• Scam Alert. Members are reminded to NOT send money to buy anything. Don't buy things remote and have it shipped - go get it yourself, pay in person, and take your equipment with you. Scammers have burned people on this forum. Urgency, secrecy, excuses, selling for friend, newish members, FUD, are RED FLAGS. A video conference call is not adequate assurance. Face to face interactions are required. Please report suspicions to the forum admins. Stay Safe - anyone can get scammed.

Gearbox croaked on the bandsaw

Ironman

Ironman

Ultra Member
The other day I was sawing some box tubing on the bandsaw and things went quiet, so I assumed it had shrugged off the blade again. Shut it down and inspected it and the blade as on the wheels.
After fiddling about with the pulley I determined the gearbox was failing. I unbolted the hydraulic cylinder and removed the cover plate a thick golden oil poured out everywhere. This was a surprise as I expected the typical Chinese Yak Fat they stick into everything. How they got oil into a vertical gear box needs some pondering. After I cleaned up the mess I used my imagination to see where the gear teeth were on the worm gear. I'm guessing it is bronze

This is a King product KC-129DS and I was surprised to see a service center less than 100 km away in Camrose. If it is a bronze gear and the Yak fat is incompatable, that would explain the faiulure.
 
Last edited:
I had a similar failure. When I called closest King parts (Montreal), they had 86 in stock, perhaps that should tell us something.
 
YotaBota said:
That sucks, how old is the machine and what kind of usage (time)?
Click to expand...
This is about 5 yrs old now, and I can only think there may be a design or manufacturing flaw. But the powdered metal like paint in the oil says that the oil is incomparable with bronze. EP zinc fortified grease will allow the zinc to amalgamate with the copper and strip off a tiny film of metal until the gear or bushing is gone. Some modern oils and EP greases are yellow metal compatible but third world...not so much.
 
Last edited:
Mine was fIlled with liquid gold as well!

Makes me wonder if they are just clueless at the factory, or they know it won't be a problem until after the warranty runs out.
 
Well, the parts gang called today. They are 3 month back ordered. It will cost $81.45 so I ordered it. I do have many ways to cut steel.
Obviously this is a problem part and they can't keep it around. If I knew a way to hob a worm gear, once I have the new one in my clutches, I would like to make one out of steel.
 
Sounds like the worm is sized too small for the load applied.
Radicon had a special light grease to put into their boxes.
Perhaps u might try something like lucas oil gearbox additive, can be used straight out of the bottle
Good luck
 
Ironman said:
Well, the parts gang called today. They are 3 month back ordered. It will cost $81.45 so I ordered it. I do have many ways to cut steel.
Obviously this is a problem part and they can't keep it around. If I knew a way to hob a worm gear, once I have the new one in my clutches, I would like to make one out of steel.
Click to expand...
They had 86 in stock in Montreal about a year ago. That says a lot. At the time I found what looked like the same thing on Amazon with various brand names Jet etc. Price was similar but you don't know if it's actually the same part, so I ordered from King.
 
wmetfab said:
Sounds like the worm is sized too small for the load applied.
Radicon had a special light grease to put into their boxes.
Perhaps u might try something like lucas oil gearbox additive, can be used straight out of the bottle
Good luck
Click to expand...
I don't think the worm is overloaded at all, a bandsaw is a relatively light load. Try turning the pulley by hand when in the cut and you will see. It is not an intermittent load, which could only happen if you had an inch or two of teeth missing. Everything points to lubrication problems

The Right Additives
One of the most important jobs of a gear oil additive is to form a protective or sacrificial barrier between contacting surfaces when the conditions exceed that of the bulk oil’s film strength.
An additive package for a lubricant in a worm drive must be selected with care, since the yellow metals often contained within worm wheels can be adversely affected by corrosion from the activated sulfur within the extreme-pressure (EP) additive, particularly in the presence of heat. Nevertheless, advancements in additive formation with deactivated sulfur have helped to reduce or eliminate these corrosive attacks.
Worm drives can present a unique boundary lubrication challenge, with the focus more on friction reduction than on the effects of wear. In these applications, a specific type of mineral-based lubricant known as a compounded oil can be used.
This lubricant is formulated with up to 10 percent fatty acid (natural oil) or acidless tallow as the compounding agent along with rust and oxidation inhibitors and other additives. This results in improved lubricity, reduced friction and decreased sliding wear.
EP oils are still commonly used in worm drive applications where they are formulated with yellow metal compatibility. However, both compounded oils and EP gear oils have a working temperature limitation of approximately 80 degrees C before oxidation rates rapidly increase, resulting in acidic products that can attack cupric worm wheel materials.

Boston Gear says:

Beyond having a ‘best’ lubricant for a given gearbox,
there are specific lubricant characteristics that are known to
damage gears. In the case of worm gearboxes, typically the
worm is made of steel and the gear of bronze. Lubricants
that include sulphur or chlorine additives will soften the
bronze gear with the result being a reduction in unit life.
Many lubricants that are classed as EP (Extra Pressure)
will include these chemicals. While it may seem intuitive
that an EP (Extra Pressure) lubricant will be appropriate
for gearing, in this case, it is actually the opposite as
EP additives will accelerate wear on the bronze gear by
softening the gear teeth. Figure 3 shows a unit where the
bronze gear teeth have
 
So what is an ideal oil for this application?

I'm afraid to open the gear box, I half expect to see liquid gold again. This is what I used.
 

Attachments

  • F4D7A89E-58D9-44A5-8CB4-ED697B1DADDE.jpeg
    F4D7A89E-58D9-44A5-8CB4-ED697B1DADDE.jpeg
    400.6 KB · Views: 8
  • 0C2B0E96-B721-41E6-BA00-10672E5D390B.jpeg
    0C2B0E96-B721-41E6-BA00-10672E5D390B.jpeg
    465.9 KB · Views: 8
This is what i had in mind. I would use this straight out of the bottle
 

Attachments

  • Screenshot_20240625-182800_Chrome.jpg
    Screenshot_20240625-182800_Chrome.jpg
    111.3 KB · Views: 5
@Ironman - is the BB, https://www.busybeetools.com/products/metal-bandsaw-5in-with-swivel-csa-cx116.html, the same as the King?

Grizzly also has what looks like the same machine.
www.grizzly.com

5" x 6" 1/2 HP Metal-Cutting Bandsaw - Grizzly Industrial

<h1>M1013 Shop Fox 5" x 6" 1/2 HP Metal-Cutting Bandsaw</h1> <h2>A metal-cutting bandsaw is a must for any metal shop.</h2> <p>The M1013 has three speeds, an automatic shut-off, ball-bearing blade guides, and many more important performance features. </p> <p>As an added bonus, it has a...
www.grizzly.com www.grizzly.com

One of these outfits might even have stock?
 
YotaBota said:
@Ironman - is the BB, https://www.busybeetools.com/products/metal-bandsaw-5in-with-swivel-csa-cx116.html, the same as the King?

Grizzly also has what looks like the same machine.
www.grizzly.com

5" x 6" 1/2 HP Metal-Cutting Bandsaw - Grizzly Industrial

<h1>M1013 Shop Fox 5" x 6" 1/2 HP Metal-Cutting Bandsaw</h1> <h2>A metal-cutting bandsaw is a must for any metal shop.</h2> <p>The M1013 has three speeds, an automatic shut-off, ball-bearing blade guides, and many more important performance features. </p> <p>As an added bonus, it has a...
www.grizzly.com www.grizzly.com

One of these outfits might even have stock?
Click to expand...
Yes, that's the one. BB may have the parts, I'll have to check with them.
slow-poke said:
So what is an ideal oil for this application?

I'm afraid to open the gear box, I half expect to see liquid gold again. This is what I used.
Click to expand...
90W or 140W "Mineral" gear oil without the additives. Or synthetic gearlube or steam cylinder oil.
But if I were you, I would pull the lid and check that gear. Even with damage it may be salvageable.
 
I have to confess to not being any kind of an authority on the subject, but I don't recall ever seeing a steel worm gear. I think I recall being taught at some point something to the effect of the dissimilar metals being used to prevent galling...... If you can make the worm out of a South Bend 10k apron work, I might know a guy......:rolleyes:
 
On reflection to that, is your wheel brass as well? Thinking more on this, I think have seen a steel worm, but the wheel was brass.....
 
You must log in or register to reply here.
Back
Top