Splitting Moulding Profiles

Technical advice on running two profiles on a single piece of stock, and splitting the pieces as they come off the machine. November 12, 2008

I'm going to run two out profiles on a U-1000. I want to split off the last bottom. I have used steel usually to do this, but am considering saws. 8000 rpm, poplar and hard maple. What do I need to consider with saws?

Forum Responses
(Solid Wood Machining Forum)
From David Rankin, forum technical advisor:
When splitting on a moulder you are required by OSHA regulations to use an anti-kickback device, or to run separate outfeed rollers to control each piece after it is cut.

Knife versus saw blade. Depends on the thickness of the cut. We are cutting both ways with great success. With knives you can cut a medium to thick split. This works best for profiles that round over or angle toward the split. For profiles such as 2 x 6 material being split into 1-1/2 x 1-1/2 pieces, saw blades work best.

The secret is:
1. Saw needs to have the correct teeth. Do not use too many teeth. Normally 12 teeth is what I spec.
2. The fence of the moulder needs to be aligned exact.
3. The pressure shoe needs to hold the material. This may require a custom hold down shoe.
4. I do not run the last piece all the way through the splitter. This reduces the risk of a kickback.
5. I suggest that you consult a technician about your specific application to discuss any profile specific need.

From contributor R:
I would like to add that if you're going the saw blade direction, an Etp sleeve for your spindle would be the way to go. That way you don't spin the saw blade on the shaft from just using spacers. They are a little costly but worth every penny. Most reputable tooling dealers will carry these.

I too would highly recommend an anti-kickback device. We don't want to hear of any accidents.

From the original questioner:
I have only split about 15 profiles. Mostly small casings, panel moulds, base caps. The problem I have with steel is regrinding the splitters without staggering the knife, which is something I don't want to do at 8000 rpm. I hold the work piece down with felt and the last outfeed wheel, and like contributor D, we don't feed the last piece out. If I could keep from having to stagger my tooling, I wouldn't even consider saws.

From David Rankin, forum technical advisor:
We have a knife product that has been used extensively for splitting profiles such as casings, quarter rounds and shoe mould. The DGK coated steel was run at one of our customer's in red oak in a splitting application at 35 fpm and he ran over 20,000 before the regrind. In his case, the profile split came down in the middle of the wood, allowing a nice blend to the splitter part of the knife.

I would recommend avoiding splitting through the entire thickness of the wood, as this can easily overheat and damage the tool.