The Best way to Make Cornice?

[PAC1]

Sorry I am asking the question not giving the answer.
After 40 years I still do not have a technique that I am happy with. As an example I made some cornice recently using age Wealdon 002,003 or 006 50mm spindle cutters (it matters not which combination of these). I make my stock oversize so that I can leave a flat top and bottom so that the stock can be pushed square against the fence. This bit works fine When finished you need to cut the excess off and cut the corners off at 45 degrees so that it fits on the face frame and does not show at the top. This is where I really struggle and it can ruin the run. The biggest problem is my saw tilts to the right so I end up putting the moulding upside down on the table. This is fine if the finished moulding has two points that are in the same vertical alignment to the original face as the moulding can sit on those two points. But not all mouldings are. I have tried with the router and a big 45 degree cutter with not much joy.
I have tried making the moulding with router cutters again Wealdon cornice cutters but that is not great and does not solve the problem
So my question is how should it be done?
I hope to avoid the answer that I just need a left tilting saw

 

[MikeG.]

Hand plane?

 

[PAC1]

Hand plane?

Yes I have done that the problem is holding 3m x 65x22 still when the face that is down rocks all over the place, but yes the last three sets have been sawn roughly to size and shape and then hand planed to the correct profile. The other problem is because the saw cut is not perfect there is a lot of correcting and fairing to do before I cut the mitres because it is those edges that you use as the datum for a mitre cut.

 

[MikeG.]

You clamp it in the vice.

If the shaped face is the issue, do the edges first. Or set your machines up so that it runs along on its back. The angled edge doesn't usually extend to meet the moulded face. There's a flat bit in between, so you shouldn't be losing your datum.

 

[Steve Maskery]

I'm not sure I am understanding you properly, PAC; do you mean that the problem is cutting the mitres rather than making the moulding?

If so, there are two methods I have used successfully in the past.

1. Use a SCMS - Most have indents at 31.6 degrees and 33.9 degrees for tilt and bevel (not sure which way round TBH) for standard crown moulding (well, American standard, anyway)>

2. Make a sled. Glue several layers of MDF together to make a sort of pyramid. The two front-facing sides are cut accurately to your required angle, say 60 or 45 degrees, whatever you want, and both faces meet at 90 degrees in plan view. When your workpieces are held against this block it should be like looking up at the corner. So you cut one piece on the LH face and the other on the RH face.

This works well on external mitres, not certain it could easily be adapted for internal ones, you might have to make two sleds.

Here you go, this is taken from my Workshop Essentials #9:

I realise that with a 3m length you might need a bit of support with the back end.

 

[PAC1]

Steve the problem is making the moulding. The mitring is good as long as the back edges are correct

 

[Droogs]

If you make a lot of certain mouldings, why not grind the profiles in some tool steel and make your own cornice moulding planes. If you grind your own blade profiles for the spindle moulder it shouldn't be much of a problem to do that.

 

[Steve Maskery]

Ah, I see.
My saw tilts the same. So for bevel cuts I move the fence to the left of the blade, like a bandsaw.
S

 

[PAC1]

Mike, I am truly grateful for you testing my methods and thinking. I am not sure if your last post telling me how you make cornice on the spindle or just making suggestions so I can check I have thought it through properly.
I cannot hold it in the vice because I need two points parallel to the back face for my vice to grip. If I had those two points I can cut it on my table saw. Once you plane one edge you simply cannot hold it in a vice. I use various hold downs on my bench but they quickly wobble loose. For shorter lengths I can just plane to a stop.
Cutting the edges before moulding is in my view dangerous because there is nothing for the stock to run on and keep it square to the fence when moulding. I suppose I could make a jig to run it into keep it tight to the fence but I am not convinced this would work without clashing with the feed rollers.
I could chamfer with the stock laid on its back with a chamfer block but it does end with a point.
Your suggestion that there should not be a zero point does not fit with my experience because you see a flat when the cornice is tilted over at 45 degrees fitted in situ but from a machining point of view that is two chamfers intersecting. Practically getting this 100% is a pita

 

[PAC1]

Steve I do not have that luxury. To the left is a slider. I can cut short lengths by clamping them to the slider but 3m is twice the length of my slider. But maybe I can make a fence and hold downs to fit on the slider. Thanks!

 

[MikeG.]

Deleted

 

[Trevanion]

I've always done it starting with the stock at its finished size, mould the moulding onto the face of it with spring guards or power feed to help it through and then followed up with a 45-degree spindle moulder block to take the chamfers off with the stock with it's back on the bed.

 

[doctor Bob]

I tend to pick up the phone and order a 500m run.

Its a no brainer as a business, per meter it works out cheaper than a mag catch or a hinge.

 

[PAC1]

Trevanion. I think I will try that next. Although it does require a profile that can run against the fence on the outfeed

 

[PAC1]

Bob I do not think I have used 500m in my life. Maybe 50m
When I was an apprentice we used to do production runs for big projects for sitefixing but since then it has just been 4-10m for a project

 

[Trevanion]

Trevanion. I think I will try that next. Although it does require a profile that can run against the fence on the outfeed

I have tacked bits of timber to the outfeed fence before to give extra support if the moulding only contacts in a single place when the material is removed

 

[Jake]

Wouldn't a set of reverse knives sort out a profile for the fence?

 

[PAC1]

I have tacked bits of timber to the outfeed fence before to give extra support if the moulding only contacts in a single place when the material is removed

Yes same here but my current spindle has a metal fence. That was why I started making the stock oversize. That bit does work well. It is the chamfer where I struggle. I looked in Stephensons book he shows a birds mouth cutter for making the chamfer. I have never seen one. So it will be the 45 block

 

[PAC1]

Wouldn't a set of reverse knives sort out a profile for the fence?

Sorry I do not understand?

 

[Trevanion]

I looked in Stephensons book he shows a birds mouth cutter for making the chamfer. I have never seen one. So it will be the 45 block

I had a look in the book since it was pretty close to hand and I see what you're talking about and I hadn't even thought about doing it like that. T'were me I'd possibly set up a couple of old-style Whitehill heads on the spindle with some knives at 45-degrees opposing each other.

Having a look around, cutterprofilers actually have bird mouthed knives for the job exactly as you need, profile C1.