Acceptable tolerance for thicknesser - parallelism of cutter head to the bed

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Fanous

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Hi all,

I've got my jointer/thicknesser in Axminster service. It's the spiral head model with 260mm width of cut. I found out that over the width of the thicknessing, it's off by 0.5mm. Cutter head not parallel to the table, and non-adjustable (or at least not meant to be by a customer). In my opinion it's too much imprecision for the money it costed me. All I am getting from axminster recently for a feedback is a statement that everything works fine, and within acceptable tolerance.

I'd welcome opinions on this, please.
 

Sideways

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Thicknessing table and block are made parallel to within a few thousandths of an inch when we restore or overhaul a Sedgwick ....
3 thou' I'd stop faffing.
5 thou' (0.127mm) I'd probably have another go.
20201024_154302.jpg
 

deema

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As Sideways says we set the thicknesser bed to less than 3 thou across say 12” (0.075mm over 305mm) but often get it to within 1 thou or 0.025mm. You need a good solid frame to achieve this, the Sedgwick PT that he has in the photo is all cast iron construction around the vitals of the machine so this is achievable. With many pressed steel construction machines, this level of accuracy simply isn’t possible as the frame isn’t sufficiently rigid to hold the tolerance. There is significant forces involved with thicknessing and a rigid frame is vital.
 
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Fitzroy

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My old dewalt is about 0.2mm across the bed 250mm. On planer i can adjust level with the knife setting, you may not have this option with a spiral head. On the Thicknesser you can just run a board through and the affix it to the thickness table to remove the offset.

Whether you should or not is another issue. Personally I think that is too far out for a new machine.
 

deema

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For every PT I’ve worked on there has always been a way of adjusting the alignment of the thicknesser bed to the cutter block. I’ve written up the process of setting up a Sedgwick which is generic for most machines on another thread. However, it’s highly likely your thicknesser bed is bolted to a column of some sort. The usual process is to shim the thicknesser bed to align it with the cutter block. This is standard on most machines I’ve worked on. It may sound unusual but, drinks tin cans make superb shim material for this job. You can buy proper shim material from an auction site alternatively. Without a proper clock, if you have callipers you can simply pass a piece of wood through it, measure either side for how tapered it is, shim and repeat. You will quickly get it far better than 0.5mm if the machine is sufficiently rigid. It should only ever need doing once, it it starts to move again in use, either your bolts are slack and the shims have moved, or the machine isn’t IMO sufficiently rigid for the task.
 
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MikeK

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I'll spare you the enjoyment I've had with my P/T (not an Axminster model), but you might be able to adjust the angle of the thicknesser bed. I attached a screen shot from an Axminster AT260SPT calibration video by Andy, The Woodgrafter, showing what appears to be the four mounting bolts and four adjustment grub screws for the thicknesser pedestal. In the video, Andy does not adjust the angle of the table.

The thicknesser table on my P/T was off by quite a bit and I couldn't find a way of adjusting it. When I disassembled it, I noticed the threaded holes for the grub screws were empty. When I reassembled the table, I added the four grub screws and was able to change the alignment of the table to the cutter head. A dial gauge is necessary to do this as @Sideways shows unless you want to run a lot of lumber through and make minor adjustments after each pass.


AT260SPT-1.png



Here is the calibration video by The Woodgrafter:

 

MikeK

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It may sound unusual but, drinks tin cans make superb shim material for this job. You can buy proper shim material from an auction site alternatively.

I was working at a remote site over a weekend and needed to shim the deck of a tool we were using. I sacrificed my inexpensive feeler gauge as a source for shim stock and it worked great. Five years later, the deck is still aligned.
 

Fanous

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Thank you all, much appreciated feedback.

I will see what will axminster do. At this point, they will either
- Adjust my machine in the shop and send it back
- Continue saying it's fine and send it back
- Send a replacement.

At this point I'm OK with either. Knowing (or thinking) about the shimms, I probably wouldn't have sent it back and just played with it. MikeK - I did notice the grub screw, if they send it back still out of whack, will have a go at it.

I'm more annoyed with their attitude "it's fine" as if woodworking is not precise work. One would thought they know better. Oh well...
 

Fanous

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Just thought I would leave it here. The feedback from Axminster.



"Good morning Mr XXX,
As you know we have had your Axminster Trade AT260SPT/AT107PT Spiral Planer Thicknesser in our workshops for inspection at your request. We are pleased to let you know that your machine has been thoroughly tested and is operating exactly as it should. We have planed a test piece on your machine and then thicknessed the piece. The timber is well within acceptable tolerance at 0.2mm end to end. We will send the test piece back with your machine for reference. We will now arrange for your machine to be returned to you.

Many thanks

XXXXXX
Servicing Team Leader"
 

Spectric

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As Deema points out there is a limit to how precise you can setup any machine due to it's construction, they used cast Iron for a reason and that is rigidity which is now being sacrificed for a cost saving. Pressed / sheet metal machines are not as rigid and a lot of us make things worse because we also move them around because of our limited space. Another point to bear in mind is how well it can retain it's setup when having to change from planing to thicknessing and back again. My PT107 had some issues but were resolved by ensuring the contact area on the adjustment bolts was flat so it always registered on the same area.
 

Fanous

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As Deema points out there is a limit to how precise you can setup any machine due to it's construction, they used cast Iron for a reason and that is rigidity which is now being sacrificed for a cost saving. Pressed / sheet metal machines are not as rigid and a lot of us make things worse because we also move them around because of our limited space. Another point to bear in mind is how well it can retain it's setup when having to change from planing to thicknessing and back again. My PT107 had some issues but were resolved by ensuring the contact area on the adjustment bolts was flat so it always registered on the same area.

Absolutely agree. I'm aware my machine will never be as rigid and stable as some of the old heavy machines that were made to last under heavy duty. But at the same time, I think it can be fine-tuned to be well under 0.1mm. I'm not moving my machine around the shop, for the same reason as mentioned above, there would be some sort of twist or movement, which would potentially undo the calibration.

I'll now wait to get my machine back, and spend a day calibrtating it all once again, this time including the thicknesser bed with grub screws, or shimms, or both.

Thanks all. I'll let you know if I succeed at all :)
 

Spectric

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One tool you will find very handy is the Veritas straight edge, I recently brought the 50 inch version to set up my planer tables, that and a set of feelers plus some
Paracetamols and you are away.
 

TheTiddles

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There’s nothing wrong with the way your machine has been made, if it’s out of alignment it was set wrong at the factory. If it’s in tolerance and it works how it should, it’s just fine.

Million pound Swiss machinery is made with sheet steel bodywork, so is that from Lidl. If old machines are somehow so much better they’d have gone up in price, not down, unless they’re somehow magically exempt from the fundamental economic principles of everything else on the planet.
 

Bojam

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There’s nothing wrong with the way your machine has been made, if it’s out of alignment it was set wrong at the factory. If it’s in tolerance and it works how it should, it’s just fine.

Million pound Swiss machinery is made with sheet steel bodywork, so is that from Lidl. If old machines are somehow so much better they’d have gone up in price, not down, unless they’re somehow magically exempt from the fundamental economic principles of everything else on the planet.

Not sure it's as simple as that. Old heavy cast iron machines were made to last the test of time. That there are so many of them still running, decades after being manufactured and having endured a tough life in joinery workshops, is testament to this. It will be interesting to see how the modern, relatively lightweight, pressed steel frame machines fare over the course of a few decades of work. I'm not talking about million pound Swiss machinery but your average Far Eastern manufactured low- to mid-range woodworking machines. I'm not hating on Far Eastern made machines either. I have a modern PT and a bandsaw made in Taiwan and am very happy with the build quality and performance. That said, I didn't have the option to buy used old cast iron machinery here in French Guiana so I took what I could get.

That the price of old cast iron machines is relatively low (in the UK at least) is likely down to a few factors (not exhaustive):
  1. They are old and rarely come with any kind of warranty. If you are mechanically minded then no problem. But if you don't know how to assess the state of a machine or how to diagnose issues that might arise after purchase then better to buy a new machine straight from the factory with a decent warranty and after sales support (including availability of spare parts) in case anything goes wrong.
  2. Many are sold when businesses go bust, are in a bit of state, and can therefore be picked up relatively cheaply. If cleaned up and well serviced / refurbished, they can be sold on for a tidy profit I'm sure. The prices of properly refurbished machines aren't cheap (see e.g. here).
  3. Many are three phase having been used in industrial workshops. This makes them less appealing to the average home user / weekend warrior.
  4. They lack some of the modern innovations. For instance on an old PT you won't find a spiral block or a quick change Tersa block. You won't find digital readouts either. Dust extraction might not be great. All of these things can probably be retrofitted or modded but many people might prefer to buy new with all the bells and whistles. Even if this means accepting lighter less stable frames, less solid tables, fences made from ali extrusion rather than cast iron, etc.
In France, the prices of old cast iron machines is quite high. I'm sure there are still bargains to be had but the market does seem to be quite different to the UK.

Are old machines "so much better"? Depends what they're being compared to I guess. For example, comparing an old cast iron Wadkin PT designed for a production environment to a modern Axminster hobbyist / artisanal machine is apples and pears. How that old Wadkin stacks up against a modern Felder or SCM PT is a more interesting question.
 

Fergie 307

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I think you are spot on with many of your observations. Same with machine tools. Think of something like an old Herbert capstan lathe. Lovely machine but obsolete as far as most commercial users are concerned, so much stuff now is cnc. Far too large/heavy for most diy people to be able to accomodate, and might need considerable skill/ingenuity to repair and maintain. Upshot is you often see them going for peanuts because there are very few potential buyers.
 

Fergie 307

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Absolutely agree. I'm aware my machine will never be as rigid and stable as some of the old heavy machines that were made to last under heavy duty. But at the same time, I think it can be fine-tuned to be well under 0.1mm. I'm not moving my machine around the shop, for the same reason as mentioned above, there would be some sort of twist or movement, which would potentially undo the calibration.

I'll now wait to get my machine back, and spend a day calibrtating it all once again, this time including the thicknesser bed with grub screws, or shimms, or both.

Thanks all. I'll let you know if I succeed at all :)
I think it's a very good point that rigidity of the casing maybe an issue. I would think if you can bolt it down carefully to ensure its not twisted, then set it up it will be fine. I can well imagine how moving it around might cause some degree of flex, especially if your floor isn't flat. Problem being few of us have enough space to be able to leave a machine like that set up when it's not being used.
 

cerro

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Anyone know how to setup or adjust a kity 637 thicknesser table so that it is level and moves up and down smoothly
 

TheTiddles

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Last time I looked at an old Wadkin price list for a machine someone was extolling the virtues of here, it was just over 50% of the annual average salary at the time, so an equivalent now would be £16k. If you are comparing anything less in price, it’s not a fair comparison and it really is that simple.

As for the fair comparison, I suppose we’d have to ask the people who buy £16k table saws now and which they buy, I’m not sure many buy Wadkin because they went out of business, which might raise the question as to why?
 

Spectric

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I've got my jointer/thicknesser in Axminster service.
Have you got it back and have you now resolved the issues and are happy with it? At some point I think @MikeK will be giving us some feedback on his new aquisition which will be interesting after his previous issues with one of the generic rebadged asian machines.
 
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