Mounting a Sawblade on a Moulder
It's a workable way to make multiple moldings at one pass, but it calls for special safety accessories. March 3, 2006
Question
I have heard that in order to use a saw blade on a moulder, it has to be equipped with a special anti-kickback device. Is that correct? I'm wondering how the force from a small kerf saw blade can exceed the force and kickback possibilities that some of our crown and casing profiles produce.
I want to produce in one pass two pieces that are each 1 1/2" in width from a 3 1/2" blank. We don't have a glue line gang rip, so that isn't an option at the moment. It's taking too long to bust the blank in half and then send each piece through the moulder one at a time. Any thoughts on how to make my existing equipment work for this job?
Forum Responses
(Solid Wood Machining Forum)
From contributor R:
Any time multiples are run on a moulder, an anti-kickback device is recommended by the manufacturer. They are concerned about twisting and turning of the piece after ripping and it getting caught by the blade. This will throw it back at the operator like an arrow. I have personally seen it happen to an operator and he was seriously hurt. They also want the multiples under the feed rollers at all times after the rip. I also recommend a (Etp) hydraulic type sleeve to hold your saw blade. This locks on the shaft hydraulically as well as the saw blade. If you don't use this type of system, you take the risk of spinning the blade on the shaft, and it will weld itself to the shaft.
The manufacturers just want you to live another day to make beautiful mouldings. Take care and please be safe.
From contributor J:
Yes, it is highly recommended for anti-kickback devices. Especially ripping multiple thin strips. With that said, I rip triples and doubles at the size you mentioned (1 1/2") from a single blank without one and haven't had any problems (knock on wood). I do it backwards (to some people). And I guess it depends on your moulder. I mount a slab of resin board to the pressure shoe and run my blades on the last bottom up into the resin board. I've never used any special clamping device, but I do make sure all strips are covered with the last set of pressure rollers and the pressure from the shoe holds everything down. Just remember, without the anti-kickback, you are always taking a chance of something bad happening. I take the chance myself, but I don't think I would put an employee in that situation. It would be worth the investment versus paying workman's comp and causing injury to someone that is working for you (or anyone, for that matter).
From contributor J:
I just reread your post. Sorry - it's been a long day. Do you want to make two sticks of crown moulding? I thought you meant s/4/s strips.
From the original questioner:
I want to make two s4s pieces 1 1/2" wide from 1x4 blanks. The blanks are already s4s from the mill, but not glue line quality. I use my first bottom head for the reference engraver and the two side heads to dimension to width, and would like to put a blade on my top head to split the blank in half.
For our lower grade panels, we just leave the staves 3" wide, but for the higher quality panels, they look so much better and end up having fewer defects if the staves are 1 1/2". Right now we split the 1x4 on the table saw with power feed, and then have to send each blank through the moulder to dimension it.
A Mereen Johnson 312 is what would do the trick for us, but that isn't in the budget for a while.
From contributor J:
I'm not sure if you have a 4 head or 5 head moulder. If you have a bottom head after your top, you can have your blades on the top, cut through (not all the way) and have the last bottom separate the strips with its light cut. If your top head is your last head, you can make a bed plate out of wood or anything, I guess, and run the blades down into that. Keep safety in your brain as you do this. And remember, a moulder is made as a standard machine. It gets shipped to everyone in the same shape. It's your imagination and craftsmanship that will allow it to do your own line of production. Drill and tap to add things, take things off and out of the way, etc. Just like standing in front of a shaper and wondering "how am I going to do this?" You will figure a way. I do like the idea of a 5 head with the blades on that last bottom. That's the last cut and no backwards force is beyond the ripping stage.
From Dave Rankin, forum technical advisor:
It is an OSHA regulation that anytime multiples are run through a moulder or planer, an anti-kickback device must be used.
You can build one fairly easily with an overhead rod and several pieces of 1/4" thick metal plate machined with an angle. These 1/4" plate pieces then need a hole drilled in each. Slide a plate onto the rod, then a flat washer, followed by another plate and washer. Continue this until the rod is filled. The rod can then be mounted to an upriser and connected to the frame of the machine or to the fence. You can also purchase anti-kickback units. OSHA's regulation also gives you the option of having independent rollers for each piece that is run. On a moulder, an anti-kickback is usually easier.
From contributor P:
If your lumber is thick enough, you can run your saw blades almost all the way through, leave about 1/32, then sand or plane that 32nd off. Hope that can solve your problem.
From the original questioner:
Thank you for your help. Are these kickback attachments available commercially, or are they a custom built item? Safety issues aside, can you get a nice quality cut with a saw blade on a moulder? Would it be anywhere near comparable to that of a gang rip saw?
From Dave Rankin, forum technical advisor:
Anti-kickbacks can be purchased. They are relatively expensive. Most smaller shops have a local machine shop make something. You can get a good finish with the proper saw blade.
1. The fences must be aligned correctly.
2. The spindles must be parallel to the tables of the machine.
3. The pressure shoe on the top spindle must be parallel to the tables and in good working order.
4. The work piece must be in total control at all times.
5. I recommend the use of a special type of saw blade, a groover type. Specified for the job, fpm, type of material, etc.
6. Use an anti-kickback.
From contributor J:
You will still have saw marks on the edge. There are many places to buy quality blades. Some are better than others. I would bet the little saw blades on the moulder would give a much better finish cut than a gang rip.
From the original questioner:
I wasn't sure, but I thought that since the blade is a much smaller diameter, the cut would be a little better since there is less chance of deflection. I was also considering using a stiffening plate on either side of the blade.
Dave, should the anti-kickback be mounted before the blade or after the blade? On my moulder it would be relatively simple to mount kickback fingers on the infeed side of the top head since there are already pre-tapped holes there.
Thanks for all your help. I look forward to trying this out.
From contributor R:
Every time I have mounted these on a moulder, it has been installed on the infeed table before the first bottom head. That way, the operator is protected at the infeed station. If you mount it someplace else, you have to be concerned about the feedbeam and rollers. There is limited room on your moulder.
From contributor R:
Just a few more ideas for you. Most quality anti-kickback devices made for a moulder have an arm to lift up the fingers of the device. This is used if you have to move the feed system in reverse after the machine has come to a stop. If you don't have this and you move the feed system backwards while stopped, you will do damage to your machine and throw precise settings off, such as infeed tables and fences.
