Goldberg's the name...Rube Goldberg...

[PHPaul]

I've been wanting a way to trim ditches and under trees.

Sicklebar and disc mowers are just stupid expensive and it doesn't make any sense to spend four or five grand on something you'll use for 2 hours twice a year, if that.

They sell a commercial version of a 3 point hitch mounted string trimmer for compact tractors, but it's $1000 plus shipping and taxes, again more than I wanted to spend.

Being a serious packrat, I had most of what I needed to make my own. I had the gearbox, the trimmer head, the PTO shaft and most of the steel. Plus, it's a major hobby of mine, making my own equipment whenever practical.

I've got about $200 or $250 in it with pulleys, bearings, belts, shafts and what extra steel I had to buy.

I'm pleased with how well the Mark I works. I do have a couple of modifications in mind tho. I originally designed it to work on my Pasquali but between the articulation and slop in the hitch, it was nearly impossible to put the string head where you wanted it and keep it there. Works MUCH better on the Cabota. Not to mention power steering, air conditioning and cup holders...

The Pasquali has a 750 RPM PTO and I sized the pulleys to provide ~3000 RPM at the string head based on that.

The Cabota has a 540 of course. Add to that the fact that I'm running 18" of string (36" doubled over on both attachment points) and I'm running into a little issue with the string folding back in the heavy stuff. I've re-ordered pulleys to speed the string head up and I think that'll take care of it. I can always take smaller bites and just creep along in low range too.

I also need to fashion some sort of guard over at least the final drive belt. Big stuff like goldenrod tends to get under the belt and flip it off occasionally. Plus OSHA of course...

 

[George2615]

Necessity is the mother of invention. Great job PHPaul.

 

[CobyRupert]

18" of string.

That thing must sing!

 

[hawkeye08]

Nice, Mark II should have tilt function

 

[Mendonsy]

I like it!!
Doesn't your Kubota have a 960 rpm rear PTO setting also?? Mine has both.
It seems like that thing should fling weeds everywhere, but I guess as long as you are hidden in the cab it wouldn't matter.

 

[PHPaul]

18" of string.

That thing must sing!

She does whistle a mite! :laughing:

 

[PHPaul]

Nice, Mark II should have tilt function

I spent a lot of time trying to noodle out a way to do that and couldn't come up with anything that fit my budget. If I could afford a pump and a hydraulic motor, it'd be pretty straight forward.

I suppose top 'n tilt on the hitch would work to a certain extent before I ran out of flex on the PTO shaft.

 

[PHPaul]

I like it!!
Doesn't your Kubota have a 960 rpm rear PTO setting also?? Mine has both.
It seems like that thing should fling weeds everywhere, but I guess as long as you are hidden in the cab it wouldn't matter.

Nope, 540 only on the rear. With the engine firewalled, close to 600, but that's it.

It does throw crap pretty hard, I may fashion a guard around the string head at some point. For now, it's easier to just wash the winders on the cab when I'm done...

 

[CincyFlyer]

I like it!!
Doesn't your Kubota have a 960 rpm rear PTO setting also?? Mine has both.
It seems like that thing should fling weeds everywhere, but I guess as long as you are hidden in the cab it wouldn't matter.

Actually, it appears to be a Cabela tractor (which may be a TYM, as are some Mahindra models). Definitely not a Kubota!

 

[teg]

Great job.... Can you post more photos up close?

 

[PHPaul]

Actually, it appears to be a Cabela tractor (which may be a TYM, as are some Mahindra models). Definitely not a Kubota!

Nope, Kubota B2650HSDC. I call it the "Cabota" because I have a weakness for puns. I had some custom decals made up, that's probably what you're seeing in the window on the bottom of the back of the cab.

 

[PHPaul]

Sure, what would you like to see?

I have some step-by-step pictures of the project here.

 

[BukitCase]

Paul, that's really slick - if you REALLY wanted a tilt function, this might work

1 - As long as both belts are, you might get away with having each belt doing a 90 degree twist -

2 - then, cut the frame about where the jack shaft is now, mount that shaft horizontally (pillow blocks), and make a PIVOT point for the outer half of the trimmer INLINE with the jack shaft (on two MORE pillow blocks), so pivoting would NOT change either belt length -

3 - once that's done, it shouldn't be too hard to add a couple of ears and a small hydraulic cylinder for tilt, run off your remote.

4 - Might wanna move that pivot point a little further outside the rear tire, especially if you have some "V" shaped ditches you don't wanna DRIVE in

Just a thought from ANOTHER "Mad Scientist" type ...Steve

 

[CincyFlyer]

Nope, Kubota B2650HSDC. I call it the "Cabota" because I have a weakness for puns. I had some custom decals made up, that's probably what you're seeing in the window on the bottom of the back of the cab.

Ya got me! I zoomed in and saw that I was had—and yet, this is the sort of thing that I do.

 

[the old grind]

Any version of what BukitCase described. :thumbsup: Suppose it can 'tilt' 30^ down OR up, if the pivots aren't exactly colinear with the jackshaft, being within an inch or two wouldn't make for much slack to be taken up by tensioners.

Adding bits would add cost, but MkII doesn't have to be a complete 'do-over'. I'm sure we're all thinking 'upgrade', right? Any other time, the fun of Rube-ing up gadgetry is bragging what you made something out of, and the less recognizeable the better.

Nice, what you have there already. :drink:

 

[PHPaul]

Never know what the future will bring. Winters tend to be long and boring around here...

Grind, I see you're from mid-Michigan. I grew up West of St. Johns, over by Fowler. Brothers in St. Johns and Shepard, headed back that way for a visit in a couple of weeks.

 

[s219]

Nice work!!! I plan to weld up something similar, only I will just stick an old lawnmower engine and mower blade out on the end.

 

[rd_macgregor]

I seem to recall seeing a commercial mower unit for use under fences that had a spring-loaded mower head that would swing back if it encountered an unmowable obstacle (like a fence post, tree etc). As long as the pivot point was right under the pulley, it wouldn't affect their length or operation during an encounter with an obstacle.

 

[coldsteelva]

Have you considered putting a saw-blade like brush cutting head on it? Instead of string.

 

[Msamt]

I seem to recall seeing a commercial mower unit for use under fences that had a spring-loaded mower head that would swing back if it encountered an unmowable obstacle (like a fence post, tree etc). As long as the pivot point was right under the pulley, it wouldn't affect their length or operation during an encounter with an obstacle.

DR has that for 3pt and ATV applications
3-Point Hitch Trimmer Mower: String Trimmer and Fence Mower | DR Power Equipment