I understand that moulders with jointing heads can run at speeds over 100 feet per minute. Would a machine like this be practical for a custom moulding business? Do these high-speed moulders include longer setup times? What are the differences between a jointing head moulder and a moulder such as Weinig's entry level moulder?
I have 12 years experience with moulders and run both high speed and slower production. We use Wienig and Iida moulders. Jointing is great if you have long runs like 30 thou and up. But it takes longer to grind tooling and set up, and of course this depends on the experience of the employee who runs it.
For custom runs, you would be better off with a non-jointed machine to start with. As you go with longer runs, go to a jointed machine.
A run of 5000 linear feet is necessary before it is feasible to use a jointed machine, because it takes extra time to set one up. A jointed head molder is almost twice as expensive as a non-jointed machine and more complicated to set up. A jointed head molder requires you to be fluent in the grinding of your knives because you have to grind a jointing stone that is the exact profile of the knife you are using and matches up with that knife at a precise angle. When a jointed head machine joints your knife, it evens up the knife so that they are all the same. You are actually dulling the end of your knife to achieve this. You have to know how to grind.
With a non-jointed machine, no matter how good you are at grinding, one knife is always going to be higher than the others. Even if it is only in the thousands of an inch, only one knife (even though the other knives are cutting) is going to be cutting on the finish. The knife marks that you see on the finished product will be the result of the highest knife only. With a Wienig non-jointed machine spinning at 6000 RPM, you can figure about 32 fpm. Plenty fast enough for manufacturing custom molding.
If the normal length of run is over 5,000 lineal feet, a jointed moulder is worth looking into. It takes about twice as long to set up a jointed machine as it does a non-jointed one.
If your normal run is under 5,000 lineal feet, a non-jointed machine is the one for you. In either case, the tooling and grinding of that tooling is the most important part of the operation.
Without a doubt, attending a class is a good move. A wide number of machines can be seen and used at different schools. The more machines that you get a chance to work on, the better it will be for you when making your decision.
Dave Rankin, forum technical advisor
Take special care of setting procedures together with tooling and grinding choices, since many false claims are made by some who do not have the technology in their machines.
A good all-around machine would be one with outboard bearings, larger spindle diameter and enough rpm to get you 60 fpm and still keep a good quality finish.
I also have a Hydramat 23. It is a 60m machine with a max feed rate of 180 fpm.
I have run 1/4 x 3/4 scribe and 1 1/4 x 9" crown profiles. These were not all run at high speed, but the versatility is a major advantage. The concept of running a jointed machine is simple. The ability to run high-speed productively requires a top-notch operator and extremely accurate tooling. Conventional runs are a lot more forgiving.
I agree with all the other statements on run lengths. I have made the break at 10,000' before I will consider a high-speed run. The problem with a high-speed run is competition. Large runs are normally high competition and low profit margins. I like the concept of Wienig's Unimat 23. I believe it's the yellow line. It's not a jointed machine but it does have higher rpm spindle rates, which could give you a high quality finish at a good feed rate. Try to see the equipment in a productive operating environment.