... |
#73
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Re: CAT330D-L full hydraulic
Hi everyone,
Well, after a long long time away from the forums i'm here again... And i'm happy for that. Today i'm going to show you my recent project of a new hydraulic open center valve. I was searching for a valve with the best compromise between very low leakage, low actuation force needed, compactness, smoothness and the higher the possible lifespan. So i built it a small scalaeproduction for me and some friends, and the final product seems to me very good. I had in my mind something that could be fitted in a wide range of models, starting from the very small and up to models that weight 40-50Kg, so there was the needing for the valve to work well even with a quite high pressure. The result is a valve that can handle a pressure up to 50-60 Bar with the Hitec HS82, but until 30-40 Bar the Hitec HS 81 is enough. To get a near-zero leakage and a good reliability over time i chosen to build it in alloy steel, hardened and ground with extra tight tolerances. Here is a demo with 50 Bar of pressure but i tried with 60 Bar and it works very well too (but my actual brushless is not happy with that pressure and became quite hot). The proportionality and smoothness seems to be very good even at the higher pressure, and this is not an easy thing to achieve. These valves are already at work on a Cat 365 of a friend That weight 40Kg and has a pressure of 45 Bar. The model has done some months of various hard testing on natural compact soil and two days at the "ModelGame Bologna" in the past december: Sathurday and Sunday around seven hours a day with almost no stops and working hard with no issues. So i'm quite satisfied. http://youtu.be/OVUPcK1UuFo |
#74
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Re: CAT330D-L full hydraulic
Nice to see you're back posting progress, went through the thread again and it amazes me, hope to see more pics and videos!
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#75
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Re: CAT330D-L full hydraulic
Hi Enrico
Great to see you posting again cannot wait to see your progress on this amazing project. Thanks
__________________
Regards Mark Over the Pond in the UK Member of Ribble Valley Radio Controlled Truck Club my weather station To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts. |
#76
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Re: CAT330D-L full hydraulic
45 bar is still quite much for a 1/14 machine, the 365? The machine must slide often when trying to dig in to hard soil, with so much power? I try to stay at max 25-30 bar, to not have my machine move around too much, reduce the noise and heat, get longer battery life. But with open center it's less problems as the pump do not need to work at max pressure when valves in center, as with the standard closed center valves used.
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#77
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Re: CAT330D-L full hydraulic
Hi Rimrock,
remember that this model is loaded with weights in the undercarriage, it's 40Kg. There are a lot of working condition in wich the excavator has a very good grip on the tracks, for example when the tracks are partially stuck in mud or soft earth. In certain condition, trust in me, this model take full advantage of this pressure and in some cases i might push it to 50bar and is not too much. With 45bar the excavator dig quite well in constipated earth with stones and small roots. This CAT had the bore of cylinders of 15mm, so quite small, and the forearm plus the quick bucket change plus the bucket itself lead to a long negative lever to operate. So raising the pressure to 45bar and with my custom built forearm cylinder with 18mm of bore, it becamed well balanced. My open center valves help to save an estimated amount of energy between 10 to 25%. The leakage is near to zero and so the amount of electrical energy wasted in heat is very low. In this model, with an environmental temperature of 20celsius, the oil never overcome 40celsius neither after 8 hours of constant work. Moreover the open center bring the current drain at a very low level when the model is in standby. Another very important thing to do during the overall setup is the optimization of the radio mixing in order to get the best compromise between autonomy, power, speed of movements, etc. Finally, the battery lasts from 2.5 to 3 hours with lights, fan, cabin display and leds, double sound module; all switched on. To go over is very hard... Here is a video.... http://youtu.be/T-F4kJgpII8 |
#78
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Re: CAT330D-L full hydraulic
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#79
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Re: CAT330D-L full hydraulic
Is the full hydraulic CAT 330 complete? I just joined the forum and found this amazing build and when I saw it was from 2014 and the updates I was excited to see the final masterpiece! I did just watch a great video on thr hydraulic tracks that was super!! more more more
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#80
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Re: CAT330D-L full hydraulic
Hi trucker 1970, thank you!
I'm working at the same time on various project, one of them is the hydraulic motors for the 330, so i hope to have it run with three motors on tracks and rotation very soon. The problem is that I Always want to do little improvements on the motors and never be satisfied.... But little by little the performance of them became good. Waiting to show you something new in a short time... See you. |
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