Author Topic: Meba Bandsaw Cutting Direction ?  (Read 9171 times)

Offline awemawson

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Meba Bandsaw Cutting Direction ?
« on: August 03, 2016, 06:50:46 AM »
Last year I acquired a Meba  horizontal bandsaw in 'very much used' condition. Apart from putting it on wheels so I can push it around and fitting a new blade I've not used it much as the previous owner was using a total loss coolant system from a tank mounted on a stanchion.

Needing to cut some Fork Lift Truck tines I was motivated to sort it out so have recently fitted an internal tank and pump. Pump was a bit of a problem as all normal suds pumps were too tall to fit, so I've ended up using a diesel transfer pump of the sort intended to drop into the 2" hole in a 45 gallon drum. Downside was that it was 12v so have had to arrange a 12v supply as well - no matter- it's all working.

Now looking at various horizontal band saws on YouTube and eBay most seem to feed coolant to both blade guides - I seem to recall that Micktoons 'Startrite Meba' which is very similar to this one does the same. However this one only has provision on one blade guide for the introduction of coolant. Blade guides are 'handed' so are not interchangeable meaning that fluid has to be introduce on the right hand guide.

Now unless the maker expects the coolant to be carried all the way round the band before it gets to the work, then this means that the blade must travel 'right to left' so in re-wiring all the previous dodgy cabling that is how I have set it up.

But this seems counter-intuitive as the cutting forces are away from the vice fixed jaw. Also every Youtube band saw video I can find has the blade going the other way.

The issue is confounded by direction arrows on the wheels - it looks as though original cast arrows have been modified to point in the opposite direction.

All very odd - anyone have any experience of these things ?
Andrew Mawson
East Sussex

Offline mattinker

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Re: Meba Bandsaw Cutting Direction ?
« Reply #1 on: August 03, 2016, 08:14:38 AM »
Hi Andrew,

I take it you've been busy! I was wondering about you as i haven't seen anything from you in a while.

I agree with you about the direction of cut, I've never seen a band saw of any kind that cut away from the drive wheel. When I added a coolant system to my 4x6 band-saw, I experimented with the position of the coolant arrival. I found that the best place to be just after the cut as yours is set up. I'm using a jet of coolant aimed at the blade from above, this means not only does it cool the blade immediately, but it also washes the chips away, keeping the rollers and the wheels cleaner.  My band-saw has a much shorter blade than yours, so the fact that the coolant goes all the way round the blade doesn't mean that it would in your case!

All the best, Matthew.

Offline awemawson

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Re: Meba Bandsaw Cutting Direction ?
« Reply #2 on: August 03, 2016, 08:26:28 AM »
It would be relatively trivially simple to drill and tap an appropriate hole in the other (left hand) blade guide, and I may well do this if my enthusiasm doesn't die first. There is also a clue in the holes that the blade emerges from and returns to in the wheel covers, as the right hand side one has evidence where a blade wiper has been fitted, whereas there is no such sign on the left hand side.

Andrew Mawson
East Sussex

Offline awemawson

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Re: Meba Bandsaw Cutting Direction ?
« Reply #3 on: August 03, 2016, 09:55:43 AM »
OK I've convinced myself to reverse the blade direction of travel and fit another coolant nozzle on the left hand blade guide.

To this end I've ordered up a 10 mm Tee piece for the coolant pipe, and made a new nozzle. I'll hold off fitting it until the Tee arrives. I supposed I'd better sort out the missing blade wiper - what do the team recommend - a bit of draught excluder brush or some neoprene sheet ?
Andrew Mawson
East Sussex

Offline John Stevenson

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Re: Meba Bandsaw Cutting Direction ?
« Reply #4 on: August 03, 2016, 12:02:53 PM »
Nooooooooooo,

Leave it, it's correct.

Spent a long while working with Starrett and later Lenox on big bandsaws. That big the blades had one tooth per inch.

They suddenly realised about 20 odd years ago that they had their ideas wrong.

Old way, sawing towards the fixed jaw, blade tilted down, if the blade grabbed it dug in and caused blade damage or failure.

New way, cutting away frome fixed jaw tilted up and a dig in throws it up and clear.
My bigsaw which is possibly a tad bigger than Andrew's ? at 12 1/2 " round gets double the life out of a Lennox blade. Get Lenox blades only from MSC J&L, anything else is a waste of money
John Stevenson

Offline micktoon

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Re: Meba Bandsaw Cutting Direction ?
« Reply #5 on: August 03, 2016, 07:27:46 PM »
Hi Andrew, I think John is right as my saw cuts away from the fixed jaw and came from Metal supermarket Gateshead , they cut lots of metal and had the saw maintained and repaired by professional company so I think they would have set it up correctly.
 All I can say is I have wondered about the direction before but I am sure the arrows on my wheels confirmed the direction was as intended on my saw. The other thing is it cuts great and straight, so I also just thought if it's not broke don't fix it lol.
  Cheers Mick

Offline awemawson

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Re: Meba Bandsaw Cutting Direction ?
« Reply #6 on: August 04, 2016, 02:40:06 AM »
Thanks Mick. I had a close look at one of the pictures in your rebuild thread and deduced the same from the tooth shape  :thumbup:
Andrew Mawson
East Sussex

Offline awemawson

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Re: Meba Bandsaw Cutting Direction ?
« Reply #7 on: August 04, 2016, 12:02:53 PM »
Well it seems to work  :clap:

If you remember from my opening post this band saw was dragged back to life to cut up some Forklift Forks to donate material to make Vee Blocks for shaft straightening on my 60 ton press.

Impatience being my middle name I had at it this afternoon. The forks are 40 mm x 120 mm - I'd have preferred 50 x 120 but you work with what you have. The saw has two speeds selected by manually changing a Vee belt (dodgy Vee belt - spare on order !) and is running at 120 feet per minute at the moment with an 8 tpi M42 blade and oddles of coolant (must cure that drip!)

It took about ten minutes and gave a remarkably clean cut - no idea what the steel is but it will be something pretty tough to stand up to the abuse of being a forklift fork.

I'm certain now that the saw was originally designed to run the blade in the opposite direction - ie left to right - as otherwise it wouldn't need a swarf scraper on the 'entry' to the right hand wheel. But in the light of John S's comments, and Mick saying his one runs right to left that is the way I'll leave it.

The eagle eyed amongst you will have noticed I've fitted the extra nozzle to the left hand guide, but it's not plumbed in as I'm still awaiting the Tee junction.
Andrew Mawson
East Sussex

Offline mattinker

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Re: Meba Bandsaw Cutting Direction ?
« Reply #8 on: August 05, 2016, 08:30:20 AM »
This reversing the direction of cut is very interesting, My cheepo Clarke 6X4 band-saw has a tendency to derail, which despite my concerted efforts still plagues me! I've trued up the wheels, checked wheel alignment and made a hydraulic down feed, all to no avail! I'm going to see if I can reverse the motor!

Thanks John for pointing it out!

Regards, Matthew

Offline awemawson

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Re: Meba Bandsaw Cutting Direction ?
« Reply #9 on: August 05, 2016, 09:03:17 AM »
It's interesting (at least to me!) that Mick's Startrite Melba cuts 'right to left' and I'm certain my (pure) Melba was intended to cut 'left to right' but has been modified. I strongly suspect that Micks is somewhat younger than mine, and maybe was made after the wisdom John S revealed became general knowledge.

It'll be interesting to see if Matthews modification to his Clarke makes a difference.
Andrew Mawson
East Sussex

Offline philf

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Re: Meba Bandsaw Cutting Direction ?
« Reply #10 on: August 05, 2016, 11:07:58 AM »
This reversing the direction of cut is very interesting, My cheepo Clarke 6X4 band-saw has a tendency to derail, which despite my concerted efforts still plagues me! I've trued up the wheels, checked wheel alignment and made a hydraulic down feed, all to no avail! I'm going to see if I can reverse the motor!

Thanks John for pointing it out!

Regards, Matthew

Matthew,

If, like mine, your 6 x 4 has the saw table attachment you won't be able to use it if you reverse the motor (and blade).  :(

Phil.
Phil Fern
Location: Marple, Cheshire

Offline mattinker

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Re: Meba Bandsaw Cutting Direction ?
« Reply #11 on: August 05, 2016, 05:15:14 PM »
Phil,

I have virtually never used the saw table attachment, I use either my plasma cutter or extra thin cutting disks for that kind of cut. I would however be very pleased if I could get over the blade derailing.

Thank you for your thought! Regards, Matthew.

Offline awemawson

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Re: Meba Bandsaw Cutting Direction ?
« Reply #12 on: August 06, 2016, 06:58:44 AM »
The 'Tee' piece for the coolant hoses arrived in the morning post, so it was fitted in short order. However the first (right hand) nozzle hogged all the flow, so it proved necessary to push a 'flow restrictor' down it to allow the left hand nozzle to receive coolant. This is just a bar of acrylic with a co-axial hole drilled down it. It took a few iterations to balance the flow between left and right by choosing different hole sizes.
Andrew Mawson
East Sussex

Offline awemawson

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Re: Meba Bandsaw Cutting Direction ?
« Reply #13 on: August 08, 2016, 05:25:06 AM »
Fitted the replacement Vee belt - I reckon failure was pretty imminent !

This now gives me the choice of approx 60 or 120 foot per minute on my 8 tpi blade. Anyone care to comment on what speeds are suitable for what cross section and materials ?
Andrew Mawson
East Sussex

Offline John Stevenson

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Re: Meba Bandsaw Cutting Direction ?
« Reply #14 on: August 08, 2016, 05:45:30 AM »
Andrew,
My saw should have a motor that drive a variable speed friction gearbox, however these are very fragile and when I went to collect my machine the guy was very apologetic and wanted to back out of the sale as someone had removed the gearbox without his knowledge for use on one of their existing machines.
However I managed to still buy it but at a reduced price as i was sure I could sort this out.

Now the company I was working for at the time had a Startright band saw, bough new just before I joined. I believe this was a 4 or 5 speed belt drive mode but in all the time I had been there no one had ever change the speed on this and it was used for everything.

So I stuck a rev counter on it and measured the speed, then worked out ft per minute, went home and did the maths on mine [ can't remember what the answer was ] but worked out that I needed about a 75 rev motor.
So raided the machinery scrap yard at work and found a 75 rev output in line geared motor.
New mounting plate and coupling and it's been on there since I fitted it over 20 odd years ago.
John Stevenson

Offline awemawson

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Re: Meba Bandsaw Cutting Direction ?
« Reply #15 on: August 08, 2016, 06:18:24 AM »
John,

I just put a blob of blue Dykem on the blade, then timed how long it took to go one rev - blade being about 3 metres or 10 foot it was simple to work out fpm.

I'd be interested to hear what your fpm actually are if you could repeat the exercise.
Andrew Mawson
East Sussex

Offline John Stevenson

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Re: Meba Bandsaw Cutting Direction ?
« Reply #16 on: August 08, 2016, 10:05:51 AM »
32 rpm on a 16" wheel

So 134 ft/min
John Stevenson

Offline awemawson

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Re: Meba Bandsaw Cutting Direction ?
« Reply #17 on: August 08, 2016, 10:37:11 AM »
Thanks John  :thumbup:
Andrew Mawson
East Sussex

Offline awemawson

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Re: Meba Bandsaw Cutting Direction ?
« Reply #18 on: August 08, 2016, 11:33:23 AM »
Come across this useful article by Lenox - amazing what's available these days on the web  :thumbup:
Andrew Mawson
East Sussex

Offline Will_D

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Re: Meba Bandsaw Cutting Direction ?
« Reply #19 on: August 08, 2016, 05:38:49 PM »
Why dont't we have a "Thank You" option?

SMF does have the facility.

Anyways - Thanks for as great pdf!
Engineer and Chemist to the NHC.ie
http://www.nationalhomebrewclub.ie/forum/

inthesticks

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Re: Meba Bandsaw Cutting Direction ?
« Reply #20 on: August 08, 2016, 06:22:48 PM »
Thank you for the download Andrew, very informative. My 4.5 X 6 Busy Bee import likes to jump the wheels on a fresh blade maybe reversing might help.

Cheers
CB

Offline mattinker

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Re: Meba Bandsaw Cutting Direction ?
« Reply #21 on: August 11, 2016, 03:03:55 PM »
Well,
I've just finished putting back together my bandsaw motor, in order to reverse the direction I had to delve inside the windings and bring out the ends of the starter circuit. I can now simply swap two wires to change directions. Unfortunately, I broke my spare blade just before starting this experiment. My blade supplier is closed for their summer holidays so I haven't got a new blade to try. The blade that I have has already seen service. So far, the results are not very good, but I'll need to do more tests before I can really say whether it"s a success or not! If anyone is interested in reversing one of these single phase motors, please let me know.

All the best, Matthew

Offline mattinker

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Re: Meba Bandsaw Cutting Direction ?
« Reply #22 on: September 06, 2016, 10:14:13 AM »
Andrew et al,

I hadn't forgotten the bandsaw cut direction experiment, I received the blades I ordered in the middle of last month from Germany to day. So far I've got the blade mounted and running fairly accurately, I've got a lot of testing to do, but the initial impression is that it doesn't seem to be very different!

A few years ago I trued up the wheels on my lathe in a effort to get over this blade derailing problem, the wheels have a flange on one side and I cut them straight, without a crown, I presume that thy don't need a crown, does anyone have any experience of this?. I have seen the Jet version of this saw running without the derailment problem, but I couldn't get inside it to find out.

Your thoughts on this please, regard, Matthew.

Offline mattinker

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Re: Meba Bandsaw Cutting Direction ?
« Reply #23 on: September 24, 2016, 10:20:49 AM »
Andrew,

I have been using my 6x4 bandsaw backwards, so far there is a marked improvement, I can cut at feeds that were previously impossible. So far the blade is staying on although I will have to reverse the clamping set up. I am very glad you asked the question and very pleased that John Stevenson answered it! As Phil says, I can no longer use the vertical set up, but I do a lot of horizontal work, and practically no vertical, this won't be a loss.

Thanks again, all the best, Matthew

Offline awemawson

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Re: Meba Bandsaw Cutting Direction ?
« Reply #24 on: September 24, 2016, 10:53:40 AM »
Nice to hear of collateral benefits  :lol:
Andrew Mawson
East Sussex