MODIFY BRUSH HOG SOME MORE

[3RRL]

Well thank you Jake. LOL ... I know John expects a bit more from what he's seen in the past. I'll leave the electronics up to Larry of course.

I know this is not the most exciting project and probably not very useful since I only mow like 2 times a year right now. But when I move up there I will have a couple more meadows to mow than I do now. It will be a fun gadget to run.

The plasma cutting sure made this a lot better looking linkage than what I first had in mind. Thanks again Larry for giving me all that stuff. Using all scrap steel and slitting that stuff to make it useful is time consuming. But I've got nothing else to do anyway. I ended up busting 3 of those slitting saws, but got all of it done except the pieces that will be welded to the RC body. But all the stuff for this frame and linkage is cut now.

I finished making the spacers for the linkage. They are sets that will fit between all the shapes that were plasma cut.



I also cut and ground the hardened bushings, then welded the links together using the spacers. The spacers also provide rigidness against twisting. I welded them up with the pins and bushings in place and clamped up to keep them in line. They are like giant links for a giant chain. They are very solid now.

 

[3RRL]

This is part of the frame that will be welded to the rear of the RC. I got a 3" cylinder with a 1-1/2" diameter rod for extra strength.



I am not going to weld up the front of the cylinder mount until I bring it up to the property. I need to mount the frame onto the RC and then position the front cylinder mount to give me the wheel travel I want. I'll have to check it there to see, by moving the cylinder in and out. Then I'll weld that part last.

Here are the links all pinned together. I still have to cut off the hardened pins to length and drill them for grease fittings. If I remember right, they are case hardened so I can tap the holes after getting through the hardened surface. (I hope). There is also a close up of the linkage. I have not cleaned up my welds yet because I wanted to post some progress before leaving for camp.



I got an email from Discount hydraulics that they just now shipped my hydraulic fittings that I ordered 2 weeks ago. Swell... they have done that every time now that I've ordered from them, so I'm not too happy about that. Just as well though, since I won't have time to finish what I need to bring up anyway. I still have to do the above and also make the bushings for the second wheel. Then make a frame of some sort to attach the wheels to the front of this thing. I won't have enough time before we leave. But at least you can see where I'm at.

 

[john_bud]

... I know John expects a bit more from what he's seen in the past. I'll leave the electronics up to Larry of course.

I probably speak for many of us in the cyber tractor world when I say, The vision, talent, skills, teamwork exhibited by the dynamic duo of Rob and Larry are stunning. Only exceeded by your ability to share and explain what you did and how you did it.


Thanks~!

jb


P.S. - I was just kidding about the laser interferometry, radar feedback could also be used! Maybe for a follow up project, you two could invent an anti-gravity generator to save some $$ on wheels?

 

[Rowski]

This is part of the frame that will be welded to the rear of the RC. I got a 3" cylinder with a 1-1/2" diameter rod for extra strength.

How heavy is it?

 

[3RRL]

Rowski,
I haven't weighed these parts but your assumption is correct, there will be added weight to the hog. Remember I am eliminating the long triangular wheel mount and replacing it with this one, so there will be a net result. I'm guessing about 120 to 150 lbs. in steel linkage and body reinforcement. Closer to 200 lbs when you consider the new wheel. However, it will be distributed over 2 wheels instead of one when in use.

John,
Your comments always put a big grin on my face. They add another dimension to these projects. This is a fun project and it's great to see someone else get a kick out of it (besides me). LOL ... I see all those drugs you took years ago are finally starting to pay off.

 

[john_bud]

Rob,

Not drugs, It's from pounding my head against the wall until all my problems go away. Or I fall down unconscious, works either way, but as you have noted the after affects are becoming more predominate.

 

[schmism]

dam you never do anything light weight do ya!

i want to see mounted pics!

 

[3RRL]

LOL ... It's dragging along so it must be heavy?
I just got back from vacation and the fittings arrived. I think I can build the hard lines for the cylinder and DPOCV now. I should be able to get a little more done on it for the pins and wheel mounts, but my log home project is moving along and requires me to get some things lined up this week. I will post more pics later.

 

[Kendrick]

nice idea.

I like the drawings... some day I would like to learn how to design on a CAD type program.

There are plenty of programs out there. some free some not It depends on what you are trying to do. I know there is some free 3d animation programs but not sure how close to cad use they get. I havent had time to mess with much the last fiew years :/


Some nice work there guys. If i could only get to start using my tractor i might find some cool projects to compete with yourse

Per question earlier there IS a poormans way of auto leveling the unit it would not like being beaten though... but may still work. off the front end you have a 3' or so leader it pushes and pulls a valve which would raise and lower the front end. I doubt it would be horibaly practicle but it would work... 1 or 2 feelers set to end about where the rear tractor tires are and level with the deck a valve that would allow a gentle to emergency up and a slow down... you could rig it so that 2 feelers could work at the same time. If you put electronics in to it you could have front and rear mower cillinders controlled so that it raises the front of the deck and lowering the back slightly. once it figured the mower crested the hill it could start reversing it so it would follow the curve. some speed electronics would be required. just depends how much fun you want with it...

 

[patrick_g]

Per question earlier there IS a poormans way of auto leveling the unit it would not like being beaten though... but may still work. off the front end you have a 3' or so leader it pushes and pulls a valve which would raise and lower the front end. I doubt it would be horibaly practicle but it would work... 1 or 2 feelers set to end about where the rear tractor tires are and level with the deck a valve that would allow a gentle to emergency up and a slow down... you could rig it so that 2 feelers could work at the same time. If you put electronics in to it you could have front and rear mower cillinders controlled so that it raises the front of the deck and lowering the back slightly. once it figured the mower crested the hill it could start reversing it so it would follow the curve. some speed electronics would be required. just depends how much fun you want with it...

I have had considerable experience with several types of servo mechanisms. What is described might work acceptably if the tractor were driven extremely slowly.

There are problems with gain and feedback. If you increase gain to try to not get behind the changes of elevation then you can introduce overshoot or oscillation. If you increase negative feedback to avoid oscillation you slow the response and can't track sudden changes. The faster the tractor goes the more "phase error" you get.

Consider the typical auto or truck running on cruise control in an area of roller coaster type hills. The system overspeeds as it crests a hill to start down the next and then goes too slow up the steep part because it doesn't advance the throttle in time. The mower deck would do this but in elevation, cutting too close followed by cutting too high every time a couple elevation changes were encountered.

Driving the tractor very slowly would allow the servo mechanism time to adjust but it would severely slow the cutting job's progress. Properly located (purely mechanical) guide wheels on extensions front and rear on the mower would actually work better at faster speeds that a servo monster as described above.

With enough compute power and image processing software as is used in the trials where vehicles have to autonomously navigate across the desert, a system that "looks ahead" at what is coming next could anticipate changes in advance and start activating actuators in time to follow the changing shape of the land. This is technically feasible but not terribly economical as it could cost hundreds of thousands of dollars to adapt existing software to prototype hardware. It would be even more expensive than that to start a "clean sheet of paper" design.

I have the required credentials to manage the project team to design,develop, and test a prototype. Let me know when you want to start salary negotiations.

Pat

 

[john_bud]

I have the required credentials to manage the project team to design,develop, and test a prototype. Let me know when you want to start salary negotiations.

Pat

From my prior post

Was expecting a full independently reactive, electro-hydraulic, 4 point mounted, laser interferometry based system able to maintain an exact cutting height (+/- 1 micron) no matter what the tractor did, ran over or how fast it was traveling --> with bluetooth GPS feedback to a heads up display driver information system that displays a calculated optimum path for minimum deck disturbance with maximum mowing productivity.



You can use that to define your statement of work.....

Once you deliver a working prototype to all members of TBN, you will be able to stop by anywhere and be welcome for a cold beer and a tractor ride.

What more could you want?

jb

 

[patrick_g]

John, How about a rootbeer float? Don't want any alcohol if I am going to operate it.

Your requirements couldn't be satisfied with the cumulative to date since inception NASA budget. But I'm wiling to give it a try for significantly less, just a small fraction of the NASA budget if you could relax your requirements a bit in the micron tolerance and number of delivered prototypes areas.

It would be significantly cheaper to smooth all land currently owned by anyone ever posting on TBN to within a few inches per yard (or say 7-10 cm per meter for our Canadian and overseas friends.)

If the goal is to be able to have a brush hog closely follow the variations in terrain it is as valid to smooth the ground as to build a device to track uneven ground. In this case it would be more economical to smooth the ground better than the average putting green (on the PGA tour) than to try to meet your specs with a brush hog. You could spent several hundreds of thousands just trying to get the vibration within your stated tolerances much less dynamically follow the terrain.

"follow the terrain" That reminded me of the last thing to go through the mind of a pilot when his TAR (Terrain Avoidance Radar) system fails.

The answer is, "The tail of his aircraft!" Sorry, it must be the subconscious effects of writing this while wearing one of my old flight suits. No, I didn't get offered a flying boondoggle, I am wearing it to spray for scorpions as it has been tooooo long sine I last sprayed and we had one run across the bed room floor last night. Its time for CYPERMETHRIN MAN!!! (3-4 months coverage NOT 6-8!!!, oops)

Ohh, and by the way... it will still not fly no matter what the conveyor does so long as it stays well under relativistic velocities (less than 0.9C.)

Pat

 

[Rara Avis]

From my prior post

Was expecting a full independently reactive, electro-hydraulic, 4 point mounted, laser interferometry based system able to maintain an exact cutting height (+/- 1 micron) no matter what the tractor did, ran over or how fast it was traveling --> with bluetooth GPS feedback to a heads up display driver information system that displays a calculated optimum path for minimum deck disturbance with maximum mowing productivity.



You can use that to define your statement of work.....

Once you deliver a working prototype to all members of TBN, you will be able to stop by anywhere and be welcome for a cold beer and a tractor ride.

What more could you want?

jb

You will be able to pickup some old Tomahawk Cruise Missle Guidance Systems from military surplus which will do what you want...The only downside is the speed your Tractor will have to cover the mapped ground...about 880 kilometers/hour...

 

[3RRL]

Well it's been over a month since I've posted about this project.
It's not dead but had to take a back seat while I got all that log home stuff done. So I wanted to update you. I've been busy at home (real work) too. But I got back on the project and got a few more things and some little details done.

I got the rest of the leveling frame welded together and the hydraulic mounts too. I had to clamp it all together for welding and keep all the pivot mounts in line. Here is the set up, partially welded. I made the wheel bushing for the new (2nd) wheel and those brackets to mount to the trailing end. Here are a couple photos with both wheels in. The dual trailing wheels sit 34" apart.



I used the old wheel bearing and cut the frame to fit my new frame and then made the new side to match. I've still got a lot of weld grinding and cleaning to do before it's ready for primer and final coat of red paint. I will most likely put it all together up at camp.

 

[scott_vt]

Evenin Rob,
Oh tell me you arent clamping your good 1-2-3 blocks inside that weldment ! Ok just kidding, very nice so far ! This is going to have GPS right ?

 

[3RRL]

Hahaha you are nuts Scotty,
Those are my Chinese 1.001 x 2.002 x 3.003 blocks. LOL .. Yeah, I had to use them for something!

Here is some more updates.
Since I am using hardened leader pins and bushings for the pivots, I had to make sure they could be greased properly due to the close fit between them. I didn't want them to rust shut. With a little warpage from all that welding, they tightened up somewhat too. But that is a good thing considering the linkage is like a giant chain link and I really wanted it as tight as possible. I don't think the 2-1/2" diameter hydraulic cylinder will care how tight it is.

Surprisingly, making those pins and bushings turned out harder than I thought because they were 60RC on the outside and 38Rc on the inside. I had to cut the pins off using my surface grinder with an 8" abrasive wheel that is 1/32" (.032") thick. It sliced the 1-1/4" diameter hardened leader pins like butter. I made 4 pins out of 1-1/4" diameter and 4 out of 1" diameter. Next was to drill the grease hole from one end and then open up to 11/32" and run in a 1/8 pipe tap reamer to help against snapping a tap off in there. Then tap.



The next photos show that I had to grind 2 flats on the pins so the grease would flow end to end. Then had to drill side holes from each flat to the middle hole. I had to grind through the case hardened surface so I could use high speed drills to drill the inner steel which is only about 38RC hardness. Still hard to drill but I took my time and used cutting oil. I sharpened my drill bit with way more angle than the normal 118 degrees (like 140 degrees) and less relief. I drilled half the length for the main hole and then from each flat to connect the path.

So here they are with the Zerk fittings installed. I recessed them so they can't be broken off.
Cool huh?

 

[3RRL]

Finally, I got to grind the retainer ring slots on the ends. These pins will use circlip retainer rings to hold the pins in. I put on a 1/16" wide cut off wheel and plunged down the depth of the groove and rotated the pin in my whirly gig. Took it all in one pass. So here they are with the clips on. I decided not to lubricate the hydraulic cylinder pins. If you look closely, you can see grease coming out each side hole. and on this last photo, I pushed a bushing over the pin to show how the flat would work, distributing the grease over the length of the pin so the entire inner surface of the bushing gets coated when it rotates.



Still got to cut more of those 2" square tubes in half (length ways) to make the body more rigid on the rotary cutter itself, but I'll get to that later. That takes like forever to do one slit. I also need to assemble the DPOCV hard line to the hydraulic cylinder too. So there is still work left before I can get it to camp. Once I get up there and weld the supports and this wheel assembly onto the rotary cutter, I will have to scrounge for hydraulic hoses, fittings and QD's. And also make the brackets and install hose clamps for the lines.

I am keeping to my original plans of using as much spare/ scrap stuff I have lying around to keep this a super low budget mod. That's why all this extra machining and stuff.
Lot's of work left, but I can see the light at the end of the tunnel ... and it ain't no train.
So did you guys forget about my little project?

 

[Colin Giersberg]

This sure has been an interesting read. I try to follow your DIY projects, because they are so informative.

In regards to CAD programs, I have used Autosketch 2.0 (made by the creators of Autocad) for several years. I like it very much, but now that i have a new 'puter, I can't use it (bummer). It has probably 75% of Autocads many features, but I think that it may be easier to use than Autocad. I recently bought Vistacad by Punch. It is billed as easy to learn, but thus far, I am not very impressed with the program. Admittedly, I have barely even tried to learn it, but when my lines don't connect at the endpoints, something is wrong. Maybe I will change my mind about it, but I think it was just a waste of money ($89.99 + tax). I am seriously thinking of getting Autocad LT, but the $800.00 price is a bitter pill to swallow. I do have a newer version of Autosketch (release 8.0 I believe) but it just didn't work like the older version, and I don't know if it is compatible with Windows Vista.


Keep up the great work.
Regards, Colin

 

[LarryD]

So did you guys forget about my little project?

Who could forget the $6K mod to a $1.5K RC.
(It would be $8K with dealer markup in my area)

 

[MJPetersen]

Nope Rob, We did not forget. We were just patiently waiting for you to get all your honey-do's done so you could get on with the machining/fabrication lesson.

Mike