Re: Dragline Crawler Build
 

Wow, those tracks look great! Are you going to put any rollers on top of the side frames to hold the track sag up?

Re: Dragline Crawler Build
 

Jared,

Thanks! I was waiting on the 2-56 screws so I could assemble a complete set and start checking the pitch and freedom of operation. I do plan on 6 lower and 2 top rollers. In fact, I think they should help keep the pads and tumblers in line for better operation. Been working on the tension system brackets and mount.

Jim

Re: Dragline Crawler Build
 

Working on one of the MANY small details. Trying some delrin for the shaft on the idler tumbler.

http://i1291.photobucket.com/albums/...psmtw0crhw.jpg

Jim

Re: Dragline Crawler Build
 

Going to redo the tension system. I wanted to use 4-40 but the wheel collars happened to be 6-32 which I think looks too big.

Just putting on the tensioner even without the proper setup helps control the runout and makes me think if I get it all lined up, add the upper and lower rollers and get the tumblers refined a bit more that I may actually get a working unit.:p

http://i1291.photobucket.com/albums/...psr0g92heg.jpg

Jim

Re: Dragline Crawler Build
 

Looking good Jim. Hope to see it in about 6weeks.

Re: Dragline Crawler Build
 

Nice work jim-good to see you back at work on this. Is it far enough along that you can turn it?

Re: Dragline Crawler Build
 

Brief update:

I once AGAIN made new side rails. Decided to try putting the tension adjusters thru the end of the beam and thread into the axel shaft on the idler tumbler. I like this design, the brackets on the outsides were difficult to the size down so they didn't look out of scale. I might have to drill a few pads with access holes to get at the adjuster screws.

http://i1291.photobucket.com/albums/...psf100mqwd.jpg

I drilled and taped the drive tumbler and powered it with my drill. I still have an problem with the pads shifting to one side and then the drive and/or idle tumbler catches the drive dog on one pad as it starts or tries to enter the drive tumbler.

Today I am going to make the lower and upper rollers and see if that helps keep things lined up.

Also going to try standard pulleys and O Rings instead of sprockets. I can make them easily, they will provide a lot of "give" if something binds and I have the parts on hand. Hope to still use sprockets and chain at some point.

Re: Dragline Crawler Build
 

Added a solid lower guide to test my suspicion about keeping everything lined up helping with operation. With the guide I was able to easily identify two pads that had drive dogs a bit off center. I replace those and tried a motion test with the drill motor.

Trouble going into reverse from this direction with no guide or rollers on the top, the pads want to shift to one side just enough to try and ride up on the tumbler.

http://youtu.be/rLnZibly4JY

Jim

Re: Dragline Crawler Build
 

Hello Jim you have a great start there keep it up. Ed

Re: Dragline Crawler Build
 

How about this for tensioner screws, Jim?
https://www.microfasteners.com/home.php?cat=576

With a hex head screw you could make a wrench to reach in from the side and avoid drilling holes in those nice pads.

Re: Dragline Crawler Build
 

Reg, yea I hadn't even thought about a hex (probably just cause I don't have anything that small). That would probably look good there to boot! ;)

Jim

Re: Dragline Crawler Build
 

Oops, thanks for the tip on hex hardware Jared. It must have been past my bedtime when I responded last night.:p

Jim

Re: Dragline Crawler Build
 

Jim-that is probably a better system for tension adjustment but as I said before, once you get the tension set correctly I don't think you will need to adjust it again. Keep working!!

Re: Dragline Crawler Build
 

I had to stop and pose the crawler for a motivation photo, it seems like there is a never ending list of parts to be made, re-made, and fine tuned, and I still feel like I don't get too far for all the time I spend on it. :p this sort of view helps me keep going!

http://i1291.photobucket.com/albums/...psccjz2zbd.jpg

http://i1291.photobucket.com/albums/...psssrldk20.jpg

http://i1291.photobucket.com/albums/...psar2kwn78.jpg

Still to do -

slip ring and mount the rest of the ring gear and spacer
Pick and mount motors, make pulleys for the drive tumblers
And at least a dozen other things I have forgot about...:thinking:

Jim

Re: Dragline Crawler Build
 

Great inspiration:cool: :)

Re: Dragline Crawler Build
 

Jim-here is the video of my shovel tracks working that you ask for-
http://i305.photobucket.com/albums/n...h_100_0953.mp4
This was after many changes I had to make to the pads and the tumblers.

Re: Dragline Crawler Build
 

Tom,

Thanks for the video! Those work good and it ALL looks good too! After seeing your mold the other day it makes me want to try again with a narrower pad front to back and something different than my riveted drive dogs. I'll keep plugging away at what I have and learning what to do different on the next one:rolleyes:

Jim

Re: Dragline Crawler Build
 

Your welcome jim-your project is looking good. Looking ahead,narrower pads will probably work better. It will take more of them but they will make the circle easier. From what I see on machines today the pads are getting more narrow and they probably work better than the older machines. Did you decide against the button-head screws holding the pads together?

Re: Dragline Crawler Build
 

Ya, the button head was a bit larger than the 1/8" pad and I didn't think it looked as good as the cap screw. I might put a bunch of them on and look again, but I think I ordered them a bit too long which won't work...:o

Jim

Re: Dragline Crawler Build
 

Motor mount. About one time in ten or twenty I feel like I machine something and it turns out like I planned. I had some 1-1/2" 1/4" wall aluminum tubing, cut off a chunk, had to square it up cause my bandsaw decided it should start out wedge shaped.:p then I cut it in half, drilled and tapped for 4-40 screws. I'm not sure how this mount and drive arrangement is going to work out? I don't like how it is going to force me to raise the ring gear and everything else up higher than I planned. We will just have to see how it goes.:rolleyes:

I thought about using the threaded mount holes in the end bell of the motor, but I didn't like that due to tight tolerance where if I mis drilled a hole it was no way going to line up good.

http://i1291.photobucket.com/albums/...psbb8rembs.jpg

No, make a small and large pulley for an O ring to drive the tumbler.

Jim

Re: Dragline Crawler Build
 

Pulleys and O ring. Need to finish the rollers now...

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

Jim

Re: Dragline Crawler Build
 

Hey Jim, Have you thought about powering the carbody through the center pin like the 1:1 machine? One motor bevel gear then make sliding jaw clutches to engage each track disengaged with a servo for steering.

Re: Dragline Crawler Build
 

Steve, that sounds interesting, probably beyond my machining abilities, but interesting! I will have to find some pictures and drawings of that, I'm not sure I know exactly how it looks?

Jim

Re: Dragline Crawler Build
 

Study my drawings I posted on the 25B build.

Re: Dragline Crawler Build
 

I see you are making progress jim-You said you would have to raise the swing gear over this motor. Is that going to cause any problems? I like 9W's idea on the movements but that would require a lot of technical machining and this is a really small model. Are you up for that challenge? :eek: I probably could not do that.

Re: Dragline Crawler Build
 

Tom,

I made a round 1/4" plate to raise the swing gear just to get it up off the deck so the pinion had a bit of clearance. So, I think I can flatten the top of the motor clamp a bit and then I will make some braces that screw to the flat top frame to hold it all together, since the motors basically split the flat part in two parts. As long as it doesn't look like the body sits up too high I should be okay. It should actually improve the digging geometry for a drag bucket.

I would love to do the central power scheme but you are right. It is just really small to make all that work. I am going to proceed with the current motor placement and try to work out the pads function . Still messing with tumblers and alignment issues.

Jim

Re: Dragline Crawler Build
 

Jim-seems like you have a good plan. Will the O-rings for the drive belt have enough grip? Aren't those track pads fun!!! :D

Re: Dragline Crawler Build
 

Tom,

If I don't know for sure on the O rings. My master plan is simple pulleys and O rings just until I get the pads working the way they should/need to. Then convert from O rings to that small plastick Chain and sprockets. I have some steel roller chain but I think it is too big to look or function well and I think plastic would probably work okay as long as the pads and tumblers are working right.

I need to put the RT back on the mill and make some more tumblers. I don't have a combination that works to my satisfaction yet.:o

Jim

Re: Dragline Crawler Build
 

Got the top plate split so I could mount both motors. Ended up making new smaller drive pulleys just cause they would fit better and the speed reduction will be good. Still haven't made a decision on how to make rollers or solid rails in order to help maintain alignment. I should get that started now, gona want to see if this thing is going to move on its own!:p

http://i1291.photobucket.com/albums/...pswrkpn1ph.jpg

http://i1291.photobucket.com/albums/...pssjsynt6o.jpg

Jim

Re: Dragline Crawler Build
 

That's lookin really beefy and tough. Kool

Re: Dragline Crawler Build
 

Wow, that looks really good! Love the old school tracks.

Re: Dragline Crawler Build
 

great job you have done there so far it is coming along quiet well keep up the good work

Re: Dragline Crawler Build
 

Thanks for the nice comments guys!

I started mounting the swing gear on top of the frame. With any luck I will have the crane in place and digging dirt by the end of the weekend.

I need to make and mount the round adapter bushing to the inside of the cab. Pictures in a few hours...

Oh, and I ordered some plastic chain, sprockets, bevel gears and stuff from servo city. I think I am going to need to learn how to make two small sprockets.

Jim

Re: Dragline Crawler Build
 

looking good Jim ..quite a challenge and not your typical build ...your working through some pretty difficult challenges ..If you have a rotory table / Drill press you should be able to make your own spockets ..I did make my own for the Dozer.. A bit of math and you probably knew already though ...your circumference should match your pitch ..10 tooth x .25 pitch = 2.5 circumference
so diameter would be 2.5 divided 3.14 = .796 .Thats where you would drill your 10 holes
Overall sproket diameter would be bigger ..dont remember how many turns it took for one rotation of the RT but im sure you would figure it out from there..I did have to touch up a few of the teeth with a dremel though
I started out with with a 3x3 square .2 thick aluminum plate ..scroled the diameter of the circumference ..drilled the center and used a bolt and nut through the center hole to mount in the RT .Once the holes were drilled i cut out the sprockets with a band saw ..hope this helps you out a little

Re: Dragline Crawler Build
 

Lou,

Thanks for the tips. My parts might be here Monday so I can see how stuff fits. If I'm lucky I might be able to use what I ordered.:p

Got a bit more done today. Actually took some video trying to dig wet sand but it sticks in the bucket so bad it wasn't worth posting. Besides, I don't have the tracks moving yet anyhow:o I just wanted to see how it looked digging, sitting on the new undercarriage!:D

These are shots of the threaded bushing that inserts into the hole in the cab. The hollow stud is an old 1/2-13 bolt that I bored to run the wires from the slip ring.

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

http://i1291.photobucket.com/albums/...psw9lpn7de.jpg

http://i1291.photobucket.com/albums/...psk7lmpd8k.jpg

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

Maybe I can dry out some sand Sunday and post a digging video...

Jim

Re: Dragline Crawler Build
 

Some more pics...

It looks SO much better all rigged with a bucket on it!:D

http://i1291.photobucket.com/albums/...psoxh6qdup.jpg

I took one motor apart to match drill mounting holes (which I ended up NOT using:o) this is a "how the heck does this sucker go back together" photo.:rolleyes:

http://i1291.photobucket.com/albums/...psonwxkur4.jpg

This shot is too close to really see the setup. This is where I clamped the cab down to the mill table and used a fly cutter to enlarge the pivot hole.

http://i1291.photobucket.com/albums/...psattwns24.jpg

Jim

Re: Dragline Crawler Build
 

Your making good progress jim. You should be moving dirt soon. You may not be thinking about this now but are you planning to R/C the truck that this dragline goes on? That's a good idea to still use the truck and the crawlers.

Re: Dragline Crawler Build
 

Tom,

My original plan was to motorized the truck and swap the crane from one to the other. I had to cut the big hole for the crawler slew but I can mod the truck bed to make that work. I actually bought a second entire truck crane just like the first so I don't know what I might do with them both now...

Jim

Re: Dragline Crawler Build
 

fantastic job

Re: Dragline Crawler Build
 

That bucket looks great!. Well, so does everything else.