CX601 Milling Machine

[Cuttings]

Yes, I have the exact same mill. It even has the lowered head crank position because I copied it from your drawing posted here. If you remove the stop for tramming the mill that you see just to the rear of the high low control knob and loosen the head pivot nut and pivot lock bolt you still should be able to roll the head over to this side. I can't tell from the picture just how much room you will have between the rear of the head and the wall, but it looks like enough to remove the inspection cover and have a look inside. You might need a mirror. I believe you are going to need access to that hole to get the gears out anyway. Another thought is to take the whole head off and turn it around. I made a frame out of four pieces off 2 X 6 on edge that just fits under the edges of the head, then lower the head down to rest on this frame on the table. I believe I totally removed the pivot lick bolt and loosened the pivot nut first. You need to leave enough room to reach up and get the nut off. Once the weight is on the frame you can remove the nut and slide the whole head forward, then rotate the whole thing around so you get access to the back and leave it sitting on the mill table. This works very well for putting the head back also. I think I would remove the motor before starting because it makes the head kind of top heavy. I may even have a picture of my head sitting on the frame. I will see if I can find it and try and figure out how to send it too you.
Sorry for the delay getting back to you. It is our wedding anniversary today so we had to go out to a nice restaurant and eat too much. I feel a little stuffed right now. I might have to go on one of your old man walks tomorrow.

[Cuttings]

OK here we go, I will see if I remember how to put a picture on here.


It worked! I see I remove the pivot positioning plunger and the down feed handles also. You can see the hole with the 3 screw holes around it.

[brian Rupnow]

That's great Larry. I will probably do the same thing.---Brian---Happy Anniversary!!!

[brian Rupnow]

So--Here we are with the head off the mill, setting on a small framework made of 2" x 8" lumber. So far this is pretty easy. There is one major bolt that holds the head to the vertical slider mechanism, and it is accessible from the front side of the machine. There is also one fairly major stud and nut combination which, when loosened allows the head to tilt left or tight to tram the mill head. The entire head pivots on that first major bolt. The entire head which unbolts is extremely heavy. I made sure that the head assembly was only a fraction of an inch above the wood framework before removing the pivot bolt and stud , because I didn't want to have to lift it when it came free. There is an inspection plate on the back side of the head, which I can now access to see whats happening in there. I will swing the entire head and wooden support frame around to give me clearance to remove that inspection panel and look inside.

[brian Rupnow]

With the inspection panel open, I can immediately see the problem. There is a double spur gear on the motor shaft (motor is on the left in the picture) which has the teeth munched off on the smaller diameter gear which is engaged when the head is set for "low range". The picture as taken is with the mill in "high range" and that gear is not meshing with anything. The second shows the mill with the selector set to "low range", and the toothless gear is supposed to be mashing with another gear.

[brian Rupnow]

This picture shows the gear selector moved over to "low range" and the gear has moved so the damaged gear meshes with another gear to give "low range". --It hasn't moved all the way into position because of the damaged teeth. I think my next stunt will be to remove the motor and hopefully the damaged gear will come out with the motor. This will give me a chance to check the teeth on the gear which the damaged gear meshes with.

[Cuttings]

That is a separate shaft with a ball bearing at each end and it has a gear on the top that meshes with a gear on the motor. Looks like your mill came with better grease than mine did. It appears to be clinging to the gears quite well.

[brian Rupnow]

Okay--My bad. The gear in question wasn't on the motor shaft. I pulled off the motor and motor plate, and see that there is a jackshaft between the motor shaft and the mill spindle. The bad gear is on this jackshaft. I have to disconnect some wires, so this is the point where I get out my sketch pad and start drawing pictures with wire colors on them so that after I disconnect them I can remember how it all goes back together. I see a c-clip on the end of the jackshaft, so now I will disconnect the motor and set it aside, still bolted to the motor plate.

[brian Rupnow]

And here is the nasty wee bugger that caused the problem. I did have to phone Busy Bee in Concord to ask how that shaft came out. I thought I seen how it came out, to free up the gear, but I have been bitten on the arse before by "What I thought!" I did have to use my snap ring pliers to remove a couple of bearing retaining snap rings, then drive the shaft out from the bottom with a brass drift punch. I checked out the gears which this one meshed with, ---They are steel and suffered no visible damage. The new gear costs $55 and they have 44 in stock. I will drive to Concord (north Toronto) tomorrow and buy a new gear.

[brian Rupnow]

Larry--Thank you so much for your picture and for the information you gave me. I would have figured it out myself eventually, but it is always a big help to hear from someone who has "gone there before."---Brian

[Sparky_NY]

So, what caused the gear to go bad? It would be painful to replace it only to have the same thing happen again.

[danlb]

So, what caused the gear to go bad? It would be painful to replace it only to have the same thing happen again.

I had the same thought. The manual for that mill says it can handle 1.25 inch drills or 3/4 inch end mills. It should have been fine.

Often the killer for those gears is switching them from HI to LOW while it's running. Plastic meshing with metal gears will not grind too loud, but that will chew up the gear.

Dan

[brian Rupnow]

I don't really know why the gear chewed itself up. I always turn the mill to it's lowest speed before changing from one speed range to another. If it chews the gear up again, I may buy a knee mill.

[danlb]

I don't really know why the gear chewed itself up. I always turn the mill to it's lowest speed before changing from one speed range to another. If it chews the gear up again, I may buy a knee mill.

My small mill (and lathe) both have hi/low ranges via a similar gear setup. Both caution you to stop the machine before shifting. Oddly, your manual makes no mention of that and even goes so far as to instruct you to change ranges while running during the initial setup test.

Odd. Maybe they want to sell spare parts???

Dan

[brian Rupnow]

If you shut the mill down completely before shifting the hi/low speed lever, you have to turn the spindle by hand to get it to completely shift.