12" Conversion

[oohhmm]

First, why... I was given (mind you given) 300+ linear feet of true 4" redwood, that came off a 90 year old bridge. It's pretty beat up, full of massive nails, bolts and dirt. It's mostly about 15 to 18" wide ( too wide for my planer) and most pieces are 6" long.

I want to remake my yard furniture. I've played a bit with the 2 pass method, but frankly it is less than desirable. I've been watching Craigslist for an old 12" belt driven saw (the direct drives only measure up the 3 1/2 to 3 3/4 inch cuts) but haven't found a cheap saw for this one time project !

In my search, I came across a BT 3000 that needs belts and nothing more. It's just the main saw, no fence, no miter etc. - I bought it for $50.

Before I bought it (I would have regardless for the motor) I looked my saw over carefully and think the housing will handle it with just a few mods. The outbound "plate" that completes the dust shroud has to go. I need to shim the blade out to clear the inboard housing and with a zero clearance plate, I'm pretty sure I can get the blade to spin clear.

I've found an arbor adapter from 1" down to 5/8ths to solve the blade fit. (there are 12" blades with a 5/8 " arbor, but they cost more than the saw did) I'm going to run a Diablo 12" combo blade to rough it out, pass it through my 12 3/4 " planer to bring it down to 3 1/2" for the finish (this will get rid of the dirt packed 1/4 surface) and can then work it on my 10" saw to a better true.

As far as power goes, this wood has been drying for 90 years, and when it went over my 10" blades in tests it was about the same resistance as 2" Poplar, so I think I'm OK there..

So, I'm wondering, has anyone changed up to 12 inches? Does any of the collective thinking out there see something I'm not considering?? any other feedback ???

[LCHIEN]

this really needs to be in the BT3x00 Related Discussions forum, not the BT3x00 related articles section as this is not a "how to" kind of article. Maybe one day it will be. I don't see any moderator tools to move it, though. There are moderator tools to move discussions from one group to another but not from the articles section.

As for the conversion, I think the two main obstacles (I don't have my saw in front of me) will be the opening in the throat plate and the clearing of the locker bracket frame.

The stock metal throat plate opening if I recall is pretty much close tot he length of the plate... so there's a strong possibility a blade 1" more in radius will hit the extremes of the throat plate opening.

The locker bracket is the metal casting that moves up and down with the arbor and motor assy, it has an "arm" that goes in the back that holds the splitter and blade guard support. I think this just clears a 10" blade, so a 12" blade would have to be shimmed out beyond this arm. Yes, you will need a 5/8 to 1" arbor adapter for most 12" blades, but shimming the blade out will also put it out over the threads for the arbor nut. The diameter of the threads is less than the arbor so the blade will sit off center a bit (wobble, vibrations, all the cutting on one side of the blade etc) and also there will be a limited amount of thread, if any at all, for the arbor washer and nut, making an unsafe situation.

[dbhost]

I can also readily see the mount for the riving knife getting in the way...

At the thickness of the stock being cut, I seriously doubt even a 12" table saw will be sufficient. It sounds like this material really ought to be resawn on a large band saw and then flattened using your favorite method of router sled, hand planes or whatnot...

[cabinetman]

My first thoughts are that the saw was designed for a 10" blade and not powered for spinning a 12" blade.

.

[vaking]

I would also be concerned about speed. BT spins blade at 4800 rpm which is on the high side even for 10" saws. 12" saws usually work at 3000-3500 rpm, not every blade is rated for 4800 rpm. Chose your blade carefully.

[oohhmm]

oops

As it was pointed out, I posted in the wrong place - so - thanks all for the points raised. I'm going to play around with this over the weekend and will come back with what I find out - in the right forum!! Thanks again!!

[Black wallnut]

As it was pointed out, I posted in the wrong place - so - thanks all for the points raised. I'm going to play around with this over the weekend and will come back with what I find out - in the right forum!! Thanks again!!

Just continue on in this thread, I've moved it for you. I'm thinking Cabinetman has hit the right answer. Dirt imbedded wood will ruin planner blades rather quickly and the abrasive dust might harm the machine itself. You might be better served finding a band saw to rough size the wood. Or even using a wire cup brush on a grinder to knock all the dirt off.

[Stytooner]

Personally I would knock the edges off with a cheap blade from HF. The cut should not matter too much if you will plane later.
Just use the two pass method. Then check with a metal detector and use a planer.
Bandsaw blades are not cheap and the first nail you hit makes it ineffective anymore.
Even a bimetal blade on a woodcutting bandsaw is only good for aluminum and brass. They are typically way too fast to cut steel.
A cheap HF blade will cut through nails etc. Just be sure to wear a full face shield and long sleeves.

[leehljp]

Dave in Cairnes who used to post here years ago, used his BT3000 to do the two pass method on expensive and hard wood. He was extremely talented and successful with wood!

[oohhmm]

Thanks for the move!!

I dug a little deeper this weekend.

I agree, re-sawing the wood would seem logical, and I'm equipped to do this, it's more about relocating my band saw to accommodate the dimensions. I misstated the length earlier. Most pieces are 6' not 6" and it is up to 15' long.

Also, I've had mixed results re-sawing this wood on test pieces, partly skill I'm sure, but my 3/4" blade drifts too much for the results I want.

The 2 step method is just not going to work on long runs with out a semi true edge, even with a sled (which I am building), again for the edge I'm looking for, without hours of hand planing/sanding. A power planer and jointer tore up the brittle knots.

I'm still leaning on the conversion and have found the following.

I found the Makita Beam Saw. 16" blade 15amps that will cut Doug Fir up to 6 1/4". It runs at the same amp rating as the BT3 and though it might still have more power, I'm putting way less load on the motor at 4" of very dry redwood - I think the power issue is OK

12" blades in the price range of less than $50 were all rated between 6-7700 RPMs, so, not a problem (excellent suggestion, thank you!!)

Examining the saw again, not only is the metal throat plate out (I'll use a zero clearance) but I will need to cut a notch in the table to accomodate the extra inch on the blade. It's tricky here.

If I shim out, I will, as pointed out, be on the threads with the blade and, the notch will cut into the standard throat mounting hole. I may go back to 10" later so this is not good.

The alternative is to grind away at the mounting block for the riving knife. This should be relatively easy with an angle grinder (I'll use for the notch as well). I know this is sacrilege, but remember I paid $50 for this "throw away saw" that has been seriously used in construction. The red paint on the stock throat plate is gone, the table has been polished by the amount of wood that's been run over it. But, the motor seems to run strong, and I have 2 more if I need to change it (I've bought 4 saws now not counting my first for $50 to $100 just to keep for parts to keep my BT for the rest of my woodworking days)

It is riskier running without the riving knife AND until I bought my shark, I used the stock knife about 50% of the time. I'll also, be running this wood on a simple sled that will ride between a router table and the left side of the saw on the rails. The "slides" will be made from 2x2 doug fir, planed down to keep the top of a ply wood "table" that will allow me to clamp the piece in place for a truer edge. The "table" of the sled will be at level with the saw's table, to keep the 4" cut.

The completed pieces will be run through either my planer or my drum sander. I don't think the dirt will damage the blades much on the planer (it's a fine powdery dust, but I may still have chipping of the knots, if so, It's the drum sander and a few belts. The goal is to keep as much of the dimension as possible, but lose the dirt and rough. I'm hoping for 3 1/2 net.

When this project is over, I'll try to keep the saw in use for more construction kind of work I do around my property. I have a couple of outbuildings that need work and a chicken coop to build. I'll go back to the 10" blade most likely, but it will be nice to have 12" if I need it for some other reason, and even the riving knife should be able to be mounted as there will be plenty stock left after I grind to drill through for mounting new bolts. I gave away a cheap Ryobi that was terrible!

Any other insights as to what I might be missing?

Thanks

[LCHIEN]

Any other insights as to what I might be missing?

please be very very careful, you are using the saw way outside its design parameters. This is your right but we hate to lose members.

[Stytooner]

We have heard of saws arbors failing before. Right Tommy?

If you do manage to get the blade to fit, the larger blade will be applying more force to the arbor. The arbor is well suited to a 10" blade on the BT's, but maybe some engineering calculations need to be done to see how it will hold up to the torque and faster tooth speed of a 12" blade.

Larger saws have bigger arbors for a reason. I have built quite a few machines in the past. I generally over build everything. Gauging an arbor below needed size is a deal killer for me.
It may work very well, but if it does fail, you will likely never know it.

Rather than do all that work, I would metal detect the stock. Remove any big metal bits by hand. Then dedicate a set of planer knives to the project.
After a few passes through the planer, then into the sander.
That is sure to yield good results and be much safer.

[greenacres2]

Any other insights as to what I might be missing?

please be very very careful, you are using the saw way outside its design parameters. This is your right but we hate to lose members.

...or members of members!!

earl

[oohhmm]

Yup, I'm way out of spec with this and yes safety is my primary concern!

As for the arbor strength. this weekend I pulled the blade from my Dewalt Miter saw I use for chopping up lumber (as in doug fir 2x4's and 4x4's) and found it used an adapter like I was planning on buying - 1" to 5/8". This saw runs at 4000 RPM, is also a 15 amp motor, and unless Ryobi used a lower grade of steel, should have similar strength?

Can you tell me more or point me to the arbor issue Tommy had? Did you mean when you said "but if it does fail, you will likely never know it" that an arbor failure is life threatening and/or seriously dangerous?

The nails and other metal in the wood is easy enough to remove and will be before I run it over the saw (any saw)and I can't get it through my planer until I rip it down to 12"'s


I am indeed fond of all of my members.....

[oohhmm]

Just thinking about the arbor question....

Wouldn't a fully stacked 8" dado put more strain on the arbor than the added blade tip speed of the 12" blade???

It's biting into a lot of wood and the radial stress has to be maybe 4 fold that of a 10 inch blade ?

I'm not an expert in this area, and am concerned this could be the flaw in my plan...

Thanks!