# HF 4x6 - Time to replace?



## Herbie555 (Jun 19, 2017)

Hello all, this is my first post here, but this seems like the place for an honest answer.

I've hit a decision point with my well-worn 4x6 bandsaw.  I'm thinking it may be time to replace it, rather than trying to refurb my current unit, but I want to make sure I'm not "wimping out".

Background: I've used and abused my Harbor Freight saw for more than 10 years. Aside from some rudimentary adjustments, and an occasional blade change, I'd done _nothing_ to it.  I was a novice, and hadn't read the (many) forums for these tools, so I did zero in terms of cleanup, and never even changed the gear oil, etc.   Recently the motor finally failed, so I tried to replace it with a 1/2hp 1800rpm unit I had on hand.  Unfortunately it wasn't a direct fit, the motor had a bigger frame and output shaft, so fitting it involved boring and re-broaching the motor pulley and notching the motor's base plate where it interfered near the tension-adjusting bolt on the mounting plate.  At that time I undertook a slightly more serious attempt at aligning the blade guide bearings.

Since that replacement/adjustment, the saw just isn't cutting.  Like, at all.  A test cut through some 1/8" angle iron literally killed a brand-new bimetal blade and wouldn't even finish the cut after swapping back to the previous blade that was working "well enough" prior to the motor swap.  To be clear, the saw was running for _minutes_ on a cut that I expected to take well less than 60 seconds.  Yes, teeth oriented correctly, belt position and feed pressure in the range of what I've used previously, etc.

Not sure where I went wrong. Willing to admit improper blade tension probably killed the new blade as much as anything, but I suspect this motor just isn't a good match.  

The problem now is that while I _could_ buy a new motor (and probably a replacement pulley), I'm looking at how worn the guide bearings are, and considering the fact that I've abused the worm gear, etc., and the math is starting to get stupid.  With coupon, a new HF saw can be picked up for ~$200, while a new motor, pulley, guide bearings, etc. will easily add up to $160+shipping and that doesn't address all the other little parts.

I'm typically a "repair, don't replace" person, but the economics of this situation seem to dictate that the time to refurbish + unknown future failures aren't justified by $40 savings. 

Thoughts?  Thanks.


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## RandyM (Jun 19, 2017)

Hi Herbie,

Welcome to HM, we are glad you joined us in the fun.

So, if you were to replace are you replacing with another Harbor Freight unit or are you thinking of doing an up grade? Same size unit or bigger?


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## Herbie555 (Jun 19, 2017)

Thanks Randy.

If I were to replace, it would almost certainly be another Harbor Freight 4x6 unit.  Nothing in the budget for an upgrade, and have a project pending where I need to get a machine up and running again soon.  Size-wise I haven't needed anything bigger and my shop isn't huge, so a bigger unit would be hard to justify.


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## DAT510 (Jun 19, 2017)

First, Welcome to HM.

Second, regarding your cutting issues......Only because I've done it......  Are the blade teeth possibly facing the incorrect direction?

Regarding a new HF saw, I have two.  An older saw (10+ years), that I was recently given,  and a newer saw that I purchased (last 5+ years).  They look the same, but the quality is quite different.  My older saw has heaver castings, better blade alignment/tensioning, adjustment knobs vs bolts,  and the Blade Guides have more adjustments.  The biggest is the blade guides being able to rotate along the linear axis of the blade, so you can straighten out the blade twist.  My newer 4x6 lacks this.  With a lot of work I've been able to get my newer saw to cut-off fairly straight.  But the older saw still cuts straighter and is easier to get cutting straight after a blade change.






Newer HF 4x6 Bandsaw    





Older HF 4x6 Bandsaw

You might want to compare your current saw to the newer HF saws, to see if you current saw has the differences I've experienced with mine. Because of the quality differences with the older saw, I've chosen to rebuild it and make it my primary "horizontal cut-off" saw and my newer HF 4x6 saw will be left in the "vertical table saw" set-up, for when I need to do free hand cuts.  If your saw has the better castings and/or better adjustment capability, that may influence your decision to rebuild or buy new.

Hope this helped?


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## Bob Korves (Jun 19, 2017)

The weight of the new motor may be different and changed the actual downward pressure on the blade.  I think the desired number is 6 pounds, measured with a spring fish scale (or similar) lifting at the blade tension knob.  Are both motors the same RPM?


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## Herbie555 (Jun 19, 2017)

Thanks all.  

Yes, I'm certain I had the blade teeth facing correct direction as I forced myself to check the teeth against the little sticker on the bed at least four times (while trying to figure out what was going on).

Thank you for pointing out the changes in the design - I wasn't aware, and that's certainly a step in the wrong direction if they've taken out the adjustments.  Yes, mine is old enough that it has the adjustments as in your second image.

I'll try to measure the feed pressure.  I'm occasionally guilty of throwing a little extra pressure on the arm, but knowing that there's a spec gives me something to measure against.

Regarding RPM, I _believed_ the motors matched up well.  My replacement motor is 1/2hp, 1800rpm, 8.5A at 115v.  The original motor from my HF saw was labelled as "1hp, 1700rpm, 6.4A".  I believe the 1hp figure about as far as I can throw the old motor, but if 1700rpm is accurate, then I should be running around 6% faster now.  Using the fastest step on the pulleys, that _should _be around 212fpm, which should be inside the envelope for a 10-14t blade when cutting thin mild steel.

I don't have a convenient way to measure the real FPM, but I could try to mark the blade and count revolutions over a fixed period or something.   

I suppose I should try once more with another new blade (after measuring feed pressure), just to make sure that I didn't compound operator-stupidity with too many changes at once.  I'm willing to invest in new guide bearings, etc. if the new motor can be made to work.


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## Herbie555 (Jun 19, 2017)

I've also be reading up on blade break-in, and it seems that's one more thing I've been doing wrong.


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## dana.young.5245 (Jun 19, 2017)

Is your motor running the correct direction?

Sent from my SCH-I545 using Tapatalk


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## Herbie555 (Jun 19, 2017)

dana.young.5245 said:


> Is your motor running the correct direction?
> 
> Sent from my SCH-I545 using Tapatalk



Yes.  Confirmed with blade markings on bed (and with the arrows I drew inside the belt drive housing prior to swapping the motor.)

Thank you for checking, though.  The change in performance is so significant it almost _has_ to be something stupid like this.


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## DaveD (Jun 19, 2017)

Couple of things...
I'd set the speed up on the middle speed (run it slower). That's where I run mine.
Put more downward pressure on the saw frame. You crank the handle counter clockwise on the spring tension arm (remove tension) to increase weight on blade.
Is the range of travel correct. The bolt that adjusts it is way back on the plate the motor mounts to if I remember correctly.
Are the  two rollers on the back edge of the blade doing their job?
Without any material in the saw make sure the saw blade/frame doesn't bind anywhere in the needed range of travel.
Is the auto shutoff adjusted correctly and not binding?
Will it cut a piece of ¾" wood?
Are you trying to cut crap bed railing?

If the blade continues to move without slowing down and the teeth are sharp and pointing in the right direction it is going to cut. It has to be something simple and you are going to bang your forehead when you find out what it is.

P.S. I have had all of the above problems!


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## Herbie555 (Jun 19, 2017)

DaveD said:


> Couple of things...
> 
> *Are you trying to cut crap bed railing?*



<Looks over both shoulders>  How did you know?  Yes, I'm cutting up a crappy bed frame to make a rolling cart for a shop tool.  Is there something about bed frames I need to know?

<Quickly googles "bed frame angle iron">  Sonufa!

EDIT:
I have taken a few moments to get myself under control.  I was in the midst of weaving a stream of expletives that might, if it had gone off prematurely, got me fired, since I'm currently at work.
Additional reading on the myriad "qualities" of bed frame steel has me absolutely convinced that this is the problem.

Just my luck that it's the very first thing I tried to cut after getting my saw put back together.  If I'd gone from cutting regular stock to the bed frame, I might have noticed that something was "different".

Dave, you've done me a huge favor.   I'm going to go home tonight, throw another blade on it, and take a series of practice cuts on some known-regular angle iron.  I expect everything to work fine.  I'll report back, just to provide closure.


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## Buffalo20 (Jun 19, 2017)

Herbie555 said:


> I've also be reading up on blade break-in, and it seems that's one more thing I've been doing wrong.



WHAT???  I made (cut to length and weld together) saw blades for 10 years as a part time job at a large industrial supplier, we never broke in any blades, we just put them on and cut. As did our customers, never had a problem. Now I got to read more crap.


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## Herbie555 (Jun 19, 2017)

Buffalo20 said:


> WHAT???  I made (cut to length and weld together) saw blades for 10 years as a part time job at a large industrial supplier, we never broke in any blades, we just put them on and cut. As did our customers, never had a problem. Now I got to read more crap.



According to my recent reading, over-feeding is particularly hard on fresh teeth?  Rx lower feed and blade speeds for the initial "so many" inches of material cut.  I dunno.


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## Buffalo20 (Jun 19, 2017)

Herbie555 said:


> According to my recent reading, over-feeding is particularly hard on fresh teeth?  Rx lower feed and blade speeds for the initial "so many" inches of material cut.  I dunno.




Interesting, I went to seminars from Lenox, Sterling and Morse, for blade makers, they never said a thing about it. I can't see how the teeth on that blade, know if its the first cut or the 10th cut. If you feel its right, do it. Good Luck, I hope it improves your blade life.


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## f350ca (Jun 19, 2017)

Bed rails can be a killer. I made the frame for a sand blast cabinet from them, had it all welded together then found the only thing that would drill it to mount the plastic panels was carbide. It literally laughed at HSS.
A note on band saw blades, if you have to change one out never put a new blade into a partial cut made by an old one. The set in the old one will be diminished and you'll take the set out of a new one as it forms into the narrow kerf made by the worn blade.

Greg


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## silence dogood (Jun 19, 2017)

I have cut through bed rails.  Maybe I was lucky.  I used sulfur based cutting oil and went slow.   Seemed to cut pretty well. Same thing with drilling.


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## woodchucker (Jun 19, 2017)

I've had no problem w/bed rails. Drills easy enough, cuts easy enough too.
Made a home made hydraulic press out of some free frames.


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## ch2co (Jun 19, 2017)

WHAT is so special about bed frames?? Is it that they are made from crap steel or that they are mad out of supertanium?

CHuck the grumpy old guy


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## tq60 (Jun 19, 2017)

All bed rails are not the same. 

A frame from a king bed of higher quality will be more tempered or harder so it does not sag in the middle.

We often get them from thrift stores for free as they receive bedding but cannot sell it and when we see it leaning in the corner asked for is usually free or a buck.

Learned same way...blamed cheap hf blades....BTW the big metal blades in our larger saw cut them fine.
.



Sent from my SAMSUNG-SGH-I337Z using Tapatalk


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## Herbie555 (Jun 19, 2017)

Well, I'm a believer. Whatever my bed frame is made of, it's apparently pretty hard.

Threw a scrap chunk of 1 x 1 x 1/8" square tubing in with a fresh, but somewhat less aggressive, blade and it cut just fine. 

Thank you all so very much! That's a lot of money saved and a weight off my mind. I thought for sure I'd screwed it up!

I'll use abrasives to chop the frame down, and go through another round of tune up on the blade guides.


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## GLCarlson (Jun 22, 2017)

Had one of these. Cheap motor died. Ran mine for the next 20 years -until I gave it away- on a 1/6 hp (!)  salvaged washing machine motor. Get it tuned up -lots of descriptions on what to do there- buy high quality blades and keep them really tight. As long as the worm gear, motor, & bearings hold out, they're unkillable. Always do a cut on a new blade with a piece of 2-3" mild steel round to condition the blade; use cutting oil or coolant.

Bedframe steel is variable- some cuts, some of it is harder'n woodpecker lips. I usually try it with a hacksaw first.


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## Cobra (Jun 22, 2017)

When I bought my 4X6 from Busy Bee in Canada (same quality as HF) it ran for a week and the motor quit.
Replaced it with a 1/2 horse furnace fan motor and have not looked back.
Good to hear that you found the issue.
Jim


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## markba633csi (Jun 23, 2017)

Harder 'n woodpecker lips! Gotta remember that one LOL
Mark
yes bedframes are highly variable, and they often don't weld very well either- I used 6011 on ac with acceptable results


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## Bob Korves (Jun 23, 2017)

Bed frames are what comes to my mind when someone says "mystery metal."  Test before using...


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## Herbie555 (Jun 23, 2017)

You know what else I love about this thread/revelation?  It explains all the trouble I had trying to learn to weld on a cheap Lincoln buzz box like 20 years ago.  Eventually took a class for both stick and MIG, but will always remember how much trouble I had that first time.  What was I working on?  Yep, bed frames, cut by hand with a hacksaw...  ugh.


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## Beone (Jun 23, 2017)

Let's see, ten years service out of a saw you can replace for $150.(cupon in mag). I think $15 bucks a year not to use a hacksaw a very good deal. Either get a new saw or a new motor


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## Buffalo20 (Jun 23, 2017)

Bob Korves said:


> Bed frames are what comes to my mind when someone says "mystery metal."  Test before using...




I was explained the difference in bed frame metal quality, is some of the frames are "Work Hardened" over time.....................


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## kvt (Jun 24, 2017)

Agree bed frames are mystery metal.   Some are hard as hell and some are soft as all get out.    I have had both.   and welds are all over the place,   Some weld great, and some,   Bolts would do better. 
Saws,   Older models seem to be better, and may cost to repair but often worth it compared to the newer ones.     Bearings and seals are all replaceable.   Get the oil on the gearbox done and keep it up. and you can keep them running for a long time.   And one that I was told of recently, was that on a new blade,  watch someone got one that had the teeth backwards.   so you would have to run the motor in revers to get it to cut.   If I ever got one I would contact the company  and see what they would be willing to do.


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## Eddyde (Jun 24, 2017)

Herbie555 said:


> According to my recent reading, over-feeding is particularly hard on fresh teeth?  Rx lower feed and blade speeds for the initial "so many" inches of material cut.  I dunno.


I seriously doubt this advice is true, perhaps a good example of "don't believe everything you read on the internet". Please provide a link, if you can, to where you read this, I'm curious as to the explanation... 
Also, Bedframes, I have a lot of experience as free materials is the way I like to roll... Yep they can vary from soft to quite hard, sometimes even on the same piece! I like Buffalo20's explanation of "work hardening" makes a lot of sense especially if the bed saw a lot of "action"  Now, I always cut bed frame angle with an abrasive chop saw.


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## Herbie555 (Jun 24, 2017)

kvt said:


> And one that I was told of recently, was that on a new blade,  watch someone got one that had the teeth backwards.   so you would have to run the motor in revers to get it to cut.   If I ever got one I would contact the company  and see what they would be willing to do.



Important trick:  A blade that has the teeth "backwards" can be reversed by turning the blade "inside out".  Like, flip the surface over and work it all the way around.  Voila', the teeth will be facing the other way.  I have to do this about one time in five as the process of taking the wire-wraps off and getting the blade out of the shrink-packaging has it come out "backwards".



Eddyde said:


> I seriously doubt this advice is true, perhaps a good example of "don't believe everything you read on the internet". Please provide a link, if you can, to where you read this, I'm curious as to the explanation...



Note that I only came across this stuff while researching my blade issues, but here are the sources:
http://www.starrett.com/docs/saw-resources/recommendations.pdf?sfvrsn=2  (This is from the blade manufacturer)
http://www.bandsawblade.com/breakin.htm (Similar here)
https://www.sawblade.com/breaking-in-band-saw-blades.cfm  (and again)
http://www.wikussawtech.com/index.php/en/einfahren (another blade manufacturer)

So like I said, this was all news to me, so I'm not preaching this stuff as gospel, just that I discovered yet another thing that I, as an untrained amateur, hadn't heard of until now that could be affecting blade life.


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## Eddyde (Jun 26, 2017)

Herbie555 said:


> Important trick:  A blade that has the teeth "backwards" can be reversed by turning the blade "inside out".  Like, flip the surface over and work it all the way around.  Voila', the teeth will be facing the other way.  I have to do this about one time in five as the process of taking the wire-wraps off and getting the blade out of the shrink-packaging has it come out "backwards".
> 
> 
> 
> ...



Wow, I guess there's some truth to it then. One of those things that doesn't seem to make sense but...


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## bob308 (Jun 26, 2017)

I bought a 4x6  saw 35 years ago. the motor went out in 6 years. I put a new  u.s. motor on it and it has run good ever since. I did have to stiffen up the base. mine cuts straight just takes it time. they do not like to be pushed.
 rule is you should have 3 teeth in the metal when sawing even if you have to use a finer blade. tubing will tear up a blade use the finest blade you can get. 
 I would rebuild the saw you have . most people considerer the h-f a kit.


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## Dabbler (Jun 28, 2017)

I've been lurking on this thread since it started, but If I may, I'll add my .02 - I greatly prefer the rebuilding of older machines, which are usually stiffer, stronger and more dimensionally stable than the new ones.  I know it isn't everyone's cup  of tea, but if you can I'd keep/rebuild the old one.


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## Rudy_R (Jul 26, 2017)

My bed frame isn't made of mystery metal... It also won't sag. 2" square tube with 7 legs with machine leveling feet. Doesn't squeak, doesn't shake, doesn't move. Two halves bolt together to make it easy to move. If only you could buy them like this from a store, I wouldn't have to make my own.


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## coffmajt (Jul 26, 2017)

Rudy_R said:


> My bed frame isn't made of mystery metal... It also won't sag. 2" square tube with 7 legs with machine leveling feet. Doesn't squeak, doesn't shake, doesn't move. Two halves bolt together to make it easy to move. If only you could buy them like this from a store, I wouldn't have to make my own.




Composition of bed frames can run the gamut on hardness because they are mostly made from remelted scrap steel and carbon content can vary greatly. With high carbon you can get carbide precipitation resulting in very hard spots, which will kill even a bi metal blade. For blade speeds I like 100 sfpm unless all you cut is aluminum. On hardened alloys even 100 is too fast. Jack


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