Question
Help! I'm frustrated. I swallowed the marketing hype and bought the WM 718 to make moldings as a side business. I love the sander and the planer, but I bought it for the molder. I've bought about $1000 worth of WM knives. I keep my machine covered, keep the shop clean, wash behind my ears... how come I get crummy moldings?
I just bought a new WM53 set - over $200 - and you'd think just taking it out of the packaging you should cut yourself. Not so. I spent 4 hours trying to run 120' of hard maple - 8 passes to get the face profile down to something usable. Then I did some white pine and it blew up - lifted the grain along the whole length.
Okay, so I've read the forums about the extension tables (nix them) and the sexy plastic bedboard (nix that too) and dangling the motor on a piano hinge to put extra pressure on the newly replaced link-type belt. Are you guys serious? Will this do the trick? What do I do for a bedboard instead? Do I forget all about extension tables entirely? And should I go up to a 4" drive pulley to rev up the RPM's? If these mods are so critical (one guy said 1/5000" of flex will cause wobble), why hasn't WM fixed this?
All sarcasm aside, I'm really frustrated. I'd love to be able to generate stain-grade moldings - I'm building up a lot of demand already - but I can't even imagine plowing through a 3 1/2" crown in one pass! That would be nirvana. Any advice?
Forum Responses
(Solid Wood Machining Forum)
From David Rankin, forum technical advisor:
It sounds to me that you have been supplied a relatively low grade of steel. A freshly sharpened set of knives should cut without a problem.
But what about the chatter problem? Other threads have suggested that the WM bedboard flops on the cast iron top, the pressure rollers aren't strong enough to hold things down, and the head vibrates because there is not enough tension on the drive belt. Suggested remedies include throwing out the extension beds, replacing the WM bedboard with one that is screwed to the cast iron bed, replacing the drive belt with a V-link type, using a 4" drive pulley instead of the standard 3" and lastly, dangling the motor on a piano hinge to get maximum tension on the belt. Any comments?
Let's start with the wood. What is the MC of your blanks? My experience is that blanks with a MC higher than 9% don't run nearly as well as drier blanks. I shoot for 6 or 7%. Also, make sure to run your blanks with the grain and not against it.
I did replace my belts with the Power Twist link type. But this is standard practice in my shop with most belt driven machines. My original belts never flopped around. But this way I can keep one spare belt that will fit 5 or 6 different machines. And yes, they do absorb vibration vs. transmitting it.
It doesn't matter if you use the poly bedboard from WM or make one yourself out of melamine. If your infeed and outfeed don't line up perfectly flat with the cast iron bed, you are going to have more problems. After having early initial problems with chatter, I went back and checked how flat and level my infeed/outfeed was. In my rush to assemble the machine and start using it, I didn't level properly. Adjusting the bed to be dead flat resolved nearly 80% of my chatter problems. Yes, check your poly bed board and make sure it doesn't crown in the middle. I have several bedboards that I've made from melamine with fixed guide rails to run stock patterns on. I see no difference in molding quality between the poly board and the ones that I make.
Sharp knives are key. But so is the MC of the blanks, grain orientation, and feed rate. I run single knives and do all of my molding with a single pass. I usually feed the stock just fast enough to not get burn marks. Clearing chips from the machine is also important. If you're using a 2hp DC with a 4" hose, you are probably noticing a lot of chips coming out with your molding. I went with a dedicated DC connected with no more than 10' of 6" hose. The difference in chip removal between a 4" and 6" hose is remarkable. We can plane 500bf of 4/4 red oak at the fastest feed rate removing 1/8". You could put all the chips that don't get sucked up into a coffee can. Chips that build up on your bedboard or don't get sucked away and land under the cutter can cause real problems with your molding. Search the WOODWEB Knowledge Base - there are several discussions about this.
You may also want to make your own guides. I make my blanks 1/8 of an inch wider than the finished profile. I make my guides by first running 1/2 inch hard maple through the jointer to get perfectly flat and square stock. I will set my jointer to a 1/16 cut and feed the guide stock on edge about half the distance. This way the guides on the outfeed side of the machine are 1/8 narrower than the infeed. The molding is held just as firmly in the guides on the outfeed as they are on the infeed.
We run molding through our WM every single week. Most of it stain grade, some paint. It's rare that we ever encounter chatter or blow out. I would hate to see you make modifications that might not solve your problems. Experiment with the machine a little more. I know the difference for us is night and day from when we first began with it. For us, it really boiled down to having properly prepared blanks, dead flat table, sharp knives, and really good chip removal.
The pretty bedboard does not lay flat on the metal bed. It does not cause chatter, but it does cause the machine to thump or bang around and tear out a chunk of wood here and there. This condition will be random, but the chatter will be constant. The bedboard will bounce into the knife – therefore, it tears out a big chunk. A piece of melamine or 3/4 flakeboard with a good coat of pastewax works great. Take the wings off. You don't need them. Either bolt the bedboard to the metal bed, or just c-clamp them on. It doesn't take much at all to hold them. This will solve tearout problems, but not chatter. I have the RBI corrugated heads, also the WM corrugated head. The RBI goes on the WM accessory shaft, the WM head is a 2 slot corrugated planer head. They will not solve the chatter problem. Your single knives and counterbalances will work fine.
The 718 does have a dust collection problem. You need all the CFM you can get to the thing. Wood chips get trapped behind the knives and cause imbalance; but this is a minor problem and isn't causing the excessive chatter you are getting. Moisture content of wood is very important, but has nothing to do with chatter. Wet wood will mould rough and have splinters, maybe even have tearout, but not chatter.
I worked as a quality control officer for a molding operation that ran an average of 80,000 lf of stain grade oak and poplar moldings daily. We had good quality machines like Ferrari resaws, Johnson gang rips, and Weinig molders. There was always an issue somewhere that had to be corrected. The WM is a very simple machine in comparison. Even with fine tuning and modifications, you can expect small issues to arise occasionally.
I know what good stain grade moldings look like and that short runs of high quality moldings can be achieved on a WM machine if you take the time to fine tune every step, from stock preparation to finished product. There is not a single fix that will be a cure-all for all your molding problems. The more you run your machine, the better you will be at identifying where your problems exist and how to resolve them. Don't give up. You just have to figure out what works on your machine and then continue to fine tune even more.
Chances are that there are as many reasons for the questioner's problems as there are solutions. I agree that it takes time and patience to get things right. There are so many things that can go wrong with even the simplest setup. I know of several people who get really good molding from their WM with a stock machine. But it didn't happen overnight. At the same time, it isn't uncommon to see an almost new WM on eBay. Contributor T, I like your guide rail setup… but I'm thinking it will only work if you make a single pass.
I was not comparing my WM to a Weinig. That would be an insult to anyone who owned a Weinig. But there are two issues here. The first one is chatter. Just this morning we ran 200 lf of cherry cove, and 220lf of red oak 3.25 crown. Our molding didn't have chatter. How is this possible without making your modifications? Why should I make the mods and void my warranty if I don't have to? If my machine isn't broke, why fix it?
Second, chatter is only one problem you have to consider. Look at the original post. He is encountering problems other than chatter. The bulk of my advice was not about correcting chatter, but more towards total molding quality. Whether it's properly preparing blanks to the correct width and thickness, insuring correct mc, proper machine setup (feed speed, hold down, guide system, number and type of knives, chip removal etc.), and making sure the crown you make this week is the same thickness and dimension as the same crown you made last month... the generic process is the same with a WM as it a commercial machine. You can have molding that is chatter free and still look like shit. Is it straight, flat, no twist, grain pull, a perfect match to profile, etc.? The questioner is looking to make this a side business. These are just some of the issues he will face and have to address if he wants to be profitable. I wish him the best. This is why I have encouraged him to look at the overall picture and address each aspect individually. Only after looking at every potential cause to his problems will he truly understand the total process and how to correct it. For him, maybe it is making your modifications. It is entirely plausible that he could make these mods you suggest and cure most of his problems, or none at all.
Contributor G, I believe you when you say these mods made a huge difference for you. But believe me when I tell you I make molding that satisfies some of the most discriminating customers you can imagine. One does not automatically have to (at least I didn't) adopt your modifications to this machine to net great results. The proof of this is sitting in my shop, on my customer's walls, and on the cabinets and furniture we make.
Contributor T, your WM can make better quality moulding than a Weinig if you make about $10 worth of mods to it. If not, I guess just keep on tweaking.
You should be able to make nice log siding this way. You must understand that the feed rate will only figure at about 7 or 8 feet per minute. It's going to take a long time to do a whole house or houses. If you change the motor pulley and speed the thing up a little, you may be able to run 14 to 16 FPM. I would check with WM before I made this mod. You will also have to run the siding twice. One pass for the back, change knives, and then one pass to profile the front. There are multiple head machines on the market that will do this job in one pass and at a much higher feed rate.
You might want to check out the Logosol. I don't like their sawmills, but the moulder looks pretty good. It all revolves around how much you value your time. How much siding you need to produce a day to make a good living. Don't think of it as a hobby. Reality sets in real quick. You're also going to have a lot of sawdust to get rid of. A lot more than what you might think. You know, isn't the PH260 a Logosol? Been a long time since I looked at their stuff. I think the 260 is a real good flooring machine from what I remember.
I have made no mods to my WM 718 and I make beautiful chatter-free moldings. I use sharp knives. I also make bedboards for each of my profiles. All of the guides are in place and all I have to do is line up the cutter. No big deal. I clamp the bedboard to the extension tables and that's that. I love it. I almost bought the Shopfox clone of a Williams and Hussey, but a couple of things changed my mind. First, WM can plane 18", or 25" for that matter. Second, the Shopfox salesman took a phone call and walked away from me in the middle of the deal! I drove to KC that day and bought my WM. It paid for itself on its first job.
