motor too weak?

[bongbong]

Hi everyone!

Newbie here with a CL-purchased BT3000 of unknown age. It's got a 15A motor, but really bogs down in trying to rip a 2x4. (Have to rip a wedge to build-up window sills to level.) I've done a search on this site and learned quite a lot from previous discussions, so here's what I can eliminate:

-it's not a low power feed: it's plugged directly (no extension cord) into outlet of 20A circuit which is wired directly to bottom of the breaker box (~2' of conduit away)

-using a very slow feed rate

-suitable blade: using a 28-tooth carbide (seems sharp enough)

-fence alignment is true

-I'm test ripping an untreated, kiln-dried pine stud from The Borg, not hardwood or anything. (Will eventually use redwood.)

So what gives? Shouldn't this saw be up to the task of ripping a 2x4? My humble (now sold to make room for the BT) old Skill TS would rip through 10' sections of 4x4's with no problem, with a 13A motor. Would replacing the brushes help?

There happens to be 2 BT's on CL now and I'm considering buying and swapping motors or maybe whole saws (and parting the other). Is it worth it, or do I need to look for other makes/models to get this job done? Not my preference as I specifically looked for a BT to build cabinets--love the rip capacity. Sorry for the long first post, but thanks in advance for any input you can give.

[LCHIEN]

A bT3000 should have plenty of power to rip one 2x4 into to 2x2, even with a 40-T blade.. DOne it many times.

I say the acid test of power margin is how much speed difference there is between going too slow and burning the wood and going as fast as you can without bogging down the motor.

If burning and bogging are occurring at the same speed then you don't have enough power for whatever reason. The things you checked are good, maybe you are dragging on the riving knife, the wood is closing and pinching the blade?
Can you rip a short piece OK? should be the same degree of difficulty, just sjorter.
Are you saying you are ripping a 2x4 into two 1x4? Then you are talking a 3.5" deep rip and that can be much more challenging, but doable.

[warrenp]

This may be stating the obvious, but just in case...

- Have you tried a new quality blade?
- And is the blade a thin kerf?

Mine slowed down dramatically once the blade became dull.

The only other time mine has slowed down was when I was ripping Brazilian Cherry.

Good luck,
Warren

[Monyet]

Sorry for the silly question

Is the blade installed in the correct direction? I only ask because I once tried to drill a pocket hole and the drill was running backwards and, well, 'nuff said.

[Russianwolf]

My first thought as well was to check for a blade pinch. Construction timber is notorious for having alot of internal stress and can pinch a blade enough to stop a 20 amp motor.

[leehljp]

And my first wonderment was - was it put on craigslist because it had a weak motor? However, if this were the case, generally it would be burnt out within minutes. Brushes perhaps?

Gummed blades heavy with pitch create a heavy drag and slow down the blade considerably, even if it is sharp!

[bongbong]

Thanks everyone for your answers so far.

Lchien: I am trying to rip vertically, so 2x4 into a wedge with max thickness at 7/8ths inch to a point on the other end. The blade is nearly fully raised and tilted at ~10 degree angle (~3.25" total cut). Glad to hear you say "doable". I've got the guard removed since I'm clamping to a waste piece and the whole shootin' match clamped to a sled so I can get my fingers well clear and feed from the side.

Others: yes, I have the blade on correctly (I have done waaayyy dumber things than that, though, so no offense....) I don't think it's a wood tension issue, since I've gotten the same results on about 4 test pieces so far. (I'd be totally fired if I had to do this for a living on the clock.)

Update: went to the Borg a couple of hours ago and bought a 24t Freud ripping blade. Came back, took off the cover, undusted the motor, installed blade, and tried again. Cut went noticeably better this time although still really slow. I made the mistake of stopping halfway through to turn off fan and light on same circuit and then restarting cut. Stupid in retrospect, but didn't think to back the piece all the way out and start over, so....snapped the belt! Aye carrraaaaaammmmbaaaaaaaaaa...

Yet another long post from the newbie, but to sum up I'd say a new blade made a noticeable difference, but it still seems underpowered to me. Maybe I'm expecting too much out of this machine?

[LCHIEN]

making the 3.5" deep rip is challenging, everything has to be right including a sharp blade as you found.

So the other thing is that some people do deep rips in two passes - just cut it 2" deep on the first pass and then raise the blade (or flip the piece over flipping probably works for a 0/90 degree bevel angle not your wedge) and cut the last part on the second pass.

You may wish to get my BT3 FAQ - see the sig line below.

[dbhost]

I grabbed a set of brushes for mine, but decided to blow the motor out with compressed air when i found good brushes, and a motor housing almost packed with dust...

[leehljp]

This is not intended to be critical but factual from observation over several years of users and the BT. Yes the BT3x00 can rip a 2x4 vertical (through the 3.5 in section), but it is a slow process. Those that had success with it were those who were content with the job and not the speed. (The time spent was passed on to the customer in some cases.) Those who needed a mixture of speed with the cut were generally disappointed.

To put it into perspective with an analogy: I make pens but each one takes its own time. If I spend 4 to 6 hours on a pen, that is fine with me as I am not in it for the speed but the finished product itself. However, those who turn and make pens for sale cannot afford to spend that much time on a single pen without driving the pen out of the targeted price range. For me, speed is irrelevant; for others it is a necessity.

Dave in Cairns used to use the BT for some magnificent commissioned pieces of tens of thousands of dollars in price. But he never went for speed and he ripped 4 inch and 6 inch boards of beautiful hardwood.

It depends on your needs. If you do need more speed, and since this is something that seems like you have done before, you may be disappointed in the BT's power for your needs. It will rip but not at a production speed.

Again, I am not being critical of you or the BT but just trying to steer you in a factual direction.

[durango dude]

I'd double-check alignment.

Long rips aren't forgiving of a mis-aligned fence.

Doesn't take much.

[Grampy122]

One belt?

When you said "I made the mistake of stopping halfway through to turn off fan and light on same circuit and then restarting cut. Stupid in retrospect, but didn't think to back the piece all the way out and start over, so....snapped the belt!"
Did you mean you only had one belt. There should be two.

[JimD]

I've ripped full depth in hardwood before with my BT3100. I had to go slow, got some burning sometimes, but it did it. But there is no power to spare so you have to have everything just right. A dedicated rip blade - flat tooth, not ATB - and thin kerf is a little better. Using a flat top rip blade with deep gullets is more important than the kerf. I mention this because home centers sell all kinds of silly blades as rip blades. Even Freud, which is what most of my blades are, makes silly blades. For a "cheap" blade, I've found Diablo's cut fast which would be a way to go if you do not want to mail order.

Cutting on an angle is harder on the saw than cutting straight up and down. If you have not put on an accesory, taller, face on the rip fence then you are not keeping the wood straight which adds a bunch of drag. I use a piece of melamine coated particle board on the left side about 4 inches tall. I have a taller piece for the other side for when I make a raised panel cut. I use nuts in the slots of the fence to attach these. It is well worth taking the time to put these on. I guarantees you of not trying to cut your rip fence with the blade and it really helps keep the wood straight. My fences are longer than the BT3100 fence because I think it is pretty short and I like the longer alignment.

When I am making one of these deep rip cuts, and thinking decently, I clean the blade first. Even a little gunk on it will slow the BT3100 a lot.

With a clean, sharp, blade of the appropriate type and a longer taller fence, your BT3000 will make this cut. But you may still have to slow down. If your blade isn't coming through the top, you should probably do this in two cuts (or more). Cutting with the blade buried is also harder. I believe part of it is the blade is not clearing the dust (which is also why a "real" rip blade has deep gullets).

Jim

[bongbong]

Thanks again everyone for the replies--this site it great! Great ideas on using two or more passes to make this cut--I should have thought of that, but didn't. Now I gotta go search threads on changing drive belts...

[bongbong]

Final wrap up for those who are interested. I managed to replace the belts (actually cheaper to buy an entire CL-listed used BT and cockaroach parts) fire it back up, and get my cuts done. I made 3 passes at it, as per the helpful suggestions of board members, and the saw hummed along nicely. Really starting to like this saw.