Thank you, Martin, for these two parts. An aside: my wife was overhearing this video, hearing your voice for the first time. She exclaimed, "This guy's voice!...it's amazing. He sounds like a narrator for PBS specials...like Rick Steeves. Very soothing." There ya go! A purpose and result you didn't foresee!
I added a thumb to my bobcat B300 backhoe. Took 2 hydraulic cylinders before I figured out I needed a crossover relief valve as I bent the first cylinder when I rolled my bucket in to clamp on a log, and it collapsed the brand new thumb cylinder before i knew what happened. Minus the cylinders, crossover relief valve, and fittings, I built everything else from thumb to mounts and hoses. There were lots of trials and errors, but it was a total game changer and worth it! Great video
Yes, two other commenters mentioned the crossover relief valve so that will be featured in version 2.0 and is discussed in Part 3. Thanks for watching!
Hi Martin, I will say it is evident that you have put much thought in to your installation. One of my coworkers and me have a saying that is SO true. "FAIL TO PLAN....PLAN ON FAILING" Do you have engineering background? Your methodical and analytical process along with step by step explanations, makes me believe you may have a mechanical engineering background. Thanks for sharing...waiting on video#3.
Martin, I have the same tractor and backhoe as you do and I also have added a hydraulic thumb. A couple of things I discovered that you may want to seriously consider. First you should not put the thumb valve/conection after the backhoe hydraulics power beyond circuit because the backhoe valve bank uses the power beyond circuit to dump the pressure relief valves. Your thumb valve blocks this circuit every time you activate the valve. So if you are moving the thumb and moving any of the backhoe cylinders you are running the risk of damaging the backhoe load valve bank/cylinders. To solve this problem just put the thumb valve ahead of the backhoe valve bank. The backhoe valve bank should allways be the last in the power beyond circuit. This is stated in the Kubota backhoe service manual. Second you should also consider putting in a hydraulic pressure crossover relief valve to protect the thumb valve and cylinder. I ran some hydraulic pressure tests on the thumb circuit and due to the geometry of the bucket, the bucket curl can put excessive pressure on the thumb circuit exceeding the thumb cylinder, valve, and hose specifications for max pressure. I used the crossover relief valve from Bolt on Hooks which from testing works better than the one from Summit. Take Care hope this helps, Tom
Hi Tom! Thank you for this great information! You got it to me in time to replumb the hydraulics and correct the information I gave in Part 2 in Part 3 for the benefit of others as well. Also, since your the second person to mention a crossover relief valve, I’ll definitely look in to it. Thanks again for your timely advice!
Awesome project Martin...I am totally impressed with everything you've done so far !! ORB's are a great invention aren't they. People sometimes mistake the threads for tapered pipe threads and tighten them down way too tightly. Btw, looks like you're feeling pretty comfortable with the MIG. Waiting for part 3 my friend.
Thank you Wendell! It’s been a fun one and I’m almost done. I do know it works cuz I’ve already done a preliminary test, which you’ll see in Part 3 along with field tests which I haven’t done yet. Thanks for watching!
Martin, Harbor Freight has a set of 5 Allen wrenches in 3/8" drive sockets for $7.99. The set includes 5/32 in. , 3/16 in. , 7/32 in. , 1/4 in. , 5/16 in. , 3/8 in. That makes torquing the solenoid to block bolts easy.
Thank you for the videos, this is something I have been thinking about doing as well. The one modification I am considering is a dual crossover relief valve to put on the thumb cylinder so the two cylinders (thumb and bucket) can’t overpower each other.
You’re welcome! I think it’s well worth doing. My early testing suggest I won’t need a dual crossover relief valve as the cylinders are pretty closely matched and seem to have similar mechanical advantage. Thanks for watching!
Good Evening Sir, You Are An OUTSTANDINGH HYDRAULIC BLUE PRINT DESIGNER SIR 😇👍🧐👌I like very Much Your SUBLIMINALL MESSAGE SENCE OF HUMOR SIR ( WELL DONE🤣🤣🤣🤣) You are also and OUTSTANDING Hydraulic Surgeon 🧐👍👍Nice welding's ( yes protection the hydraulic cylinders for sure !!! ) 🙏🧐 Have a nice Week End Sir Cheers 🍻🍻
Neat add on Martin. I have the L3901 and backhoe also. The mechanical thumb is nice but I'm liking the idea of a shop project. I also have a 3rd function for my grapple. Is there any issues with adding another one for the thumb operation?
Hi Frank! I don’t think there would be because my backhoe works with the 3rd function added exactly like it did before I added it. Thanks for watching!
Great video! Thank you for sharing with us! Excellent design and workmanship! On a side note… if you only had a 12” bucket for your BH77… would you buy a 16” or 24”? lol! Asking for a friend 😄
Thanks! Glad you liked it! Tell your “friend” that if I just had a 12”, I’d probably get a 24” to be able to get more material per scoop. 😉 BTW, Part 3 is out, if you haven’t seen it yet.
Thank you, Martin, for these two parts. An aside: my wife was overhearing this video, hearing your voice for the first time. She exclaimed, "This guy's voice!...it's amazing. He sounds like a narrator for PBS specials...like Rick Steeves. Very soothing." There ya go! A purpose and result you didn't foresee!
You’re welcome! Part 3 should be out by next weekend if all goes well. Thanks for sharing your wife’s comment! I really appreciate it!
Looking good. This is more complicated than I first imagined it. Well done!
Hey Marty! Yes, it’s the most complicated tractor mod I’ve tackled but it’s been fun and most importantly it works! Thanks for stopping by!
I added a thumb to my bobcat B300 backhoe. Took 2 hydraulic cylinders before I figured out I needed a crossover relief valve as I bent the first cylinder when I rolled my bucket in to clamp on a log, and it collapsed the brand new thumb cylinder before i knew what happened. Minus the cylinders, crossover relief valve, and fittings, I built everything else from thumb to mounts and hoses. There were lots of trials and errors, but it was a total game changer and worth it! Great video
Yes, two other commenters mentioned the crossover relief valve so that will be featured in version 2.0 and is discussed in Part 3. Thanks for watching!
Hi Martin,
I will say it is evident that you have put much thought in to your installation.
One of my coworkers and me have a saying that is SO true. "FAIL TO PLAN....PLAN ON FAILING"
Do you have engineering background?
Your methodical and analytical process along with step by step explanations, makes me believe you may have a mechanical engineering background.
Thanks for sharing...waiting on video#3.
Thank you! Yes I do. I am an electrical engineer but spent most of my career in telecommunications and IT. Thanks for watching!
Martin, I have the same tractor and backhoe as you do and I also have added a hydraulic thumb. A couple of things I discovered that you may want to seriously consider. First you should not put the thumb valve/conection after the backhoe hydraulics power beyond circuit because the backhoe valve bank uses the power beyond circuit to dump the pressure relief valves. Your thumb valve blocks this circuit every time you activate the valve. So if you are moving the thumb and moving any of the backhoe cylinders you are running the risk of damaging the backhoe load valve bank/cylinders. To solve this problem just put the thumb valve ahead of the backhoe valve bank. The backhoe valve bank should allways be the last in the power beyond circuit. This is stated in the Kubota backhoe service manual.
Second you should also consider putting in a hydraulic pressure crossover relief valve to protect the thumb valve and cylinder. I ran some hydraulic pressure tests on the thumb circuit and due to the geometry of the bucket, the bucket curl can put excessive pressure on the thumb circuit exceeding the thumb cylinder, valve, and hose specifications for max pressure. I used the crossover relief valve from Bolt on Hooks which from testing works better than the one from Summit.
Take Care hope this helps,
Tom
Hi Tom! Thank you for this great information! You got it to me in time to replumb the hydraulics and correct the information I gave in Part 2 in Part 3 for the benefit of others as well. Also, since your the second person to mention a crossover relief valve, I’ll definitely look in to it. Thanks again for your timely advice!
Martin, you are doing a awesome job with the install and the videos on it. Looking for Pt. 3 Have a great weekend! See ya!
Thanks, John! Hope you have a great weekend too!
Awesome project Martin...I am totally impressed with everything you've done so far !! ORB's are a great invention aren't they. People sometimes mistake the threads for tapered pipe threads and tighten them down way too tightly. Btw, looks like you're feeling pretty comfortable with the MIG. Waiting for part 3 my friend.
Thank you Wendell! It’s been a fun one and I’m almost done. I do know it works cuz I’ve already done a preliminary test, which you’ll see in Part 3 along with field tests which I haven’t done yet. Thanks for watching!
Very professional install Martin!!!
Well done!👍🏻
Thanks, Gary!
Martin, Harbor Freight has a set of 5 Allen wrenches in 3/8" drive sockets for $7.99. The set includes 5/32 in. , 3/16 in. , 7/32 in. , 1/4 in. , 5/16 in. , 3/8 in. That makes torquing the solenoid to block bolts easy.
That’s great to know, JC! Thanks!
How's she goin'? This is a very professional install Martin. It's fun to watch. I think the thumb will be a game changer eh!! Take 'er easy!!
Thanks, Mike! It’s sure been fun to do even though it’s fairly complicated. Yes, it will definitely be a game changer! Thanks for the visit!
Great job Martin . You will enjoy using it after all your hard work doing it.
Thanks Sam!
Thank you for the videos, this is something I have been thinking about doing as well. The one modification I am considering is a dual crossover relief valve to put on the thumb cylinder so the two cylinders (thumb and bucket) can’t overpower each other.
You’re welcome! I think it’s well worth doing. My early testing suggest I won’t need a dual crossover relief valve as the cylinders are pretty closely matched and seem to have similar mechanical advantage. Thanks for watching!
As always a great video! They never noticed me about your videos. Stay safe and warm. Later
Thanks, Mech! You too!
Good Evening Sir, You Are An OUTSTANDINGH HYDRAULIC BLUE PRINT DESIGNER SIR 😇👍🧐👌I like very Much Your SUBLIMINALL MESSAGE SENCE OF HUMOR SIR ( WELL DONE🤣🤣🤣🤣) You are also and OUTSTANDING Hydraulic Surgeon 🧐👍👍Nice welding's ( yes protection the hydraulic cylinders for sure !!! ) 🙏🧐 Have a nice Week End Sir Cheers 🍻🍻
Bonsoir Dave! Merci, mon ami! Yes, it’s been awhile since I used the subliminal message bit. Thank you for the kind words of encouragement!
Good Morning Sir, I hope that you are doing very well ( coldest morning this year up here -18.4 f ) Keep Warm Cheers 😇😇👌👌👍👍🍻🍻
Hi Dave! I’m doing well. I’ll be releasing more videos soon so stay tuned! Cheers!
Good evening Martin.
Good evening Gary.
Neat add on Martin. I have the L3901 and backhoe also. The mechanical thumb is nice but I'm liking the idea of a shop project. I also have a 3rd function for my grapple. Is there any issues with adding another one for the thumb operation?
Hi Frank! I don’t think there would be because my backhoe works with the 3rd function added exactly like it did before I added it. Thanks for watching!
Great video! Thank you for sharing with us! Excellent design and workmanship! On a side note… if you only had a 12” bucket for your BH77… would you buy a 16” or 24”? lol! Asking for a friend 😄
Thanks! Glad you liked it! Tell your “friend” that if I just had a 12”, I’d probably get a 24” to be able to get more material per scoop. 😉 BTW, Part 3 is out, if you haven’t seen it yet.
@@DIYMyWay Haha! Thank you!! I will share your advice. 😄 I’ll be sure to check out part 3!