PC1800 Front Shovel (1/12)

[Cooper]

Awesome!! Definitely going to be going back to many of the obstacles you have overcome and study. Appreciate you taking the time to post progress and details of your builds. Only bad thing is now I have more of an idea how to do similar and less of a reason not to!! Love the bigger machines. !!

[skeeter]

Them grousers are mean looking. I think they'll handle some seriously hard working conditions

[DADSGARAGE]

Thanks Cooper!! Scratch built models sure do have obstacles but the challenge and the reward of figuring it all out is well worth it!!
(You know all about it I'm sure!!)

[DADSGARAGE]

Thanks Skeeter!! Yup the track pads/grousers are a bit aggressive for a shovel....LOL....these are the original tracks that were on the D11 dozer, only needed to add a few more links and pads to the original length......it was an easy way of repurposing old parts.

[DADSGARAGE]

One step forward two steps back......LOL......more obstacles!!!
Decided on improving the seal design on the swing bearing, the original neoprene
"lip seals" did not like the grease and started to distort/swell making it difficult to turn the bearing.....

[DADSGARAGE]

The new plan was to incorporate some small 1/8" quad rings to act as seals but decided to go with o-rings instead. (less contact area making it easier to turn)

The "inner race ring" will be installed upside down and an o-ring added to seal against the inside face of the shoulder that supports the 100 - 1/4" balls on the stationary outer race. (Sorry the photo shows the quad ring)





A new taller top spacer ring was made with an o-ring installed that will seal up against the ID of the sprocket.



The new top spacer ring also needed to be a bit bigger in diameter to match up with the original ID of the sprocket.....Yikes....just enough clearance for the balls once the angle was cut on the spacer.......fun fun......more obstacles!!

[DADSGARAGE]

This is the order of how all this mess fits together....LOL...still need to drill the holes in the new top spacer!!












Hopefully this will help someone else get ideas on building a swing bearing from scratch!! One thing to remember is that the rolling elements (balls) are only running on a flat surface and not on a radius. Because this bearing only has point contact on the balls it will most likely wear a bit faster.

Thanks for looking!!
KP

[kerst]

Beautiful work!

Kerst

[DADSGARAGE]

Thanks Kerst!!

Did some work on the electrical slip rings for the track drive motors.......it even works!!! LOL

[kerst]

Nice! I like the slip ring.

kerst

[modelman]

I don't know if the issues with this site have been fixed or if I just got lucky tonight but I was able to log-in and post for the first time in many months. I really like the slip ring you have built. It looks similar to some I have seen on full size draglines. This should work great and last forever. Your shovel is looking fantastic and should be a "digging machine". Keep posting!!

[frizzen]

Progress on the machine is looking great!

I'm really digging that homebrew slipring, is the brush side built off a terminal strip of some kind?

[Lil Giants]

GEZUZ WHAT A BEAST!!! the AWESOMENESS of that last picture

What's it weigh (approx) as it sits now?

What's the length - width of the tack stance?

[DADSGARAGE]

Thanks guys!! Glad you like the slip ring.

Frizzen, All the parts are made from scratch, the brush fingers are .062 thick brass cut and bend to shape.

Joe, The weight of it in that photo would be 125lbs , outside width of tracks is 18.5" , OAL of tracks is 24.25" , distance from floor to ground is 7.25", the house floor is 16.5" x 26.375", CTC on boom pins is 19.5".

[DADSGARAGE]

Finished making the boom pins and soldered the keepers in place. Mounted the hydraulic tank, pressure gauge and hoses.....slowly getting this done!!

[Cooper]

Definitely a beast!! Of the two parts I'm dreading, the endless rotation ring and the slew ring, I don't see any better design on the endless rotator!! And before seeing this post I had a similar idea of loose fitting o rings for grease seals in the slip ring. Trying to source (fairly inexpensive) internal/external spur gears of similar size for the slew ring has not been kind. I've recently decided to get started on a similar machine. I like how you are building this. I know it is a premature question but are you going to have a self tensioning devise on the chain for the slew ring or just have a static adjustable motor mount? One thing I hate is the excessive slop in my small excavator slew assembly. And on such a large machine made to be working on level surface a little slop isn't an issue. Was just wondering.

Looks great by the way!!!! Always impressive!!

[DADSGARAGE]

Originally Posted by Cooper

Definitely a beast!! Of the two parts I'm dreading, the endless rotation ring and the slew ring, I don't see any better design on the endless rotator!! And before seeing this post I had a similar idea of loose fitting o rings for grease seals in the slip ring. Trying to source (fairly inexpensive) internal/external spur gears of similar size for the slew ring has not been kind. I've recently decided to get started on a similar machine. I like how you are building this. I know it is a premature question but are you going to have a self tensioning devise on the chain for the slew ring or just have a static adjustable motor mount? One thing I hate is the excessive slop in my small excavator slew assembly. And on such a large machine made to be working on level surface a little slop isn't an issue. Was just wondering.

Looks great by the way!!!! Always impressive!!

Thanks!!

Have you considered creating a (2D) DXF file drawing of the ring gear you need and then price out getting it cut at a laser or waterjet shop??

I still have not decided on what type of tensioner will be on the chain for the swing, most likely will be fixed with no spring. The preload/friction of the o-rings in the swing bearing create just enough drag to stop it from moving to easily and acts a bit like a brake which should help smooth out any backlash in the swing drive set up, hopefully!! LOL!!

[DADSGARAGE]

Got some work done on the stick, still not finished......

[DADSGARAGE]

Not sure why the last pics are displaying so large, they are all posted the same way??

[Hemi1966]

Nice work
I'm also wondering why pictures are displaying so large, I was about to update my grader build, but I on the preview I noticed the same thing and I did not submit it yet.