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The Shop => Tools => Topic started by: Jo on April 10, 2017, 03:12:59 AM

Title: Startrite 352 Bandsaw mods
Post by: Jo on April 10, 2017, 03:12:59 AM
I have been trying to pick up a nice metal working bandsaw for a while but they are all huge and expensive  :bugeye:

At the weekend I was dragged over to look at pricing up some WOOD  :palm: machine tools for a friend. Honestly I would not have touched them but the Startrite bandsaw under all that saw dust has potential. The deal went: I could not have one I had to have all of them and they will be delivered next Saturday. What have I done all I wanted was the bandsaw and I have been conned into taking a big wood lathe, a planer and yet another pillar drill, wood tools are not allowed in my workshop so they will have to go. In the meantime they can sit outside so that my boys don't think I have gone over to the dark side.

Leaving me with the 352 bandsaw.... 

I have no idea on the speeds all it says is low and high on the back  :( It does mention cutting brass but I will want to cut steel as well. I was thinking whip out the 240 volt electrics and fit it with a three phase motor and a VFD. The other option is to fit an additional pulley set to drop the speed. Has any one done this to one of these?

There is also an issue of blade guides: It seems to have a couple of pieces of plastic acting as blade guides... I thought most decent machines had ball bearing guides, or would bronze work....

Jo

   
Title: Re: Startrite 352 Bandsaw mods
Post by: awemawson on April 10, 2017, 03:40:59 AM
Jo there is a standard 10:1 Startrite gearbox that they fit to some of their saws to give a wide range of speeds - I seem to remember that it's pulley in and pulley out so easy to implement. Gear change is by pulling a knob in or out engaging a dog clutch.

There are scrap Startrites for parts that occasionally turn up on ebay
Title: Re: Startrite 352 Bandsaw mods
Post by: Jo on April 10, 2017, 03:51:08 AM
10:1 would work: I am lead to believe that one of the speeds is 1000mm/s and I want something around 65mm/s for thick steel.

I have a few pulleys kicking around  :thumbup:

Jo
Title: Re: Startrite 352 Bandsaw mods
Post by: PekkaNF on April 10, 2017, 03:53:35 AM
I have metal cutting band saw and difference to wood band saw is very much lower band speed. If you don't do production work you can opt for low speed for iron metals and use that speed to cut all metals (just a little slower and a little less productive, not biggie for us hobbyists).

Therefore I recommend jack shaft and extra pulleys to reduce the speed to bearable level. You don't need VFD, unless you really insist, no point of adjusting the speed down with VFD in stead of jack shaft reducer.

One thing that you might consider is that for wood coolant is not used (except logging saws), but often for metal, least cutting oil and brush on cutting saw.

About the guides....the material should not be plastic. It might of fiber material, sintered metal, bronze or that sort of stuff. Could work on metal cutting bandsaws too, but needs adjustment, cleaning and it does wear out. Not a game changer if you use gently and not all the time. Personally I would do the speed conversion firs and then see how much of an issue this is. I would plan of putting bearings on back of the blade and use those orginal stationary guides on side, if it is easy to modify that way. You don't really want to force the piece against the blade anyway with too much force, the blade must cut freely and carry the chips away.

You need the metal blade...have you checked if there are ready made blades for that width/length? Wood blade probably will work for brass and aluminium when used at lower speed.

pekka
Title: Re: Startrite 352 Bandsaw mods
Post by: Jo on April 10, 2017, 04:45:35 AM
Thanks Pekka,

Thankfully the machine takes a standard size blade, available for both metal and wood cutting.

I have a spare set of 5 speed reducer pulleys that could be used to reduce the speed down by 1/5th by using a counter shaft. Just have to work out how :scratch: And not getting the machine to Saturday does not help.

In the meantime I have made sure I have plenty of Fairy power spray ready for cleaning it up  :thumbup:

Jo
Title: Re: Startrite 352 Bandsaw mods
Post by: AdeV on April 10, 2017, 05:03:10 AM
About the guides....the material should not be plastic. It might of fiber material, sintered metal, bronze or that sort of stuff.

I don't know if this is true of all StartRite saws, but the ones I've seen had ball bearings for blade guides - one either side & one at the rear positioned in such a way that pressure from the blade caused the bearing to rotate - minimum wear on both blade & guide.
Title: Re: Startrite 352 Bandsaw mods
Post by: velocette on April 10, 2017, 04:51:43 PM
Hi Jo
Go for it a metal cutting band saw is a great asset in the workshop.
Aim for 30 to 60 metres a minute band speed for metal cutting  or around 700 metres minute for wood.
As you can see even with a variable speed drive it will be difficult to achieve with a single gear ratio
"Polly Vee" belts and pulleys will give excellent drive at slow speeds and wider ratios over normal Vee Belts.

Eric
 
Title: Re: Startrite 352 Bandsaw mods
Post by: Jo on April 12, 2017, 08:39:57 AM
Thanks Eric, that looks nice.

Andrew: looked into that gearbox thingy. Seems like it is an epicyclical arrangement which is as rare as rocking horse do-das (the expression used to describe finding one included "W - hore house" and "virgin in a"  :bugeye:  ) Their recommendation was that it would be cheaper to sell this machine on and buy a real metal working band saw.

The machines still have not landed: They are being delivered Saturday :thumbup: Lathe and Planer already has a new home so I won't have to dirty my hands cleaning them up  :clap:

Jo
Title: Re: Startrite 352 Bandsaw mods
Post by: Jasonb on April 12, 2017, 12:07:14 PM
Nothing wrong with the solid guides Jo so I would leave them as is for now. As you know I use my old small vertical bandsaw for metal cutting and that had graphite impregnated plastic guides though a good oily hardwood also works well too.

Can't really complain about the cut it gives and very straight too, this is 3" sq 6082

(http://img.photobucket.com/albums/v156/jasonballamy/Engineering/Lightweight/DSC01001_zpsdqsy86ls.jpg)
Title: Re: Startrite 352 Bandsaw mods
Post by: awemawson on April 12, 2017, 01:11:56 PM
Solid guides are supposed to be more accurate - not sure why  :scratch: But they are the type fitted to my Startrite.
Title: Re: Startrite 352 Bandsaw mods
Post by: Jo on April 12, 2017, 01:25:38 PM
Thanks Guys,

I was told by a tool dealer that the standard guides cost an arm and a leg and he confirmed that as standard they are good stuff. But I am not sure how good they were on this machine I was trying not to show too much interest in it when I agreed to buy it in case it impacted the price :coffee:

Still tempted on the motor swop over plus a VFD to give slower metal cutting speed. Did I mention it comes with a pair of WOOD  :palm: cutting blades. Was thinking they might be suitable for cutting my firewood to length. 

Jo
Title: Re: Startrite 352 Bandsaw mods
Post by: PekkaNF on April 12, 2017, 02:16:06 PM
VFD+motor swap by only measure is NOT the way to go. Let's assume that you want 10X reduction....e.g. you need 280 rpm instead 2800 rpm (50 Hz system, 60 Hz a little higher). Therefore you need 10 times slower frequency and that gives you very little power, but when you load up the motor it will heat. BUT as the motor rpm is down so is fan speed. At that speed there is practically no airflow.

Gear motor or jack shaft + belt..

Pekka
Title: Re: Startrite 352 Bandsaw mods
Post by: Jo on April 12, 2017, 02:55:47 PM
Thanks Pekka,

The first stage is to fit a 1425 motor, that will halve the speed to start with and should be an easy swop with another 220V mains one. The items that use the higher speed setting I don't need it to cut..

I am trying to avoid fitting the second shaft. It still may be the way to go.

Jo
Title: Re: Startrite 352 Bandsaw mods
Post by: velocette on April 12, 2017, 10:00:45 PM
Hi Jo
The original build on my band saw used two motors more info @

http://madmodder.net/index.php/topic,11037.msg128134.html#msg128134

Eric
Title: Re: Startrite 352 Bandsaw mods
Post by: Jo on April 16, 2017, 09:29:12 AM
Thanks Eric,

I have tested the new band saw and was surprised it cuts 1/4" Ali like it is a bit of fire wood  :ddb: Looking at the highly complicated motor mounting arrangement it shouldn't take much to swop the motor over to a slower one if I wanted. I won't rush things.... give it a bit more testing before I modify things  :thumbup:


I'd say that was a good £100 well spent, even if it is a WOOD  :bugeye: working tool

Jo
Title: Re: Startrite 352 Bandsaw mods
Post by: mattinker on April 16, 2017, 09:37:53 AM
£100! That's about 1/4 of what I would have thought it was worth!

Regards, Matthew
Title: Re: Startrite 352 Bandsaw mods
Post by: PekkaNF on April 16, 2017, 09:42:42 AM
Yep. Aluminium and such, specially extruded channels goes pretty well with wood cutting saw, if you don't push it. Wood blade is not the best for it, but goes.

1/2 speed would should be fine for aluminium, but it is still too fast for iron metals. You don't get good life out of band saw blade.

Don't try thin steel plate with too coarse coarse blade pitch. You probably guess how it goes.

Pekka
Title: Re: Startrite 352 Bandsaw mods
Post by: Jo on April 16, 2017, 11:04:14 AM
£100! That's about 1/4 of what I would have thought it was worth!

The band saw was the carrot to go with the stick of having to clear out the rest of the wood worm infested 50+ year old stuff. As for the electrics of the other machines I was amazed they have three pin plugs fitted but none have any insulators on the pins, the rubber mains cables had long ago rotted through  :palm:

I have a lot of what should have been very nice pieces of wood for turning that are so full of hole they are of no use to anyone, not even as firewood. What a waste  :bang: and it all must be cleared as part of the deal. All the good quality tooling has been put to one side for the original owner to sell on Flea bay...


I need to find a good quality blade supplier, any recommendations?  These are 112" long. I will be looking for Bi-metallic/HSS blades...

Jo
Title: Re: Startrite 352 Bandsaw mods
Post by: Pete W. on April 16, 2017, 03:40:04 PM
£100! That's about 1/4 of what I would have thought it was worth!

The band saw was the carrot to go with the stick of having to clear out the rest of the wood worm infested 50+ year old stuff. As for the electrics of the other machines I was amazed they have three pin plugs fitted but none have any insulators on the pins, the rubber mains cables had long ago rotted through  :palm:

SNIP

Jo

On modern plugs, insulating sleeves should ONLY be fitted to the live (aka 'phase') and neutral pins.
If you encounter a 13 amp plug (i.e. purporting to conform to BS1363) with an insulating sleeve on the earth pin it is non-compliant and illegal!   :zap:   :zap: 

Such plugs do turn up on IT accessories from the far East.  Some have no fuse and have a small body that risks the user wrapping their fingers round to the pins.   I even had one recently with a kite mark moulded into the body, conclusive proof that it's counterfeit. 
Title: Re: Startrite 352 Bandsaw mods
Post by: awemawson on April 16, 2017, 04:25:06 PM
Oh - yes danger abounds  :bugeye:

I had one last year that supposedly conformed to BS1363 but the clever designer had omitted the fuse to make the body so small that fingers easily could contact the pins which had no shrouds  :bang:

One variety I saw once had the cable moulded in, had strands of wires emerging to the surface of the moulding  :zap: but admittedly it did have the fuse.
Title: Re: Startrite 352 Bandsaw mods
Post by: Jo on April 17, 2017, 01:55:15 AM
As you mentioned Pete, only the live and neutral should be insulated but a fair few PC power supplies I have found have plastic earth pins. (The fuse is there to protect the equipment not the operator....) I find that old mains plugs are a good source of nice little bits of brass for my model engines  :thumbup:


I think I have tracked down some nice blades: Starret 6/10VP and 10/14VP £30.78 each :bugeye: It can't be avoided there is no point in having cheap blades they won't last.

Jo 
Title: Re: Startrite 352 Bandsaw mods
Post by: Pete W. on April 17, 2017, 04:19:39 AM
As you mentioned Pete, only the live and neutral should be insulated but a fair few PC power supplies I have found have plastic earth pins. (The fuse is there to protect the equipment not the operator....) I find that old mains plugs are a good source of nice little bits of brass for my model engines  :thumbup:


I think I have tracked down some nice blades: Starret 6/10VP and 10/14VP £30.78 each :bugeye: It can't be avoided there is no point in having cheap blades they won't last.

Jo

I bought a couple of blades for my Burgess from Tuff Saws at https://www.tuffsaws.co.uk/ (usual disclaimer).  I've been very happy with both the service and with the blades and I learned of them via lots of other peoples' recommendations.

I haven't researched the official IEE (aka 'IET' though they didn't ask me for permission to change their name!!!) opinion on plastic earth pins but I guess, if properly engineered, they'd be OK feeding a double-insulated device.  I guess the relevant 'department' of the IET would be the one that publishes 'Wiring Matters'.

A couple of YouTube channels that are full of electrical safety horror stories are those by John Ward and by BigClivedotcom, well worth a browse!

My understanding is that the fuse in a BS1363 plug is to protect against damage to the flex cable - the device should have more local protection.   
Title: Re: Startrite 352 Bandsaw mods
Post by: Pete W. on April 17, 2017, 05:23:21 AM
I'm sorry if this is  :offtopic:   :offtopic:   :offtopic:  but I've started so I'll continue!

I can't post the link directly but I just Googled "Wiring Matters" and then typed 'counterfeit plugs' in the search box.  The references that came up make interesting but sobering reading.