LR634 is HERE!!!!! Tracked loader

[avel]

I made a test piece out of laminated styrene to replace the stock link that curls the bucket. I know it looks horrible, hopefully my final one is out of aluminium and will look a lot better. I lengthened it twice because my measurements were way off, eyeballing it didn't work



Ok, the stock distance from hole to hole is 62.9mm. The new one is longer and the distance from hole to hole is 66.5mm.

This is the stock link.



Here is the modified link, camera wasn't moved. I didn't check the focus that's why its blurry and looks like the camera was moved.



Modified link again. Bucket curl maxed out, hitting the arms.



Stock link at a little less than maximum lift.



Modified link.



I forgot to take this picture with the modified link installed, but to get this range of motion I took out the glued on spacer around the curl piston rod that limits how much the piston can extend.



Here's a picture of the spacer. It is 15.1mm long.



Tracking says I should get the Orings on Monday, so hopefully I will have a video by then to show the new range of motion and/or any catastrophic failure

[Cooper]

What is the third piece in above picture? Is it a spacer/restricter for the travel of ram? Just curious.

[avel]

Cooper. Yeah I placed the spacer next to where it was originally on the piston rod, it limited the extension. The piece to the left of the spacer is the threaded hydraulic cylinder end.
Does that make sense?

[Espeefan]

Nice idea for increasing the bucket curl performance! I'm curious to know if by removing the cylinder's internal stop sleeve you might run into problems with the bucket bellcrank getting stuck in an over cam/over center position when dumping the bucket?

[avel]

When dumping the piston retracts. The internal stop sleeve only limited things when the piston extended.

Now their might be issues with the lengthened link/bar/thing. I might still have to adjust the length because of the overcam thing.

[Espeefan]

Originally Posted by avel

When dumping the piston retracts. The internal stop sleeve only limited things when the piston extended.

Now their might be issues with the lengthened link/bar/thing. I might still have to adjust the length because of the overcam thing.

Right you are about the cylinder retracting to dump the bucket. I didn't put two and two together. When you do get try the long bucket to bellcrank link, let us know if it does over cam itself.

[avel]

I definitely will. I plan to have a video of it operating by 8pm Monday if the Orings arrive like they should. I brought in a bucket of dirt last week, so rain or shine I can test things out.

[avel]

Espeefan, you were partially right. It did cause problems leaving the internal stop sleeve out. Now I can curl the bucket back more but this causes problems if I don't uncurl it a little when lowering the bucket. The lift pistons fight the curl piston when lowering the bucket with it curled back. I blew a tube and ballooned another one in two spots.

With all the hydraulic lines connected the pressure jumped to 22bar at times. I am going to lower it a little and try to operate it the way it is. Normally when operating and lifting a bucket of dirt I always dump it and then lower the bucket so I don't think this would be an issue in normal operation. I am uploading a video right now, doesn't explain things that well, but at least you can see what is happening.

[avel]

http://youtu.be/HFAJzpG8cpE

The Orings kinda worked, in that I had to cut down the OD to fit into the grooves. On the lift pistons one of the sealing edges was torn out too. So the Quad or X rings that I got didn't really work without modification. I might try some other sizes if I want to purchase a 100 of each size from Mcmaster. This order was from theoringstore.com which lets you buy them individually.

I used my Xuron flush cutters to trim down the outside of the Orings, and so far everything is sealing.

For screwing the hydraulic cylinders closed I used two pieces of bicycle inner tube. Just wrap it tight so its stretched and twist. Then I used some tube to cushion the jaws of pliers to tighten it down a little.

[Lil Giants]

Monkeying with the geometry of the Scale Art loader bucket caused over-cam problems too, and I can tip the bucket too far back in a lower position as well... but I always keep the bucket level after it's emptied. I set the pressure to 17bar.

On the bucket, the distance between the connection points of the drag link & loader arms with the S/A was about 36mm (my memory is ?) and the Stahl WA500's bucket was less, I think it was 31mm. That wee bit of difference made a huge diffrenece in the dump radius, especially at lower height of the arms.

To correct the over-cam issue, I drilled & installed a bolt just below the drag link, so at full height of the arms & full dump of the bucket, the bolt stopped the drag link from over centering.

I saw Rcguy's Carson bucket at the St Louis meet in 2012 and measured the distance between the two points, I can't remember what the number was, but it was greater than the OEM Scale Art.

[avel]

Joe, I went through your whole thread on the 4x4 forum last week and saw that when you changed the bucket on the S/A loader. It kinda also pushed me to try modifying mine too.

My brain!! I just spent some time with the radio and watching Youtube videos on how to program it, I have a lot too learn.

I setup a switch that when flipped opens both of the valve servos without activating the pump to release the pressure in the lines.

As for my pressure relief valve, I turned the pressure down but then turned it up, and turned down the speed that the pump turned at. Now the pressure averages around 15bar but if I keep raising or curling it slowly climbs and peaks around 20bar I think. I like it this way better, it's smoother and it takes awhile to increase pressure over 15bar. I still have SO much to learn about programming the radio.

[4X44DAD]

Nice machine

[Supermario]

Just saw your video on the bucket binding issue Avel. The link is definitely too long. The reason it only happens at a certain range or boom height is when in a lower position the bucket hits the boom before the Z arm ( the link between the cylinders and the "dog bone" ) can travel beyond center.
The best way I can describe is ..... As you curl the bucket back the link is pulled straight back. Yours I see very well at the 4:20 minute mark, the link stops pulling straight back and starts to rise. Now when you boom down the bucket can't pivot and dump and binds.
Clear as mud?
To figure out proper link length I think you should calculate your length with boom in that trouble spot and be sure that it is still level or linear and not rising at end of stroke.

If you want to maintain new dump range, the only way to fix is a longer Z arm on the lower pivot point.

Congrats on a beautiful machine. Just the sound of the hydraulic system says Quality. Very nice., wish I had one.

Mario

[doodlebug]

I've never seen a perfect Z-bar linkage, my neighbors hough has a relief valve on the bucket cylinder, for binding issues!
Cheers, Neil.

[Espeefan]

Avel, I would try and remake the link for the bucket too. Like Mario suggested, position your loader arms and bucket in the position where the binding begins and see if you can figure out a new dimension for a shorter bucket link that would alleviate the problem. It might take a little trial and error. You could use a piece of threaded rod with some rod ends to make an adjustable link. That will make it easy to adjust the length for testing so you can hopefully find a happy medium.

[1/50diecast]

Way cool!!!

[Steve1503]

Any progress on your loader?

[JAMMER]

What you need to do is make a smaller spacer try one half the size first and go from there. Ed

[avel]

No new updates, it just sits there on my desk. I started a new job as an Over The Road truck driver, and have only been home 3 times since. Still getting used to the new job, and haven't taken the loader with me. I only have my Legos with me in the sleeper for when I do a 34 hour reset

[Kausekaos]

Wait you have to weld the chassis?