How Hot Is Too Hot??

[jstone]

My Z truck gets very warm to the touch after I get carving. I did a carving that took almost an hour and stopped it a few times throughout to check to see how warm it was getting. I never knew it to get very warm before until I got the bit set. Then when I changed out a bit for another I noticed how warm it was. Before I just had used the 1/16" carving bit and had no need to touch the Z truck. It carves flawlessly but with all I have read about over lubing and the bearings going, its making me nervous. I don't believe I over lubed. I soaked and then let drip dry for an hour or so just to make sure the flex shaft was done proper. I don't have any idea about what temperature it gets, just thats its very very warm but it cools off fairly quickly. Any input would be greatly appreciated. Thanks in advance.

[Dan-Woodman]

Your z- truck should not be getting hot. Your flex cable will be warm, but should be cool enough to touch and hold for several seconds or longer.
You might try pulling the flex shaft out of the z-truck and spin the chuck by hand seeing if it spins freely.
later Daniel

[hotpop]

I believe the spindle bearings are sealed bearings are sealed but they might just be dust covers. I haven't pulled mine apart to find out. I suspect it to be dust covers since some people get their flex lube into the bearings.

You might try to put a drop of light oil on them, like sewing machine oil, 3in1. or even WD-40. All though they're sealed or covered a light oil will still migrate into the balls.

[Ken Massingale]

I measured mine yesteday after getting an IR therometer from HF for checking the flex shaft temp. The temp of the truck above the QC chuck stayed at around 70 degrees throughout a 1 hour carve.
BTW, WD40 is a degreaser, not a lubricant for high speed mechanical parts. It's o.k. for door hinges, etc. but don't trust it to maintain lubrication for bearings at 20,000 rpm.
ken

[hotpop]

Thanks Ken - Didn't know that.

[jstone]

Has anyone ever lubricated the spindle bearing? I work in a pulp mill where we have bearing grease for just about every situation from high pressure to high speed to high temperature or a combination. It seems a waste to having to change out a bearing just because it is made disposible and can't have a little PM done to it.

[Jeff_Birt]

I would not say that the bearing is made 'disposable', it is however made 'sealed'. Being sealed, the lubrication will last the life of the bearing unless you happen to flush it out with excess flex shaft lube. (Been there, done that.)

The spindle bearings use a rubber seals so you could pry them up and re-grease. While these types of seals are much easier to remove than the metal ones you can still damage them easily. If you damage the seal then the bearing will go bad in short order due to contamination.

[jstone]

My Z truck was getting very very warm. To me this was an indication of excess friction in the bearing for what ever reason. I had another 6000 bearing that I used as a test bearing before hand. The rubber seal is snug fit but comes out very easily if your careful. I used a Stanley utility knife since the blade has a very pointed end. Being careful not to cut, I slid it into the outer edge of the seal and gently removed the seal. It has a lip that helps it seal against the side of the bearing. Replacing it was just as simple. Very easily done.
I removed the top where the flex shaft goes into the Z truck. Again an easy task with a small phillips screw driver. Next, I removed the snap ring with the appropiate snap ring pliers. Simple so far. Doing what I did with my test bearing, I used a Stanley utility knife to remove the seal. What I noticed inside kinda baffled me. Everything looked perfect. I checked the balls with a magnifying glass for scratches or wear. Nothing. The chuck turned flawlessly by hand. Nice and tight, now loose play. I did notice that there seemed to be minimal grease. Again, I used the blade of the knife to apply a synthetic extreme grease for bearings to the inside. I used it sparingly. Just a dab on each ball. After, I reassembled everything back in reverse order. I will be trying a carving out hopefully later today to see if I have a great reduction in heat. I will let you know what happens.

PS. Before I started any of this procedure, I vacuumed the complete inside of the machine (could eat out of it clean) to rid of the dust. The whole process from cleaning to finish took maybe 10 minutes. If this workes OK, I can possible seeing it saving a few bearings in the future.

[Traveler]

My Z truck rises to around 125 degress after 30 minutes of carving and definitely feels hot. After another hour or two or three, the temperature does not go up more than a few degrees.

I noticed that the IR thermometer gives different temperatures depending on the color of the object measured; so, I attached a small piece of black electrical tape to the front of the truck and measure the temperature there. In this case, there is about a ten degree difference, with the black measuring hotter.

T

[jstone]

Is this temperature OK? I have carved for almost an hour and my Z truck gets very hot to touch (not sure of temp). Everything is working fine, no odd noises. I don't want to destroy anything, but to me high temperature means friction somewhere so I keep my carving minimal. It makes me nervous.

[hotpop]

I don't know the actual temperatures but it is normal to be warm. If its hot and uncomfortable to hold it needs to be relubed.

[jstone]

I borrowed a IR temperature gun. My z truck on the top side got up to and basically maintained 113F. Does this seem a bit high? I was talking to some bearing experts and they say that a bearing of this type can handle higher temps and not to worry. They gave me a small amount of a synthetic grease to relube it if I want. He said that should bring the temperature down lower than 113F. He also noted that over greasing a bearing is just as bad as under greasing. A little goes a long way basically. Anyone else able to get an accurate reading of the temperature of their Z truck? I would be interested in hearing what others are getting. Thanks.

[The "DH"]

Here is what I get on both my machines. I use extreme pressure moly-graphite grease very thin every 20 hours, on a five hour cut the temp for both flex shafts never went above 75 degrees (shop temp of 72 degrees). As for the z truck, qc, bits and rails I use 3in1 high performance dry lubricant and on the same 5 hours cuts the temp averaged between 80 and 85 degrees for the z truck.

[DocWheeler]

DH

I assume that you are using the grease on the flex-shaft and the 3-in-1-dry on the chuck, bits, and rails. What else gets the 3-in-1? And, how do you appy the grease?

[The "DH"]

Doc,
Here is the link for the 3in1 High Pro Dry lube http://wd40.com/Brands/3in1pro.html found it at Northern tools. I use it on pretty much everything except the flex shaft.
Here is a link for the grease that I use on the flex shaft http://www.crcindustries.com/auto/content/prod_detail_print.aspx?PN=SL3330 . I use rubber gloves, take a bunch of grease in the palm of my hand and rub it into the flex shaft, then I wipe off the excess grease from my palm and continue rubbing the flex shaft to achieve a thin layer on it entire length, once the flex shaft is back in the sheath with the spring I wipe of both ends and put it back onto the machine. I do this every 20 hours of machine time. Found this grease at Harbor Freight..
Stay Cool
“DH”

[Kenm810]

This Morning at one hour into a carving project I pulled out my infrared thermometer to check the Flex-Shafts Temperature, and thought I’d check a few other spots that might be of interest.

The Shop temperature was 68°F, with no fans or additional air on the machine other than the DD Cabinet blower and the 5.lb compressed air jet attached to the “Z” trucks carving Head.

73.4°F Flex-Shaft where it comes out of the back of the machine
72.3°F Flex-Shaft where it arches and makes contact with the wire support guide
76.7°F Flex-Shaft where it enters the Top Hat on the Carving Head
75.6°F Top Hat on the Carving Head
84.5°F Carving Head assembly
80.1°F Quick release Chuck
78.8°F Carving Bit
82.5°F “Z” Truck Rails
78.6°F “Y” Truck Rails
84.2°F “Y” Drive Gear
83.1°F Muffler Connection at back of machine

All Temperatures were Checked with an Infrared Thermometer
At a Distance of Approximately 6”
While the Machine was Carving
At 50% into a 2 hour Poplar Carving Project

There’s a File below, you can print out to help keep a record of your Machines Temps.
Plus Please add any other Spot Temps. That might be of interest to you.

[www.go3d.us]

I wonder if the manufacture of this machine has the answer on this one?
HT

[rjustice]

We have Makino High speed CNC machines where i work, and the MFG says that a 20-40 degree rise in temp above ambient (current room temp) is normal operating range. This is on a 20,000 RPM spindle. We dont consider the machine warmed up to its maximum accuracy potential until it is at 90 degrees. Accuracy at that point is +/-.0002... the machine may warm up to 100-110 after that. Another thing to note. Not only if you overlube they run too hot... but if the bearings are loose they run too cool. How's that for confusion.
So what i conclude is that those that are running in the 110 range or so, you are probably fine. When getting up to the 125 range... hmmm.. sounds a bit too warm to me..

Ron

[jstone]

I just want to thank eveyone for their input. I don't feel so bad now. My Z truck maybe warm, but sounds like I may be on the high side of normal at 113F. Thanks again.

[jstone]

After cleaning the bearings of grease and then re-greasing them with a high quality synthetic bearing grease, the temperature still went up but took quit a bit longer to do so. I am thinking that it may be normal. The bearing is just releasing heat that builds up. Also, the bearing experts that I was talking with said that bearing can take lots more heat before it can be damaged. The 113F I was getting was not a problem to worry about according to them.