puttin' lipstick on a pig (bandsaw mod)(Epic)

[Curt Harms]

Hi All

This is my first attempt at an illustrated post, so be nice . I've owned a G1148 15"bandsaw since about 1996. It was fine til I discovered the internet, woodworking forums and resawing. I read about bandsaw tuneups, checked the wheel coplanarity, called Grizzly about how to adjust it. got some Timberwolf blades. So far, so good. This bandsaw has a max resaw of 7 1/2" and a 3/4 h.p.13 amp.motor. That should resaw 7 1/2", right? WRONG! It'd sorta do OK with softwood, but Oak or Ash gave it fits. The blade would appear to stall even with slow feed rates, back off the stock, the blade would start turning normally and cut another inch.

The question then became new band saw, or try to get this one to work. In favor of the new saw was greater resaw height, more likely parts availability (wouldn't surprise me if Grizzly discontinues this one) and stronger frame. In favor of trying upgrade the existing saw was ~$200 vs $750-$1000, lower table (I'm vertically challenged) the existing saw fits my space well, it'll be easier to get out of a basement shop if I need to, and most importantly SWMBO picked it out at Grizzly; said it was "cute"

I started looking at motors. The compressor duty motors at Harbor Freight were interesting pricewise but turned the wrong way and were not reversible. I looked at motors at Grainger & MSC but they were pricy. I looked on Tractor Supply's site and found a 1 1/2 h.p. GE for $169, web site said it had a 56 frame and the local T.S. had one. Next item-pulleys. I think part of the problem with the old motor may have been a too small motor pulley on low speed and not enough motor on high speed. Grainger had die cast ones for cheap. I used OWWM's calculator to pick sizes that yielded about 3000 fpm. Motor pulley is 3 1/8 with 7/8 bore, driven pulley is 8" with 5/8"bore. I got the motor home and it didn't have a 56 frame but something different (don't remember what) so the new motor didn't fit the existing mount; 2 bolts worked and 2 didn't No problem, add a plywood pad on the base, countersink 2 bolts and life was good. When I checked the lower wheel shaft without pulling the wheel, it looked like 3/4". When I went to mount the driven pulley, it didn't fit. I found out that 20 mm is just SLIGHTLY larger than 3/4". I checked Grainger for metric bore pulleys and couldn't find any prebored. I probably could have gotten a cast iron pulley and separate hub but I'm doing this on the cheap, so some filing, sandpaper wrapped around a dowel and it fit good enough.

I then mounted the motor, mounted the motor pulley, driven pulley, lower wheel and take a deep breath. Powered it up and viola, the lower wheel turned true and the pulley just wobbled a little I then mounted a 1/2" T'wolf blade tightened it up. I cut a piece flat just to see if there were going to be any major problems. Nope. I then mounted the fence, got a scrap piece of 6" wide ash, jointed one face,set the fence for about 1/4" and let 'er rip. OH MY!! Huge difference!! I played around some more, checked some resawed pieces with a dial caliper. The thickness was within .01"-02" the length of the piece.. I can live with this.

Why does a motor that draws 15 amps @ 120 volts (G.E.) rated 1.5 h.p.produce so much more apparent power than one drawing 13 amps@120 volts (Grizzly) rated .75 h.p. I don't know, belt slippage may have entered into it. Would I do it again? Probably. If I had a larger shop or did more projects, the larger saw might have been the way to go. For anyone with a 14" or 15" saw that seems underpowered, a motor upgrade certainly adds new life.

I took some pics (didn't want any late-night visits from the pic patrol) I don't know how to mix pics and narration so I'll do the best I can
Pic 1- The victim
Pic 2- Motor in place. Capacitor start, Capacitor run
Pic 3- Lower wheel & pulleys
Pic 4- Old motor and pulleys

[Bruce Shiverdecker]

Evenin' Curt:

You've doubled the HP. That's where the POWER is coming from. The new G.E. Motor is more efficient, thereby getting you a lower operating amperage.

Bruce

[Mike Cutler]

Nice post Curt. I struggle with a 14" Jet at times, and have done everything short of changing the motor to get it to resaw better. Now that I've read your post, and Dominic's on changing motors, maybe I'll try that route before I buy a new BS.
I had not thought of changing the pulleys. That was an interesting concept, I'll keep that in mind also.

[Kelly C. Hanna]

Nice mods! You did a great job of making things better. Remember hp means nothing in terms of motors...it's a calculated figure that's often exxagerated.

[Dennis McDonaugh]

Bruce hit the nail on the head. You compute the effiency of a motor by the ratio of input power to the output power. The input is close for both motors, but the output is double for the new motor. The new motor probably has a lot more copper in the windings, better commutator and brushes, and better bearings so it has less power loss.

[Curt Harms]

Hi All

Thanks for your replies. I'd never have thought that two motors, one rated at 13 amps and another at 15 amps could have such a difference in apparent power. I didn't check each motor under load with an ammeter; that would've been interesting.

Mike, if you're otherwise happy with your Jet, it's sure worth consideration. I'd read the discussions re Taiwanese motors being less efficient but was skeptical. I may have to rethink that, although I have a G1023 which doesn't seem to lack oomph. A couple more pics, seeing as I'm wasting disk space & bandwith already Pic 1 is a cheap but effective mobile base. The rear two casters are fixed, the two casters attached to the pivoting piece swivel. Moving the handle 90 degrees either moves the swiveling casters under the base or move the swiveling casters parallel to the floor so the front of the base sits on the 2X3. It makes for a surprisingly stable base. The swiveling caster setup probably wouldn't work well with a 400 lb. machine, but it works quite well with a 160 lb. machine.

The second pic was my solution to the factory tensioning knob. That thing was just a pain to use, literally. It was too small for my woosy grip. I bought a hand wheel and handle from MSC, brought it home, drilled & tapped it. bought some new threaded rod to replaced the fixed factory knob and it works well. Thanks for looking

Curt

[Denny Lawson]

Nice mods! You did a great job of making things better. Remember hp means nothing in terms of motors...it's a calculated figure that's often exxagerated.

Thats true of universal type motors,the HP is rated at the point where the motor self desructs. but not necessarily induction type motors. I would expect that the GE motor would actually perform very close to its rated HP.

Denny

[craig caldwell]

Well this is my first post on the site. I too put a little lipstick on my pig. I also added some blush and a pair of dead sexy pumps. It might be a recipie for disaster but I managed to shoehorn a 3hp baldor motor into my 14 inch limited edition delta. One of the white ones (real perdy). All it took was 2 link belts the idler pully out of my drillpress some 1" thick plate steel and a couple of hours. Any one else out there playing with fire?

[Jack Hogoboom]

Craig,

Where'd you put the chrome exhaust pipes??!! That sounds like a modification Tim Taylor would be proud of.

Jack

[craig caldwell]

Well Jack, I'm going for more of a stock look, so when I pop the hood at this weekends show 'n' shine... If you'll excuse me I've got some Turtle Wax and Armor All that needs buffin'.