Frustrating chopping

Steph

SGF, Supreme Grumble Framer
Joined
Mar 27, 2005
Posts
2,880
Location
NY
I'm getting pissed. I have a used Jyden chopper w/MOrso blades freshly sharpened. No matter what adjustments I make I am still getting chipouts on the lip and back. The lip situation is finicky but I can usually control it. The back chipping is killing me. My shop is small and not a proper place for a saw. At home I have a Dewalt compound miter saw w/ tha phaedra arm system. It doesn't amke sense for me to drag moulding there 20 minutes away everyday. I love using a chopper but I know there must be something I could be doing better. Sorry but I want perfect cuts!! My blades are flat ground. Should I suck it up and buy new ones? I did search the topics but I need more info please. HELP

Steph
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Steph,
Frankly, I just avoid those profiles that have that annoying swayback.

When the lip starts to chip and splinter (some profiles seem to be worse than others...), I start with teeeeny tiiiiiny bites into the rabbet.

edie the thatshowidoit goddess
 
Steph, is all the moulding chipping or just certain profiles?

I find that certain mouldings don't chop well even when I use freshly sharpened blades.

Sorry, I don't have a solution to your problem.
 
First are you using a rabbit support?
This sounds elementary but I have seen some choppers sold used with out a rabbit support.

Second does the blade go all the way to the back of the guide wall?
The blade should extend into the gap between the left & right guide.

As stated above, some mouldings aren't good choices for choppers.

One thing I have done with success is to use a stick of lattice behind the moulding. This way the blade is not cutting with the very tip and the back is supported during the cut.

My final solution is to get a bigger shop and a saw. I used a morso for 18 years then 5 years ago I bought a Pistorious 14" dbl miter saw. Oh what a dream of a difference.
 
It is usually 'gessoed' mouldings with the back chipping. As far as the lip yeah I do the same thing smaller bites on the delicates. Of course since I posted the same moulding hasn't been chipping as much, I have several of these to do for an artist. I think the chopper heard me threaten to spork it if it didn't shape up

Steph
 
Dave, Yes to all your questions, I always double check the rabbit support. And don't make a frustrated girl laugh...a bigger shop and saw?!?

Thanks
Steph
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Well it's better to make a frustrated girl laugh than to make her cry.
 
Steph, whenever I change the blades in our Jyden I run a bead of silicon down the gap on the inside of the fence (or whatever the area is called where the apex of the blades reach their furthest point towards the operator). That gives the moulding a little extra something to push against and helps prevent chipping. After laying the silicon I set the blades all the way towards me and give it one push to the floor, and then wipe off the excess silicon on the blades...

I usually don't see chips on the lips of the rabbit unless its a hardwood and I'm a hurry.
 
Steph,
I've had similar problems with my Hansen Chopper.
It's usually with mouldings that have a thick gesso or (?) on the back side, as mentioned by someone earlier in this thread. Now I order chops for those profiles, when I can, since most/all of the vendors are using saws for their chops. Like you, I can't put a saw in this location. Besides, I like the Chopper for most of the profiles as well as fillets.
kaffeetrinker_2.gif
 
I have a Jyden and a Prisma CE.

There are some mouldings that you just can't chop! Any kind of a scoop back will be a problem. Also thick finishes are usually a problem.

Sometimes taping the back before chopping helps limit chipping.
 
Having the same problems, and hoping to get some tips at WCAF Show. I seemed to have solved problem similar to Framemaker but instead of lattice, I ATG a piece of 4 ply mat board to the fence and then took a slice out of it with the chopper and that moved the moulding forward enough to almost completely solve the problem. It seems without doing that I just cannot move the tip of the blade forward enough to be into the groove in the fence. Of course my Morso is a 1958 model, maybe newer ones have some fine adjustments.
 
I maybe asking a dunce or newbie question, but have you concidered finding a replacement moulding for problem mouldings?


<font size=1>My dream job is getting paid to just bang my head against the wall 8 hours a day.</font>

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Originally posted by FrameMakers:
Well it's better to make a frustrated girl laugh than to make her cry.
As a female that has been frequently frustrataed I would agree with the above statement... wholeheartedly.
 
Oh yeah..... Blade Oil...
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Steve, very interesting idea...

I was think that you could also get a tighter fit by applying the silicon and letting it cure over the weekend, then it will cut clean with the first pass.
 
Thanks all for the info.I tried the silicone and let it set overnight. I put in a black moulding scrap that is notorious for chipping and no chips!!!! Thanks Steve. And just for the info all the mouldings with gesso I struggle with are flat backs. I tend to stay away from scoop backed profiles, and I agree there are some mouldings that are not chopper friendly. As usual everyone was very helpful, thank you and my mood is much improved today.

Steph
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Originally posted by Baer Charlton:
I maybe asking a dunce or newbie question, but have you concidered finding a replacement moulding for problem mouldings?


<font size=1>My dream job is getting paid to just bang my head against the wall 8 hours a day.</font>

kaffeetrinker_2.gif
I want that job!!

To expand a bit on mouldings, I also find it frustrating to find replacement mouldings. I am pretty happy with what I have. But I hate going to a trade show and seeing crap mouldings on the wall. There are some vendors I won't give the tiem of day and am horrified with there offering. Sorry but I want quality at a fair price. For me it has to more than a pretty moulding, I look at everything about it, profile, substrate, and finish. They can't pass off a crap finish on me ...I won't have it. I know my customers I need to be middle of the road on my pricing . I try and offer a full range though. I carefully choose where my more reasonable mouldings are coming from as much as my middle to high end. I feel like I have to cherry pick my way through to get a well rounded selection for my customers.
I'm sure I am not the only one who feels this way. I look forward to the trade shows and dread them at the same time. Any co. I deal with has to have the same values as me, if they can't back me up I can't sell their product. I just don't have the time for them to blow smoke up my skirt.
I want it all, and why shouldn't I, its what I deliver to my customers.
O K....sorry apparently my mood hasn't improved. What the heck I'll throw this out there any way, I love a good discussion

Steph
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I just had the same problem. I changed the blades (I have 2 sets) and found that there was a chip in the blade. They are doing good so far.

Also, I don't quite understand what you did with the silicone? Could someone please explain a little more clearly. And are you talking about silicone that drys hard and clear and can be used in shadow boxes? or is there another kind of silicone I'm not aware of?
I hate sounding stupid, But I really don't get it.
Jennifer
 
Thanks all for the info.I tried the silicone and let it set overnight. I put in a black moulding scrap that is notorious for chipping and no chips!!!!
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Jennifer, Yes same ol' Tub and Tile Caulk.... or Fine Framing Stick It Down and Never Moves....

When you stand at the chopper and look down on it, the two blades meet in a point; and when the final cut is made, that point is slightly past the back of the moulding and is reliefed into the gap between the back wall support arms.

It is that gap that Steve suggested be filled with silicone goo. Let it dry, and then chop through it, and it makes a closed support.

It is much like closing the mouth on a hand plane. The tighter the mouth, the smaller the chip allowed to be plowed up and therefore the finer the cut.
 
OK then do you "smooth" the goo to be flush with the guide, or does it press flat when you hold the moulding agin it?
 
I usually smooth it out with one pass of the chopper, but as Baer suggested its probably ok to let it cure and then the first time you cut a stick it'll shear off any excess, plus the silicon is flexible enough to move out of the way but still support the back of the frame. I like smoothing it out, as every blue moon it likes to bunch up and peel off instead of shearing, probably depends on the amount of silicon used and its adhesion to the top of the gap.

And I didn't mean to ignore you earlier Jennifer, I hit submit and then went to get ready for work and didn't see your next post until now...
 
Originally posted by Bob Doyle:
OK then do you "smooth" the goo to be flush with the guide, or does it press flat when you hold the moulding agin it?
The silicone wants to be "in" the groove, not out front of the back rail alignment.
 
I must say the silicone solution is a great idea...I used cut problem muldings by extending the back rail with another moulding, preferably a scrap poly expander and cutting through a small portion of it together with the moulding that I'm chopping, this supports the back and prevents chipping except for gesso frames. Also works great when your in a tight fix and the blade tips are a little dull (duh!)...saves a little time till that trip to the grinder.

The silicone works well until you need to chop mouldings in another angle...then you have to do it all over again.

I also find it hard to squeeze myself in the space between the chopper and the wall( just where the waste chute is...)to shoot goo in the gap between the back rails.
 
Hi all
Steph - just spotted your post. Like the others before me I build out the fence on the guillotine with 5mm hardboard ( masonite ? ) so the tips of the blades are not doing the cutting. I also , and esp in winter , use a heat gut to warm / soften the backs of gesso'ed mouldings. This works great for me - the moulding cuts like cheese ( havarti not feta )
Cheers.
 
Using silicone to close the gap sounds like a neat idea, but why not just do it right and adjust the blades so you have a .001-.002" gap? You can do this by using a piece of 20# copy paper (if you don't have a feeler gauge) - hold between the blades and the fence and adjust the knives until the paper is a snug/tight fit. Make sure it's not too tight(!) before using it or you'll chip your knives bad.

FYI, the adjustment is via a cam below the pivot point for the fences (under the table).

If you don't have a perfectly matched set of blades and make sure that the mating surafces are clean when installing them, you should double-check/readjust each time you fit new blades.
 
No one on this thread has suggested ordering the moulding chopped by the supplier. Why not do that?
 
To lubricate the flat side of the blades, use a floor wax. I like Johnson's down here in OZ, but you would probably have a similar product up there. It makes the surface really slippery.
 
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