Workshop Blog
Experience report on the Holzmann ZS640p cylinder grinding machine
Sep
Is a cylinder grinding machine worth it? What does it actually do? And how is it handled? Questions upon questions that I would like to answer in this blog post. I was looking for a detailed report to make it easier for me to buy the machine - unfortunately in vain 😱. In the end, I decided to buy it and, on the whole, I don't regret it. But more on that in a moment...
Which machine is it?
It is the Holzmann ZS640p with a working width of 64cm. Holzmann has several machines in their range. Among others smaller ones, which in my opinion are also used in Bernardo or other machine manufacturers, just in a different color. The ZS640p, as well as the larger zs970p seem much more solid. Not only the weight of the machine, but also the performance and the workmanship make a completely different impression - of course the price 🤓 is a different world.
What is a cylinder grinding machine used for?
At Holz-Liebling we process cutting boards in different sizes. Our largest Hob covers have dimensions of up to 90 x 59cm. Until recently, we worked on them with a belt sander after gluing and then with an eccentric sander after soaking them in water. Sanding them flat with the belt sander was very time-consuming and energy-consuming. It also resulted in a significant loss of quality, as small grooves were quickly sanded into the board using 60-grit sandpaper. We needed a solution and that's how we came up with the cylinder sander. Since we rarely have widths over 60cm, we opted for the 64cm version.
In theory, I imagined it would work like this: put a plate in at the front and take out the 100% ground flat at the back. Unfortunately, I have to pull the tooth out for you now. Unfortunately, it's not that easy 🤗.
The cylinder sander is perfect for sanding several wooden panels of the same size. I emphasize... several panels of the same size. Why? It's easy to explain when you use the machine.
What is there to adjust?
The grinding machine has four parameters.
- The sanding belt
- the feed speed of the carpet
- the height of the table
- Height of the second wave
The Sanding belt should be clear. The coarser it is, the more material is removed and the coarser the surface of the piece of wood ultimately becomes. The machine has two shafts. As standard, it is supplied with coarse 80 grit sandpaper on the first shaft and 120 grit on the second shaft. However, as I always run my workpieces through the machine several times, this was one of the first things I changed. Both shafts now have a coarse sanding belt with 80 grit mounted. I'm saving the 120 grit because otherwise I'd roughen up the finely sanded surface again with each additional sanding pass, only to then finely sand it again... With two 80 or 60 grit sanders, I remove more material and I have to rework it with the orbital sander after soaking anyway.
The Feed rate can be adjusted using a small wheel. I felt that the belts broke more quickly when the speed was too high and the amount of material removed was also less than when the speed was reduced. That's why my machine now runs at the lowest speed setting. However, panels with a length of 90 cm need around 30-45 seconds per sanding process.
The Height of the grinding table is the parameter that probably has to be adjusted most often. Using a very solid crank, the table can be raised or lowered with a precision of tenths of a millimeter. I will go into this in more detail in the next section, "Handling".
The Height of the second grinding roller I had completely ignored it at the beginning. But this setting is actually a really important one! The machine only works properly when the second shaft is perfectly adjusted to the first shaft. If the shaft is too high, only the first roller grips. If it is too low, the belt breaks because too much pressure was applied. Using a hexagon socket, the heights can be adjusted on both the right and left of the roller. A few test runs later, the correct height should have been found. Unfortunately, the scale provided didn't help me at all 🤷♂️.
Grinding rollers 
Adjustment wheel rear grinding roller
The handling
I thought it would be easier to use than I thought. To be honest, it took me two weeks to get used to the machine. I completely destroyed the first sanding belt that came with it on the first try. The 25m I ordered were also gone within a day 🤬. What did I do wrong?
The sander is not a planer 🤪. This means that only the smallest possible chip removal should be set here. If the workpiece is always the same, the setting is easy. Once set correctly, it should fit for life. If the workpieces always vary in thickness (and this can be as little as 0.5mm), the machine should be adjusted again and again. So I always work my way step by step and crank the shaft up a tenth of a mm by a tenth of a mm, with each pass, until a reduction can be heard and seen. Despite proper suction, I always see a small pile of sawdust. This always tells me exactly whether I am removing too much or too little material.
What's so bad about a higher chip removal? Quite simply, the belts break and it happens quicker than you'd like. The force exerted on the belts is so great with a high removal that a crack appears at the end of the sanding belt, where it is mounted in the shaft. You can hear this very quickly 🤭. That's why it's important to always work with small removals. I personally set the feed carpet to the lowest setting and get a decent result that way.
The extraction
The ZS640p has two extraction nozzles, the 970 even has three. The diameter of each opening is 10cm. I personally operate the cylinder grinding machine on my Record Power cyclone cutter. Of course, all common extraction systems with volume flow can also be operated on the machine. The only thing is that the extraction capacity should be at least 2000 m³/h so that proper suction can be achieved through both openings. One thing is certain, operating a cylinder grinding machine without extraction is like seeing through fog.
My conclusion
I now use the machine every day and I enjoy it. But there is one crucial factor that I particularly like. With particularly long panels and a low feed rate, I have about 45 seconds between each sanding pass. I use this for all sorts of things. Cleaning up the workshop, gluing panels, cutting smaller pieces, milling edges, etc. After working on the machine for a while, you get a very good feeling for how long you have between each sanding pass. Of course, you shouldn't take too much time, otherwise the panel will fly to the floor from a height of 1.20 cm 😓.
For me, it is the ideal machine for achieving a super flat sanding result and for being able to do small jobs (within a small radius around the machine 😂) between sanding processes. The belt sander is not completely out of service after purchasing the ZS640p, but it has significantly fewer working hours on its clock.
Questions?
If you have any questions or your own experiences with the machine or its handling, just write in the comments.
Hello everyone, I bought the Holzmann ZS640P cylinder sander with 400 V. But when sanding, it doesn't completely suck up the sanding dust. There's always some left on the wood. My question is what can I change or improve in the settings? I'm looking forward to some good advice.
wolfgang
Hello Wolfgang,
What kind of extraction do you have on the machine? With 2x100mm nozzles, you need a decent volume flow.
Best regards
Mark
Hello Marco, thanks for your report, it definitely contributed to my purchasing decision.
Can you tell me what width the sanding belts are?
75 or 100mm
I'm currently waiting for delivery and I haven't found any precise information about it online.
Thank you!
Hi Matthias,
Since we have already sold the machine and switched to a wide band, I can't tell you exactly. But it is important to use a linen band. Paper bands would tear much too quickly. The width is negligible. You have to cut them yourself anyway. It is best to always use a template that fits "perfectly".
Have fun when you first start and don't remove too much material :-). It's better to push it through a little more. The machine and sanding belt will thank you.
Best regards
Mark
Hello Marco
So you would recommend a wide belt machine? Holzmann also has a "cheap" wide belt sander on offer.
Greetings Alain
Hello Alian,
I've just seen that Holzmann has these in their range. Basically, I would always choose a wide belt sander over a cylinder sander. The set-up time for the sandpaper alone. In addition, the sandpaper on a wide belt runs over a sanding pad and on a cylinder sander on steel rollers. They don't forgive you a millimeter too much :-).
Best regards
Mark
Hello Marco,
great review.
I'm also thinking about buying one. What do you think is the maximum workpiece length for which the machine can be used?
Kind regards
Christian Bons
Hello Christian,
There's actually no limit to the length. The only thing is that the removal table isn't really long. It would be best to use dollies there.
Best regards
Mark
Thank you for the interesting article. I can also highly recommend this model. It is important that you buy something of higher quality. Otherwise you will be disappointed.
Best regards
Jan von http://www.kugellager-profis.de
Hey Marco, great review👍
I've been looking for experience myself over the last few days, but unfortunately you can only find a lot in the American YT area.
I think I will also opt for the large Holzmann, but only in a few months when I have saved up the necessary money for the investment😅 😊
Hi Jonathan,
I'm happy, thank you very much 😅. Basically, you can't go wrong with this machine. I was also torn between this one and the smaller ones. When I was able to compare the machines in person, I decided clearly to go for this one. It looks great and seems to be of high quality. Best wishes, Marco
Hello Marko,
Would you recommend the machine with 220 V or 400 V or does it make no difference?
Where can I see the machine in action?
Best regards
Jens Keil
Hi Jens,
definitely the 400V. When we want to sand our end grain boards quickly, we notice how difficult the 400V version is sometimes. I don't even want to imagine how 220V would be. Exhibitors are super difficult to find. If you are near 83544 Albaching or are on holiday in the area, just drop by 🙂
Best regards Marco
Hello Marko,
Unfortunately I don't live around the corner (100km south of Berlin), I have a job in Reutlingen soon. I think that's 250km from you, so let's see if I can make this little detour on the way back. I'd need your address and a phone number if that's possible here.
Best regards, Jens Keil
Hello Jens, just look at our imprint or under "Contact" where you will find the address and telephone number. Best wishes and a good start in your new job ;-). Marco
Albaching?! 😄 Very good, I'm in Hohenlinden!
Hello, Dieter Schützenauer here. I'm struggling with whether to buy a ZS560FU. I'm currently making a special kind of Platzeller as part of my occupational therapy due to the corona virus.
Can I come by at short notice?
lg