FEL WeedWacker

[J_J]

A motor spool will let the hyd motor free wheel when you shut off the hyd.

Detent allows one to turn the motor on and let it run with out holding the lever to on.

Motor spool and detent can be on the same spool.

Pb will allow full pressure to build downstream.

The hyd motor should have a relief whether it is on the valve or across the motor itself.

If your valve has multiple spool for different operations, the valve itself has a relief valve for all the spools. If you want a lower relief on the hyd motor, install it across the hyd motor.

You will need a gage to set it.

As far as hyd motor speed, there should be a happy medium in relation to the speed of the motor and the string length. You really are trying to achieve a string tip speed to do the job at hand, whether it is to cut just grass, or cut small saplings and heavy weeds, and not break often.

You might try different size string, round, square, or splined. Some just cut better than others. I have used string as large as .155 in diameter.

If the line is to heavy, or too long, it may wrap around the shaft, and you can usually hear the sound you want when the string is fully extended, and everything is cutting right.

 

[gtrippleb]

Dusting off this thread... I want to make this... Has there been a Mark II version?

I have the hydraulics and I can figure out the mounting to the tractor. I might need more help on attaching the string trimmer / blade. First off, would you be interested in making the part for me? :laughing: (let me know how much...) Or Do you have more details about "...made an adapter on my mini-lathe..." so I can see about maybe getting it done locally here.

Essentially what you will need is a piece that can mount to the shaft on the motor and the other end can accept a bolt as you will more than likely be using the bolt to tighten the trimmer head to the shaft. If you have a weed eater, you can look at how the string head is attached to the shaft.

Here are some pictures of what the RC folks use when using a weed eater motor in the airplanes. This is from http://wackerengines.com

 

[gtrippleb]

If you look at this picture, you can get an idea of what you need. I assume copndoc3 machined it so the end would fit in the hole on the blade. Looking at the PVC piece that holds the string, you can see this edge on the top of trimmer head.

Looking at this picture, this is the bottom piece that sandwhiches the blade. It has a hole in it that the bolt can go through to thread into the adaptor.

This picture shows the adapter mounted to the engine shaft. As you can see the adaptor slides over the shaft from the motor. The cotter pin holds them together.

 

[kubotakid USA]

I think if you install a gauge you will find that your only running 3-500 psi, at the most, my fence line mower will have two hydraulic weed whip motors running in oppisite directions, so the post is cleaned on both front and back as you pass it, Iam using a hydraulic drivin front mount deck,. the spring back motors are mounted in the right front corner of the deck, over laping the deck cutting width I designed this trim mower for my sister who opperates a 65 acre certified organic farm, She pastures sheep NO CHEMICALES are alllowed on certified organic farms, Or, ROUND UP is the best solution, she has nearly 2 miles of electric fence, and weeds are a problem with electric fences, I dont have any pics to share, but will post when I do. Eric

 

[copndoc3]

Dusting off this thread... I want to make this... Has there been a Mark II version?


Also, Is this the motor you used?
https://www.surpluscenter.com/item.asp?item=9-1365&catname=hydraulic

Love that price... looking forward to this project. :thumbsup:

Also, after using it a bit... is there anything you would change or modify? (have it stick out more or less?)

No "Mark II" version, Mark I seems to do the job quit satisfactorily.

Yes, that is the motor I used.

Perhaps the only thing I would change, would be to make some sort of quicker mounting system. It does take a little time to bolt everything up and hook up the juice hoses. Haven't had any issues with the nylon strings as long as you don't hit any metal, then they kind of break off and have to be replaced, but that was expected anyway. I just pre-cut a bunch of strings and threw them in the tractor tool box when I was using it. If one broke , I just replaced it and went on.

 

[teg]

Thanks for getting back with me... I'll be making my list for surplus center... bits and parts, placing an order soon.

 

[tglass]

No "Mark II" version, Mark I seems to do the job quit satisfactorily.

Yes, that is the motor I used.

Perhaps the only thing I would change, would be to make some sort of quicker mounting system. It does take a little time to bolt everything up and hook up the juice hoses. Haven't had any issues with the nylon strings as long as you don't hit any metal, then they kind of break off and have to be replaced, but that was expected anyway. I just pre-cut a bunch of strings and threw them in the tractor tool box when I was using it. If one broke , I just replaced it and went on.

Used this motor too, and after a little time the shaft broke, thought it might be to small in the first place, and a string or wire rope didn't work well for to long either. I expect to hit fence post and if mine will not hold up or reverse movement I've built it wrong. Finally started over and mounted a lawn mower engine on mine so I wouln't loose hyd. to the cutting motor or 3-pt. Still it is hyd. extendable to 30", spring loaded to flex around t-post, but still has alot of things to overcome for safety reasons and simply do not like to have a lawn mower engine doing the cutting when I have a full hyd. system capable of it.The idea of mounting it on the loader is great, alot more precision cutting from the seat.just don't quite understand the mounting and how I could make it extend sideways for bush trimming etc. around the house. This could also be used to trim hedges with the proper design. Keep working on it..like to hear more.

 

[tglass]

Anyone have a reply onto using a heavier motor to run the trimmer or using a mower blade?

 

[N8ghz]

This thread is interesting and I may also build one.

It is no surpirse that the motor shaft is not designed for this kind of loading.

If I were to build one, I'd think in this direction:

sort of a small-scale version of the hydraulic brush-hogs for mowing along country roads. They have a plate/block housing with I suppose, 2 tapered roller bearings to support the cutter shaft. The motor just spins it.

This small weed-eater thingy would not need giant bearings, but tapered-roller (outer auto front wheel type?) would be my choice and looked at.

For the shaft, I'd use a shaft coupler that the motor would plug into and modify it to run in the 2 bearings and the bearing hub.

I am thinking a complete front hub from a compact car that is not front drive would be a good start followed by a little lathe work.

 

[teg]

Thinking about using this motor...
https://www.surpluscenter.com/item.asp?item=9-6618-8&catname=hydraulic

Using a pulley mounted on the shaft... drilled to hold the string.