Saw blades

[Don Case]

I'm looking for 4" blades with 1/2" arbor and high tooth count. I can find them this size but they are called jewellers saw blades. Will they work for our purposes. I have 3 Thurston I-293 blades but they are 80 teeth(I think) and I need something finer for making gratings. The jewellers saws are 200 tooth.

[Gregory]

I get the cutting blades from Malco.    On my last orders a few months ago, they have required $100 minimum order.

 

I don't see any thing in the 200 tooth range.   I know I have made super fine cuts with teeth in the ~100 range.

 

Byrnes also sells blades   Not sure about the arbors, but they also sell arbor adaptors..

 

For the gratings look for a thickness that suits your job.  

Edited June 14, 2021 by Gregory

[allanyed]

What kerf do you plan to use?  For 1:48, I used a 0.045 which gives just over two inch squares.   My blade is a three inch diameter blade with about 200 teeth for the circumference of the blade and is a jewelers' slotting blade.     As you are cutting wood, a good quality blade is suggested but it does not have to be a super expensive blade.  The key is making the board with the slot for the blade and guide.   The guide has to be about 0.043 wide and should be 0.045" from the edge of the guide and the edge of the blade.  Note that the guide should be a couple thousandths smaller than the width of the slot.  A metal guide is ideal, but I used boxwood with no difficulties.  It should also be waxed to prevent the piece being slotted from binding and yawing.  Pics were recently posted in the Charles Galley build log on June 1 if you want to follow this method which follows actual practice, but you can also opt for the cross hatch type found in most kits.  I have never had success with the latter method, but I think other members have so you may want to give it a try as well.      

Allan 

[Gregory]

13 minutes ago, allanyed said:

My blade is a three inch diameter blade with about 200 teeth for the circumference of the blade and is a jewelers' slotting blade.

Allan, I think Don is looking for a source..  Do you have one?

 

I would be interested also..

 

Thanks

Edited June 14, 2021 by Gregory

[Don Case]

I can get them from Fastenal here in Canada. I just wasn't sure if jewellers saws would work for our purposes.

I have made one grate that turned out OK but when I'm cutting the battens the workpiece was chattering and moving around resulting in inconsistent thicknesses. I thought more teeth would help. The blades I'm using have 80 teeth and a .040" kerf which is close enough to 2" for me. The one on the left was my first try, the left is my second and the block in the middle is a jig to assemble them on.

[Gregory]

The one on the right is looking good..  Just take care to remember the holes are square, so the battens should be shaped to make that happen..

 

I'm not sure what the pluses and minuses are for the increased tooth count..   Someone with more info would have to chime in..

Edited June 14, 2021 by Gregory

[Roger Pellett]

Don,  

 

Any blade with the right kerf width and tooth count will work as long as the teeth are not “set.”   Metal slotting blades regardless of their market description should work.

[allanyed]

Overall, the right grating looks much better than the left and much better than many kit gratings.  Great start!!   There is really no need to make a jig.   Errors in the spacings in the jig will be transferred to the grating as can be seen with the variation of the widths of the grating ledges and a few of the grating battens in your example on the right.  

 

Allan

[Don Case]

The one on the left was just a test. The one on the right was a more detailed test. I need the jig to assemble them. My hands are too shaky. It's actually fairly easy with the jig. Once I get my saw zeroed in I can make a more accurate jig. The jig is actually just the first step in cutting out the ledges.

 

Anyway I got hold of our local Fastenal and they want $150. I don't know if that's for one or 100. So now I am looking for a source

[Gregory]

What kerf are you looking for?

[Chuck Seiler]

    Why 4 inch?  When I used to build ships that had gratings, I used Thurston 3" .030 kerf slottings (I think).  They worked fine.  As mentioned above, Malco is a good replacement for Thurston.

 

    Malco Jewelers Slotting # JS30281200, 3 inch, 1/2 inch arbor, 220 teeth $16.67.  I just got several at .028, .010, and .006.  They also have 4" blades (and 1 and 1.5 and 2 and 2,5).

[Charles Green]

Don:

Look into MSC Industrial Supply under the categories of slotting blades and jewelers blades.  You will find an enormous range of blades made of HHS or solid carbide of any tooth-count, thickness, diameter and arbor size you could want.  $25.00 minimum.  You must establish an account - just contact info - no cost.  

[Jaager]

Last month, I was browsing Travers Tool for cutters and came across a sale, so I bit:

 

Travers Tool Co. Inc.

TTC PRODUCTION 10-200-385 3" .012" Thick 1" Hole Dia. 280 Tooth High Speed Steel Jewelers Saw
Item # 10-200-385   Price:$25.55   You Pay:$12.78 EACH  Save 50%    $12.78
TTC PRODUCTION 10-200-395 3" 1/64" Thick 1" Hole Dia. 230 Tooth High Speed Steel Jewelers Saw
Item # 10-200-395   Price:$26.53  You Pay:$13.27 EACH   Save 50%      $13.27
TTC PRODUCTION 10-200-410 3" .023" Thick 1" Hole Dia. 230 Tooth High Speed Steel Jewelers Saw
Item # 10-200-410   Price:$19.23  You Pay:$9.62 EACH  Save 50%           $9.62
TTC PRODUCTION 10-200-445 3" .051" Thick 1" Hole Dia. 168 Tooth High Speed Steel Jewelers Saw
Item # 10-200-445   Price:$26.01   You Pay:$13.01 EACH   Save 50%     $13.01

 

I bought a 1" to 1/2" bushing from Jim Byrnes so these blades are ready to go.

 

Fine tooth jewels blades have no set.   They  are great for cutting a shallow mortise. They are not so good at ripping.  The greater the number of teeth per inch on a blade, the less suitable it is as a ripping blade.  The gullets fill with wood and the either stop the blade, offer a lot of resistance, and or burn the wood.

 

As long as a 4" tablesaw is able to crank into play a 3" blade, it should be high enough above the table to do the necessary depth of cut.  A 4" blade will do it  too, but it is overkill.

 

A shallow, interlocking mortise in the grating boards - both NS and EW  - if done correctly does not need a jig to get a square finished product.

 

I see two ways to cut the mortises that sort of idiot proof the process. 

1) cut the mortises in a block that is the thickness and length of the grating boards and rip that into the final board width.  - this loses about 1/2 as kerf.

2) cut the boards to there final size. Temporarily bond them into a block. Cut the mortises in the block and then use the appropriate solvent to release the bond.

[Don Case]

I need a .04" kerf to make 2"(scale) gratings. My saw was originally built around a 4" blade and going to 3" would substantially cut down my depth. I could work with a 3" if I had to.

I need 4". My saw is built around an old grinder and I need 4" to work around the motor

 

Thanks for the hints on sellers, I'll check them out.

Edited June 14, 2021 by Don Case