Snipe on thin stock

[Rattie]

Hi all,

My HMS260ci is a pretty competent planer thicknesser and now that I've ground and honed the blades the finish is really very nice indeed.

On stock over a couple of cm thick there is no detectable snipe on either soft or hard woods. However when thicknessing some 8mm oak lippings I get slight but repeatable snipe on the END of the pass. This occurs even when I carefully support the outfeed.

The snipe itself is usually a single dip in the surface, rather than the classic thinner section from the start of the snipe to the end of the piece. It looks to me like the stock is twanging up as it leaves the in feed roller then settling down again.

Has anyone else had this problem, especially Scheppach owners? Anything I can do about it?

I was wondering if putting thin stock through on a plywood substrate might help, as one would use for really thin stock to make up the thickness - possibly with double sided carpet tape to stick the lipping down. Could do a few at once then.

Cheers

Martyn

 

[Newbie_Neil]

Hi Martin

What you've described is exactly what is required.

Have a trailing edge a little higher than the rest so you can push everything tight against it and it should keep things from moving backwards. Double sided tape is good.

Cheers
Neil

 

[Adam]

Hi Martin

What you've described is exactly what is required.

Have a trailing edge a little higher than the rest so you can push everything tight against it and it should keep things from moving backwards. Double sided tape is good.

Cheers
Neil

I notice at the NMA demonstrations, when they thickness down to 1mm use a melamine "insert" which effectively raises up the bed. This is left in position - and the wood passes over it. So it is possible to go thin without a backing piece. Perhaps give NMA a ring? Or see them at a show?

Neils suggestion would work fine as well I'm sure. (in fact that'd be the solution I'd be tempted to go for in fact.....)

Adam

 

[Rattie]

Hmm, interesting. I've seen NMA at shows but missed the melamine insert. I guess a really smooth surface like melamine would also create a little bit of "ground effect" under the lipping and hence keep it sucked down.

Also thanks for the encouragement Neil, I think I'll try both methods. They both have another benefit of avoiding the slight marking of the underside of the workpiece by dirt on the scalloped bed. I haven't been able to get the bed clean enough to stop this entirely - mucky lines on the piece - I don't know if anyone else has had more success.

Cheers

Martyn

 

[gidon]

Martyn
I've done this a lot with my HMS260 - down to <2mm with no problems. I use a plywood substrate with a lip at the front to stop it getting pulled through. I've not stuck them down either - they just slide over the plywood jig. Melamine as suggested may be even better - but I would try it with whatever you have hanging around for now.
The lipping aren't warped or bowed in any way are they?
I don't get the dirt in scallops problem - they had to be one advantage of having bought a HMS260 just before they switched to cast iron .
Cheers
Gidon

 

[Rattie]

Cheers Gidon,

I'll try making a jig this weekend. Sounds like the way forward.

The lipping aren't warped or bowed in any way are they?

Nope, straight as anything, direct from the bandsaw.

On the dirty scallops thing, I guess a bit of elbow grease and white spirits will probably sort it.


Cheers

Martyn

 

[Adam]

On the dirty scallops thing, I guess a bit of elbow grease and white spirits will probably sort it.

I use this http://www.axminster.co.uk/product.asp? ... e=1&jump=8 (Liberon Lubricating Wax) on my thicknesser table - it's really good stuff - and brings the cast iron up super smooth.

Adam

(PS: When I first purchased the machine, I used degreaser to get all the gunk on the machine bed off - then waxed it after afterwards. I've had no problems since.)