Re: Ny-Lint Mobile Dragline Conversion
 

Wow, those are some nice track pads! I think you will want to make the sides of the rollers and idler thicker so they don't wear down as fast. Maybe about twice as thick. At least that would be a problem on a 1:1 machine that sees thousands of hours of operation.

Re: Ny-Lint Mobile Dragline Conversion
 

Jared,

Ya, you are spot on! Problem is, to do them any wider I will have to move the frame rail out and that changes everything else down there. So for testing, I'm going with it as is. If I like the new tumbler and drive arrangement i plan to widen the rails and make new parts.

Jim

Re: Ny-Lint Mobile Dragline Conversion
 

Jim-I like the way you made the lugs on the track pads but was just wondering why you made the tumbler so wide. I'm sure you have a plan. Have you wrapped the pads around the tumbler to see if they will work. I always had a problem with this part. I never quite figured out how to do this. I got close but never got it perfect.

Re: Ny-Lint Mobile Dragline Conversion
 

Tom,

They wrap around pretty good, I am hopeful that they might work better than the old style I tried first.

I know what you mean about the width. I may be wrong, but to fit/clear the lugs on the pads I made them as wide as the base of the lug plus the width of the side walls of the tumbler.

Thought I was going to be testing by now but I busted off a 6-32 tap in the tumbler and screwed it up trying to get it out. Darn I hate breaking taps!:mad:

I have a replacement half finished, but got sidetracked the rest of the day getting camping gear ready for the trip out to Brownsville.

With any luck I will get to try one side Sunday.

Jim

Re: Ny-Lint Mobile Dragline Conversion
 

Get some #5-40 taps Jim. They are smaller but the finer thread make it easier to tap.

Re: Ny-Lint Mobile Dragline Conversion
 

Made some progress this weekend. Here is the new prototype drive tumbler just about ready to go back together for a test. I will make a new wider one with wider side flanges, once I see how it works. I moved the side rail out another 1/4" and made new lower idlers.

http://i1291.photobucket.com/albums/...ps2133avpx.jpg

Jim

Re: Ny-Lint Mobile Dragline Conversion
 

I am reworking the frame rails for my crawler, but, it has a twist in it. Here is a short video that should explain what I mean.

http://youtu.be/0Eqewf_Ekmc

Part of the reason I wanted to rebuild these parts was the same twist in the old parts. :(

I tried to carefully drill the two sides while clamped together in the mill vise.

I tried to carefully turn the spacers in the lathe. The order was...

Chuck the stock in the 3 jaw, center drill, drill center clearance hole to size.
Turn outside diameter down just enough T to make it round and concentric to the center hole.
Part off. I faced one of them to match the length of the first.

I DIDNT machine the inside mating surfaces of the bar stock.

If I loosen the clamping screws a bit and tweak it as I tighten it is better but I want to try and figure
out what I might be doing wrong.

Jim

Re: Ny-Lint Mobile Dragline Conversion
 

Try to check if the bar stock is straight without the spacers and then face both sides of the spacers. I think it is something to do with the face of the spacers.

Re: Ny-Lint Mobile Dragline Conversion
 

I'll try that. I might try and put a slight cone shape on the face ends of the spacers so only the outer diameter touches the bar stock. I guess I could set the spacers on the surface plate and try to check if the ends are parallel?

Re: Ny-Lint Mobile Dragline Conversion
 

The spacers need to be faced square with each others end You probably chucked them and they were not running true. Then when you turned them around to do the other side it was running out again. Before you do that, try rotating them some so one will counter the other and maybe it will sit flat. Sometimes the flat bar stock will bow when you machine one side only due to surface tension.
All of the "I" beams I made for my dragline had a bow until I machined the other side.

Re: Ny-Lint Mobile Dragline Conversion
 

Steve,

Thanks for the tips! I was able to lightly clamp the assembly in the drill vise and then tighten the screws. This seems to allow it to stay flat enough to satisfy me for now.

Here is a video of the first test of the new drive tumbler. I have already started on the other side.

https://youtu.be/MTlgXVtkDjM

Jim

Re: Ny-Lint Mobile Dragline Conversion
 

Jim-looks like you nailed it. The tracks are rotating smoothly with no jumping or jerking. Good job. If you still had the twisting problem I was going to suggest you bolt the-2-rails together tightly and see if they laid flat. Sometimes the holes can run-out enough to cause this. If the other side works this good you will be ready to go.

Re: Ny-Lint Mobile Dragline Conversion
 

Thanks Tom, can't wait to try it in some dirt! All we have here today is MUD, we got 3.5" of rain in about 4 hour today :o

Jim

Re: Ny-Lint Mobile Dragline Conversion
 

Second video of the crawler upgrade test. This is the same bit of video with some slow motion.

http://youtu.be/AYBJFvvS7wY

Jim

Re: Ny-Lint Mobile Dragline Conversion
 

Jim-I can't see well enough to see the old tumbler but the new one seems to work perfectly. I like it!!

Re: Ny-Lint Mobile Dragline Conversion
 

I'm getting it! Got the upper and lower idlers made, just need to install them and put the track on and side two is complete! :cool:

http://i1291.photobucket.com/albums/...ps7skowss2.jpg

Jim

Re: Ny-Lint Mobile Dragline Conversion
 

Well, that only took about a weeks worth of full time working in the shop! But, it is pretty much finished and I think it will perform much better now. Ball bearings on the new drive tumblers should really reduce the friction and stress on the chains and motors. The frame rails are now 1/4" wider than before and the tumblers and opposite end rollers, as well as the upper and lower rollers are wider to help keep the tracks flatter and support the machine. I changed the tension screws to an external location which is MUCH easier to adjust now.

I took it out in the back yard and tried it in the grass and a dirt pile by the pond. Seemed to work real good. I'm not getting any of the jerking like it did with the old drive tumblers. I think they were just to tight, but I really like the new style. Much easier to make than the old ones!

I want to make a dust cap for the bearing pockets but other than that, I like it! Brownsville will be a great field test for it, I hope we get some good weather, man was it soggy at the spring show!:o

Oh, and it anyone has a thought on it, I would like a better way to finish the tensioner. The way they are now, the brass rod rotates and the tension hold it against the tensioner bolt. Not ideal. I would like to put a collage around the end of the shaft but it can't be threaded, otherwise it would screw into the rod and seize it. I need to see this, guess I'll start searching the inter web...

http://i1291.photobucket.com/albums/...psffssumi1.jpg

http://i1291.photobucket.com/albums/...pstcxddalr.jpg

http://i1291.photobucket.com/albums/...ps1vlvhp3d.jpg

Re: Ny-Lint Mobile Dragline Conversion
 

Jim-sometimes these jobs take way more time than expected, but as long as the results are what you want is all that matters. I don't see a problem with the tensioners. Once you get them set, I doubt if you will need to adjust them unless you plan to crawl this model many many hours. The new track system looks and works great!!! You might consider putting a jam nut on the tensioner bolt in case it wants to move. Just a thought.

Re: Ny-Lint Mobile Dragline Conversion
 

That's looking really nice.

Why not shave the first couple threads off the drive tensioner, and make a saddle to support the axle so the tension screw won't be wearing on it. It already looks like you're wearing away at the brass.

Re: Ny-Lint Mobile Dragline Conversion
 

Friz,

Ya, you are right. I just haven't decided exactly how I want to do it yet. I'll probably let it wear fora few hours and see how it goes. The shaft will be easy to replace and I might also make them in steel. But I plan to eventually make some sort of saddle/collar on the shaft. Somehow then I should be able to let the delrin bushing run free on the shaft and hold the shaft fixed with the collars or something.

Jim