Mortiser Question

When cutting/drilling a mortise is it normal for the chisel to follow the grain?

When I was practicing on a 3/4" square piece on a through the board Mortise the chisel went in about 3/16" at the top and exited about

1/16 " from the same edge at the bottom. The grain slanted that way normally.

I was using a 3/8" bit.

On soft wood it did not wander.

I am practicing for doors, for cabinets down the road.

Reply to
OFWW
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In soft wood (or green wood) it is difficult to keep a cut straight: the wood deforms ahead of the cut, and when the chisel is buried in the cut, that deformation springlike pushes it sideways. It might just be the quality of the test scrap.

Check, by rotating the chisel, to see if it has a dull edge, which might also make it prone to wander.

If it always cuts that direction, you'd want to shim the fence parallel, of course.

Reply to
whit3rd

It shouldn't, no (obvious, I suppose? :) ).

Something is letting the chisel get off plane; as another noted if it isn't honed well/evenly it takes more force and that is possibly contributing. From your other saga re: fit 'n finish, who knows what else may be going on?

A quality mortiser is quite capable of square (to the surface, that is, not just the hole) resulting mortises in hardwoods and not being excessively influenced by grain direction, yes. The amount you're talking about implies a major movement of some parts of the mechanism.

Reply to
dpb

It should not have moved that much. Is your work clamped in place?

ALSO regardless of the brand of mortiser you need to sharpen the chisels first, just like with regular wood chisels.

The outer surfaces should have a mirror like surface and the inner end should be sharpened with a cone shaped stone specifically made for this purpose.

Reply to
Leon

On 10/23/2016 8:56 AM, Leon wrote: ...

And, like lapping cylinder seats, the stone and its arbor needs must be concentric to the inner faces and not have excessive runout or out-of-round--else't, the variation in wall face angles/material will tend to make for such asymmetries.

From the sounds of the tool rework just to get a most minimal even functioning apparatus you'd probably get better results from a drill-press addon than this thing's going to do. Although certainly cheap, poorly sharpened punches and drill bits can wreak havoc on results even with the better light-duty mortisers such as the Delta or Jet. The heavier fella's like the larger Powermatic have enough "beef" they can overcome at least some of that, but still work _much_ better w/ quality and well-tuned chisel sets.

Reply to
dpb

Good idea, thanks

Reply to
OFWW

I've read about bit wandering if when making cuts right next to each other when only 3 sides are in contact with the wood. Suggested was to drill a hole at each end then in the middle so that all four sides of the bit are in contact with the wood, and then cut out the smaller portions left over where only two sides are in contact so as to prevent wandering due to the stresses on the chisel.

Seems I have more checking to do per recommendations given here.

Thanks

Reply to
OFWW

Hmmm, this made me rethink the situation. This bit is not mirror finished on the outside. It is a bit rough to the eye. This bit also had a raggedy edge on the hole where it entered the wood. Made me wonder about it at the time but I was too focused on other things.

Guess first priority today is the bit itself, after I rotate it and see if the bit wanders accordingly, then to the sharpening part.

Thanks Leon.

Reply to
OFWW

Indeed... :) What's the holder diameter on the bit sets? I've seen some really flimsy-looking ones on some of the knock-offs, at least by the 'pitchurs; not had those in hand to actually see...

Also, by "movement" above, it's relative of machine/wood, if the holddowns aren't up to the task, that's a problem, too. Just a light rod or similar probably isn't enough to prevent rotation in hardwoods, even if not bulk movement.

These are cases where "Bulk is Better!" almost universally...

Reply to
dpb

Get that mirror finish on the outer surfaces and it takes considerably less effort to plunge.

Reply to
Leon

I can't see any reasonable way to explain such wandering. The chisel is moved straight down on its carriage and there is no way for it to veer short of the chisel bending and even the smallest one is very stiff. Is the chisel well locked down? Is the carriage free of side play? Unless, of course, what you are seeing is the stock itself moving.

Reply to
John McGaw

You are right, but here is the rest of the story. ;)

In looking at the square holes with glasses I noticed it was rounded on the sides and only the corner was square. I pulled the bit out and realized that the bit was bigger than the chisel at the opening. I then looked at the other3/8 bit set and it too had a larger bit than chisel opening. So I reinstalled it, grabbed a file and ran the mortiser holding the file next to the chisel.

I made a hole about 1/2" deep and now had a square hole, fairly clean.

Pulled it apart and polished the chisel to a mirror finish and put just the chisel in and went back to the same hole since the drill went lower than the chisel. The polished chisel went in nice and smooth and cleaned up the hole perfect. So I reassembled the bit and chisel, repeated the whole process going through the 3/4" oak. Made a through hole and measured from the top edge and bottom edge there was a 1/16" drift, spun the chisel was the same I could see the chisel come towards me as I applied increased pressure. :(

I am thinking that the bushing between the cast body and the chisel is just too sloppy.

Per Dadioh's suggestion I ran just the bit and it bored straight through on its own.

Going to see if I still have some shim stock around and make measurements and hope I have something that fits. The last Mortiser I had the shim fit in the body tightly but at this point I don't think I can count on the casting bored hole for the Chisel being the same. If I cannot find shim stock around in the garage I am just going to take it all back and undo it.

I cannot imagine making cabinet door with the mortise's all off like that.

Reply to
OFWW

I have a Delta mortiser and used it a hand full of times. It cut pretty good but it cost me too much time to make mortises that way. And the primary reason that I switched to the Domino.

Reply to
Leon

In this particular case it ended up being the bushing the chisel fits into. The bushing would fall out of the housing on its own if you were to completely take out the hold down screw.

There is minimal play between the bushing and the chisel.

Reply to
OFWW

Couldn't find my shim stock, took a piece of my wife's alum foil, wrapped the spacer the spacer once trimmed and edged it, gently fed it into the body casting. Re-assembled the bit and chisel, found one side of the chisel still had a bit of the Bit cutting outside of the chisel very slightly, ran a test hole and it straightened up quite a bit. It is now less than 1/32" off. Might never have been noticeable had it been this snug in the first place.

As to keeping it? ??Thinking.

Reply to
OFWW

TL;DR the thread, but did you insure that the bit and table are perpendicular?

The head and mechanism on the Chiwan products are not always attached and/or made/assembled with precision.

Reply to
Swingman

Yes, that was the first thing I checked on this last Mortiser. from all angles. It was surprisingly vertical per my square. Even when moving up and down, all four sides.

I cannot believe all the variations in problems between these three Mortisers. These last two even had similar problems with the bit head being slighly larger than the chisel.

Reply to
OFWW

On 10/24/2016 3:19 PM, OFWW wrote: ...

That seems fairly frequent recently; I've seen some complaints that sets from Woodcraft are showing the same symptoms...also to the point of actually leaving rounded holes observable, not just a tiny amount...

Reply to
dpb

That is exactly what these last two sets exhibited. The First one was actually spot on.

Thanks for the heads up on Woodcraft.

Reply to
OFWW

On 10/24/2016 9:21 PM, OFWW wrote: ...

They're one distributor need to be wary on...they're reputable business-wise as far as not failing to deliver product or the like, but much of their WoodRiver-branded product is just run 'o the mill import stuff of only marginal quality ime...I've pretty much quit ordering any of it.

You might want to at least consider

Reviews are mixed but for the price point the xy table is a one-of-a-kind afaik in what's currently available. If, as demonstrated by the effort put into the HF units, you're willing to do some tuneup, you might just have a nice machine in the end. I think my primary concern would be the 1/2 hp being weak for larger mortises in hardwoods. Clearly, the chisel sets with it aren't to be expected to be much by the reviews.

Reply to
dpb

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