Cat 951-C in my sights

[Nitelite]

Thanks for the info Tony, I rely heavily on the advice that is so freely forth coming from experts like yourself who post on this forum. I have the sprockets just about ready to weld. When they are for sure level, square, and plum I intend to tack them with my mig welder. I can use the mig just fine but the stick welder is out of the question for me. My pacemaker/ defibulator just won't allow it. I forgot about the implanted device in my chest one day. I was kneeling on the ground and struck an arc. The zap knocked me down to the ground. I picked myself up and thought that the problem must have been caused by me kneeling on the damp ground. I got a piece of plywood to kneel down on and struck an arc again with the same explosion in my chest. Then I remembered the medical device handbook saying,"NO WELDING". I have contacted and arranged to hire a welder friend to take over for me after I get it tacked. I, being a ," do it yourselfer", just hate that I can't finish the welding job but I don't like getting hit by lightning bolts either. Being hit with the voltage also depletes the battery life of my device. I have exhausted the battery on three units and I have #4 implanted at this time. I have never heard of anyone having #5. My projected battery life at this time is about five more years. I expect to go for #5.

 

[Nitelite]

Keep on keeping on with notable progress!

Ready to tack weld.

The rim hanging and pulled to one side in order to remove the paint from the inside surface of the new rim to prep for welding.


A good fit.


Hard work seems to pay off, I don't like the grinding part!


I needed a good way to hold everything in place to get it all lined up and running true.


Ah, a brainstorm to solve the problem and hold things in place!

 

[Nitelite]

More pictures

Using # 10 cap screws and washers as spacers holding the new rim in place also allows for adjustment for the tack weld :cool2

with the cap screws at spaced around the new rim I can fire up the engine, spin the rim and adjust with a hammer while spinning.


A screwdriver prying in the gap and moving the cap screws around provides any needed adjustment prior to tack welding.


Prior to cutting the old rims off of the sprockets I cut two sticks, one for each side. I marked the center of the old rim so as to be able to weld the new rim in the exact location as the old rim.


I just love it when a good plan comes together. Running straight and true and ready for the tack weld. Now to get the same fit on the other side!

 

[kshansen]

Don't think those #10 screws will work too good when you get to digging that pond out!

Looks like a good way to hold it in place to get things lined up.

 

[Dickjr.]

Nitelite , your sharper than the average bear for sure.

 

[Nitelite]

Quite a compliment coming from you Dickjr , thanks. I just try to figure it out as I go along, just hoping that things don't get knackered too bad due to my fumbling along. Today I was cutting down the left side sprocket and the hot slag fell on my oxygen hose and burned a hole in it. I am really glad that it was not the acetylene hose. I was sitting on a brake stool and the fire would have been between my feet. I had a spare hose, no problem, but we won't even mention how close the family jewels came to being scorched!

Kshansen, I wish that I could have shown you that trick, BEFORE, you retired. It is not very useful to you now as side cars don't have sprockets do they!

 

[Nitelite]

How to mark the sprocket cut lines

In order to be complete and not leave loose ends, I need to back up and show how I measured and marked the cut lines on the sprockets to replace the rims. My new rims for the 951 inside diameter measure 26 3/4". The end product of the cut sprocket needs to be about 26 1/2" after cutting and grinding is complete. With the center hub blocking any accurate method of measuring the cut line I removed the cap from the dead shaft and used the countersunk dimple in the end of the center of the dead shaft to locate center for my custom fabricated divider.


This is my home maid divider fabricated to mark the cut lines.


The point on the left side is taper ground to fit into the dead shaft dimple. On the right the top end of the tubing has been crushed to size as a holder for a small peice of soap stone fitted for marking the line.

Be sure to replace the end cap before cutting and grinding to protect against metal dust from entering. Use gasket sealer to keep moisture out and apply a liberal amount of "never seize" on the six 3/4" bolts as they are replaced. When you cut with a torch, cut beside the line not on the line, so as not to destroy the line, leaving the cut line intact on the remaining sprocket, just as you would in a band saw operation. If you destroy the line it becomes difficult to follow with the torch. Next, grind to the line to clean up the slag and clean up the ragged edge. Last bevel the edges in prep for welding. This last operation destroys the no longer needed cut line.



On the lower left of this picture you can see barely the small piece soap stone inserted in the end of the crushed tubing marking the cut line as the divider is rotated around the perimeter using the dimple as an anchor point for the divider.



Completed cut line.


The measurement for all sprocket rims for the 951 may differ depending on the brand. On any rim just measure the inside diameter of the new sprocket rim and divide that measurement by two and then subtract 1/8 for clearance. The sum total will be the distance from tip of point to tip of the soap stone inserted in the divider. My measurement happened to total 13 5/16" "Measure twice and cut once". :notworthy

 

[Nige]

Nitelite , your sharper than the average bear for sure.

Can't be - I don't see no pic-a-nic basket .......... :tong

 

[Nitelite]

Nige, you don't see no pic a nic basket because the name is Nitelite not Yoggie.

Yoggie needs that basket to carry his lunch. He can afford to eat a pic a nic lunch out in the park every day because he is employed by the US Park Service. I, on the other hand, am unemployed and I stay broke from feeding the Cats. I don't need a pic a nic basket to carry my lunch snack, it fits in my watch pocket. I do on occasion see a boo boo though.

 

[workshoprat92]

Hey this may be a crazy idea but have you thought about mounting some sort of tool post to the machine, starting it up and putting it in gear and cutting the sprocket down with a lathe bit? Of course you would need some way of holding the opposite brake clutch pedal in. I have seen stuff done kind of like this in line boring operations by welding temporary fixtures to the machine that were cut off later. Seems to me would be far cleaner and more acurate to get concentric. But like I say may be crazy idea. Just a thought and in no way saying that your not doing an awsome job cause ya are. Just the machinist in me that thinks it would be a fun projec to try.

 

[Nitelite]

I do have a cutter bar that holds the bit that came off of an old brake lathe. I thought about rigging something up to mount and cut the spinning sprocket. Also thought about using a plasma cutter torch mounted to the frame and try spinning the sprocket holding the brake to control the spin speed. In the end I just used what I already had, the gas ax and plenty of grinding. I don't intend to ever need to do a repeat of the job again so as a one time job the torch seemed to work just fine. I am a wood worker, not a metal worker, but I can pretty well take on any job and expect to eventually figure out how to accomplish the task with what ever means I have on hand at the time.

 

[kshansen]

I can pretty well take on any job and expect to eventually figure out how to accomplish the task with what ever means I have on hand at the time.

Sometimes it would be nice to do the same type of job several times in a year that way you could justify the time spent tooling up to do the job. In a case like yours it probably would have taken as long to design and build the mounts for the cutter as you spent with the gas ax and grinder. It would be a whole different story if you had a fleet of 10 of these 951's that would need the same repair over the next couple of years. If that was the case you'd have your brother over and the two of you could have the tooling made in a couple days!

 

[workshoprat92]

Sometimes it would be nice to do the same type of job several times in a year that way you could justify the time spent tooling up to do the job.

No really I am darn happy if I only have to do it once ever LOL.

 

[kshansen]

No really I am darn happy if I only have to do it once ever LOL.

I was thnking more on the line of doing the same thing on multiple machines with some one else paying you for your skills and effort! Not rebuilding the same piece of equipment more than once out of your own pocket! I could talk about that from recent experience but as it is not technically Heavy Equipment despite having "HD" on the side I'll leave that to another forum!

 

[workshoprat92]

I was thnking more on the line of doing the same thing on multiple machines with some one else paying you for your skills and effort! Not rebuilding the same piece of equipment more than once out of your own pocket! I could talk about that from recent experience but as it is not technically Heavy Equipment despite having "HD" on the side I'll leave that to another forum!

I know. I was referring to the physical effort to do the job any one machine let alone a whole line of many of the same kind LOL. It all just wears me out anymore paid or not I dont want to do it unless I absolutely have to. I would much rather be working on building my airplane.

 

[Nitelite]

It all just wears me out anymore paid or not I dont want to do it unless I absolutely have to. I would much rather be working on building my airplane.

I understand, I would rather be working on my yacht, but at least now I have the two anchors for the it.

 

[Nitelite]

Ready to weld. Welder is lined up for next Monday.

You might call it luck or you could overlook the luck part and just call it skill. I tightened all of the #10 cap screws as I tapped on the rims with a three pound hammer. I set up my indicators on both rims to check for run out and wobble. I fired up the engine and put the tractor in gear and just let the sprockets spin. I checked both rims as they spun. The right rim was perfect and I only needed to smack the left one twice with the three pound hammer to correct a small wobble. In every direction measured the rims are running true within 1/8" and that is plus or minus 1/16". I really did expect to need to spend quite a bit of time adjusting. As dark stopped me today, I will tack weld with the mig tomorrow. I plan on doing three tack welds 120 degrees apart, inside and out. I will let the welder finish it up with a 100% weld on Monday.

Yep Nige, I will peen the welds as the welder changes his rods.

My ultra modern work site equipped with heavy duty hoisting equipment. Note the open roof design, comfortable seating and more than adequate overhead lighting.


I can't even begin to guess how much time and work those little #10 cap screws saved.


There are two of these pictures because I had extra time to take photos due to not needing to waste all of that time on adjusting the new rims to run true.


Like I said, within 1/8 in every direction.


The ink mark is the center line of the sprocket and in line with the rear bottom roller and front idler that was checked with a laser level set up and measured before removal of the track frame.


While I am waiting on the welder I might get some more cleaning, sanding, and painting done on the old gal. I'll can't wait to be able to put the track frames and new chains back on her. Then I can finally put her slippers back on, might even paint them too.

 

[Nige]

Yep Nige, I will peen the welds as the welder changes his rods.

If you want to keep the workpiece at the correct interpass temperature then IMHO once you've got going after first preheating a welding job like that is a 2-man job; one man to weld, the other to do the needle peening and clean-up. Needle peening will remove the slag and stress-relieve at the same time - two for the price of one so to speak.

 

[Nitelite]

Right on Nige! I for obvious medical reasons, I can't get too close while the welder has his arc going, but I can stand by at a safe distance ready to do the slag removal and needle peening while he changes rods. I will also take care of the preheating before the welder strikes his first arc. I would think that once the welding process began that no more preheating would be needed with the torch. Am I right about that or should occasional preheating be done during the entire welding and cool down period?

 

[Nige]

On a summer day in TN I would say that once you have the workpiece up to temperature the heat of the welding process should maintain the required temperature without any need for additional pre-heating.

According to SEHS7750 so long as the parts are at room temperature you can start welding, so there is no pre-heat called for at all. However if it was me I would be at least warming the parts up to around 100-120 DegF before starting to weld simply to drive out any moisture that may be present before striking the first arc, especially if you are starting first thing in the morning. Also note the comments on the procedure regarding keeping the workpiece free from drafts while welding. When the welding is completed it would be a good idea to throw a fire blanket or something similar over it to keep drafts out until the whole assembly is cooled back to ambient temperature.