Computerized Straight Line Rip Saws: Worth It?

A shop owner shopping for a straight-line rip saw asks about capabilities and quality. September 25, 2014

Question (WOODWEB Member) :
We currently have a Northtech TRS-300, which is essentially a fairly normal SLR with a second arbor and saw blade. The second arbor is manually adjustable via a handwheel from about 3/4" to just over 8" between the blades. There is also a fence, so that after the first pass you get two pieces rather than one and the fence can be set to a different width than the distance between the blades (we rarely, but occasionally, operate in this manner).

We are looking to replace it with an upgrade in the width capacity. We'd ideally like to be able to rip 13-1/8", as that is the maximum blank size for our moulder. We'd also like to be able to rip 12/4 material - the TRS-300 maxes out at 2-1/2" which won't do real world 10/4 in the rough. However, all I've been able to find so far are the new breed of "optimizing moving blade gang rips", such as the Raimann KM 310, Kentwood R340 M1 or the Mereen Johnson 312-DC/SR. These machines seem to me to be overkill in our application. Yes, I know you don't need to use the optimizing part of it, but still…

We do relatively short runs (typically 100 to 2,000 LF, sometimes up to 10,000) in a huge variety of widths. Further, we do several types of product, and we believe that overall it's more efficient to be able to use certain boards, or parts thereof for certain profiles versus a different profile. So I don't see ganging really working for the most part.

The one place I could see the computerized saw working is on our wide plank flooring, as we are essentially cutting each piece to the maximum size (in 1" increments). However, even there, since we pre-plane our flooring stock we currently just sort for width off the planer. I would foresee using one of these newer type saws with just two blades - one fixed and one moving.

Am I underestimating the usefulness of one of the above saws in our shop?
Secondly, assuming that a machine similar to the one we have now is a viable option, does anyone make one? Are there any other brands/models that you'd recommend?

Forum Responses
(Solid Wood Machining Forum)
From Contributor E:
I have just started looking at the shifting blade gang rips myself, and I'll share with you some of the things I have found out and hopefully it will help you determine if this is the right saw for you. I had an opportunity about a month ago to ask a couple of different users their experiences with their saws and they both shuddered when asked about ripping thick stock with their saws. They didn't feel they had the rigidity in the arbors.

Having said that, I have no idea on how well they have kept up with their maintenance and if the bushings already needed to be replaced. With the shifting blades the hubs that the blades move on have a bronze bushing that permits it to shift on a spinning arbor, permitting the bushing to wear rather than the hardened arbor. This is a regular maintenance item on these saws.

Now if you are ripping for glue ups or for moulder blanks of different sizes, those computerized infeed tables are the ticket. They measure the board and show you the best solution for what you're after, and if you like it the fences and blades will shift and the board is fed into the saw.

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From Contributor E:
A few more thoughts. After re-reading your post, you might be under estimating what the optimization software can do for you. If you're ripping a number of different widths and you know how much you're after of each width the software can suggest the best choices for the board and then keep track of the footage for you. Also by assigning values to certain widths it will go for those whenever given the opportunity, as well as letting you establish the waste factors you are willing to accept. It can take a lot of the human judgment out of the decisions being made with each board. As for one or two shifting blades, even though you may only need one 90% of the time, for the cost of the second blade, you'll kick yourself for not getting it when you had the opportunity. Last but not least, look at the maintenance costs for these saws. There is a big spread between the different brands in what it costs to have the chain re-built as well as the cost and frequency of the bushing replacement on the shifting blades.

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From the original questioner:
At this point I'm most inclined to go with a gang/multiple rip saw, with locking collars. I'm impressed with the Mereen-Johnson as their laser holder flips the lasers towards the saw blade for easy alignment, and then back to the infeed area for operation. Plus they're still made in the USA and about the same price as the Taiwanese Kentwood.

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From contributor M:
I ran a MJ 419 gang along with an SCMI and a slr saw. The orders where assigned a saw by the quantity, the MJ took longer to set up so it saw the big runs, the SCMI was a little quicker set up but smaller capacity, and the SLR for the 100-200' orders. We changed out the MJ with a Raimann, two moveable blades, and to be honest between that and the SLR we got it covered. I still have the SCMI for some reman work but rarely use it. There was a point when we ran orders in 4/4 red oak that where in the 60-70K lf range and the MJ cruised through it like butter plus you had 19" of arbor but we have not seen those types of orders in years. The Raimann made sense for our shop and the direction we headed.

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From Contributor W:
Just an FYI, we ended up getting a Raimann fixed arbor (QuickFix) saw. There were a few issues that had to be addressed when we first installed it, but probably a result of the fact that it was a demo, built in 2009. I think it sat somewhere for a while. The MJ looked like a great machine as well, and I could be persuaded to get either machine under the right circumstances. There were three main factors that led to my decision.

1. The Raimann was in stock and ready for delivery. Since we were trying to spend the money in 2012 that was important as the MJ was six weeks out.

2. The Raimann had a demo unit that they were very willing to deal on price.

3. While I'm sure MJ has good service, we have personal experience with that from Weinig.

I don't think any one of the above points would have caused me to make the Raimann choice, but the combination made the difference. We've only been using it for about a week but so far we are quite pleased. The only thing I am less than impressed with at this point is the laser mounting system - the way they adjust side-to-side is pretty sloppy, so the process to lock them down with any precision is a bit of a guessing game, and with six of them it can take a few minutes. That may improve with experience. Once locked down they hold fine.