PDA

View Full Version : 4x6 bandsaw repair



plunger
12-05-2010, 03:35 AM
My little bandsaw started sounding real rough under load only. I thought I adjusted the blade bearings to much but theres no problem there. I decided to look at the gearbox and was shocked to find there is considerable wear mainly on the worm gear.The worm also has wear but not nearly as badly.
First obvious observation is that the worm and gear are made of very soft material.
Is this something that can be made in a homeshop ? Especially by a noobie
Buying spare parts for this is not an option . Will I be able to put some other kind of worm gear in from maybe a reduction gearbox or similer
Has anyone made one or know how I could go about it as I would be real happy to have my bandsaw running again(feels like there has been a death in my tool family)
I am also suprized as this machine does not work hard
Kind regards Eugene

drmico60
12-05-2010, 04:47 AM
My little bandsaw started sounding real rough under load only. I thought I adjusted the blade bearings to much but theres no problem there. I decided to look at the gearbox and was shocked to find there is considerable wear mainly on the worm gear.The worm also has wear but not nearly as badly.
First obvious observation is that the worm and gear are made of very soft material.
Is this something that can be made in a homeshop ? Especially by a noobie
Buying spare parts for this is not an option . Will I be able to put some other kind of worm gear in from maybe a reduction gearbox or similer
Has anyone made one or know how I could go about it as I would be real happy to have my bandsaw running again(feels like there has been a death in my tool family)
I am also suprized as this machine does not work hard
Kind regards Eugene
Hi Eugene,
Have alook at this page, http://mini-lathe.com/Bandsaw/Gearbox/4x6%20bandsaw.htm , on Frank Hooses site. He made some extensive repairs to his bandsaw gearbox
Mike

DICKEYBIRD
12-05-2010, 07:59 AM
You have to put a www. after the // in the link for it to work.:)

plunger
12-05-2010, 06:47 PM
on further investigation I found the bearings to be gone. Most amazingly the bearings have been pressed into its housing but the housing was painted so the bearings are very tight and probably the reason for it packing up.

Still hoping to know if anyone can tell me how to make a worm and wheel in the homeshop invironment

Mark K
12-05-2010, 08:59 PM
There are years of good posts on the Yahoo group '4x6bandsaw'

Lots of real world (and world wide) experience with these tools, including gear box sorrows.

Mark

Ries
12-05-2010, 09:27 PM
Dont they have a postal service in South africa?
Or Fed Ex and DHL?

I order new CD's from england, and the postage is under ten dollars.
Why couldnt you get replacement gears from Grizzly or Enco or Jet, and just pay the international shipping?

Surely that would be quicker, easier, and probably cheaper, than making gears from scratch?
Depending on the gear needed, you usually need a special mill that, in the USA, anyway, costs 3 or 4 times as much as the new gears do. Then you need a rotary table, and a mill with a head that tilts.
Sure, you can do this on a bridgeport with a rotary table, if you have the right cutter.
Assuming its straight cut, and not helical, gears.

mechanicalmagic
12-05-2010, 09:38 PM
Still hoping to know if anyone can tell me how to make a worm and wheel in the homeshop invironment

The worm is relatively easy. It is like an Acme thread, except that the sides are angled. If you can cut threads the same pitch as the worm you are in luck. If your lathe does not have that pitch, you are out of luck. Can you cut the proper pitch?

macona
12-05-2010, 09:43 PM
You should be able to get the parts from harbor freight.

RobbieKnobbie
12-05-2010, 11:16 PM
My four cents to this one...

$.02 x 1) Harbor Freight (and grizzly/jet et al) tend to be very good with parts, and reasonably priced to boot. I have had bad experiences with Enco's parts dept though. International shipping isn't all that bad, I've sent stuff to Europe and Australia and, while expensive, it's not prohibitive.

$.02 x 2) The oil that came in my 4x6's gearbox was low grade oatmeal. I won't go throught the whole story, but after I replaced it with something more suitable the whole thing ran noticably quieter and cooler.

Black_Moons
12-05-2010, 11:17 PM
Grizzly/Horror Freight should have the parts.

Alternateively, theres some posts on this forum about making an acme threaded rod (Or your own threaded rod made on the lathe) into a hob, that then can be used to make a gear.

AFAIK, the pitch only needs to equal an even number of teeth all the way around the gear, So your not limited to one pitch.

And technicaly you could reduce or enlarge the worm, so that the gear itself is bigger or smaller, If you need. (So you can use a pitch your lathe can make, Or that you can find premade rod for)

plunger
12-06-2010, 01:21 AM
I would be hesitant to buy a gear from overseas. First to get the right gear may be a problem. How would I measure it exactly as my machine is branded differently to yours. Second you guys are backward when it comes to measurement and like to confuse things by measuring things in thousands of a inch:) :) I have never bought anything overseas so wont know how.I just remember my wife boasting about buying a hairdryer(ghd) for less than she could buy it in the shops. She did get it cheaper but when she picked it up the taxes made it much more than she could get it locally.
I think if I could basterdise these gears from a machine it could be make to work. What type of machines use these gears.? Black moons may be on to something.
The gear is a 21tooth. I cant measure the pitch accurately as I cant figure how to knock the worm out as they didnt allow this in their design. ( easy to knock in but no acsess to knock out)
How hard is it to hob a gear like this .Is there anyone with hobbing experience?
It looks like the pitch is about 6 or 7 mm and my lathe can cut up to 6mm. I have seen alot about hobbing when it comes to telescopes but they are doing many fine teeth and the teeth are very small. I read about a guy whose gear also packed up and his was a 23 tooth .Another question I have is that I have a dividing head that when I bought the mill was atached to the lead screw of the mill with a combination of gears. What is the purpose of that and what application would it be used for?

The Artful Bodger
12-06-2010, 02:21 AM
It is a tough one Eugene and I do not think I could find the spares in New Zealand either.:(

Toolguy
12-06-2010, 10:53 AM
The dividing head attached to the lead screw is for cutting spirals and cams.

Ries
12-06-2010, 12:46 PM
While these small saws are NOT all the same, they are certainly similar, and use similar gears in the drive train. It might take boring a hole a bit, or making a bushing, but you should be able to easily adapt a gear set from any of the major brands to your saw.

Here is the online manual, with parts breakdown, for a similar saw-
http://content.wmhtoolgroup.com/manuals/414458_man.pdf

I am assuming you want the parts numbered HVBS462-091, Worm Gear, and HVBS462-094, Worm gear with Shaft.

You may be able to order these thru the South Africa Jet distributor, Strand Hardware, in Port Elizabeth.

http://www.strandhardware.co.za/strandNew/

However, if not, you should be able to order direct from Jet/WMH, either from the USA or europe. These would fit in a standard envelope, and weigh very little. Not expensive to ship. I have no idea what taxes would be in SA, but I cant imagine you can make functional replacements anywhere near as cheap as you can buy them.

I have purchased all kinds of things from overseas, with no problems- it has become very common these days to ship things all over the world- I have several friends who have purchased an elegant wood and brass pinhole camera that is made by a gentleman in Hong Kong, for instance, with no problems whatsoever.
http://www.zeroimage.com/web2003/EntryPage/entryFrameset.htm
I have purchased machine tools from Germany, myself- they are made to order, take months, and come over on ships in crates as big as automobiles.
Its easy- you just email, and then pay.

plunger
12-06-2010, 03:29 PM
I have found a s african company that has a wheel and worm shaft. However mine is 21 teeth and 47 od and this one is 24 teeth and 53mm . I have been warned that if it does not fit there is no refund and I have to order it 600 km away from me. However the price is good and the gear is bronze and not cast iron. I dont know enough to figure out if there is enough clearance for this to line up in the existing bores. Ries that is a beautifully presented catalogue. You guys in the states are real spoilt for choice.
I had a quote to make a worm and wheel and I could buy 2 bandsaws for the price.
I also notice the driven wheel of the jet is running on bearings where as mine is on a steel bush with lots of slop. My machine had to have its motor rewired as it packed up in the first 5 minutes of use. It also would give me a shock when I would touch it. The blade tensioner handle broke after the second week and I had to replace the vice handle and build a proper stand for it So much wrong and yet I still like the little machine.
I would still like to know if this gear could not be made in a homeshop