Thread: Power Hacksaws V's Bandsaws

Originally Posted by simonl

I also rang the local steel place for a price on 100mm length of 150 diameter Phosphor Bronze bar.
Simon

Of course Simon, to cut that to size you really need a large bandsaw .

Shed, it's 40 to 1

Michael

ok, thanks Micheal, nothing ventured nothing gained

Ronson Gear list a worm & cast iron wheel in M3, 40:1. Don't know how well this link will work but.....

KHK Web Catalog Dimension table

To save you the trouble, no results in bronze.

PS: Does anyone else think this would be worth splitting into a new thread?
"Heska bandsaw worm drive repair" for instance?

Hi,

It's late and I'm working at 8:00am so I'll be quick!

Hi Bryan, That link worked and it's the same size, module, No. teeth etc so it may be a contender! Perhaps I'll give them a ring too. How would cast stand up to the task you think?

Hey maybe I should make a 20 tooth gear, just think how much quicker it will be to cut stuff!

Edit: Also for reference, my calculations tell me that I need a blank of 126mm OD and it's 25mm thick. Even if the stuff sells for $1000/M I'm still only needing $25 worth?

Cheers,

Simon

Originally Posted by simonl

Hi,

Edit: Also for reference, my calculations tell me that I need a blank of 126mm OD and it's 25mm thick. Even if the stuff sells for $1000/M I'm still only needing $25 worth?

Cheers,

Simon

Brace yourself for this Simon -
PB (Medium).jpg
I don't know how representative these prices are but if you could get the stuff for $1000/m and then resell, you could make a fair bit of money. Based on those prices (which would be bumped up for "off the street" retail), the price seems to be around $30/kg. Trade pricing would be less than that - I'll talk to a few people I know.

Attached below as a PDF is a section of the blank that I think you will need. Your calculations are correct for a spur gear but a worm wheel has a slightly different shape. I think you need a piece 131mm in diameter (not that it makes that much difference if you buy a 150mm round blank). Metal is sold by the kg and the piece you need is 3.5 to 4kg.
simons gear Model (1).pdf

Cast would work

Michael

Bryan - perhaps the whole thread should be renamed - "The Heska bandsaw story" or perhaps "Look what followed me home..."

Originally Posted by simonl

How would cast stand up to the task you think?

I wouldn't really know, but cast iron and steel are supposed to work well together in general. They wouldn't offer the combination if it didn't. The loads on a band saw should be smooth and steady, and you're not going to be using it for mass production.

But I'd hate to spoil Michael's fun.

This looks like a link to the manufacturer Heska Maschinenfabrik GmbH

... and the same model is still listed - or one very similar: Google Translate
Be fun to get a price. Couldn't see any mention of spares though.

found this, 1,950 EUR

RESALE.INFO details

Michael, those prices are scaring me! I begining to think I did them a favour by removing it from their shop
Also, the drawing of the gear (thankyou!) shows a tooth height of 9.11mm, my calculations and according to Ivan's book the tooth height shoud be (from memory) about 6.5mm Have I got my calcs wrong or have I been reading the tables incorrect?

I have a bit of cast laying around, I would prefer to use original materials but if those prices are reflected in suppliers here, then it ain't going to happen! What is the worst that vcan happen if I use CI? Premature wear or I just ease off of the feed rate in use?

Thanks Shed & Bryan, that link to the manufacurer may yet come in handy. The band saw for sale for EU1950 is identical to mine. Mine has a lot of stuff (hydraulics etc) that have been disconnected - but still present. I can use the picturers if I need help in putting it back together. Also I'll try to match the paint colour. I would be hoping that mine will look very similar once I'm finished.

Cheers,

Simon

The formulas that you are using are for a spur gear - flat across the tooth. A proper worm wheel is curved to nestle into the worm (better fit = better power transfer)
You could use cast iron if the worm is hardened. It may wear a little faster than the bronze but for the amount of material you are likely to cut it should not matter.

Those links are intersting - it may be worth contacting the manufacturer and seeing whether they do sell spares. It will certainly be quicker to buy one and the price may not be too outragous. If nothing else it will give you a basis for comparison.

Michael

Originally Posted by Michael G

The formulas that you are using are for a spur gear - flat across the tooth. A proper worm wheel is curved to nestle into the worm (better fit = better power transfer)
You could use cast iron if the worm is hardened. It may wear a little faster than the bronze but for the amount of material you are likely to cut it should not matter.

Those links are intersting - it may be worth contacting the manufacturer and seeing whether they do sell spares. It will certainly be quicker to buy one and the price may not be too outragous. If nothing else it will give you a basis for comparison.

Michael

Thanks Michael, I agree. I assume the worm is hardened (although I have not tested with a file) as it has blackened discolouration which looks like the result of heat treatment process.

Simon

I had a fairly good look around on the internet to see if I could find anything on fly cutting
worm gears ............. found nothing ?

That puzzle's me because in the past my father has made me 3 worm gears, I just rang my brother, who worked with him for some years, and he confirmed that yes indeed he (my father) did fly cut them on the mill, but my brother never had anything to do with it, so not much help there other than confirm that senility has not quite set in.

The worm gears that he fly cut for me, 1 was for a over head winch, 1 was for a 3hp tiller and 1 was
for a Pasquali rotary hoe.

To my knowledge those gears worked without a problem and there was no premature failure.

So what is missing here ?

Why exactly can't a worm gear be cut on a mill with a fly cutter ?

Pictured below is the brobo saw that the old boy made, and yes he fly cut the worm gear.

Originally Posted by shedhappens

I had a fairly good look around on the internet to see if I could find anything on fly cutting
worm gears ............. found nothing ?

That puzzle's me because in the past my father has made me 3 worm gears, I just rang my brother, who worked with him for some years, and he confirmed that yes indeed he (my father) did fly cut them on the mill, but my brother never had anything to do with it, so not much help there other than confirm that senility has not quite set in.

The worm gears that he fly cut for me, 1 was for a over head winch, 1 was for a 3hp tiller and 1 was
for a Pasquali rotary hoe.

To my knowledge those gears worked without a problem and there was no premature failure.

So what is missing here ?

Why exactly can't a worm gear be cut on a mill with a fly cutter ?

Pictured below is the brobo saw that the old boy made, and yes he fly cut the worm gear.

Nice old saw good to see that the saw kept in the family.Lifts my heart to see things made by our fathers ''keep on keeping on'' they came from hard times and generally put the best of their resources and input into these long living machines and tools.Cheers John

Originally Posted by j.ashburn

Nice old saw good to see that the saw kept in the family.Lifts my heart to see things made by our fathers ''keep on keeping on'' they came from hard times and generally put the best of their resources and input into these long living machines and tools.Cheers John

Seen my old man fly cut worms admittedly much smaller but is the tricky bit the set up as it has to be off set am sure he swung the table as it was a universal mill if the mill a straight table might be hard to get the helix angle right skinny or waisted tee bolts and studs might just make it.The old man used to make his own replica Meccano and his parts were of equal quality to the genuine stuff. Worked an old Qualos mill with fly cutter to do his gears was blind for last 2 yrs of his life and worked that mill with manual indexers of different numbers with pimples on them. Couldn't stop the old boy till his kidneys failed. My sister sprung him using the big old Lang lathe when he was near blind., heard the machine going when she arrived and there he was working in the dark.Not for the faint hearted thats for sure. and he never got wound up in it like we thought might happen.he was warned off there and then. Got lots of stories to share Cheers John. He used to get his cutters done in Melbourne some where wire cut EDM machine to the profiles and checked with and old comparitor.