Options for a Long Straightedge...

[Michael Schumacher]

I'm looking to tune my G0490 jointer and want to make sure the beds are coplanar, but I don't have a long straightedge to use. I see that Lee Valley has a 50" one, but that isn't quite long enough for this jointer (at least I'm thinking so right now). The price is right for it and I'd be willing to pay a bit more (up to $120) for one that would be longer.

Anyone have recommendations for a long straightedge like Lee Valley has?

Or maybe someone here in Omaha would be willing to come by to help me verify that my jointer tables are coplanar.

Michael

[John Harden]

Enco and other will be happy to sell you a 60" Starrett, but I think they're like $350 or so. Personally, I don't think you need one that long. I have the 50" LV one and used it to calibrate my new jointer that has a 78" bed.

In my view, you really don't need anything longer than 50".

With feeler gauges or (ideally) with dial indicators attached to the far end, you can dial them in dead on perfect.

Regards,

John

[Doug Shepard]

http://www.amazon.com/Empire-Level-4...8752782&sr=1-9
???

[Philip Rodriquez]

My 10" jointer has an 84" bed. The big LV one is actually big enough.

[Mike Gadget]

Michael

I don't have a long straight edge, but I do have lots of lumber we could run through it ti check it out.

Ok, so i know that is no help, but I do not often see anyone from the Omaha area on Sawmill Creek.

Good Luck

Mike

[Eddie Darby]

If you have a few pieces of wood laying around that are long enough and some screws, then you can do this job without a straight edge.

Take one board that spans the full jointer bed, and put 4 screws in it, 2 for each bed, evenly spaced. All 4 screws are adjusted so that they touch the planers bed. Mark the in-feed and out-feed ends.

Do the same for the next piece of wood.

Now take one of the pieces of wood and reverse it 'end for end' so that your in-feed end lines up with the out-feed end of the other piece of wood. When all 4 screws on one board touch all 4 screws on the other board, then you have your tables in plane.

Then imagine the various scenarios and draw up examples and you can see that you will be able to reach your goal of having everything in plane.

[Neal Clayton]

or cut a strip from an 8 foot length of ply on your table saw and use the factory edge from the plywood to check it.

[Alan Schwabacher]

The approach using screws into the edge of a board will work to very high precision, it just will not stay that way over long times as a steel rule would (until you dropped it.) The key to the method is that you need to make 3 of them. Adjust one (A) to have the screws aligned as straight as you can, then use A to set the B and C to match. Check for any gaps with a feeler gauge. Once B and C fit to A with no gaps, check B against C. If there is a deviation, adjust A by about half the error, and start over.

This will give you points that are aligned to 0.001" or better, over the length you need. It's easier to make them to match the length you want to measure than to make one with lots of points. Usually, if you are careful, you can get by with only 3 points (screws) in each bar, which makes for a fast setup.

This procedure is described and illustrated in detail by John White, in the context of alignment of jointer beds, in his book "Care and Repair of Shop Machines". It's an excellent book.

http://www.amazon.com/Care-Repair-Sh...8764680&sr=8-1

Comparing 3 bars against one another ensures they will be aligned straight. The problem with only two, even if you swap ends, is that alignment to a large circle would fit.

[glenn bradley]

Lee Valley's 36" steel unit has served me well. I have the G0490X and along with a set of feelers that go to .001", the 36" straight edge did fine. A 50" would be even better but I don't think you NEED one that goes the full length of the tables.

[scott vroom]

I'm confused. My understanding when I purchased my G0490 was that the parallelogram feature prevented coplanarity problems with the beds. At least that's what Grizz tech support told me at the time of the purchase. What am I missing?

[Joe Meazle]

I used the Lee Valley to set the tables on a 12" Oliver jointer (now owned by Rick deRoque) and on my current 16" General 880 jointer. I am not sure that longer than that is needed. It might make it go faster but I was able to get it done with 50". The actual jointed edges the machine produced was the final test anyway the straight edge/feeler gauge just got me close, real close.

[keith ouellette]

I bought a 5ft straight edge from HF. To test if it was actually straight I took two of them and slid against each other on edge and checked for gaps. I also did it with the 5' and 3' straight edges. It was straight. A machinist told me it was an easy way to check. I assume he was right because my jointer beds are parallel.

a have also heard that a long level is really good to use. They have some very long ones at home depot

[Joshua Layne]

The //-ogram bed feature just _allows_ you to set the beds coplanar without shimming, as you would have to do with dovetailed ways. It doesn't actually auto-adjust itself (per my understanding anyway).

[keith ouellette]

I'm confused. My understanding when I purchased my G0490 was that the parallelogram feature prevented coplanarity problems with the beds. At least that's what Grizz tech support told me at the time of the purchase. What am I missing?

When I bought mine I was told it made it very easy to adjust the tables if they are not coplaner. which it does. If they were set up in a hurry buy a factory worker they could probably stand some tweaking.

[Paul Simmel]

Nothing is going to beat a nice 50" SE, but with a piece of BB ply, you can edge joint that either on your machine or another's. If your tables happen to be fanning downward you can still get a perfectly straight edge if if you keep some pressure on the outfeed table.

Edit: You can also screw a cheap aluminum straight edge to the BB, and get a VERY straight cheep aluminum straight edge by jointing both at the same time. I've done this with great success. Look me up for more details.

Paul