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

[rogxwhit]

To do with new screws, their heads - whether hex or square - must at no point of their rotation protrude above the cutterblock. And if they're different, it's also necessary to be sure that their spanner can engage and turn sufficiently in the space available.

If they lacked relief beneath their heads, I might lightly countersink the threaded holes. But it might not be necessary. One thing at a time.

 

[Housey210]

CNC machined all that and as offered in singles, not paired, their confidence demonstrated.

 

[Housey210]

you could try ams machinery or daltons as they may sell new bolts.

 

[Andy's Shed]

Well it's all gone to pot now. I got hold of some screws from Fastpack, threads all the way up, similar weight to the originals, although they're hex heads. I bought some easy outs, a file just in case too. I drilled through the snapped bolts with the drill press, got my easy outs and the smallest one which fit the hole stripped it's own threads and eventually snapped.

Back to the drill press with a slightly larger drill, still taking care not to hit the threads in the v-ledge, got the next size up easy out, got a good grip with it .... snapped off level with hole! It's stuck solid and I can't get a smaller drill to it as it's not level enough and the drill skips off.

I have tried WD40 and heat along the process, but I reckon that's it.

I've emailed Scheppach Germany who list the replacement part, asking if I complete my order as their website only seems to allow me to select Germany or Austria from the address registration. I've also emailed a UK company who sell some Scheppach parts, asking if they can source the bit that I need. I haven't received a reply from either company, but fingers crossed I'll be able to get something sorted before too long.

Thanks again for all the advice.

 

[Inspector]

Take the gibs to a small machine shop and see how much they will charge to get the screws out. Might be cheaper than replacements.

Pete

 

[Andy's Shed]

Cheers Pete, I can't seem to find one locally.
I think for now I'll stick with plan B and try to get a replacement, I'm a bit reluctant to throw more money at it for now. If for some reason I can't get the new part then I'll have no other option but to continue with the old bit.

 

[Ollie78]

You could drill and tap a small hole in the centre of the broken bolts. Then insert a bolt into the new hole with some permanent loctite or superglue and use this bolt to turn it out. I have done this before. I have never had much luck with those stud extractors.

Or if you know a friendly welder, tack something on to the bolt, an old screwdriver or allen key for example and try that.

This kind of thing is always a ball ache.

Ollie

 

[Inspector]

There is one other option and that is to appeal to the forum's metal workers near you to see if they would tackle them.

Pete

 

[Fergie 307]

I tried turning the stripped bolts in both directions and they just span round endlessly,

I've managed to remove the blade and the wedge after cutting the 2 bolt heads off with my Dremel type grinding disc tool. That's a relief.

View attachment 142709

I don't have any Easy Out tools so I need to buy them, but I think I need to find out if I'm able to buy a set of replacement clamp bolts first. I know that Scheppach supply them with the replacement v-clamps, but they don't appear to sell just the bolts.

I think the bolts are nearer to M5 in size, approx 5mm width and just under 13mm in length.

View attachment 142710

View attachment 142712

I'm wondering if I should just order a replacement v-clamp for 40 Euros plus postage and it'll come with the bolts, the cost of buying some easy outs and then the price of the bolts (if available) might not make it viable.


EDIT: If they are M5, would these be fit for purpose?
https://www.screwfix.com/p/easyfix-bzp-steel-set-screws-m5-x-12mm-100-pack/5738h?_requestid=183994

Looking at the images it should be easy to Helicoil them. You don't need to take the broken part out as the correct size drill for the coil will be slightly larger than the thread. You do need to make sure you drill straight down the middle of them. Personally if they are M5 then I would run an 4mm drill through first to remove the body of the old bolts, then run the correct size drill down for the coil. If you do but a kit then they don't usually come with the drill, you have to buy that seperately. Tracey Tools are a good source for both. A Helicoiling kit is going to be around £30. Alternatively take it to a local engineering shop or maybe a motorcycle repairer, they will probably have the kit and shouldn't charge a great deal to do them for you. You could use regular hex head bolts in place of the original ones, but I would compare the weight with the originals. If need be you can change all the bolts to keep it in balance.

 

[Fergie 307]

There is one other option and that is to appeal to the forum's metal workers near you to see if they would tackle them.

Pete

Well it's all gone to pot now. I got hold of some screws from Fastpack, threads all the way up, similar weight to the originals, although they're hex heads. I bought some easy outs, a file just in case too. I drilled through the snapped bolts with the drill press, got my easy outs and the smallest one which fit the hole stripped it's own threads and eventually snapped.

Back to the drill press with a slightly larger drill, still taking care not to hit the threads in the v-ledge, got the next size up easy out, got a good grip with it .... snapped off level with hole! It's stuck solid and I can't get a smaller drill to it as it's not level enough and the drill skips off.

I have tried WD40 and heat along the process, but I reckon that's it.

I've emailed Scheppach Germany who list the replacement part, asking if I complete my order as their website only seems to allow me to select Germany or Austria from the address registration. I've also emailed a UK company who sell some Scheppach parts, asking if they can source the bit that I need. I haven't received a reply from either company, but fingers crossed I'll be able to get something sorted before too long.

Thanks again for all the advice.

Ok I replied before I had read to the end. Now you have a broken easy out you are really going to need someone will a milling machine. A solid carbide mill will deal with this without too much problem. Have you tried CNC machining services or similar locally? If you can find a local engineering firm they tend to know each other so even if they can't do it they will probably know someone who can.

 

[Fergie 307]

The other way of removing the broken bolts would be with a spark eroder. Engine reconditioners are a good bet for this, if you have one locally.

 

[Housey210]

Welding nuts on, milling out, or spark erroding you will be putting your hand in your pocket, if you can find anyone local and prepared to spare the time. Seen two of these broken in half at hole, in my career. For me its a no brainer, new part. Plenty of used pts on facebook market place.

 

[Andy's Shed]

I've had one email reply from a UK parts company and they say it's either unavailable or they are unable to supply. I'm still waiting for a reply from Scheppach Germany and also NMA here in the UK. I'll try and call NMA this afternoon.

 

[Housey210]

Is there a tech college near your? Done an engineering course at mine and they had spark erroder, removing the broken taps appeared a daily job for the store room technician. . My local pattern maker also had one. Again, if one near but again its a cost. One home made penetrating solution, as seen on youtube, is 50 50 mix of auto transmission fluid and accetone. The tub I made up worked for me, but I did leave the job soaking for a month. Again a cost. A welded nut onto what is left, by pro welder, is another vid on youtube and the heat did loosen the stud. Perhaps that is why it was sold?

 

[Andy's Shed]

Scheppach Germany have since replied by email and they only ship to Germany, Austria and France, they recommended that I get in touch with NMA Associates. I've just got off the phone with the parts dept at NMA and I 'think' I've got my order in for two of the replacement v-ledges with screws. I say 'think' because although they've got my payment details and the part number, they're waiting for the other parts chap to place the order with Scheppach.

Hopefully the parts will be available for them to order, they are at least shown on the German Scheppach website as available to add to the basket.

I'd also like to thank the very kind chap here on the forum, giving me the option to order the bits and have them shipped to his address in Germany. I may still need to do so if the order with NMA isn't successful. Thank you very much indeed.

 

[Housey210]

fingers crossed

 

[Andy's Shed]

Good news, the replacement parts arrived today which was a nice surprise, I wasn't expecting them until next month. They came with hex bolts too.

I've only fitted the one v-ledge so far, the other one seems to be OK and I've been able to adjust both of the cutting knives. A test run showed some snipe(?) at both ends of the test piece, after some head scratching, some cursing and spanner clanking I think I've got the tables set quite nicely now and the test piece looked good.

I thought I'd try out the thicknessing too and I don't think the feed rollers are working, at least they weren't pulling my test piece through.
It could be that they're too worn to make contact with the wood, I'm not really sure at this stage. Further investigation is needed. If they are worn out I think I'll just have to manage, I don't really want to spend any more on the machine at this stage.

Thanks again for all the help you've given, I do appreciate it.

 

[rogxwhit]

I thought I'd try out the thicknessing too and I don't think the feed rollers are working, at least they weren't pulling my test piece through.

And you engaged the feed?

Otherwise, the relationship between knife projection and roller height might be out of synch - in that the outfeed table could be set too high, and thus the knife projection when tallied with it (as you do when knife-setting) is too great. This means that when thicknessing, the knives start to cut without the rollers engaging.

In a simple, cylindrical cutterhead, the heel of the knife bevel would normally be about on a level with the lip of the recess in the head. How does yours look?

And yes, a slightly deeper cut at the end(s) of the work is snipe.

 

[Andy's Shed]

And you engaged the feed?.......

In a simple, cylindrical cutterhead, the heel of the knife bevel would normally be about on a level with the lip of the recess in the head. How does yours look?

I've just had another look and made sure the lever was in the 9 o'clock position (I did try both positions earlier just to be sure), the feed rollers are indeed working although they're worn towards the middle on both of them. I think my earlier test piece was too small and I was aligning it with the gaps on ths rollers. The piece of wood was only 20mm thick by 40mm ish.

I've just tried feeding a larger piece of wood through, a 2' x 4' piece of cls and it made it through on all but one of the attempts, it got most of the way through but then sat under the cutter towards the end. Another try after adjusting the cutting depth and it made it through again.

With the machine unplugged, I put a wood straight edge between both rollers and rotated the cutters, the rollers are just lower than the knives until I turn the head and the knives make contact for a moment.

Here's a couple of pics of the infeed and outfeed rollers with a straight edge along each of their lengths, you should just be able to see the gaps where the rubber has worn.

Infeed roller

Outfeed roller

 

[rogxwhit]

Ah, rubber - well that could be a job for another day! A bit disruptive to remove them, but I believe that they can be re-coated. The answer meantime is not to make too light a cut, I suppose.