Official Luthiers Forum!

Paul, I'll race you. We each get 1 dozen rough neck blanks, with the job of surfacing and squaring them up. You get a well adjusted plane, I get a well adjusted jointer, and we both get a table saw. Who do you think wins?

We were talking tops, though, not necks. Each tool has its place, blah blah blah.

I use a hand plane cause I don't have a jointer, but if I had a jointer I'd use it.

This week, I had 30 mandolin backs to joint. That 60, one(plus) inch thick, by 16-20 inch long, flamed maple boards that need to be perfectly jointed. I'd still be at it if I were trying to use a hand plane. As it is, I have two to go! And all this only took maybe 15 minutes of each day.

But the dang jointer is out of whack again; I had to carefully set it all up before starting(new knives), and now it's cupping the cuts a little. I've gradually moved the fence back, using up all the knive's surface. But something in the tables has moved; always does....

I need to make up a jig(have it pictured in my mind...) using guitar tuners to bring some strings tight to use as straight edges. I have a feeling one or both tables is doing a slight twist. Any other ideas on how to check these? I have a machinist's straight edge that has been checked and is dead-on, but it is only 24" long...

Where can you get a jointer that does not need this kind of pampering? I want something that NEVER needs to have the bed realigned. I would prefer never to have to sharpen the blades either but realize the hoplessness of that. The jointer I have now is a delta 6 inch jointer. I moved up from an old Sears jointer which was a nightmare. But this Delta is letting me down too.

John

Well, we could keep our eyes peeled for old ones, where the cast iron has done all its settling-in, and can be trued once and for all. The older, heavier machines were more stable, but I believe the new Deltas can be fine ocne set up. Mine was spot on, dead perfect for 4-5 years, then started moving.

I'd just like to know what brought-on the movement, and how best to correct it. This machine was so sweet for so long....

As for knives, we're screwed. We need a soft enough knife to take a keen edge because of the softwoods we joint, yet we kill it by running the ultra hard, abrasive woods through it, also. We need one machine with carbide knives for backs, sides, fretboards, and another for tops. Hmmm, isn't this where the hand plane comes back in? Hmmmm!

Mario,

You wanna check to see if there is twist from end of your Jointer to the other, put a straight adge across the six inch width at each end, one on the leading edge of the infeed end and one at the end of teh outfeed end and then just sight them. Two framing squares 24 inch long will let you know if there is any twist in the tables at all.

Jointers are one of the simplest machines in the shop. But when they get moved around we do that by grabbing the end of the infeed/outfeed tables. Typically all of the casts are large enough to handle this but the weighs weren't designed for it so it is risky. I ran a cheap Tiawense 6 inch joint for a good 15 years with complete success but recently bought a second hand 8 inch General and a 15 inch General bandsaw (both Canadian made) for $1100 CDN. That is nearly $5000 worth of machines and I got them at a garage sale!! Those kind of deals are around but only if you have time to wait forthem and are prepared to act when they do show up (I missed out on a few of them in the past...).

Back to the set-up. Once you have sighted the two staight edges use another long staright edge, like a four or six foot carpenters level (that hasn't been kicked about to often) and place it half on each table and then use feller gauges (or just raise the infeed table which is much easier) and see if the tables are running in the same plan. If these two things are good then the issue is just setting that outfeed table absolutely in the line with the top of the balde arc and adjusting your infeed table to the depth of cut of choice. After that just make sure you apply good consistent pressure as you feed through the machine, some boards are tricky!

Shane

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Canada

John, you never did say what brand of jointer you are struggling with. I have an old, I mean very old! Craftsman. The outfeed table is not adjustable. What these guys are telling you is correct. The blades must be dead level with the out feed table on any jointer. The infeed table must be dead parallel to the outfeed table. On my old craftsman I can adjust the infeed table for height or twist but it is a time consuming trial and error task best done while completly sober and nothing else to do. What you are discribing sounds like you are low at the front end of your infeed table. There are gibs to adjust this . Be sure to check parallism next to the fence and at the outside of the table. Good luck!

make a master bar from some MDF and drywall screws (per White's book or his FWW article)

Okay, I'll scratch that book off my wish list <bg> I'm using a 24" Starrett straight edge and still frustrated. MDF? No thanks....

Shane, I've checked things like you say to(sighting), but I believe I'm chasing a twist that is a thou or two, and I just can't "see" it using these methods. I'm needing something very precise, methinks. Guess I'll also need a machine shop to true the table(s) back up....

What I'm seeing here is that if the jointer is simply out of adjustment, the 'fix' is pretty simple and doesn't need accurate tools. But if regular techniques don't fix it, then it needs some seriously accurate checking and truing. I say this because I've tried all the regular stuff and it doesn't help out. It always comes back to trial by error.

It is such a simple tool, yet because it is so simple, it is complicated.

Mario I actually think the MDF straightedge would work. I can copy a few pages from the book and send them to and see what you think. I believe the 24" Starrett isn't long enough. It should be the length of the inboard and outboard tables combined.

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I agree with Bob, if it's straight, it's straight. You really don't need a fancy piece of machining hardware to check a jointer. I use a 48" cutting edge from an art supply store. As long as the MDF is straight to begin with it will work fine. Though, without a jointer, I'm not sure how you would get it straight to begin with.

Though, without a jointer, I'm not sure how you would get it straight to begin with.

That's part of what I'm wondering, then, how does one check it? I'd also be weary of it flexing when held over the full length? A 4' aluminum straight edge I tried actually flexed a few thou when used.

I agree that 24" is too short, which is part of my problem with measuing the things..., but at least I know this one is dead straight and doesn't flex when half of it hangs over the table.

To check for twist you might take a dial indicator with the base on the outfeed table and drag the dial across the infeed table, if the tables are parallel the the indiactor doesn't move.
Good luck!Jim_W38675.6899189815

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Jim Watts
http://jameswattsguitars.com

Todd, forgive my ignorance but I can't figure out how you could check to see if a table is not parallel with this. If you are counting on the three points you are omitting two critical points: the cutting end of both the infeed and outfeed tables. From what I'm understanding by your description, you could be 1/4' out of parallel and wouldn't know it because the end of the table, the blade and the end of the infeed table are all level. Am I missing something?

Todd, brilliant! Thank you for your patience with me.

Correct me if I have the following wrong, but here's how i see it working:

Don, I see where yuo're going, and was about to retort with the same replay, then it hit me. The center screw in Todd's setup touches just in front of the cutter, on the infeed table. If we take the straight edge and flip it end for end, the center screw now touches the outfeed table, just behind the cutter. In use, adjust the infeed table to where all three screws make equal contact; flip the straight edge, and if the center screw now has a gap between it and the outfeed table, then we know it dips there; if the straight edge rocks, we know it is high.
To check for twist, adjust and tweak until it is dead-on parralel at one edge, then check it along its other edge.It should be spot-on; if not, twist.

Very nice pic's and explanation Todd.
Mario that's what I offered to copy from the book and send to you.Bobc38675.7660416667

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Beautiful and unusual tone woods at a reasonable price.
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The Zootman
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Kenmore, NY 14217
(716) 874-1498

I read about this in woodworking magazines, and in my limited experience it's been true: The factory edges on a sheet of MDF are true enough to work as a straight edge.

[QUOTE=CarltonM] I read about this in woodworking magazines, and in my limited experience it's been true: The factory edges on a sheet of MDF are true enough to work as a straight edge.[/QUOTE]

Yep. I count on that fairly often when I want to route a straight line. Pre-made routing templates done easy.

Brad and Todd, thanks for the tip. As a woodworking novice this is the kind of reference book I really need. For anyone interested, "Workshop Machines" is available at Amazon for $12.21. Mine is on the way, thanks again.

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Don Atwood
Arlington, VA

Way up in the posts its mentioned that the person bought a couple old General machines. These have probably the best cast top plates of any machine on the market. Not that others arent equally well machined, but General used to (not sure if they still do) leave all the casts out into the Quebec winters for like six months. This supposedly destressed the casts better than anything else, before they were machined. At a local machine store, they told me that they could raise the temp in the store and measure the movement in a Unisaw top, but the General wouldnt move.

I am with you all on the set up issues with jointers. Mine was close enough to do tops and backs (I was getting a great sprung joint, few thou gap in the middle ala cumpiano) , but I was making a new table alittle while back and the 44 inch pieces were rocking once they got to the far end of the outfeed. So what to use to shim the table ?? Hmmm .. need maybe ten thou, and metal - razor blades - it worked great. You can now sight the table top pieces and they are dead on, no cup at all.

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"