How flat should I expect an extension wing to be at the mating surface?

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Forum topic by skatefriday posted 05-08-2014 10:16 PM 1657 views 0 times favorited 21 replies Add to Favorites Watch
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416 posts in 1477 days

05-08-2014 10:16 PM

Hello all,

I recently purchased a Grizzly G1023RLW and despite lots
of fiddling was unable to get the router extension wing
completely flush with the main table.

The real problem is the edge is not dead flat. Running
a finger along the seam from the back to the front, the
extension appears to have about a 10/1000” hump in
the middle (I got out my feeler gauges to measure so I’m
pretty sure I’m accurate with that number).

I currently have it set up so that it’s 5/1000” below the
main table on the rear, 5/1000” above the main table
in the middle, and perfectly flush at the front.

So the question is in the title here. What should I expect
and far as mating of these two parts? Is this unusual or
par for the course?

Thanks all.

21 replies so far

View HorizontalMike's profile


7755 posts in 2908 days

#1 posted 05-08-2014 11:38 PM

I hate to be crass, but your wood will breathe more than that overnight, depending on the humidity. Are you sure you want to be a woodworker, with all of the wood movement, flex, swelling, shrinkage, warping and all?

In other words, if you can get your cuts within ~1/64in (15.625 thousandths of an inch) then you should be OK. If not, then find a new hobby… ;-)

-- HorizontalMike -- "Woodpeckers understand..."

View TheFridge's profile


9444 posts in 1480 days

#2 posted 05-08-2014 11:44 PM

Call grizzly and get another.

-- Shooting down the walls of heartache. Bang bang. I am. The warrior.

View kdc68's profile


2657 posts in 2271 days

#3 posted 05-09-2014 02:10 AM

You should be fine. Don’t sweat it and start enjoying your new saw/router table

-- Measure "at least" twice and cut once

View Dark_Lightning's profile


3159 posts in 3103 days

#4 posted 05-09-2014 02:30 AM

I personally would try to get the thing replaced. It’s brand new, so it should be dead flat. Just make sure it isn’t your table saw that is low in the middle instead. Cabinets will never see this, it is insignificant for that. If you just want to shove wood through it, it should be OK. But I do some intricate work, and if I had to suffer that lump in the middle, it would be annoying. A small box would be a different story. I bought a 50+ year old table saw that has less than .004” total indicated out of flat over its entire surface. It really depends on what you are building. Some of my boxes have sliding lids that have to not rattle when closing, and not seize in bad weather. A lumpy table (saw or router) doesn’t cut it.

-- Random Orbital Nailer

View AnonymousRequest's profile


861 posts in 1543 days

#5 posted 05-09-2014 02:44 AM

That’s what they sell. If people accept that, that’s what you get.

View skatefriday's profile


416 posts in 1477 days

#6 posted 05-09-2014 05:19 AM

Hmmm, we are currently running 50/50 on getting it replaced vs. just enjoy it, with one outlier who’s not a Grizzly fan. :-)

View unbob's profile


810 posts in 1898 days

#7 posted 05-09-2014 06:02 AM

I find it interesting that there appears to be no minimum standards on woodworking equipment.
The closest I have found is a small hang tag that came on a 70s Powermatic 66 table saw. This tag had a few specs such as, the table is flat not over .010” out, and arbor run-out not to exceed .002”.

On the metal working machines there are industry standards. There are also special machines such as jigborers where alignment of spindle to table not to exceed .00008” or eighty millionths out of true.

An interesting “to me” observation is woodworking equipment designed for casting pattern making shops. This equipment is much more like high end metal machines in detail such as massive weight, fine adjustments, and some with high precision spindle bearings with circulating oil systems.
An example would be a Wadkin pattern makers table saw, and some shapers and planers.

That type of equipment of course is for work demanding more precision then needed for a chicken coup.

View Woodbum's profile


812 posts in 3060 days

#8 posted 05-09-2014 11:35 AM

You sound like a machinist. Wood is not metal, it is a living, breathing, moving thing even after it is cut. What are YOU personally willing to live with? 5/1000 is pretty minimal for woodworking, not so much for metal. If it were me, I would “nail it” as it is. Send off for a new one, and it may or may not be better or worse. What is your time that you have invested worth? IMHO, Griz is better than many other consumer product on the market today. In fact quality control and customer service is so bad in most cases, that we live with a lot of things that are not quite right because it is too big of a hassle to try and get them fixed. Enjoy your new equipment and have fun and work safely.

-- "Now I'm just another old guy wearing funny clothes"

View unbob's profile


810 posts in 1898 days

#9 posted 05-09-2014 12:36 PM

There is a perception that metal is more stable then it really is.
Metal can have a grain structure, internal stresses, hard and soft areas, and other problems that results in warping and twisting after machining processes.
Cast iron can be pretty bad for warp and twist from internal stresses that relieve after machining. Some of the better cast iron machines, the raw castings are allowed to age out in the weather for several years before finished into the final product.
An example of problems with cast iron warp would be the Bailey hand plane, those can be pretty bad.

I assume the saws wings are held with 3 bolts, those can be played around with a little by tightening perhaps the middle bolt, then pivot the wing slightly to align one end then tighten, the lift up the low end and tighten.
The wings are more flexible then one often thinks.

View bigblockyeti's profile


5112 posts in 1715 days

#10 posted 05-09-2014 12:47 PM

I would try to get it replaced, the precision of the work you produce from the saw has more to do with your setup and skill than the extension wing. That being said, if Grizzly can make the table flat, they can make the wing flat too, you shouldn’t have to deal with this.

View Bogeyguy's profile


548 posts in 2062 days

#11 posted 05-09-2014 12:58 PM

Just use it and forget about getting it”perfect”. When your routing the critical area is at the bit. The fit where the tables meet is not going to be critical IMHO.

-- Art, Pittsburgh.

View R_Stad's profile


408 posts in 1837 days

#12 posted 05-09-2014 08:24 PM

I agree with unbob (post #9 instructions). Use a block of wood and a clamp and you should be able to get it real close. Good luck with your new saw.

-- Rod - Oregon

View skatefriday's profile


416 posts in 1477 days

#13 posted 05-09-2014 08:50 PM

I was able to get it effectively flush by taking unbob’s suggestion. I had the front
already flush, so I loosened the middle and back bolts, used a rubber hammer to
flush up the middle, tightened it, and then flushed up the back with the hammer
and tightened it. It’s not machinist perfect, but as the other half of the
posters note, it’s good enough and is no longer so out of whack that it annoys
me every time I run a polishing cloth over it after use.

Pretty amazing how that big hunk of metal will flex.

View HorizontalMike's profile


7755 posts in 2908 days

#14 posted 05-09-2014 08:51 PM

Yee haw! Now go make some sawdust! 8-)

-- HorizontalMike -- "Woodpeckers understand..."

View Redoak49's profile


3239 posts in 1983 days

#15 posted 05-09-2014 08:52 PM

I would not be worried about him being a machinist or wood being a “living breathing thing”

My concern would be that an edge sticking up like that could cause a scratch in the wood….that is a problem.

Grizzly describes the top of the saw as “Solid cast iron table is first heat treated to remove warpage, then milled perfectly flat & ground to a mirror like finish”. Based upon this, it should be flat and 0.010” is more than I would like.

I just looked at the diagram for this saw and router extension. It has three bolts that hold it to the saw. As one poster said use a block of wood and clamp and see if you can get it to fit all the way across. I would line it up in the middle and bolt it tight and then use a block of wood and clamp on each side.

showing 1 through 15 of 21 replies

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