woodmaxx flail mower?

[leonz]

Hi Leonz, just find this from their manual. Woodmaxx claim it is NPTF thread for couplings.
View attachment 565958

It's better to use British Standard Pipe Parallel (BSPP) and an O ring to seal it.

In China here, we have to use tape or glue on the tapered thread, otherwise it will leak oil very easily. We don't trust the accuracy of the tapered thread surface here. I don't think NPTF is suggested to be used on hydraulic system. Can't believe they use NPTF these years. It seems US users are very kind to solve problem by themselves.

Does US machines often use teflon and pipe dope on tapered thread? Or is there already pipe dope on the tapered thread?

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Hello Mr. Yuan,


I am about ready to scream!~!!!!!!!!!!!!!!!!!!!!!!!!!
I looked at the picture you uploaded from woodmax and it certainly looks to me that who ever put those hoses together crimped the fitting over the hose protector sleeve. THAT is a definite NO NO as the hose fitting barb cannot completely crimp to the inner fitting barbs to provide an adequate and safe to use hose end.

The hose and fitting makers adhere to the JIC standards and they make all thier NPT fittings and hose ends using a schedule 80 steel blank from what I remember.


They do not use teflon tape they use a proper paste sealant ment for hydraulic system use.


If you can you should invest in some RIGID pipe dies and pipe taps to chase the threads on your hydraulic fittings and invest in a case of the Loctite 577 thread sealant for the the pipe thread hose fittings that you have to use.

The one excellent thing about buying a set of RIGID brand N.P.T. taps and dies is that you can chase the die over every male hydraulic fitting and run the tap through every female fitting to make sure they are properly threaded and the minute you start running the tap through the female fitting or running the die over any make hose end you will know immediately if you want to use that hose fitting or hydraulic fitting you intend to install in a cylinder as there will be no wobble when you pass over it with the female die or when you insert the male tap

Any bad hydraulic fitting that is installed in one of your mowers is one fitting that could break and leak and potentially injure or kill someone.

If you can locate a RIGID dealer in Tapei and order pipe taps and dies and a rigid pipe vise I would do it.


I hope all is well on your side of the Pacific pond. I agree with you that British Standard Pipe is much easier to use and much more adjustable(forgiving)to prevent hose and fitting failures. Ine has to make sure that they have the Blue Dot BSP orings in their tool box to replace an o-ring that has been under compression for a long time as they will become deformed over time due to the heat generated by the hydraulic system.

Its never, NEVER, NEVER a good idea to use teflon tape with hydraulic systems as the tape particles can cause damage to control valves and prevent adequate control of a hydraulic function allowing them to creep.

You never ever ever use teflon tape on JIC 37 degree fittings ever as they are designed and machined to seal completely with the mating male or female fitting mounted on a valve body or a hose connection.


I have no idea who they purchase their hydraulic fittings and hydraulic hose from but if they are using poor or substandard thread dies to thread the crimp on fittings at the manufacturer they are asking for trouble and lawsuits at woodmax if someone is injured from a hydraulic leak which results in penetrating wound that will eventually kill someone if they do not reach a hospital in time to have the wound opened up and the oil washed away before it enters the bloodstream.

 

[PatMcD]

I'm looking pretty hard at the FM-96H to replace my worn out Mott 88. I'll be mowing my rocky new England fields with it; plenty of small rocks, ledge poking out, etc. Which of the two blade choices would be better for me "zinging" over ledge?

 

[leonz]

Hello and good morning PatMcD,

How worn out is your Mott 88?

Save your money and buy a used John Deere 25A or John Deere 290 flail mowers for sale and you will be much happier.

The 25A and 290 will allow you to use either the scoop knife or the side slicer knife. The scoop knife is less costly than the side slicer pairs especially when you purchase them in quantity.

 

[Fallon]

I'm looking pretty hard at the FM-96H to replace my worn out Mott 88. I'll be mowing my rocky new England fields with it; plenty of small rocks, ledge poking out, etc. Which of the two blade choices would be better for me "zinging" over ledge?

The Y side slicers are lighter & cheaper. They will bounce easier, good for rocks & what now, but not as much for brush.

I hit a rock the other week with the several lbs hammers on my new Peruzzo flail & it did a number on the hammer I could see. Some chips on it & a really rounded edge now. It still works & I'm being lazy on pulling it to resharpen.

I mangled some side slicers on my old 917 with rocks & a well head, but more often than not the knives were ok. I never sharpened them once & they still gave a pretty darn good cut quality. The thinner knife is still sharp enough even when completely worn & rounded in the cutting edge. I'm sure sharper would cut better, but just wasnt worth the effort for me.

I'd go wyh the Y side slicers to survive rocks better, especially if you dont have any brush over finger size to mow.

 

[slckeys]

Leonz...
I see you recommend this wet grinder and angle setter often, could you link to them? I saw 2 different options on grinders... Thank you.

 

[leonz]

Leonz...
I see you recommend this wet grinder and angle setter often, could you link to them? I saw 2 different options on grinders... Thank you.

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Micro-Mark - The Small Tools Specialists Item #86566 now $77.99+ tax +shipping
(wet well grinder)


Woodworking Plans & Tools | Fine Woodworking Project & Supplies at Woodcraft Item # tor-WM-200 now $29.00+tax +shipping
(tormek anglemaster)

 

[slckeys]

Thank you so much.

 

[leonz]

You are most welcome.

 

[PatMcD]

Hello and good morning PatMcD,

How worn out is your Mott 88?

Save your money and buy a used John Deere 25A or John Deere 290 flail mowers for sale and you will be much happier.

The 25A and 290 will allow you to use either the scoop knife or the side slicer knife. The scoop knife is less costly than the side slicer pairs especially when you purchase them in quantity.

It works as-is, but she has seen a lot of use. The more I think about it, I might put the money into rebuilding her. I'm into it pretty cheap, right now.

 

[otus_branch]

Woodmaxx FM 78H update / first impressions:

Well, I finally got my Woodmaxx the rest of the way assembled and mounted onto my Kubota.

Regarding Jack Yuan's earlier question, the cylinder was empty of hydraulic fluid as far as I can tell. Hooking it up to my rear remote (partially - more on that in a moment) hardly moved the fluid level on my tractor though, so no problem. Also, although the Woodmaxx manual claimed that the bearings would come pre-greased, the zerks sure looked clean and dry, so I gave each one a very few pumps just to be sure some grease was in there. I felt no back pressure or any other evidence that they were indeed pre-greased.

Woodmaxx shipped me new hoses at no charge last week, and the 1/2x14 fittings threaded on these new ones successfully. I took ericm979's recommendation and purchased a bottle of Loctite 545 hydraulic/air threadlocker instead of tape, and used a bit of that. Unfortunately, after all that, one of the female ends of my third rear remote seemed frozen / unable to accept the fitting. I chose to use the top and tilt cylinders in the other two remotes, so for this initial mowing, I zip-tied the Woodmaxx hoses to the hitch and just mowed in the position it arrived in. The T&T setup makes it easy to eliminate scalping or other similar problems.

I mowed ~7' high weeds for about two hours: mostly ironweed, goldenrod, and boneset, along with grasses, etc. The Kubota L-39 (30 hp at the PTO) needed every bit of engine power when geared all the way down to 1st or 2nd gear in order to handle these tall weeds. I'm glad that I didn't source a 7' mower (or larger): 78" is plenty for my machine! I think that when people say ~4 hp (or even less) per foot of width for a flail is adequate, they are talking about mowing lawns. I expect more out of my flail, and therefore am glad that Woodmaxx specs their flails as they do.

The volume of debris coming off weeds this height is pretty astounding, and it's important to keep an eye on the temp gauge, and clean the screen in front of the radiator every hour or sooner.

On the FM 78H, the bearings spun smoothly, the mower cut well, and I was happy with the results. In the future, I'll try to cut weeds and grasses at 3' high or so, and anticipate being able to mow in 4th gear or higher. All bolts seemed tight still at first glance afterward.

A few problems developed with the Kubota recently (unrelated to the Woodmaxx), so it's in the shop at the moment. Hopefully, they'll get that third rear remote working again, along with other matters so that I can do some more mowing soon.

So far, so good. Will add more later.