3-point question, rear blade build

[JackDWaller]

Hi All,

As I progress with my rear blade build I am wondering about the set-up of my 3-point linkage. Is there any criterion used to determine where the links are placed? This could affect the next stage of my blade design.

I have included a pic that shows the iMatch with the blade support "inverted T" locked into it. Flush with the bottom of this "T" will be a substantial pivot point since I want offset capability.

Initially I will not include the hydraulics, but am designing with hydraulics in mind. The blade proper is 6'2" and is obviously very heavy. This reflects the fact that all the materials are scrap and free. I hope it does not become too heavy - it's probably not going to exceed 400 or so lbs. There is a loader up front on the JD 2320.

The blade is being designed to have tilt, angle and offset capability following the LandPride format. Thus, the rectangular tube rising off the blade that provides the tilt. I need to determine how tall this tube needs to be. I know I need to be able to clear the main support for 360 degree rotation but am wondering if there are other things to consider. That led me to question what height capability my 3-point provides and how I should determine where the links should be pinned.

Having never cleared snow with ******* I'll no doubt be in for some surprises but would like to keep them to a minimum, so helpful advice is always welcome.

Apologies for the pic quality - had to depend on my son's phone.

Jack

 

[teg]

Looks very good... heavy is not a bad thing with blades. I'm guessing with all the adjustments that you'll be doing more than just moving snow.

 

[bullbreaker]

Worksaver Rear Tractor Blades

Worksaver RBHD-Series Rear Tractor Blades
From here you can go to manuals/parts breakdown list.
Just more good info IMHO.

Boone

 

[teg]

Here's a Tufline with all the adjustments... offset, tilt and rotate

 

[GPintheMitten]

I really like the design of that tough line. Ingenious to use the rounds to accomplish the adjustments.

 

[JackDWaller]

Thanks for the food for thought and picture/manual references. Still looking for some advice regarding the 3-point settings relative to blade height. Should I be designing with some mid position of the lower arms? How much clearance height is needed with a blade? Do you ever find yourself pulling snow from a pile or whatever. This is new to me.

I do hope to use the blade for landscaping which led to me deciding to add some tilt. I'm wondering if anyone has used tilt in a floating mode levelling hilly areas? I don't have pipe at my disposal, but agree it can be pretty efficient for rotational positioning with pins. Also I definitely want to have a center gauge wheel setup.

Jack

 

[teg]

...Still looking for some advice regarding the 3-point settings relative to blade height. Should I be designing with some mid position of the lower arms? How much clearance height is needed with a blade?...

I guess we might have a problem understanding your question a little bit... most blades start below where the 3 point arms hang down from - this is mainly to allow the blade to swing around 360*. If you are talking about "Mid Position" the blade can't spin. Material (snow/dirt) will roll out the sides (or if angled, one side) before the blade builds up too much material. confused: did I answer the question??? )

 

[JackDWaller]

Sorry for not being clearer. I realize that I need to have clearance to rotate the blade 360 degrees but some blades seem to be down lower than what that would imply. That got me wondering about the nominal setting of the 3-point linkage since it will influence how high the whole blade contraption will be able to be raised. In my case I need to decide how tall (long) the rectangular tube coming off the blade proper needs to be and also to decide where to locate my pivot point at the iMatch "inverted T" - flush or slightly below. Once I cut some critical pieces I won't have options in this regard (including how far back to locate the blade).

So, first of all I need to know where the 3-point itself should sit relative to the tractor (linkage choices). Does that help explain?

Jack

 

[Yellowhair42]

Looks very sturdy except that rectangle tube. You might want to consider making that a solid bar at the very least.

 

[teg]

I'm also sorry if I don't understand... Let's not worry about that.

Is it the length (how far back behind the tractor) the blade sits? If that is what you are asking, it's not cast in stone. I think the further away the more leverage it will have and that is only a problem with a light tractor.

If you are talking about a side view... I would make it to be somewhat level with the blade at 90* when the toplink in the "middle" position so that you can screw the toplink in to angle the blade to be less aggressive (skim off the top) or you can extend the toplink to make the blade dig in and cut more.

Again, the worst thing either of us are doing is bumping your thread up to the top so maybe someone else might see it and chime in with correct answers

 

[GPintheMitten]

Would you like me to measure from the ground to the bottom two points on my blade when the A-frame is perpendicular to the ground? If you want other measurements, let me know. I have a Woods 5' back blade.

 

[JoeL4330]

coming along well, glad to see the post and the interest it generates.

One thing to consider is how high you can raise the blade--especially when you mention "hilly"--because, as the 4-wheelers will tell you that determines your approach/departure angle (when you are not cutting with the blade). same approach/departure issue when/if you need to load onto trailer or rollback.

 

[JackDWaller]

OK, I think I'm beginning to see some of this better. Right now my top link is in about mid position. I'm hearing that it would be desirable to have my blade with its cutting edge sitting flat on the pavement in that case. That gives me adjustment to make it more or less aggressive in its bite with the leading edge (being just under 3/4" thick there is a fairly wide flat, around 7/8").

There is also another aspect to this. My "blade" is two blades fastened together and the top blade edge is very narrow and sharp, with no flat. Is there any merit in flipping the blade pair over so as to have this as a cutting edge, say when levelling dirt??

Getting back to the 3-point, in one pic one can see my lower links which are pinned at the lower, further out, maximum weight point, I guess you'd call it. That enters into the discussion relative to how high the blade will lift and also how the top link will influence the angle of the blade looking from the side, no?? So before I establish an attachment swivel point on my iMatch "inverted T" I need to select where my 3-point lower arms are pinned, no??

Yellowhair 42, you have hit a nerve. I agree the 2x4x1/4" tube looks too small relative to the whole contraption. After I went ahead with it, I learned that the unit I was patterning after likely had a 4x6x1/2" tube, but that LandPride blade is for a much larger tractor than my 24 hp and the blade is 7', not 6'. I have since enquired about 3/8" wall and couldn't get it. When I got to frettin about this I decided I could weld a 1 1/2 x 1 1/2 x 3/16 tube inside this 2x4, by drilling some holes and plug welding them. I'm kind of stuck since the blade backing is all welded up. My friend suggested going with one or more swivel mounts off to the side of the blade a couple feet or so to take some of the torque off that tube.

On the other hand, this frettin led me to examine various points associated with the 3-point hitch and I can't imagine my tractor being able to mangle that tube - not saying it couldn't happen though. :ashamed:

Jack

 

[JackDWaller]

GPintheMitten, my post fell in before I saw yours. I'm not sure exactly which measurements you are referring to. But if you were able to anotate a side view picture I'm sure it would help.

Normally when I have built other contraptions I have been able to tack weld a mock-up to "test" whether everything is going to work out. This is the first time I've ever dealt with anything this massive.

Jack

 

[GPintheMitten]

Ok, I'll take some measurements tomorrow. You could also mock up the side view on paper to scale and test the pivot with paper cut outs.

 

[JackDWaller]

Hi and thanks for the efforts to assist in spite of the confusion. I have gone out and clamped a length of tube onto the "inverted T" that locks into the iMatch of my JD 2320 and investigated the lift that is available from the 3-point with a particular setting of the pins in the lower arms. It would seem I need to pin in closer to the tractor to achieve a higher lift although without serious dips and hills, I guess it would be OK as is.

Please take a look at the attached pdf and comment since I really should get on with this fabrication if things look OK.

Regarding the 2x4x1/4" tube that is a weak point, I have determined that I could weld two 1 1/2 x 1 1/2 x3/16" tubes internal to it. The fit is excellent and I guess I have nothing to loose by trying to beef it up by plug welding these in place??

Thanks to all who are try to follow and help. I know my descriptions haven't been the best.

 

[GPintheMitten]

I don't see an attachment.

 

[JackDWaller]

The pdf file is attached (at least on my view here) and it contains text and annotation on the pic.

Jack

 

[GPintheMitten]

My apoligies . I'm on my android using the app and the attachment didn't show.

 

[MtnViewRanch]

JackDWaller do you have or plan to get any rear remotes? A hydraulic top link would take care of any blade height issues during transport. You can do amazing things with a rear blade that has a hydraulic side link. Just some other options to consider.