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Our 75 HP Gang RIP Saw Broke Down

6745 Views 13 Replies 12 Participants Last post by  KentS
Our 75 HP gang rip saw broke down yesterday, and we had to pull the pressure roll assembly off to repair it. I thought you lumberjocks might get a kick out of these photos. My brother and I did a little calculating and we've had this saw for 10 years and figure that we have fed thru this saw about 100 million linear feet of boards. The operator forgot to tighten the internal arbor nut and when he turned on the saw the inertia of the saw caused the nut to tighten up essentially making it nearly impossible to get off. We rarely have to remove the pressure feed roll assembly. It is a major job. We did this in order to be able to have room to handle a 3 ft long pipe wrench. The wrench would not initially budge the nut so we had to heat the nut up with a torch. It finally broke loose.

This is the side view of the saw.

This is the view of the saw after we removed the pressure roll assembly. The large hex nut on the end is the nut that would not come off.

This is pressure roll assembly that had to be removed in order to get it out of the way.

This is the arbor sleeve containing the saw blades. Unfortunately the spanner nut on the end of it would not budge either. There is a plastic spacer that melted from the heat and it melted enough to make it nearly impossible to remove it. We had to weld up a special tool that would lock into the keyways on the bottom of this arbor and then we layed it on to 2 sawhorses and used the special tool on one end and the 3 ft pipe wrench on the spanner nut. When even pounded on by a 4lb hammer the wrench would not budge. The only thing left to do was take it to a machine shop. They put the whole arbor sleeve saw blades and all into one of their lathes and turned the spacer nut down to the threads. Our lathe was not big enough to do this. Total cost of the repair was two days down time on the saw and probably $500 or so for the nuts plus the machine shop time. Fortunately most of my days here at the plant go a little better. We got it back together on the first day but the other day is waiting on the nuts to arrive. It should be going again around 11:00 AM on Friday.
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I gotta' get me one of those …. ;-)

Sorry for the meltdown. Glad (it sounds like) you're back up and running, though !
Cool! I had no idea such devices existed, and now I want one. Even though that'd rip pretty much all the cabinet door frames I could possibly ever see myself wanting for the rest of my life in about 45 minutes.
Could have been a hellufuwreck. Glad nothing else got damaged in the process glad to see you are back up and running…...................................Schloemoe
Big machines, big headaches! Glad you found a solution to this one.
Hope the operator that forgot to tighten the arbor assembly was helping you take it apart! :)
Hey, stuff happens; always has always will. I love machines but they will always be a pain in the butt every now and then.
Sorry about your troubles. Thanks for posting the pics though, very interesting.

This machine scares the crap out me! I guess I shouldn't get so nervous setting up my 8" dado stack.
Helluva Machine 100 million lineal feet Is no Joke, That's a lot of lumber.
How often do you have to change blades?
Great post Thank you for posting :)
Man, think of the dado that could cut.

waow that is one serius M…...F…... of a maschine
using a forklift to take this apart how cool can it bee

sorry for your downtime, glad no one was haert
thank´s for leting us see some haevy stoff from the production line, very interressting

Thanks, fellas. It rips whatever you want. The arbor is 24 inches long so you can put saw blades along it wherever you want. They are spaced out with a combination of spacers. Of course it is rare to send a board through it that is 24 inches wide. Generally rough hardwood lumber comes in random width and so some might be less tan 6in some maybe 7-8 inches some 9-12, whatever. Most probably average around 7 or 8 inches. So what you do is set up a series of patterns along the 24 inch arbor. At one spot you might have 2 2inch and 1 1in, and then maybe 2 2-1/2 inch and a 3 inch - whatever you want. You have some laser beams that make a red line on the table of the rip saw - one laser for each saw - these show the operator where each saw blade is. So the operator can send the board through the saw at the right pace depending on it's width so that you minimize waste. The idea is for your board to come out yielding a small thin piece of waste on either edge.

So far as the 100 million feet - That is the number of linear feet of hardwood boards that we estimate has been fed into the saw since we have had the saw. Since the boards would generally average around 7-8 inches wide the outfeed would be somewhat less that 100 million. And of course you have the waste. 75% has probably been poplar and the rest oak, cherry, mahogany, walnut, sapele, ash etc. We do run some pine, white pine, some ceadar, some cypress, a lot of basswood, ect. Most of the lumber come from places like North Caralina, the Virginias, Pennsylvania etc.
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If you need a spare, I have one for sale--Cheap! It's old, but has been rebuilt.
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