# What tool to buy for high precision/repeatability/speed?!



## Aurora North (Aug 4, 2015)

Hey guys...

So this seems like it should be extremely obvious, but I am having a VERY hard time getting ultra precise square end cuts...

By precise, I mean if the blade deflects as much as a 1/64 my finished joint looks like a steaming pile of quality. 

Right now I am cross cutting with a chop saw and a fresh forrest saw blade. Now the actual squareness of the cut isn't so much an issue. So long as I clamp the wood down I don't have a problem with the end being a very precise 90 degrees. The issue lies in the deflection of the blade giving me an out of square cut as it passes through the thickness of the wood. 

To give you some idea mentally as to the application... I need a perfectly or nearly perfect flat end grain edge because it becomes the female shoulder of a dovetail slot. When the male shoulder of the dovetail lid meets the female shoulder, if I have any degree of an untrue edge it shows. 

For the life of me I can't figure out how to get a precision end...

I am hit or miss for repeatability with the chop saw. A handful are perfect and some are "acceptable" though they pain me to even look at. And my box of unacceptable keeps getting added to.

I need to correct this problem.

Methods I have tried involved cross cutting with the chop saw first and then using an oscillating edge sander to precisely square the end. This worked so so, but was time consuming and delicate. I do not own one though so I am debating wether or not it would really be the way to do it or if there is a cheaper and FASTER way. 

I also tried running the stock on a sled with hold down clamps against a flat shaper cutter. Perhaps this IS the best way, but I am having an issue with snipe as the leading edge first makes contact with the cutter. This wouldn't be a problem, but long ago I cut lots of expensive figured wood to final width dimensions (stupid) and have no room to rip the snipe edge off. screwed myself.

Recently I bought a Jet 12" disc sander to again try kissing the dovetail end to correct any slight blade deflection. Well, that machine could have worked if it was more precise. I'm sending mine back due to a wobble in the spindle. 

Speed and repeatability is a must as I am trying to minimize my production time. If there is a way to cut these time after time with the precision I'm looking for then that is the absolute ideal.

I was looking at CTD pneumatic miter saws, but man they're pricey at 5k. I would need to speak to a rep about the precision of the cut before more seriously considering them. 

I was also thinking of trying a bottom bearing straight cut router bit that rides along a Class 2 block as a precision straight edge. 

I even thought of ditching the woodworking tools all together and looking at overhead milling machines and CNCs. Very pricey and very large/heavy equipment. Out of the budget at the moment and I'm not convinced there is not a cheaper/simpler/faster way to go. Some sort of jig and router combo?

I just don't know how to proceed with equipment in order to get the precision, speed, and repeatability I seek. 

If anyone has any recommendations I'm all ears.


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## Schroedc (Aug 4, 2015)

I do boxes that rely on a perfect 45 degree joint to give a tight seamless fit and I use a sled on a table saw with a stop block for cutting many parts the same size. I use a Wixley angle gauge to double check my setup and a machinists square to check that I'm perfectly perpendicular to the blade as I go over. Maybe I'm not picking up what you're laying down but this seems similar to what I'm doing when I run a batch of boxes....


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## Aurora North (Aug 4, 2015)

It's indeed similar. I need that seamless look, but my seam is between a 90 degree end cut for a sliding dovetail lid. 

I have actually been meaning to get some machinist squares. They're expensive, but I think for the precision I want it's the only way. 

Ever head of TS-Aligner.com? I'm probably going to be giving this guy some business. I've been thinking about getting the TS-Aligner just for stuff like this for some time. I keep putting it on the back burner along with the set up squares though. Maybe it's time to prioritize.


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## JR Custom Calls (Aug 4, 2015)

I would think the table saw would be your best bet as well. A good sled, which is surprisingly easy to make, and proper setup of the saw makes for very precise cuts.


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## Schroedc (Aug 4, 2015)

Aurora North said:


> It's indeed similar. I need that seamless look, but my seam is between a 90 degree end cut for a sliding dovetail lid.
> 
> I have actually been meaning to get some machinist squares. They're expensive, but I think for the precision I want it's the only way.
> 
> Ever head of TS-Aligner.com? I'm probably going to be giving this guy some business. I've been thinking about getting the TS-Aligner just for stuff like this for some time. I keep putting it on the back burner along with the set up squares though. Maybe it's time to prioritize.



A 90 degree cut is no problem either with my setup. I just zero the gauge to the table, stick it to my blade and dial until it's at 90. as far as how much money into a table saw, I'm using a Rigid with a portable base so I can roll it around that I've had for 10 years. It gets banged into walls, used as a workbench and otherwise used in a manner inconsistent with its labeling and I can still get precise cuts every time with it. A jet, Grizzly, powermatic, etc. would all give you what you need and they do show up on craigslist regularly. the other thing to keep in mind are the blades, I use Freud thin cut blades that I'm partial to and while they are 90-100.00 each, they last a good long time and I've never had any noticeable deflection.

Looking at your setup as you described I'm thinking that pushing the blade into the wood with the cutting happening from the top middle down and out instead of pushing the wood into the blade where it cuts from the side just seems to be less precise since you're moving the blade and any play in the pivot point can be transmitted to your work.

Reactions: Agree 1


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## Aurora North (Aug 4, 2015)

Hmm... I originally cut many of the first blanks on a table saw. To be exact... I was cutting them on an F45 Altendorf sliding table saw. And believe it or not even then I was still getting open seams due to either deflection or the saw marks. Either way, I'll give it another shot. I'll try it out on the delta unisaw also. Already have a sled made for that one.

Reactions: Like 1


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## DKMD (Aug 4, 2015)

Most of the segmented turning crowd seems to rely on a table saw and sled setup for precision cuts although Macolm Tibbetts(arguably the top of the food chain) uses a miter saw... Festool if I'm not mistaken.

Most all of them use a very flat surface with sandpaper to eliminate saw marks... Glass or granite slab with sandpaper affixed.

None of that may be of use, but I'm a turner...


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## Aurora North (Aug 4, 2015)

Nonsense David! It's these small techniques that are obvious to you experienced guys that could be the difference for me having an open seam that I'm ashamed of or the nearly invisible seam that I seek.


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## tocws2002 (Aug 4, 2015)

I would think a sled on the table saw would work fine once it's dialed in, but another option would be a miter plane and shooting board.

Just cut the pieces on your miter or table saw then clean up the edge with a miter plane and shooting board. Would only take a swipe or two after trimming on the power saw and your results should be very repeatable. Just a thought.

-jason

Reactions: Agree 2


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## barry richardson (Aug 4, 2015)

Deflection is indeed a problem with chop saws, even the best of them with the best blades will deflect slightly, especially with angle (other than 90 degree) cuts... a dialed in sled on the table saw is as good as it gets. But it will start deflecting as well if your blade is dull. Thin kerf blades are also more prone to deflection...

Reactions: Agree 2


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## Aurora North (Aug 5, 2015)

Ugh...

Just checked the prizes on miter planes. If I go that route I'm not buying a cheapo piece of crap. Especially with a hand plane. 

I think I'm going to give a 1" diameter top bearing router bit and a precision straight edge a try. I literally just need to kiss the edge and remove discrepancies in the squareness. 

If the table saw and router can't deliver I guess I'll look more at the miter plane and shooting board. I'm not opposed to hand tools, but in the past when I first tried the planes out I had a real hard time shaving burls and other figured woods.


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## TimR (Aug 5, 2015)

Lots of good suggestions, and the ones suggesting a table saw are definitely a more solid approach. I don't recall if you implied trying the Wixey or equivalent digital gage to check the alignment of the chop saw to the table? And I can't tell from your description if the deflection is in the 'bevel' direction or in the 'miter' direction. By 'bevel' I mean the tilt of the blade, vs 'miter' being like a cut from a miter box. 
If it's in the 'bevel' direction, the Wixey would be the best way in my opinion to check squareness. If it's in the 'miter' direction, a top quality square is indispensable and the only real way, short of trial and error, to get it right. I had used crap squares for many years, and thought I had my table saw and compound miter saws 'all dialed in'...hah! I found some good used squares on ebay, got things squared up and am frustration free now. A good test was a couple boxes and the corners came out great, and that was using my compound miter saw for the cuts.


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## Kevin (Aug 5, 2015)

Haven't read the thread so forgive if I repeat anything. Using a miter saw you must amke sure to leave enough wood on the off-cut side of the board or the blade will deflect every time. 

If you do use a router to clean up, make sure to use a sacrificial backer board on the tail end or you'll get tear out no matter how slow you go and how sharp the bit. I always use a backer board even on my miter sled. 

Speaking of table saw miter sleds - IMO nothing beats them. And do not use a thin kerf blade they will deflect even before they overheat. And they will overheats if used for many quick repeat cuts such as in production. A HD thick kerf blade is the only kind my arbors have seen in years.

Reactions: Like 1


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## tocws2002 (Aug 5, 2015)

Aurora North said:


> Ugh...
> 
> Just checked the prices on miter planes. If I go that route I'm not buying a cheapo piece of crap. Especially with a hand plane.



You wouldn't have to purchase a miter plane specifically, you can use various hand planes if it is tuned and the blade is sharp. As an example, and since you mentioned figured wood, a Low Angle, Bevel Up Jack should work well for you. Both Lee Valley/Veritas and Lie Nielsen offer one for ~$245 that should work well and both companies produce quality tools.

One other option if you decide to try your miter saw again is to make your cut on the end of the board and leave the blade in the down position, but no longer spinning. Push the fresh cut edge up against the blade (not the teeth, but the blade), raise the blade back into its upright position and make a second cut. This will only shave about 1/64" off the end, but it should be clean and square.

-jason


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## Kevin (Aug 5, 2015)

tocws2002 said:


> Push the fresh cut edge up against the blade (not the teeth, but the blade), raise the blade back into its upright position and make a second cut. This will only shave about 1/64" off the end, but it should be clean and square.



This is a recipe for blade deflection IMO.

Reactions: Agree 1


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## Aurora North (Aug 5, 2015)

Hey Jason,

I actually tried this method and found rather quickly that the cleanest cut was coming when I did the following (as Kevin accurately stated):

the first cut at the end of the stock was cut with 1" or so of waste that was making contact with the fence on the cut off side of the blade (right side). Then each consecutive cut had the full length of the pieces up against the fence (on the right side of the blade) with the remaining board length to the left side of the blade. Seems with a miter saw this was yielding the most accurate cuts in terms of minimal blade deflection. But I still get ever so slight deflection which shows up in the finished product.

Tim,

You hit it on the head. I've over thought this simple issue so badly that I can't even describe it in a way that makes any sense.

BEVEL! -DUH!

Yes, my issue is not in the 90 degree miter, but in the blade deflecting and beveling the end cut. The actual 90 cross cut is right on.

I prep my stock with a jointer until I have a perfectly or very near perfect square edge and face. Then I send the stock through a thickness planer to parallel the faces. It then goes into a drum sander to knock off the final 32nd from both faces and bring to precise thickness. After that I put the true edge to the fence of the saw and rip it to width. I use the auto feeder to keep it tight to the fence the whole way through the rip cut just to try and get the most precision square on all sides as I can. It's not perfect, but I'm trying to get it as close to it as I can because it all compounds on itself if something is out from the get go.

Kevin,

I agree with the thin kerf blades. I was looking hard at them for awhile and then decided not to due to what I was reading on the deflection. I went for the Forrest woodworker II. Cuts damn nice, I work very close by their facility, and it's what I've been cutting on at the shop on every saw. Plus, there are plenty of other reviews out their to back up my own experience with them. Pricey, but worth it in my opinion. I didn't think the Freud blades were bad either. Seem to wear out a lot faster than the Forrest blades though when running serious board footage. I don't see a thin kerf taking the cross cut abuse I'm going to put them through for production.


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