How much flatness is OK on a jointer?

[LKB]

Greetings:

I recently took delivery on a Rojek MSP310 12" jointer/planer combo machine. While the machine appears to have arrived in undamaged and good condition, I'd like to make sure before a my inspection period runs out. Unfortunately, the operating manual doesn't have any specs on the table / fence flatness tolerances.

Question for the group: How flat is "good enough" for a better machine? (I'm not expecting aerospace industry precision, but then again this isn't exactly a cheap Far East import either.)

Here's what I've measured, using 1 year-old, always-handled-like-a-sacred-relic 24" Veritas steel straightedge (0.001" tolerance over its length), a brand new set of feeler gauges, a

0.001' resolution dial indicator, and a Starrett combination square:

Infeed table (about 26" long x 13" wide) has dips of about 0.004" along the front and back parts of the table (measured about 1" from the edge), and a crown of slightly under 0.002" down the middle. Polishing marks seem to indicate that the center part of the infeed table was machined a bit more than the rest of the table.

Outfeed table (same size as infeed) also has dips (about 0.0025") along the front and back parts of the table, but is essentially flat down the middle.

Outfeed table was parallel to the Tersa cutterhead (less than 0.001" difference front to back) out of the crate. Infeed table was originally about 0.010" out of parallel with outfeed table, but after adjustment is now within 0.001".

Fence (6" wide, 48" long, aluminum) is cupped a bit (about 0.0015" near the cutterhead, about 0.004" at the ends).

What does the collective wisdom think? Flat enough or should I be complaining?

Thanks in advance, LKB in Houston

[Toller]

Oh yeah; my jointer is accurate to 0.00000012", and that is pretty marginal. Take it back immediately and demand a proper one.

(are you using it to make integrated circuits?)

[Morris Dovey]

| What does the collective wisdom think? Flat enough or should I be | complaining?

Joint the edges of two reasonably straight-grained boards, hold 'em up to a bright light with the jointed edges together, and take a look.

If you don't like what you see, ship it to me and I'll send you my 6" Griz jointer and 12" Griz planer (I've never taken measurements of either; but both pass the light test with flying colors.)

-- Morris Dovey DeSoto Solar DeSoto, Iowa USA

[A.M. Wood]

First off I would bitch about the huge misalignment of the tables. That IMO is unacceptable, but probably the result of the rather large distortions in the surfaces.

I would send it back and demand a refund. I've never heard of these Rojek machines but what you describe is pure crap.

After all, you did use the $23.50 Veritas straightedge. Those are machined flat to 0.003" over the length.

IMO, you'll never get true and straight edge with that machine on a piece of wood you've dried for six months in your kiln and have had stored in your perfectly shop that's inside your PERFECTLY climate controlled compound.

[A.M. Wood]

warped he'll never get a straight/flat/square edge on that POS machine. We're talking 1.5 thousandths of an inch here, almost half a pubic hair width. Not worth wasting the scrap wood for a test cut if you ask me.

[A.M. Wood]

First off I would bitch about the huge misalignment of the tables. That IMO is unacceptable, but probably the result of the rather large distortions in the surfaces.

I would send it back and demand a refund. I've never heard of these Rojek machines but what you describe is pure crap.

After all, you did use the $23.50 Veritas straightedge. Those are machined flat to 0.003" over the length.

IMO, you'll never get true and straight edge with that machine on a piece of wood you've dried for six months in your kiln and have had stored in your perfectly shop that's inside your PERFECTLY climate controlled compound.

[A.M. Wood]

warped he'll never get a straight/flat/square edge on that POS machine. We're talking 1.5 thousandths of an inch here, almost half a pubic hair width. Not worth wasting the scrap wood for a test cut if you ask me.

[Toller]

Do you have the feeling you have said things before?

[CW]

There is nothing you will ever do on that machine that would come close to testing that kind of accuracy. It's a good one.

[lwasserm]

I can't imagine any of the measurements you mentioned having any discernible effect on cutting wood. If you don't mind the question, what's the ballpark cost of a machine like that, anyway?

[cselby]

It just means he's twice as mad.

Pete

[Paul D]

He must have thought he was talking to someone else in here about a jointer

[Jimmy]

It's here:

[LKB]

Thanks for the reply. You can find information on Rojek machines at:

you'll see, they're currently running a "free shipping" sale on the

310 J/P combination.

Another similar machine to consider is the Hammer A3-31. This is made by the same folks who make Felder machines. It's more expensive than the Rojek, but has a few more bells and whistles (like digital readout on the planer). Not cheap but still less than comparable machines from Minimax and Knapp.

is extremely heavy duty (the machine itself is about 800 lbs), and the Tersa head makes knife changing ridiculously easy (under 1 minute, with no subsequent adjustment necessary). Infeed table height control is a parallelogram design, and thus fine-tuning the alignment of the infeed table with the outfeed table requires just a socket wrench -- no shims required. Fit and finish are excellent; runs quietly and with minimal vibration. Gonna run some stock though it today and we'll see how it passes the real world test.

LKB

[LKB]

Actually, I used the $42 steel one, not the cheaper aluminum one you mention. As I noted in my message, it is machined flat to 0.001" over its length. You can see the difference between the two here:

[B A R R Y]

Nice looking machine!

I was reading the .pdf for your machine and have a question. Is EACH jointer table 50" long, or is the total jointing surface (infeed + outfeed) 50"?

Thanks!

[LKB]

Total jointing surface is 50". If you need longer tables, they have table extensions available as an option.

If you have any other questions about the machine, feel free to write.

LKB

[Leon]

Snip

With any machine, you should be happy with the price you paid for it.

From there, does it produce acceptable results? If not, complain. If so, enjoy your purchase. Your technique may have more to do with accuracy than the tolerances of the tool.

[B A R R Y]

[Mapdude]