Hello,I’m new,oldish,retired and live in Spain. Please forgive any newboy mistakes but I would like to know if anyone knows of any uses to which I can put my still-sharp broken 1/4in and 3/8in bandsaw blades. I have only a very modest Draper saw with 36.1/4in blades but I seem to break them often!
I keep “hanging my nose” over the article on the walking beam saw (FW Making and Modifying Machines) and wondering whether some form of beam saw, like a sort of scroll saw, would be feasible.Any help would be appreciated.
Replies
Hi Ray and welcome to the board. It's perfectly OK to ask beginner type questions. There are probably others out there who are afraid of asking the same questions. Now... back to your blade problem. I am assuming that you have the bandsaw properly adjusted and that you are not forcing the blade to make a tighter radius cut than it was designed to make. Are you over-tensioning the blade? This will sometimes cause a poor weld to snap. If the blade is breaking at the weld, it means it is time to find a different brand of blades. Most bandsaw blades can be 1 to 1.5 inches shorter than specified and still fit onto the saw. Can you find someone who can re-weld the blade? Shops that sharpen blades usually have the equipment to do this simple repair. Is there a woodworking shop in your 'area'? Ask them if they can help you. Let us know your results.
SawdustSteve Long Island, NY
Many thanks for reply and your welcome. Am "on the case" following your points and will report progress - or lack of same!
Ray,
Welcome to the Knots Forum. Bien Venido!
I use an INCA 710 (3 wheels) so my experience is limited to that particular band saw. However, the principles of operation are very similar save for the idiosyncrasies of each brand and model. And, operator, it must be added.
My blades are 104 inches in length so they are much longer than yours but I have only broken one in all the time that I have owned it - 9 years or so. I believe that the cause of that was a small piece of wood which fell through sloppy insert and ended up between the blade and the tire. This most probably stressed the blade at that point and weakened it. That problem no longer exists, but if you tilt your table to 45-degrees or so, this will damage your insert. It is best to either have two inserts: one for normal setup and another if tilting the table, or else just remove the insert if tilting the table. Otherwise you would have to have an insert to match the blade for every angle of tilt. Having said that, if you have an insert which allows small cut-offs to fall into the band saw itself this could be your problem. However, there are many other things which could be causing your breakage.
Your query was not overly informative with respect to how you set up and use your band saw. More information would be a big help such as how you determine blade tension, what brand of blades you use and so on.
As the first responder to your query suggested, you could be turning radius' which are too tight for the blade. Perhaps you are forcing the blade into dense wood causing heat which results in stress on the blade. In addition, because of the short length of your blades, they have little time to cool down which only amplifies the problem and could ultimately lead to premature failure.
Your blade guides could be out of alignment which also leads to stress. There are a multitude of ways to over-stress and break your blades. And in my opinion, because they are quite short, I would think that you would have to very conscious of your set-up and operation. Short blades cannot be as forgiving as longer blades which therefore makes proper set-up more crucial. I base that comment on nothing but my gut feeling and a few years behind my band saw.
Dirty tires cause blades to run off and become damaged. Pine is the worst in my experience. It sticks to everything. The list of probable causes is quite extensive.
Ray, give us a bit more information and perhaps we can focus our search and determine the solution.
By the way, I was born in Santa Fe, NM and my ancestors were from Espana. My Grandparents raised me and my Grandfather always spoke of the 'old country'.
Warm Regards,
Phillip (Felipe) Oak Park, IL
To all:
Broken bandsaw blades can be cut (with tin snips) into, say, 12" segments, which are then aligned side by side, with the teeth all facing the same way, but offset from adjacent ones (aligned with the adjacent gullet), and taped together at the ends only. In this manner, they make an excellent, if aggressive, rasp, and if they begin to clog, you can flex them to eject the accumulation. Someone can send that into FWW for hints .... might win a prize!
John
Dear Tailsorpins,
Many thanks for that reminder - I think I read it somewhere else but the author of that one suggested soldering the blade pieces. Your idea sounds much easier!
Ray
Dear PhillipB,
Many thanks for your comprehensive reply. My saw is a Draper 3-wheel type bought secondhand years ago but little used until I came to Spain 4.1/2 years ago. Looking at the last broken blade, it did break at the weld but have no reason to doubt supplier quality as my son in UK uses the same ones with no problems. Have cleaned up all the dust inside and from the tyres (renewed a year ago) and checked top thrust bearing which revolves OK. Bottom roller type bearing is a bit worn in centre but otherwise seems OK. Blade guides fitted are steel cylindrical about 4.5 - 5mm dia, will try to check alignment of guides and shim if necessary.
Will "follow through" all the other points you helpfully made and have another go. Thanks again,
¡Hasta luego!
Ray;
Had the same prob with two cutomized saws cutting billiard rail cheeks
(a straight cut but rubber and oak in the same plane)The problem turned out to be wheels of too small a diameter.A jet of air played on the return of the blade doubled life.They stiill don't last long enough to get dull,but the rig still does a two end cut at one pass and has dropped production time on this job by 90-95%.Not bad for a jury rig that cost less than2k.
' ... checked top thrust bearing which revolves OK. Bottom roller type bearing is a bit worn in centre but otherwise seems OK. '' ... have no reason to doubt supplier quality as my son in UK uses the same ones with no problems.'Ray,Those two statements sent up a 'red flag' for me. If you mean that the 'bottom roller type bearing' is the lower thrust bearing then that may be the problem. In addition, if your son uses a Draper as you do then we need to know how his guides are set up.First of all, I tried to research your 3-wheel Draper on the internet but all I came up with was the 2-wheel version. I was interested in seeing what type of blade guides were on your machine but found little of value. This is what I have surmised.My INCA uses roller bearings for both thrust and lateral control as may yours from what you mentioned. The band saw blade should NOT be anywhere near the center of the thrust bearings: it should be about 3-4 mm from the EDGE of the thrust bearing otherwise the bearing will remain static and that is NOT what you want. You want it to rotate with the blade (same direction) when contact is made. Very briefly, the thrust bearing should be about 2 mm away from the blade AFTER the blade has reached equilibrium on the wheels. I use the thickness of a dollar bill as a guide. If the thrust bearing is rotating while under no load (no wood being sliced) then either the blade and/or the thrust bearing(s) need to be re-adjusted.The apparent reason why your thrust bearing is showing wear in the center is because it cannot turn as it was designed to do. I am, of course, assuming that the mechanism (shaft in my case) which holds the thrust bearing will allow your to position the bearing to the edge of the blade. My thrust bearings are pressed onto a shaft which is not centered on the bearing: the shaft is eccentric which allows the bearing to move laterally (in an arc). I hope I am explaining this clearly enough. My thought in all of this is that it appears, from what you wrote, that if your BS blade is centered in the thrust bearing, then the bearing is not able to rotate properly. If this is the case, then what you have is a source of very high friction which could be causing your premature blade failure. Friction causes heat which produces stress and ... You already know that story.I must say, and forgive me if I seem to be beating a dead horse, but - if you are adding 'over-tightening a thin, short blade' to this equation, then this amplifies the problem as I see it. Lots of variables in this equation.This, my friend, is the best WAG that I can come up with from what I understand. WAG: 'Wild A** Guess'. Best I can do for the time being. Hope I made a little sense. Keep me posted. I would like to know about your guide set-up if you have tiempo.¡Hasta luego!
Phillip,
Thanks again. I'm still working on the case! In my "filing system" AKA (also known as the junk cupboard in the Study) I found a leaflet which I obtained after I bought the saw secondhand. It shows the upper guide assembly as is on my machine though the bottom guide assembly seems different. I'll try to fing a source of spares (think I have one "somewhere 'cos I remember buying 3 new tyres and a replacement top bearing about 2-3 years ago........
Re your comment "thrust bearing should be about 2 mm away from the blade" ...."dollar bill"... We don't use a lot of dollars here in España but my guess would be that you meant 0.2mm (or even 0.02?) Or perhaps That nice Mr Bush has had all your currency notes increased in thickness?
Will try to scan the relevant pages of the manual, (Model No is BS250 by the way) and attach. Your continued patience is appreciated!
Afternote - scanned OK but not clever enough to attach them will try to email them.
Ray
" Or perhaps That nice Mr Bush has had all your currency notes increased in thickness?"Ray,You're Right! That is in fact the case. And, as any American will attest to, this is good because our wallets are much fatter now. Ha, ha, ...On a more serious note, I think I know why your attachments did not work. If my memory serves me correctly, you first select 'Choose File' to select a file to attach. At this point you should see 'No file selected' to the right of this button. Now, after selecting your file, I believe that you select (click) the second button which is 'Upload' ( I hope ). Now, my mistake when I began this jouney, was to NOT wait long enough for this to happen. I would wait a minute or so, then select the 'Done' button which would cancel out the upload. So, if you have waited for the upload to do its thing, you will see the name of your file to the right of the 'Choose File' button. When you see this, then you can select the 'Done' button and you'll be good to go. Or you could also select another file to upload, wait for the upload to take place, and then, click the 'Done' button. Hitting 'Done' should take you back to your email message where you will see that you did, in fact, attach your file(s).It's odd to me that the upper and lower guide assemblies are different on your BS. Mine are exactly the same. Who knows ...¡Hasta luego!
Phillip
Ray,
I use mine for scrach stock blades. I grind the teeth off first then use small files to make the profile I wan't and scratch away. Narrow blades are especially nice for making beading stock.
J.P.
They do make silver soldering stuff to fix broken blades.. Just a thought
Not to expensive. Three wheel break blades faster en' two wheel. I think?
Thanks for that one Will, I'll check out the silver solder, though at first sight I wouldn't have thought it would stand the stress. Seems you're right about three wheelers!
Regards, Ray
Ray, Woodcraft sells the bandsaw repair kit
Very affordable. The fixture holds the ends
of the blade in the proper position for brazing.
It includes instructions , brazing rod and flux. You must use MAPP gas, as it burns hotter than propane (Not included)I believe you must use a 'Scarf' joint
rather than a 'Butt' joint.This joint shortens
the blade's length about 5/8" because
the scarfed ends overlap. To make the scarf , you have to grind away
each end to a flat taper, which when
silver soldered, does not make the joint
fatter than the blade. Practice on an old blade 'till you become
an expert
Then buy the blades in hundred foot lengths.
(From Starrett)Steinmetz.
Edited 2/12/2005 1:30 am ET by steinmetz
Steimetz,
Very clear, thankyou. Only one small point regarding "MAPP gas"; I presume that in England (native home) this would be butane, and here in Northwest Spain (adopted home) it would be butano.
Will enquire locally to see if such kits are available.
Regards, Ray
Ray,
Not quite. MAPP gas is made by combining liquefied petroleum gas with Methylacetylene-Propadiene and burns significantly hotter than propane or butane.
Formerly just 'Don' but not the 'Glassmaster Don' or the lower-case 'don'.
Don,
Grateful thanks - that explanation should ensure that I get the right stuff when I go to the ferretaria (Spanish for ironmongers!).
Incidentally other readers (clearly not someone as knowledgeable as you) might be interested in looking at one or two of the following sites if they are less-than-familiar with brazing techniques:-
http://www.laymar-crafts.co.uk/laymar_crafts-techniques.htm (Website where I found all the other references)
http://www.handyharmancanada.com/TheBrazingBook/contents.htm#Index (Detailed-materials used are from Handy & Harman Canada)
http://www.brazing.com/techguide/procedureMain.asp
http://www.geocities.com/steves_workshop/brazingnotes.htm (Simple treatment but I found this very useful - being something of a numbskull metalworkingwise)
http://www.phred.org/~josh/build/brazing.html Another more technical ref,useful tips re brazing with other metals eg brass)
Do I need to make some sort of forge area to retain heat whilst brazing? Any ideas?
Regards, Ray from Spain
Ray,
I've never brazed or welded anything with as little mass as a bandsaw blade so I can't give you a definitive answer, however, I believe the torch should be providing enough heat to a small enough area of little mass that other means of heat retention would be unnecessary.
Formerly just 'Don' but not the 'Glassmaster Don' or the lower-case 'don'.
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