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Vertical Bandsaw Project Ideas & Parts Collection 
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Joined: Tue Jan 15, 2008 2:31 pm
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Location: Home sweet home!
And one day, build.

The only single-phase metal cutting bandsaw machineryhouse sells is $4370 NZ inc GST and has: https://www.machineryhouse.co.nz/B010A

power 0.37kw / 0.5hp
speed range of 20-90 m/min
throat of 310mm
height of 175mm
blade 2510mm
weight 225kg

So I bought some 18" motorcycle wheels to use as bandsaw wheels for 150nzd: https://twitter.com/FredCookeNZ/status/ ... 4241274881

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And have my eye on a $200+ brand new high quality NOS geared motor with 0.55kw 3/4hp that spins 274 RPM.

What I'm wondering is if I lose say 2 inches on the wheels after machining/mods then what lineal speed will I get direct coupling that motor to the lower pulley? Let's find out.

16" in mm is 406.4, let's call it 400 D, 200 R, 400 throat
PI * R = C
3.14159 * 200 = 628.3mm, let's call it 630 or 0.63m
274 * 0.63 = 172.6 m/min

Which will still need a step down to achieve metal speeds of at least 2:1 and at most 8:1 but a VFD can be used to achieve a significant speed reduction (or minor speed increase) without loss of torque or any other issue.

Wood bandsaws seem to run about 500-1000m/min speeds and much higher power levels. Ignoring the power requirements of high speed because lower end saws have similar to my intended power, a step up of between 3:1 and 6:1 is needed.

Stepped pulleys with 6" down to 2" on both sides would give the bare minimum reduction/increase of 3:1 but using a two-belt approach could yield better pulley sizes and better ratios or same pulley sizes and more extreme ratios of 9:1

So if I just provide 3:1 up, 1:1, and 3:1 down then I should have decent performance on wood and great performance on stainless steel and everything in between. If I can make that 4:1 and maybe have 2:1 in between as well, that'd be even better. Speed guide from above model: https://twitter.com/FredCookeNZ/status/ ... 5895561216

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Style wise, it'd be nice to have round covers over the top and bottom wheels, something like this sweet old thing: https://twitter.com/FredCookeNZ/status/ ... 2781006848

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Other random stuff to consider:

1) Brushes on the wheels to keep them clean
2) Contact material, inner tube rubber or cork bonded on?
3) Dust/chip extraction/collection
4) Blade cooling via air
5) Coolant supply and capture/recycling and removal from blade before hitting wheels if so
6) Blade guide design
7) Blade guide height adjust design
8) Blade tension design
9) Belt tension design if belts used
10) Frame design
11) Table design with tilt and trunnion design
12) Blade cover near frame
13) Wheel mods to get max diameter for max throat depth
14) Double sheer wheel support design

And probably 50 other things.

Note, I have the steel for the press that I didn't use and ended up buying a used frame for. Highly likely to be used for this. IIRC 80x80x5 box 1800 tall or so? Should be ample.

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Tue Aug 27, 2019 9:19 am
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Wheels are in-hand :-) With tyres still on, and brake disks and ABS sensor ring and full hubs and bearings etc, kinda heavy. I think maybe I can just create spindles for them and they'll slide on and spin happily with some sort of drive on one side of the lower one. Will get more photos, measurements, progress reports on tyre removal etc done soon. Browsing lathes on trademe thinking about the pulley setup to net wood and steel speeds from the one unit. I think the geared motor I have my eye on is spot on for that. Not good direct drive, but close enough to either side of the spectrum to be geared there with belts and pulleys.

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FreeEMS dev diary and its comments thread and my turbo truck!
n00bs, do NOT PM or email tech questions! Use the forum!
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Wed Aug 28, 2019 11:10 am
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Measured up the tyres and wheels the other night. Decided to go big or go home, so went big. Tyre diameter = drive diameter = about 640 or 650mm. Upper wheel is about 630mm or so.

Sizes are 140/70R18 @ 67V and 110/80R18 @ 58V which should have rolling diameters of 653.2mm and 633.2mm respectively when new and if to spec.

Garage joist height from concrete is 1890mm and bottom of joist to bottom of polystyrene insulation is 150mm so total absolute max height is 2040mm assuming it could be slid into place without feet/wheels or some such and lifted up.

Table height to be comfortable needs to be around 950-980? (workbench to drill press current table height). Let me check my old thread on this topic... "Standing work surfaces 920-970"

Ref: viewtopic.php?p=40427#p40427

So irrespective of where the lower bigger wheel goes below the working surface in the 900-1000mm high range, that leaves us with 2040 - 640 - 900 to 1000 = 400 - 500 max throat height, which is ample.

I think I would like at least 250, ideally 300, bonus for 350 or 400, and 500 is perhaps pointless? Maybe useful for something weird and wooden, I guess.

Within the 900 to 1000 from the floor we need to fit:

655 of wheel/tyre
130 castors
~50 table and trunnion
10-20 lower cover and clearance

Leaving design tolerance in the range of:

900 - 655 - 130 - 50 - 20 = 45mm
to
1000 - 655 - 130 - 50 - 20 = 145mm

And the corners above the lower wheel are available to stuff functionality in and increase that.

Max distance between wheel centres is going to be about...

150 from ground, 655 of wheel, stuff and gap, 635 of wheel, 20 of clearance/cover, from 2040 total max, + half of 1290 which is 645 =

2040 - 150 - 655 - 635 - 20 = 580
580 + 645 = 1225mm

And the 80x80x5 box that I have is about 1600 high or a little more, so...

1600 - 1225 = 375
655 / 2 = 327.5
20 = 20
375 - 327.5 - 20 = 27.5mm left over!

Perfect :-) Between the $100 press frame, the free press project steel becoming available, and this project kicking into life, it was meant to be.

I actually have two sticks of that big box the same length, so I can use the other one for horizontal beams top and bottom and possibly some corner bracing on top of that.

I want to use polycarb sheet for the sides of the top and bottom covers and keep the bike wheels/tyres/brakes as exposed/obvious as possible. Coolest looking bandsaw *ever*? I think so.

Best start the new YT channel before I do the build as this could be popular. :-)

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FreeEMS dev diary and its comments thread and my turbo truck!
n00bs, do NOT PM or email tech questions! Use the forum!
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Tue Sep 03, 2019 11:07 am
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Joined: Tue Jan 15, 2008 2:31 pm
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Motor is in hand, and it's lovely. I will post some details about it here for the record, but it will work beautifully for this project. Guy who had it has an American DoAll bandsaw, and a bridgeport, and some other cool industrial gear. He ran me through mounting and shaft attachment and anti-fretting paste, and oil fill levels and so forth. Neat.

Image

_________________
DIYEFI.org - where Open Source means Open Source, and Free means Freedom
FreeEMS.org - the open source engine management system
FreeEMS dev diary and its comments thread and my turbo truck!
n00bs, do NOT PM or email tech questions! Use the forum!
The ever growing list of FreeEMS success stories!


Tue Sep 10, 2019 2:35 am
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