"How" to adjust guides on 20" Bandsaw at NC State Craft Center Workshop

[PhilCK]

The NC State Craft Center Workshop has, in addition to a 24"(?) spiral head planer, drum sander and 12" spiral head jointer, a Rockwell 20" bandsaw with a 3 hook tooth per inch blade and ball bearing guides (an upgrade from the original steel guides). The problems is that there is a significant gap between the guide bearings both above and below the table so that when you attempt to resaw, the blade wobbles and resawing wide pieces is almost impossible (also blade needs to track the gullets on the crown of the wheel and the bearing behind the blade needs to be adjusted for the correct blade position- see Resaw thread).

I am a non-NCSU person and paid the fees to use the workshop to be able to use the commercial grade machines that are beyond by basement workshop capability, especially the 20" for resawing white oak for panels for cabinets I am making.

The what to do is not an issue- I have a copy of the original manual for the 70's era saw and have read many articles, watched videos on setting up a bandsaw and have set up my 14" Rockwell at home. But how do I convince the people in charge at the shop to let me adjust the saw correctly? When I was looking at the saw and figuring out how to make adjustments, one the people in charge said that the setup was not a problem (they advocate resawing using a 1/8" multiple purpose table saw cut on both sides and them use the bandsaw to cut out the remaining middle- he even said the kerf of the bandsaw blade was not much thinner than that of the table saw blade) and "that is the way it is". He did not seem to be concerned about the slop in the setup and seemed to think adjusting the blade guides would harm the blade. I came in a few days later and while bringing up the bandsaw issue with another person, was told the bearings had been adjusted. The top bearings had been slightly moved together but the bottom guides, tracking and rear guides seemed unchanged. There was still way too much slop for resawing.

How/who do I approach to get the saw set up correctly? Given the structure of the saw and the apparently good blade on the saw, it should be a resaw beast (certainly compared to the 14" saw at home). Does anyone here know someone who works at the Craft Center that would be open to speaking to me about setting up the bandsaw correctly? I am worried about coming off as some arrogant know-it-all who will ignored or worse at the workshop.

- Phil

 

[ehpoole]

I can not provide any instructions for your blade guides as I do not know exactly which of the many possible guide styles your saw is equipped with. However, riding a blade with the gullets on the crown is only a concern when using bandsaws with a heavy crown, which is almost exclusively limited to the 14" and smaller bandsaws as larger bandsaws typically have flat to very lightly crowned wheels. It is very rare to see a larger bandsaw with heavily crowned wheels because the heavy crown exists to improve the tracking of blades smaller than 1/4", which are not ordinarily used on larger bandsaws, plus a heavy crown reduces the contact area on larger blades which is not especially desirable when using the wider blades typically used in heavy resawing (such as your 3-TPI blade).

If your blade wobbles a lot you may also not be adequately tensioning your blade as that is more typical of an under tensioned blade, as are effects like barrel cutting, etc. If you pluck the tensioned blade you should get a very low but crisp musical tone from the blade (if the room is quiet enough), any muddieness to the tone and it is definitely under tensioned. If you press on the blade sidewise after tensioning then deflection under modest sideways pressure may be around 1/4" to 3/8" or so over the full vertical span. When sawing boards that do not need the bandsaw's full resaw height the upper blade guide/guard should be lowered to between 1/4" to 1/2" above the highest point of the workpiece you are sawing, which will further limit deflection and help protect the operator from accidental contact with the exposed portion of the blade (but still remember to be careful come the end of the cut when the blade exits the workpiece). For this reason the blade guides should be configured after lowering the blade guard into position (particularly the upper guides).

But every guide system has a means to adjust the three guide bearings or surfaces both above and below the table. Some are toolless, which are very convenient, but many will require a screwdriver or Allen wrench to adjust. Many simply work on the principle of loosening a locking bolt or setscrew and then sliding the bearings into the proper position before locking them back down again. The rear bearing should just barely get occasionally grazed by the blade in normal operation so is adjusted after you have the blade tracking how you like and the two side bearings should have a small gap of a few mils (thousandths of an inch) to each side of the blade so that they only contact the blade when it is actually deflecting. This gap is also critical to ensure that the weld joint dos not get hung up on the guides, which would be very violent and likely break the blade, so you never want to snug up the side bearings to your blade. Many will suggest that beginners use a simple dollar bill folded in half around the blade and use the paper thickness as your gauge for all three guide bearings, and that is fine for starters but after awhile setting up that gap should become second nature and you will need to aids.

I am not sure why one would suggest a double-sided cut at the tablesaw over a straightforward bandsaw cut as that is usually a cut that is done out of desperation by those whom lack a bandsaw to begin with. But if your bandsaw is using a typical 1"x3tpi resaw blade then they are likely to be correct about the kerf width, especially if the tablesaw really has the more common narrow kerf blades installed in it as the kerf for such a bandsaw blade is typically going to be somewhere around 3/32", which can be similar to a tablesaw.

Still, they need to inspect their bandsaw and set it up properly for you. It may very well be that whomever is supervising us not terribly familiar with bandsaws and they were never properly instructed on bandsaw setup as the bandsaw is not the most common tool for the average home DIYer or even a typical handyman to have owned and operated to any significant extent. They may even have been mentored in the wrong ways for much the same reason as it is really only serious woodworkers and metalworkers who are likely to have much time on the bandsaw.

 

[Berta]

Isn't removing a blade guard from the table saw for any reason against OSHA standards? I refuse to remove blade guards (except the scrollsaw). I think that would be my first thought, not calling OSHA, but finding out.

 

[PhilCK]

". . . However, riding a blade with the gullets on the crown is only a concern when using bandsaws with a heavy crown, which is almost exclusively limited to the 14" and smaller bandsaws as larger bandsaws typically have flat to very lightly crowned wheels. ..."

Blade is 1/2 or 5/8" blade. Wheels are crowned but maybe not heavily

"If your blade wobbles a lot you may also not be adequately tensioning your blade as that is more typical of an under tensioned blade,..."

Also they don't want you to adjust blade tension

"But every guide system has a means to adjust the three guide bearings or surfaces both above and below the table. Some are toolless, which are very convenient, but many will require a screwdriver or Allen wrench to adjust. . . . small gap of a few mils (thousandths of an inch) to each side of the blade so that they only contact the blade when it is actually deflecting. This gap is also critical to ensure that the weld joint dos not get hung up on the guides, which would be very violent and likely break the blade, so you never want to snug up the side bearings to your blade. Many will suggest that beginners use a simple dollar bill folded in half around the blade. . ."

Guides are on eccentric cams and are locked with allen screws. Gap is at least 1/8" up top currently, more down below. Back bearing presses on blade even without wood contacting the blade.

"I am not sure why one would suggest a double-sided cut at the tablesaw over a straightforward bandsaw cut as that is usually a cut that is done out of desperation by those whom lack a bandsaw to begin with. But if your bandsaw is using a typical 1"x3tpi resaw blade then they are likely to be correct about the kerf width, especially if the tablesaw really has the more common narrow kerf blades installed in it as the kerf for such a bandsaw blade is typically going to be somewhere around 3/32","

That is the way they do it. Shop uses std combo blade, 50 tooth- 4 ATB, one raker in 10 sets, 1/8" kerf. From the look of the bandsaw blade (little set), unlikely kerf is 3/32".

"Still, they need to inspect their bandsaw and set it up properly for you. It may very well be that whomever is supervising us not terribly familiar with bandsaws and they were never properly instructed on bandsaw setup as the bandsaw is not the most common tool for the average home DIYer or even a typical handyman to have owned and operated to any significant extent. They may even have been mentored in the wrong ways for much the same reason as it is really only serious woodworkers and metalworkers who are likely to have much time on the bandsaw."

So that gets back to the question of how do I get them to properly set it up?

- Phil

 

[PhilCK]

Isn't removing a blade guard from the table saw for any reason against OSHA standards? I refuse to remove blade guards (except the scrollsaw). I think that would be my first thought, not calling OSHA, but finding out.

Blade guide on table saw is off most times. Not sure if OSHA applies for a non-commercial shop.

 

[jazzflute]

1. Set a small fire in a trash can.
2. Adjust guides and tension.
3. Resaw.

K

 

[nn4jw]

The basic truth is that when you rent time on someone else's equipment it's their rules, right or wrong. If they disagree with you on something like this there's really not much you can do to force the issue.

 

[Dan Bowman]

Ask for George Thomas

 

[ehpoole]

The basic truth is that when you rent time on someone else's equipment it's their rules, right or wrong. If they disagree with you on something like this there's really not much you can do to force the issue.

For better or worse the above is too true. However, as the OP has already concluded the bandsaw is not remotely setup properly for safe and proper use. If they are not prepared to setup the bandsaw for safe and proper use by their members then they really ought to simply remove it from the available equipment "list" as they are endangering their members rather than protecting them and, worse in she respects, teaching very unsafe habits to those whom may know no better which should be contrary to their charter.

The best thing at this point would be to try and approach whomever is in charge of the workshop at the highest level, perhaps by first speaking to whichever dean is in charge of the particular college that the workshop is a part of and discuss both your concerns and ask whom would be the best person in charge to speak with and then setup a meeting with that person. Take a list of concerns and mistakes you have noticed, particularly as applies to safe and appropriate use of equipment and then discuss those matters with that individual in charge. Do not use it as a list of items to attack the college on nor approach the matter with any hostility, just be professional in outlining your concerns and desire to improve upon the safety and habits in the workshop and emphasize your passion for the hobby of woodworking and how much you appreciate that the college cares enough about their students and alumni to maintain a well equipped woodworking shop for their students, faculty, and alumni to use.

Before you make that visit find a fellow woodworker with a friendly attitude and passion for the hobby and whom knows the proper use, setup, and safety habits for each of the pieces of equipment you have found deficiencies in whom lives within a reasonable distance and would be willing to hold a free lesson in their workshop to demonstrate and explain the proper setup and safety habits for each piece of equipment in question. This needs to be a very knowledgable individual whom is a real expert in proper and safe setup and use and whom is happy to share that knowledge freely and in an upbeat manner. They should focus less on pointing out what is wrong and more so on how to do things right, in other words, avoid telling them they do not know what they are doing, which puts them on the defensive, but rather show them how to do things right, which is educational and nonthreatening. This expert may even be a team of two experts working together to demonstrate both proper use and safety if need be.

Then ask the individual in charge if they would allow that expert to hold a mandatory meeting for all shop staff and, optionally, any interested shop users in the workshop some evening or weekend to share their knowledge and passion for woodworking. This way everyone who needs to relearn how to safely setup and use the equipment has the opportunity to do so in a positive environment.

Odds are decent that you could find someone from our group to give such a presentation, but if not you may also approach other woodworking groups to do the same. But realize that your attitude and demeanor on first impression will greatly influence your chances of success so have a positive and friendly attitude and present yourself not necessarily as an expert (unless you really are) but as a concerned party and user whom nonetheless knows enough to recognize a number of deficiencies that affect both shop safety and establish bad shop habits amongst the users since many will be learning such habits based upon that which the learn while in the shop unless they are already highly experienced.

I'm sorry that this has been your experience as that is unfortunate both for yourself and for those whom use the workshop. You basically have two options at this point, one, as outlined above, is to take the necessary initiative to educate them in an appropriate manner, the second is to throw up your hands and befriend a fellow NCWW member whom has the shop equipment you need access to and is willing to allow you the use of their equipment whenever you need for the cost of good conversation and, perhaps, a cold drink of their choosing. Fortunately, we have many members whom are happy to help one another out, so you really do have options. I most hope that you may consider going the route of trying to educate the college as that is what college is meant for, but I will certainly understand if you throw up your hands as you do need patience to work your way through the usual bureaucracy and fiefdoms.

PS -- Ignoring the other deficiencies already outlined, if you are making the sort of heavy resaw cuts that one typically turns to a 20" bandsaw for then a 1/2"x3-TPI blade is really much narrower than ideal for heavy cuts as it is not only less stiff but the gullets are much shallower than ideal for thick resawing, making proper tensioning, guide bearing and guard setup, and slow feed rates that much more critical. For most resawing operations, I typically use a 1"x3-TPI blade with deep and aggressive gullets. The wider blades are considerably stiffer than their narrower blades as they are not only wider but the band itself is much thicker (typically 0.035" to 0.042"). These wider blades will have a correspondingly wider kerf (around 3/32"), but their added stiffness and resistance to wandering and barreling are well suited to resawing as they behave very well and track very nicely without trying to follow the grain. Smaller blades are typically best suited to cutting curves or resawing much thinner materials. This, of course, assumes that the bandsaw's specs are appropriate for heavy resawing and that this is not an underpowered bandsaw, but most large bandsaws are reasonably specced for such use. Otherwise, they may be using undersized blades to compensate for too little horsepower (ideally such a saw should have at least a 2HP motor, but blade speed, in feet per minute, also influences the horse power requirements with lower speeds needing less and faster speeds requiring more horse power to perform adequately).

I wish you all the best!

 

[PhilCK]

Ask for George Thomas

Who is Mr. Thomas? One of the supervisors at the Craft center? One of the instructors for the woodshop classes? A minder at the Shop?

Is he affiliated with NC Woodworders?

Thanks.

- Phil

 

[crbuildersinc]

The NC State Craft Center Workshop has, in addition to a 24"(?) spiral head planer, drum sander and 12" spiral head jointer, a Rockwell 20" bandsaw with a 3 hook tooth per inch blade and ball bearing guides (an upgrade from the original steel guides). The problems is that there is a significant gap between the guide bearings both above and below the table so that when you attempt to resaw, the blade wobbles and resawing wide pieces is almost impossible (also blade needs to track the gullets on the crown of the wheel and the bearing behind the blade needs to be adjusted for the correct blade position- see Resaw thread).

I am a non-NCSU person and paid the fees to use the workshop to be able to use the commercial grade machines that are beyond by basement workshop capability, especially the 20" for resawing white oak for panels for cabinets I am making.

The what to do is not an issue- I have a copy of the original manual for the 70's era saw and have read many articles, watched videos on setting up a bandsaw and have set up my 14" Rockwell at home. But how do I convince the people in charge at the shop to let me adjust the saw correctly? When I was looking at the saw and figuring out how to make adjustments, one the people in charge said that the setup was not a problem (they advocate resawing using a 1/8" multiple purpose table saw cut on both sides and them use the bandsaw to cut out the remaining middle- he even said the kerf of the bandsaw blade was not much thinner than that of the table saw blade) and "that is the way it is". He did not seem to be concerned about the slop in the setup and seemed to think adjusting the blade guides would harm the blade. I came in a few days later and while bringing up the bandsaw issue with another person, was told the bearings had been adjusted. The top bearings had been slightly moved together but the bottom guides, tracking and rear guides seemed unchanged. There was still way too much slop for resawing.

How/who do I approach to get the saw set up correctly? Given the structure of the saw and the apparently good blade on the saw, it should be a resaw beast (certainly compared to the 14" saw at home). Does anyone here know someone who works at the Craft Center that would be open to speaking to me about setting up the bandsaw correctly? I am worried about coming off as some arrogant know-it-all who will ignored or worse at the workshop.

- Phil

Hey Phil,

Cant help you with the staff but I have attached a pdf for my saw. Its an older 20" Powermatic hope it helps.

View attachment Model 81 Bandsaw Manual.pdf

Chris

 

[PhilCK]

Thanks. Was able to locate a pdf of the manual for the Rockwell saw but the shop saw has upgraded roller blade bearings.

- Phil Klein

 

[PhilCK]

Ethan-

Thanks for the long, considered reply. I am in agreement with you on this about getting an expert to come in and show them how it is done (I am a competent intermediate who knows how to read manuals and set-up articles) but the problem is finding the expert who is willing to come in and who will be recognized as an expert by the workshop people. I am more than open to recommendations.

A few notes on the bandsaw and set-up. It is a 1970's (I assume) Rockwell BS-3A, No. 28-340 20" bandsaw. Don't know the HP but I am sure it is at least 1.5HP. Blade is 1/2" 3 tpi. While they have several 14" bandsaws and a 3 wheel Inca bandsaw with an 18" or so beam clearance, the 20" is clearly not just set up for resawing though from my experience that is the only thing it is used for (hard to cut much of a curve with a 1/2" blade). Properly setting up the blade is one thing; doubt I can get then to purchase a 1" blade to set up the bandsaw as a dedicated resaw machine.

With current adjustments, would estimate gap between upper guides is 3/32", lower guides at almost 1/4". Don't think this is a safety issue but as I stated in my first post, the blade does not track and using a curved fence to position the wood being resawed is a challenge beyond my skills as a woodworker.

So if anyone wants to volunteer to present a united front, please let me know.

- Phil

 

[danmart77]

Phil I might have some useful information on the saw. I have the same one essentially and I have done a bunch of resaw work over the last few decades.

1. A half inch or 5/8 blade is not going to do the trick very long in 10" or wider boards.
2. As others mentioned blade tension is important but I don't fall in the camp of tighter is better. I have good results with just tight.

3. I don't even have bearings on the sides of the blade on top or bottom. I have a bearing to keep the blade from moving back under load.

A few weeks back I cut 24 pieces of walnut veneer 1/16-3/32 that were 10" wide x 8' long.

I used a bimetal blade not carbide. The blade is 1" wide 3tpi. No drift.

If you want to come over to Durham some time, it might make more sense to get your hands dusty. If I was cutting veneer 13" wide or better, I would go and see Scott Smith. His machine is just in a league of its own. If you are down in the lower widths I would strong suggest a wide blade. The 20" wheel can handle thicker and wider blades than you might think.

Dan

The blade in the photo is a carbide

​

 

[PhilCK]

Dan-

Veneers look very good.

You have the steel blocks as guides vs. the roller bearings to guide the blade. These are what I have for my old Rockwell 14" bandsaw.

Bought some qtr sawn white oak from Scott Smith a few weeks ago and had him resaw some 12" boards but was planning on doing the narrower boards myself.

Don't think it is a option to get another blade as it is not my saw.

- Phil

 

[Dan Bowman]

Phil - George Thomas is the director of the NCSU Craft Center, and also an incredibly talented artist. If they still have their show of employee's work up, check out George's wood carvings.