Large jointer planer combo tables not flat, looking for suggestions

[Josh vincze]

So far the company I purchase the jp combo off of has been extremely accommodating and for that reason I care not to mention their name. I purchased the tool about a year ago and quickly brought to their attention that the tables where not flat. With a little effort on my part within a couple of days they agreed to send me a new machine and promised to thoroughly check it before it arrived at my shop. Now I have two machines that I find far from acceptable when it comes to the tables being flat never mind coplanarity table to table or table to cutter head. Please see my attached picture and confirm or dismiss my concerns. Are there any techniques that I can use while jointing to produce a high quality product with in of these machines? I expect to be able to straighten/flatten a 10' board within a 32nd. Is all hope loss?

[Stewart Lang]

How many thousandths of an inch are they away from being flat? (I can't see the picture, sorry)

My 16"x47" jointer beds have around 0.002-0.003" dip in the middle going left to right. However, with them dialed in, I can get a perfect seam (under 0.001", infact I can't even measure it with my machinist feeler gauges) across 6' boards. Haven't really jointed anything longer in a while. Now, if they go out of alignment by just a few thousandths of an inch, or if the outfeed drops a thousandth or two below where it needs to be, I'll get a gap in those same 6' boards of maybe 1/64".

As long the beds are within tolerance of most manufacturers (I think most are 0.010") you should be able to get a good seam, but it's VERY MUCH in how well you set everything up, as far as alignment. And don't neglect the importance of having an outfeed table perfectly parallel with the knives. Your beds can be set to NASA-level precision as far as coplanarity, but if the outfeed isn't perfect with the cutterhead, you'll never get a good seam. Vice-versa too. That's all from my experience at least.

[Mike Kees]

Josh I have no idea where to even start trying to help . I think if you want help from anyone who knows anything about your machine you will first have to identify it. Do I understand you correctly that you now have two of the same machine and neither of them is acceptable to you ? There must be some measure of adjustability in the tables of these machines,but there is no way for any advice to help you if you can not tell us what the machine even is. Good luck.

[johnny means]

Stop measuring and cut some wood. I've never set up or checked any machine beyond what a couple of levels and a and a machinist square can do. Too much time on these forums will have you trying to split an atom.

[Patrick Kane]

A few things, first, what are you taking measurements with? Is this a certified straight edge? Next, and maybe more important, but what are the manufacturer's specs? This came up somewhat recently in the FOG with a guy who just received a new AD941. He was pretty miffed at spending $10K+ and the machine being out .002" over 16". I think Felder's spec was about that, which isnt 'perfect', but still pretty precise when it comes to woodworking. Next, what are the dimensions of the tables? In your one diagram, i see .003" over the length of the table, which i assume means it has a .003" dip or hump across the length. If your tables are 48" long, then that is really not bad at all. I think my starrett straight edges are only guaranteed at .001" per 12". Anyway, post your method for measuring the bed errors, size of the beds, and maybe look up the manufacturer;s spec.

[Josh vincze]

Sorry my picture doesn't seem to be helping anyone. On the outfeed table of the new machine they supposedly checked I am confident within .002" that their is a .013" dip on the diagonal. I am using a certified straight edge with feeler gauges.
The older machine has a similar dip of .01 on the diagonal of the outfeed as well.
Yes, the machines are the same and I'm holding on to both of them until problem is resolved.

[Andrew Hughes]

My suggestion is to return both machines.
Start a quest for a use jointer. Buy a 36 inch groz straight edge to take with you so you can inspect the tables before you buy it.
Even if it takes a year or more looking at a half dozen machines.
Heres what the groz straight edge I have.
Good Luck

[John TenEyck]

As mentioned earlier, can you joint a straight edge? If you can't then there is reason to look into why. If you can, nothing else matters.

John

[johnny means]

My suggestion is to return both machines.
Start a quest for a use jointer. Buy a 36 inch groz straight edge to take with you so you can inspect the tables before you buy it.
Even if it takes a year or more looking at a half dozen machines.
Heres what the groz straight edge I have.
Good Luck

Time is our most precious resource.

[Stewart Lang]

Sorry my picture doesn't seem to be helping anyone. On the outfeed table of the new machine they supposedly checked I am confident within .002" that their is a .013" dip on the diagonal. I am using a certified straight edge with feeler gauges.
The older machine has a similar dip of .01 on the diagonal of the outfeed as well.
Yes, the machines are the same and I'm holding on to both of them until problem is resolved.

Just my opinion, anything over 0.01" on the jointer bed and I'd look at getting something else. Seems like that would be outside of even Grizzly's specs. The fact that they were willing to send you an entirely new machine, seems to kind of confirm that with me. Perhaps you just got bad luck of the draw on the second one too. This is largely the reason a lot of us (including me) buy machines used, because we can check for this beforehand.

[Darcy Warner]

Not sure how much tighter the tolerances will be on any other machine. I believe NF calls for a .003 to .005 on their tables, which are cored and well seasoned before machining.

It's a basic combination of poor casting practices and whatever they can hold on the machining side (probably blanchard ground I would guess)

[johnny means]

Flattening a 10' board within 1/32" seems a little unreasonable to me. Have you ever worked lumber at that scale? 7000ths on your jointer bed would be pretty inconsequential.

[John Lanciani]

I expect to be able to straighten/flatten a 10' board within a 32nd. Is all hope loss?


You’ve had the first machine for a year now, have you used it? If so, what results are you getting? If not, why not?

[Josh vincze]

Thank you Darcy. I do believe that it's a casting problem combined with being blanchard ground. At a 6k price tag maybe I'm asking to much. I just wish that the company would set expectations better. If I knew the second machine was going to be a repeat I probably would have saved everyone a lot of time and money.
At this point I am very reluctant to return both of them. I would like to think that all of my time, effort and money will produce something.

I tried for years to get something used of quality for reasonable price in the South Carolina area with no success.

[Josh vincze]

John and John with the old machine I have become very good at spring joints. Just because I can make a panel with the old machine doesn't mean I've gotten what I paid for. I believe a good craftsman can produce good results with even the most flawed tooling as long as they know how to manipulate it in their favor.
I feel two well jointed boards should almost produce a flawless seem without clamps. A little glue and rub them together and done.

[Darcy Warner]

Thank you Darcy. I do believe that it's a casting problem combined with being blanchard ground. At a 6k price tag maybe I'm asking to much. I just wish that the company would set expectations better. If I knew the second machine was going to be a repeat I probably would have saved everyone a lot of time and money.
At this point I am very reluctant to return both of them. I would like to think that all of my time, effort and money will produce something.

I tried for years to get something used of quality for reasonable price in the South Carolina area with no success.

It's really a sum of all parts, poor casting seasoning, machining still warm castings, a worn blanchard grinder sucking the table down to the mag chuck that is worn, poor set up, etc. Too hard to pin down the exact reasons, but for sure it's a combination of some or all.

[Phil Gaudio]

I have more experience with adjusting jointers than I really deserve and I can tell you that it helps to be patient. Given the numbers you have provided, I would put your concerns about table flatness on the back burner for now (not saying you are wrong, just saying that those numbers may not be a show stopper) and move on to dialing the machine in. I was in a similar position when I took delivery of a Minimax 16" J/P a year or two ago, and decided to invest in a Starrett 72" precision straight edge. I read all that I could about the mechanics of measuring and adjusting, and I dove in. You may be surprised at how well you can get the machine set up. I do think its a shame that even these multi-thousand dollar machines do not necessarily come to your door ready to work and are frequently in need of hours of careful setup.

[Josh vincze]

Phil that is a painful reality that is slowly setting in. I spent hours dialing in my old 8" jet which eventually produced results that I was very happy with. I hoped with an extra 3-4k that was behind me. I guess I'm really just paying for the extra width and helical head. Can I borrow your 72" starrett.🙂

[Dan Friedrichs]

Josh, maybe I missed it, but what are the table dimensions?

And, do I understand correctly that your drawing is showing the maximum "dip" you can measure between the table and a straightedge in a given line?

It may be more instructive to consider a "topographical" map of the tables. If you have a 0.013" dip that spans the majority of the infeed (or, to put it another way: if the start and end of the infeed are noticeably higher than the middle), that would be very worrying. But if it's a 0.013" dip that's ~2"x2" near the front edge...well, that probably doesn't matter.

Another thing to consider: what tolerance would be acceptable to you?

[Phil Gaudio]

My best jointer was my first, a 6" Jet: perfect out of the box. I "upgraded" to an 8" DJ 20: that is where I got all kinds of experience dialing in jointers. To confirm that I am a glutton for punishment, I voluntarily chose to "upgrade" a second time to a 16" J/P. Sometimes I wonder who is enjoying that Jet 6" machine. It is great to have the 16" width and helical head on both the jointer and planer. I now have my machine running well, but not perfect. Perhaps the jointer gods will smile on me one day and I will achieve the 100% dial-in that seems more precious than the holy grail:)

I should mention that if you were in my neighborhood, I'd be happy to supply the Starrett and all my hard earned experience to help you out.

[Josh vincze]

Definitely a dip. I went side to side under the straight edge incrementally increasing the gauge of the feeler gauge until the low point could be determined.

[glenn bradley]

As mentioned earlier, can you joint a straight edge? If you can't then there is reason to look into why. If you can, nothing else matters.

John

For the most part I agree with this. I don't play it quite as loose as some others. If your jointer, or planer yield an error that will multiply as you build your piece and end up with a 1/64" gap at a joinery intersection, its a problem. Sliding dovetails won't, air tight miters aren't and so forth. If your finishing protocol involves 12 mil of plastic spray as a top coat, you have no problem; it will hide almost anything. :D

My point being, as some have mentioned, we can get caught up on the numbers and try to solve a problem that doesn't exist. Make some small and intricate boxes. these are quick, use little material and involve the same joinery as a lot of larger pieces. If any problems present on a piece that is 5 x 7 x 12 inches it will be hell trying to assembly a hallway table. Make sense?

[Curt Harms]

Stop measuring and cut some wood. I've never set up or checked any machine beyond what a couple of levels and a and a machinist square can do. Too much time on these forums will have you trying to split an atom.

Like this. Properly set up machines make joinery easier & better ... to a point. Where is the point of diminishing returns? What's the question.

[Tom M King]

I wonder how flat they would stay even if they were re-machined.

[Rod Sheridan]

Hi josh, if you joint 2 pieces about 4 feet long and put them edge to edge, what gap do you get?

If you get a small gap in the center only ( ends of the pieces touch) that is as far as I go on adjusting a jointer.

If you get perfectly straight to a small center gap ( for sake of argument let's say 0.010") that would satisfy my expectations.

I wouldn't measure table flatness unless you cannot achieve a suitable joint................Regards, Rod.

[Josh vincze]

I believe when jointer tables are not flat there is a point of diminishing return with the number of passes you do. The greater the tables are bowed, cupped, dipping and twisting the more your return quality diminishes. Yes, even when tables are not perfect a person can get adequate results and know when to stop to begin dimensioning the other sides. I thought spending 6k would limit this law.
There are a multitude of reasons that someone would want to take multiple passes past the point of "flat" making coplanar, flat and inline with the cutterhead important.
Rod, I truly do appreciate your reply. Your reply really got me thinking. I now believe jointing short boards are going to be my real problem and not the 7' + I'm used to for doors and gates.
Please don't take this as malicious in anyway but yes I can get decent results. I can also frame a really nice house with a handsaw.

[Rod Sheridan]

Hi Josh, thanks for the kind words.

I would try the jointer out and see what the results look like.

If it produces accurate enough work I would leave it at that.

As a technologist I have a bad habit of chasing things down the proverbial rabbit hole, normally to no good effect:D

Regards, Rod.

[Derek Arita]

I feel you pain. I purchased a MM jointer/planer years ago and discovered both tables were not flat, similar to yours. MM was not interested in solving the problem, so after months of trying to adjust the machine, I finally hired a machine adjuster referred by MM. He came out and did the best he could, but still, I could not get the machine to joint a proper edge. So, the machine sat unused for about 5 years. I finally had the itch, so I took the tables off and had them machined properly to within .005". I've been using the J/P with good success for a few years now, but I had to pay an additional $800 for machining.
The moral is, you can adjust the heck out of your machines, but your always going to have issues either with short boards or long boards, depending on where they hit the dips. If you have the option, I'd send back the machines now, before you get stuck with one of them like I did. There are too many good makers of machines out there that will work with you to make sure you get a good one. Don't do as I did.

[Josh vincze]

Derek, did your tables stay flat after grinding? I really don't won't to return both of them because of the effort that takes. This is my personal shop and it's in my backyard.

[Brian Holcombe]

That’s a shame, I have checked mine and another friend’s Minimax machines and anywhere on the table I can trap a .001” feeler gauge.

I have a Jet cast iron router table, all of those type of tables looked like they were out if the same factory. The table has about a .012” crown to it, it’s offensively out of flat to me. Called the company and they told me it’s acceptable based on their tolerances. ‘Good enough for woodworking’ is the comment that stood out.

It’s not any harder to grind something flat than it is to grind something out if flat, it’s just that ‘good enough woodworking’ gives certain manufacturers the excuse to pass off stuff that should be reworked.

[Darcy Warner]

That’s a shame, I have checked mine and another friend’s Minimax machines and anywhere on the table I can trap a .001” feeler gauge.

I have a Jet cast iron router table, all of those type of tables looked like they were out if the same factory. The table has about a .012” crown to it, it’s offensively out of flat to me. Called the company and they told me it’s acceptable based on their tolerances. ‘Good enough for woodworking’ is the comment that stood out.

It’s not any harder to grind something flat than it is to grind something out if flat, it’s just that ‘good enough woodworking’ gives certain manufacturers the excuse to pass off stuff that should be reworked.

The only way you get bad results like that is crappy set ups/fixtures or just worn out machines.

I believe a lot of old American blanchard's have ended up overseas

[Derek Arita]

Derek, did your tables stay flat after grinding? I really don't won't to return both of them because of the effort that takes. This is my personal shop and it's in my backyard.

Josh, so far it's been about 6 to 10 years and all is well. I'd hoped for flatter after grinding, but what they did made all the difference. Depending on where you are, you could probably find a cheaper shop than I found. I really should have returned the MM J/P, but the back and forth with MM took so long, that I was just fed up dealing with it. That said, after all I went thru with this machine, the $800 was worth it. The lesson for me was, don't buy a major machine without being able to check table tops first.

[Josh vincze]

Derek, Without spending 10k+ what manufacturer would you recommend outside of mm and hammer.

[Derek Arita]

Josh, I wish I could make a good recommendation, but I'm a hobby woodworker, always worked out of my garage and only have direct experience with MM. I've read a lot of good things about the Hammer J/Ps, but along with the bad, I've also read good about MM. I have a feeling, the more you pay, the more control you'll have over what you actually receive.
If I were buying my J/P again, I'd ask MM to tell me the exact flatness of the tables that they are sending me. If they can't do that, I'd move on, cuz when it comes to jointers and planers, table flatness is essential. If you're buying from a local retailer, I'd insist on being able to measure flatness before purchasing. Pay no attention if they tell you the tables are within tolerance of .01", which is what I was told, because .01 is way too much, no matter how well the tables are adjusted.
I have no doubt that J/Ps from Jet to Felder will do the job well, as long as the tables are flat or at least within .005. Good luck.

[Brian Holcombe]

Derek, Without spending 10k+ what manufacturer would you recommend outside of mm and hammer.

Buy used. This is not without its own set of aggravations but often enough you get a much better machine for the money and have the ability to inspect the actual machine you will be receiving.

Typically when I buy used I budget in the cost of making things to the spec I want them to be, so If I want the tables flat I assume the amount part of the cost of the machine.

[Josh vincze]

Anyone have any experience with Robland? From what I've read this would be a down grade for me but I would be able to drive to their North Carolina headquarters and possibly put my hands on the machine before purchasing.
This would not be my ideal direction seeing how it would take more effort but maybe with compelling arguments it's a possibility.

[Mike Kees]

I agree completely with Brian. In fact in my shop,there are currently only two machines that I purchased new out of thirteen total.

[Derek Arita]

Used is a great option, as you can get more for your $ and take all the measurements you desire. That said, if that's not an option for you, then yes, Ive heard good things about Robland.
if you can put hands on the machine you're thinking about purchasing, its ideal. Just make sure you take your measuring tools with you, don't hold back and don't let the salesperson convince you out of what you know and want.

[Alex Zeller]

Here's my take. If you are not happy you never will be. Short of having the tables remachined it's always going to be in your mind. If it didn't bother you then you wouldn't think twice about it. I would suggest sending them both back unless the company is willing to go beyond what they have done now and possibly having them machined. Are there any local places that sell what you want? If so I would pay the extra they may charge so they can get a machine in and you can inspect it before paying. I would be upfront with them and what you expect.

[Jacob Reverb]

I wonder how flat they would stay even if they were re-machined.

+1

I also wonder how much the measurements/shapes of the castings continuously change due to temperature changes in the shop, Δt values and differential thermal expansion within the castings.


With all the talk you hear around here of feeler gages, mils, tenths, interferometers and Planck lengths, it's a wonder any wood ever gets cut.


Just sayin'.

[Brian Holcombe]

+1

I also wonder how much the measurements/shapes of the castings continuously change due to temperature changes in the shop, Δt values and differential thermal expansion within the castings.


With all the talk you hear around here of feeler gages, mils, tenths, interferometers and Planck lengths, it's a wonder any wood ever gets cut.


Just sayin'.

Unless it's a complete disaster of a casting then change in temperature is not going to affect the flatness so much. Yes, if you're scraping in a machine table, then you'll want the temperature consistent. But in a realistic use scenario a bit of temperature change isn't going to be so drastic an effect that one should not consider flattening a table considerably out of flat.

No need to make the great into the enemy of the good. A .001" change in flatness over the course of temperature change isn't the reason why you stick with a .010" out of flat table.

I like to consider the fact that having a machine which provides repeatable results is a time saver in my shop. Putting the effort in to ensure that it is accurate is relatively painless by comparison to fighting joinery/glue ups.

[Derek Arita]

I introduce enough human error all by myself. I always try to reduce error coming from my machines, whenever possible. I always think about the 5-cut method as an example of how a tiny error can result in a huge error in the end. I can't predict what the castings will do over time, but I can look for the best starting point as possible.

[Jacob Reverb]

I guess I never broke out the feeler gages with my jointer. I put a Starrett 24" combo square blade onto the tables of my PM jointer before accepting delivery and unloading it off the lift gate, set it up, tried it – it worked – and called it good. Let's not try to make this into a false dichotomy between those who hate accuracy/measurement/minimizing error and those who don't. Everybody settles. The question is merely, where?

If a 10-mil belly in the middle of a 4' outfeed table is unacceptable, then jointing with nothing more than a Stanley #7 must introduce astronomical errors by comparison. Yet somehow, it works – and has for centuries. If a tool does what I want it to do, that's good enough for me. Life's too short. YMMV.

Good luck with whatever you decide to do, Josh.

[Brian Holcombe]

In a time period where one can purchase a granite plate 18x24 flat to three one hundredths of a thousandth for a couple hundred dollars, I can’t see where a precision ground table can’t be made near perfectly flat. The difference is that one set of customers will definitely reject poor quality results and in the other case the customer most likely will simply let it slide.

The point at which to settle, in my opinion, is the point at which the level of surface flatness or similar metric no longer has a meaningful influence on the work. That number is closer to .001” than .010” in my experience.

[David Kumm]

.010 dip on either end isn't a deal breaker. A hump is worse and either across the width near the head on the outfeed is really bad. Given that the tables are relatively small, the standard should be better but we should also ask what that standard is before buying. Knowing the possible error at least allows for an email history of expectations between buyer and seller. I rejected a 20" , 8' Porter with recently ground tables that were .008 off. I figured if newly surfaced tables weren't flat, it was better to avoid. Seller actually agreed. Dave

[Chuck Wintle]

In a time period where one can purchase a granite plate 18x24 flat to three one hundredths of a thousandth for a couple hundred dollars, I can’t see where a precision ground table can’t be made near perfectly flat. The difference is that one set of customers will definitely reject poor quality results and in the other case the customer most likely will simply let it slide.

The point at which to settle, in my opinion, is the point at which the level of surface flatness or similar metric no longer has a meaningful influence on the work. That number is closer to .001” than .010” in my experience.

i wonder if the manufacturers are sourcing their raw castings from a factory that does not allow enough time for the cast iron to settle? After grinding the metal can probably move too much resulting in a much less than flat surface.