Dc motor dismantle/dry ice

[elevator joe]

Rippin stuff apart is always fun, especially when you don't have to put it back together. We're taking off a drive sheave on our third DC motor by packing the armature with dry ice then heating the hub of the sheave with a weed burner while using the home made wheel puller. It's the second one done using the dry ice method and seems to work very well, it was a fun day! Here's a few pics.

 

[jhelrey]

I looked at that pic and I was like, elevator. Then I looked at your user name.

How do you like working on elevators? I've thought about it!

 

[elevator joe]

Good, been doing it for a long time.

 

[alan camby]

Do they still use dc in new units? Assume they would use ac 3 phase with vfd's?

 

[akdiesel]

I have heard dry ice and I believe acetone to get even colder.

 

[elevator joe]

You are correct, AC drives are pretty much standard now days. Some are regenerative and feed power back to the grid.

 

[elevator joe]

Acetone? Wow what would happen when you throw the torch to the work?

 

[geologist]

Acetone? Wow what would happen when you throw the torch to the work?

 

[pcmeiners]

Geologist, nice touch

 

[alan camby]

I would think most elevator technicians would do a lot of head shaking at the beginning of the movie Speed. So many false things happen on that elevator that it was hard to be entertained.

 

[elevator joe]

The picture is cool!, i heard that the floor was done by a company that made high tech TV. monitors. I think it would be fun to see the reaction of people when the elevator is in flight and the monitors turn on . I Suppose you would have to keep a mop,bucket and baby wipes handy!!

 

[DanarchyCustoms]

The picture is cool!, i heard that the floor was done by a company that made high tech TV. monitors. I think it would be fun to see the reaction of people when the elevator is in flight and the monitors turn on . I Suppose you would have to keep a mop,bucket and baby wipes handy!!

Something like this?


Awesome pictures. Its always cool to see stuff like that having to be done just to finish a job.

 

[hibrid]

Nice pics

Im an elevator mechanic in seattle and have done the same thing a few times. That looks like a nice puller setup!! Mine have always been made up of a few counterweights and 3/4 allthread and a porta power or bottle jack.

I was doing a mod at the VA hospital where we replaced a 1940s westinghouse gearless machine and had to pull the driver off just like you....SOB would simply not come off with dry ice and weed burner and a 30 ton ram. Must have been too much shaft material to "shrink". We had to get the driver off to get it out of the machin room and to distribute weight wile he got the new machine in and running.

Ended up having to cut the armature with a sawzall right behind the driver. 9hours and 2 sawzalls later it was free.

Ill dig up some pics

Good thread! cheers

 

[hibrid]

Good times...sorry for the big pics

 

[elevator joe]

(9 hours) I feel your pain! the dry ice was suggested by my pops who was in the trade for 30+ years, tough to beat old wisdom!!. I was lucky with only two hours for the sheave. I'll bet the trap door in the floor was nice to get rid of your machine, not always the case. which style of saws all blades worked best for you on the armature? Regards JOE

 

[hibrid]

We tried about everything and the best by far was RIDGID from home depot.

I think we bought about 10 12" blades and only used like 6. Still have a few that are good.....pretty impressive.

The trick was to run the sawzall trigger stop in a bit to slow it down and zip tie the trigger on. I ran the saw through a capstan foot pedal and had blocked up the saw with 2x4s, then sat a 50lb weight out of a weight cart ontop of the saw and poured pipe cutting fluid on liberaly. Otherwise your arms would be dead quick!

 

[neonnblack]

How do you like working on elevators?

It has its ups and downs.

 

[Rogue1987]

It has its ups and downs.

I was wondering when that was going to show up.

 

[elevator joe]

It's amazing what the brain will do when you're put in to certain situations. Nice move on the foot pedal,mind if I use it?

 

[hibrid]

Sure! I do it pretty regularly with other tools (drills and portaband). Keeps the hand/arm fatigue away. I'm young compared to most in the trade but have a lot of friends and family that have been in forever that have arthritis and constantly moan about pains. I try to use whatever means available to make things easier.