Scheppach HMS 260 (new to me) - Cutter Block Problems

[Andy's Shed]

A couple of days ago I bought a used Scheppach HMS 260 Planer/Thicknesser. I spent most of today cleaning the maching and trying to level the beds as best as I could. I then moved onto 'trying' to set the height of the blades and this is where I can see that I have some problems.

On one of the blade blocks there's a small screw missing, or it may even have sheared off in the past (not by me). On the other side of the cutter block I think 2 of the screws may be stripped as they just seem to be spinning. I honestly don't know if I did that, but it is a possibility.

Is it possible to replace these screws, or is it even possible to find another cutting block if new screws can't be fitted?

Also would someone be able to clarify the correct procedure for the blade adjustment please, i.e which bolts and screws need to be loosened and tightened and in which order? I've watched so many videos on various machines that I'm feeling quite confused now, even after now having the blades set 'almost' right.

Thanks for any help, it's very much appreciated.

 

[baldkev]

I just did a quick google, found a replacement spiral block, but expensive.
Id take the whole cutter block out and find a local engineer. Theyll probably remove the bolts, re_drill and tap to a bigger size. Or those helicoils if appropriate?

 

[Andy's Shed]

Thanks very much Kev, I did a bit of searching too and spotted some Sheartech spiral cutting blades but wow they're expensive! I found this page which lists some replacement parts and I'll keep it in mind just in case v-ledge cpl. - Scheppach Spare Parts

Tonight (after the cleaning etc) it was the first time that I plugged in the planer and powered it up, wow it's loud I did three test passes on a bit of CLS and the results weren't too bad. I'll have another go tomorrow if it's not too late.

 

[Ollie78]

Those are the bolts to pinch the wedge that holds the blade. I agree with baldkev about just re tapping the holes a size bigger. If I remember they are about M6 so you could re tap to M8 I think there is enough material to do it ( I used to have a very similar hms 2600 ).

I would just cut off the ones that won`t allow the wedge to come out and then see what the situation is when you have the wedges out.

To set the blade height first loosen the wedge bolts, then you will see a couple of allen head bolts under the blade. Adjust the height by turning these up or down (they are very sensitive) when you think its right pinch the wedge bolts tight. Repeat until satisfied (usually at least twice)

Ollie

 

[Owd Jockey]

Hi Andy, i've had a Hms 260 for about three years now. Another way to ensure your blade height and level is right, is to use a set of Planing blade gauges (see photo). They are Chinese, quite cheap and nasty, but seem to work for me. I got these from Woodfordtooling.

 

[rogxwhit]

I wouldn't run the machine before you've sorted the full set of clamping screws. Isolate the power supply. One side of the cutterblock at a time, slacken them all off, lift out the knife and wedge bar and lay aside. Each wedge bar may have a mark that tallies it with which side of the cutterblock it belongs to - if present, this will refer to when the cutterblock was balanced at manufacture. Balance is a factor to consider in such an item that rotates at high speed.

Check out all the threads, both male & female, and do an overall assessment to decide the way forward.

If there are threads in the wedge bars that seem beyond just cleaning up with a tap - ie they are seriously chewed up - I'd try to source new wedge bars. It's unlikely that there'd be room for larger screws - things are usually pretty tight in there. And replace all the clamping screws at the same time. Any replacement screws should be high tensile.

If replacement bars are unavailable, you could get some made by a local engineer.

Setting the knives is the next story ...

 

[Ollie78]

I wouldn't run the machine before you've sorted the full set of clamping screws. Isolate the power supply. One side of the cutterblock at a time, slacken them all off, lift out the knife and wedge bar and lay aside. Each wedge bar may have a mark that tallies it with which side of the cutterblock it belongs to - if present, this will refer to when the cutterblock was balanced at manufacture. Balance is a factor to consider in such an item that rotates at high speed.

Check out all the threads, both male & female, and do an overall assessment to decide the way forward.

If there are threads in the wedge bars that seem beyond just cleaning up with a tap - ie they are seriously chewed up - I'd try to source new wedge bars. It's unlikely that there'd be room for larger screws - things are usually pretty tight in there. And replace all the clamping screws at the same time. Any replacement screws should be high tensile.

If replacement bars are unavailable, you could get some made by a local engineer.

Setting the knives is the next story ...

You make a good point about the balance, I had not considered this when suggesting replacing the bolts with larger ones. Maybe do all of them to keep it even ?
I am not sure what the tolerances are o these machines. I saw no balancing marks on the wedges on my scheppach.
There must be a fair amount of tolerance for the variability in knives. Some which have been really ground a lot vs new ones etc.

Ollie

 

[Spectric]

If your blades are anything like the Record PT107 then setting the blades can be a nightmare and to get good results is very important. I brought this machine without considering this aspect otherwise with hindsight it would have been something else but I ended up fitting a blade carrier that takes disposable double side blades which is a big initial outlay but then the blades are cheaper.

https://www.advancedmachinery.co.uk/machinery/tooling.asp?section=esta-bruck-knife-system-382

 

[Against_The_Grain]

You make a good point about the balance, I had not considered this when suggesting replacing the bolts with larger ones. Maybe do all of them to keep it even ?
I am not sure what the tolerances are o these machines. I saw no balancing marks on the wedges on my scheppach.
There must be a fair amount of tolerance for the variability in knives. Some which have been really ground a lot vs new ones etc.

Ollie

You should never mix knives that have been ground with new ones, they should stay in their set from new as when they are sharpened they are balanced as a set. If you were to run a heavily reground knife with a new one you will get horrendous vibration and the planer will walk across the room.

The cutterblock is a very precise piece of equipment, it requires very close balance of all the components, and also all the contact surfaces need to be very clean with no wear to effectively clamp the knives and prevent knives being ejecting from the block during cutting. You’ll find that all the screws are exactly weighted for balance.

 

[rogxwhit]

You make a good point about the balance, I had not considered this when suggesting replacing the bolts with larger ones. Maybe do all of them to keep it even ?
I am not sure what the tolerances are o these machines. I saw no balancing marks on the wedges on my scheppach.
There must be a fair amount of tolerance for the variability in knives. Some which have been really ground a lot vs new ones etc.

Ollie

About increasing the diameter of the wedge screws, I was reckoning on the fact that there isn't often much room for a larger-headed screw, given that whether hex or square headed the whole screw head would be beefier, and there has to be room in the slot to (1) get the spanner on the head and (2) actually turn it incrementally till it's tight.

Not all machines id the wedges for specific placement. Some do.

Knives should always be balanced, whether new or worn down. That's why they tend to be ground in pairs.

 

[rogxwhit]

I ended up fitting a blade carrier that takes disposable double side blades which is a big initial outlay but then the blades are cheaper.

Fair enough, but you still use the original wedge bars? And his immediate problem is the wedge bars and their screws ...

 

[Andy's Shed]

Thanks very much for all the advice, I'm very grateful.

So just so I've got this straight, the Allen/Hex bolts allow you to alter the blade height only, once the height is set there's no need to touch those bolts further?

The 5 bolts on the side of the blade clamps are there to hold the blade in place. Turning them anti-clockwise tightens the blades in place and turning them clockwise loosens the blades allowing them to be removed if need be?

Yesterday I found that the Allen bolts on my machine did allow me raise the blade height, but turning them in the opposite direction didn't lower the blades, I had to tap them with a piece of wood to do that.

Another thing, I didn't see any movement in the blade clamps themselves with the bolts loosened, it may be due to dirt etc holding them in place? It sounds as though it should be possible to remove them along with the blades?

Re the balancing, as there's already one clamps bolt missing (or if the head has been sheared off at some point), that will have a slight effect on the balancing won't it?

I do have another question about setting the blade height using the two 5mm marks on a straight edge method, should this be done with the cutting dial depth set at zero?

Thank you!

 

[rogxwhit]

So just so I've got this straight, the Allen/Hex bolts allow you to alter the blade height only, once the height is set there's no need to touch those bolts further?

Yes. You do it every time that you change the knives. It's a sensitive business, might drive you crazy, but stay calm and it's do-able! You tighten the wedge bar till its almost gripping, because you want the knife to be as close as possible to its final plane, and you can unscrew the adjuster to raise the knife - but if you want to drop the knife, screwing the adjuster screw down doesn't in itself drop the knife - you have to tap it (with a piece of wood). With experience and being methodical it can be very quick. It can be tough whilst your finding your feet. When you feel happy with the height, you tighten all the gib screws (the hex or square headed ones). Don't get distracted and forget.

The 5 bolts on the side of the blade clamps are there to hold the blade in place. Turning them anti-clockwise tightens the blades in place and turning them clockwise loosens the blades allowing them to be removed if need be?

Yes!

Yesterday I found that the Allen bolts on my machine did allow me raise the blade height, but turning them in the opposite direction didn't lower the blades, I had to tap them with a piece of wood to do that.

Don't worry about it. Just improvise as necessary.

Another thing, I didn't see any movement in the blade clamps themselves with the bolts loosened, it may be due to dirt etc holding them in place? It sounds as though it should be possible to remove them along with the blades?

Blades out first. Then tap the bars gently and remove them, and do a clean-up.

Re the balancing, as there's already one clamps bolt missing (or if the head has been sheared off at some point), that will have a slight effect on the balancing won't it?

Of course!

I do have another question about setting the blade height using the two 5mm marks on a straight edge method, should this be done with the cutting dial depth set at zero?

We're galloping ahead now. Always register off the outfeed table, as long as the infeed is set lower so as not to interfere it doesn't matter on the exact setting.

 

[rogxwhit]

When knife setting I don't know who uses a 'straight edge', which to me implies a metal tool - I wouldn't want any metal to touch my knives. I use a flat slip of wood kept for the purpose and mark one edge with a series of lines about 4mm apart. If the cutterblock was 100mm diameter, a knife at the right height might carry the gauge forward by about 8mm. I haven't got a feel for smaller blocks but it would be correspondingly less because the geometry's different. 5mm could be about right.

Knife too low and a planing cut would run out to zero as it progressed. Too high and you'd get sniping at the end of the cut.

Tables that are crowned or hollow along their length means all cuts will be like a banana one way or the other. What's easiest to adjust depends on the planer design. If the cutterhead height appears difficult or 'impossible' to adjust, then that's an indisputable reference from which all else follows. Thickness bed and outfeed table are independently adjusted to it. Then the infeed is registered to be in line lengthways with the outfeed, at all points across its width.

It's like fitting and hanging a door, in that there's a logical sequence to follow that's dictated by the circumstances.

 

[Inspector]

I assume from your questions you don't have the manual for the machine. A search revealed a number of places with them. Some you have to pay for and some free like this one. Scheppach Hms 260 Manual - [PDF Document] Knife setting is covered.

While a replacement insert head would be expensive if you had to buy a new straight blade head, wedges, blades etc as a replacement because yours was damaged beyond repair you would be in the same price range assuming new ones were still available. You a ways from needing to do that yet.

Pete

 

[Andy's Shed]

When knife setting I don't know who uses a 'straight edge', which to me implies a metal tool - I wouldn't want any metal to touch my knives. I use a flat slip of wood kept for the purpose and mark one edge with a series of lines about 4mm apart. If the cutterblock was 100mm diameter, a knife at the right height might carry the gauge forward by about 8mm. I haven't got a feel for smaller blocks but it would be correspondingly less because the geometry's different. 5mm could be about right.

Knife too low and a planing cut would run out to zero as it progressed. Too high and you'd get sniping at the end of the cut.

Tables that are crowned or hollow along their length means all cuts will be like a banana one way or the other. What's easiest to adjust depends on the planer design. If the cutterhead height appears difficult or 'impossible' to adjust, then that's an indisputable reference from which all else follows. Thickness bed and outfeed table are independently adjusted to it. Then the infeed is registered to be in line lengthways with the outfeed, at all points across its width.

It's like fitting and hanging a door, in that there's a logical sequence to follow that's dictated by the circumstances.

Brilliant and thanks again for the clarification, I needed to get it straight in my head!

My straight edge is a strip of plywood with one factory edge, I should have made that clearer.

The blades do appear to be very securely fixed in the cutting block so far with no signs of being able to move at all, they are surprisingly sharp too, I have a cut on my index finger as proof. I think the previous owner must have changed them relatively recently, he also handed me a spare set of blades but on checking they look as though they must be the old one's.

 

[recipio]

From memory I'm guessing the bolts are M5 The easiest option is to re- tap the holes in the wedge bar if possible. Using an M5 tap they will ' clean up '.Incidentally check the width of the blades as they may have been ground down by re-sharpening. They should be 19 mm wide. For setting the blades I always find that setting a batten to move 6-8 mm is too much. You will always get snipe. Best to lightly tighten the blades and set one side to just ' kiss ' a softwood batten then move along the blade raising it with a screwdriver until you get the entire blade to ' kiss' the batten. It's more felt than heard !
The HMS 260 is a great machine and will give a lifetime of service. Shame Scheppach stopped making them.

 

[Andy's Shed]

I assume from your questions you don't have the manual for the machine. A search revealed a number of places with them. Some you have to pay for and some free like this one. Scheppach Hms 260 Manual - [PDF Document] Knife setting is covered.

While a replacement insert head would be expensive if you had to buy a new straight blade head, wedges, blades etc as a replacement because yours was damaged beyond repair you would be in the same price range assuming new ones were still available. You a ways from needing to do that yet.

Pete

Thanks Pete, I'll take a look at the manual. I have already downloaded some docs but the one in your link may be just the ticket.

I posted a link further up in the thread (at least I think I did) and there's a German retailer that sells the single blade clamps for around 40 Euros each, they appear to come with the 5 screws too. My blades appear to be tightly mounted so far, fingers crossed I may have gotten lucky, but I'll keep the replacement clamps in mind if anything changes.

 

[Ollie78]

I would strip everything down and clean it all up.
With regards to the blade setup I found 3mm movement or drag to be about right.
I used a steel veritas square for it so it's easy to see the drag.
The device that originally came with the planer for blade setting is galvanised steel u shaped thing.
You are only using tiny force for this and I never damaged a blade.
I found it best to set the knives low and creep them up by increments. Because as you say you will have to push them down.

The depth setting doesn't matter as you reference the outfeed table only.

Ollie

 

[Andy's Shed]

From memory I'm guessing the bolts are M4. The easiest option is to re- tap the holes in the wedge bar if possible. Using an M4 tap they will ' clean up '.Incidentally check the width of the blades as they may have been ground down by re-sharpening. They should be 19 mm wide. For setting the blades I always find that setting a batten to move 6-8 mm is too much. You will always get snipe. Best to lightly tighten the blades and set one side to just ' kiss ' a softwood batten then move along the blade raising it with a screwdriver until you get the entire blade to ' kiss' the batten. It's more felt than heard !
The HMS 260 is a great machine and will give a lifetime of service. Shame Scheppach stopped making them.

Thanks very much When you say to lift the blades with a screwdriver, how are you doing that exactly, are you using the small gap beneath the very end of the blades?