Project 2 from Hooda. Category: 4) Custom welded Shop tools and improvements:CNC PLAS

[SeanMurphy265]

Those old band saw's are the best! I have worked at two shops who had WWII surplus band saw's and both ran like champs! I've had good luck with my HF 4x6 but since I've moved it will not cut square, if fell over when I unloaded it by myself....

[fdcmiami]

I'm not a pro fabricator. The original poster is continually making posts about this being his career. If one is going to buy tools for your livelihood, and is fixed on precision cutting, then a better saw is what should be bought.

you got that right. i read your post it was right on and i am a professional fabricator. i saw the photos of the cuts and welds, how sad. just did not want to arouse the ire of the politically correct moderator whose purpose seems to be protecting the feelings of sensitive posters. years agoi ran a fab shop for a co. that mfg'd computer based photo/lith equipment; each unit, a large framework, had several hundred feet of square and rectangular tubing to exacting dimensions. every single cut was made on a 12 in cold saw; dimensioning was precise. every weld was done with a miller mig welder.

i fabricated a table, 4x8 that was ground 3/4 plate; we drilled and tapped holes in it with a magnetic drill for bolting down fixtures.

these days i do most of my cutting with this ellis 1800; i can cut through a piece of 8 x8 x 1/4 wall tubing; for example, without any noticeable drift.

again, why is this person insisting on forcing his inability to tig weld on a first article for a customer. that's okay, the 'moderator of feelings' will come to his defense.

if you are a hobbyist that is one thing but if you are planning on being a player and you're presenting stuff like i'm seeing in those pictures, well get ready for some criticism.

thank god for paint, though i doubt even paint will help much.

[SeanMurphy265]

Guys I realize what you said is correct, but sometimes when you read something it may not come across the same as being face to face (loosing tone and facial expressions).

They don't want to have a WW mentality where people come along and bash other's work. I always welcome input, but some may take it the wrong way.

Hooda is a customer and no one likes to see their customers get bashed on a forum that's suppose to help fellow customers and prospective customers.

Constructive criticism is fine, sometime I have to read before I post something because it sounds harsh if I'm not careful. The lack of face to face contact can cause issues sometimes.

[geezer]

When it comes to tuning a bandsaw to cut straight you must check the swing angle of the arm relative to the bed, if it swings on an angle it will cut on an angle, next leave the support arms that have the guide wheels in one position, constantly adjusting the cut length inbetween them causes problems as they are seldom made square and will tilt the guide rollers ever so slightly,,,have a 200 dollar cheapey bandsaw,,,tuned it up,,,that took some time,,,but it cuts so square that when I chuck up a piece of pipe or round bar in the lathe,,,there is no depth to a facing cut,,,it takes time and patience to make these cheaper tools work the way they are supposed to,,,but it can be done if you have the will and the time to do it...

[hooda]

While the Rage or similar may work, they are nowhere near as rigid as a real cold saw.

If you are trying to make a living with tools, where your time is money, you will never be ahead by buying tools that are not made to save time.

I'm not saying the Rage saws aren't nice for a hobbyist or casual user, but if you are serious about making this your livelihood and getting into the metalworking business, you really should be looking at a more industrial level cold saw. WAY more money, but also WAY more saw.

I know you mentioned that you wanted to tig the first one, but really, the GTAW process isn't the right fit for this type of work. Basically no benefits in this case, other than possibly spatter removal (nothing a little anti-spatter wouldn't eliminate). GMAW all the way for this.

Welding some stop blocks to your table for setup would allow you to ditch most of the clamps and save 50% or more on the setup time as well.

First one down, time to start cranking them out :-)

The main reason that I'm looking at the Rage is affordability. I've worked in enough machine shops to know what a really GOOD cold saw is like (and costs). Assuming that there is indeed a market for my finished product, I will follow every word of your advice (because it's good), but for now, I'm just trying to SURVIVE.

As far as the decision to TIG weld this particular unit, I currently have a ESAB MigMaster 250 that needs a couple hundred bucks worth of general "fixing up" to get it tip-top. I will for sure have this done, and ready before I tackle my next unit. But this afforded me what I'm in serious need for on the TIG front: PRACTICE! There's about 140 linear inches of weld to get the basic chassis welded together. I looked at it as a perfect opportunity to really get to know the 250 EX, and so far, I've accomplished just that. Had I fired up the ESAB, The 250EX would just be sittin in the corner gathering dust, as would my limited TIG welding skills. This had for sure made me a better TIG welder, even if just by a little bit

[jakeru]

When it comes to tuning a bandsaw to cut straight you must check the swing angle of the arm relative to the bed, if it swings on an angle it will cut on an angle, next leave the support arms that have the guide wheels in one position, constantly adjusting the cut length inbetween them causes problems as they are seldom made square and will tilt the guide rollers ever so slightly,,,have a 200 dollar cheapey bandsaw,,,tuned it up,,,that took some time,,,but it cuts so square that when I chuck up a piece of pipe or round bar in the lathe,,,there is no depth to a facing cut,,,it takes time and patience to make these cheaper tools work the way they are supposed to,,,but it can be done if you have the will and the time to do it...

Thanks for sharing your thoughts, geezer. Unfortunately, it's not so easy. I have already adjusted the swing of the arm to be perpendicular to the table surface (as well as to the fence.) But it still doesn't prevent the blade from twisting and veering in the middle of the cut. What I can see is, the blade veering off in a crooked cut channel. Then by the time the blade gets to the bottom of the cut, it can be off (sideways) quite a way from where it would usually be.

That's a good idea to leave the support arms in the same position. But I don't think that's going to solve everything either. The problem is that the cut is inconsistent depending on the geometry and material being cut, feed rate, etc.

I have a new idea as to what the problem may be lately. Blade tension! The way you set the blade tension (according to the owner's manual) doesn't leave much to question, so I've never, until just now, thought it might be off. There is a spring that you are supposed to compress to 1/4" before you tighten the idler wheel, which sets the blade tension. However, here is what I'm thinking... maybe after 50 or so years (or however old these saws are) that tensioning spring has taken on some "sag"! And further along those lines, the .025" blade may need more tension that the .020" blade the recommendations are provided for.

I think I'm going to try ordering a new tensioning spring and see if it's different than the used one!

Just *feeling* the tension of the blade (by grabbing it and giving it a wiggle - purely subjectively) it sure seems to me to be a little on the loose side. When I set up say my hacksaw, I set it up a lot tighter (so tight I can "twang" it.)

The more I think about it, the more it makes sense! It wouldn't surprise me if Hooda has only tried setting up his blade tension with the owner's manual 1/4" spring distance, and probably is on his original spring like me also.

Are there are generic guidelines for bandsaws as to how much tension to set up their blades with?

I think I'll try measuring the force on the original tensioning spring in it's "as installed" position.

[DaveO]

You mentioning tightening until it twangs: here's a post from Practical Machinist that includes a link to a calculator for tightening the blade, along with MIDI files of what the blade should sound like when you twang it. I was surprised to learn that blades are tightened 15,000 to 30,000 pounds.
http://www.practicalmachinist.com/vb...htness-211224/

How cool would it be if Hooda could get the use of his saw back, just by replacing a spring!

[KSmith]

There's a ton of information on 4x6 bandsaws on this forum http://groups.yahoo.com/group/4x6ban...yguid=81201657 Helped me alot in setting up my new Harbor Freight 4x6. I have seen many on the forum mention tightening the blade tensioner as tight as they can, to get straight cuts, and also to use low feed pressure. I don't need to tighten that much, to get straight cuts, but some do.

Jakeru,
In one of your pics earlier in this thread you show a homemade felt oiler. In the pics, it looks like the roller is actually touching the teeth of the blade. Maybe just a camera perspective problem. But that can cause the teeth on one side of the blade to get damaged/flattened. Unless the teeth are the same quality on each side of the blade, the blade cannot cut straight. Damaged teeth on one side will cause the blade to cut at an angle.

ken

[KSmith]

Another thing that affects straight cuts, is the distance between the roller guides front and back. It is good to have them set no wider than necessary to cut the size metal. There is more tension in the blade when having a smaller distance from front and back guides. The problem with adjusting that distance from work piece to piece, is that the blade angle changes. The blade guides have to twist the blade as it comes off the drive wheel to get it perpendicular to the saw table. Not sure I am clear about this. The blade guide closer to the drive wheel has to twist the blade more, the closer it is to the wheel. The blade guide at the idler side should also be adjusted in toward the work vise to narrow the gap, and alleviate blade wander.

on mine, I normally cut smaller pieces, so I have the distance between front and back guides set in the area so I don't have to move them. That way I can adjust the rollers (bearings in my case) accurately to maintain a vertical cut.

ken

[geezer]

Thanks for sharing your thoughts, geezer. Unfortunately, it's not so easy. I have already adjusted the swing of the arm to be perpendicular to the table surface (as well as to the fence.) But it still doesn't prevent the blade from twisting and veering in the middle of the cut. What I can see is, the blade veering off in a crooked cut channel. Then by the time the blade gets to the bottom of the cut, it can be off (sideways) quite a way from where it would usually be.

That's a good idea to leave the support arms in the same position. But I don't think that's going to solve everything either. The problem is that the cut is inconsistent depending on the geometry and material being cut, feed rate, etc.

I have a new idea as to what the problem may be lately. Blade tension! The way you set the blade tension (according to the owner's manual) doesn't leave much to question, so I've never, until just now, thought it might be off. There is a spring that you are supposed to compress to 1/4" before you tighten the idler wheel, which sets the blade tension. However, here is what I'm thinking... maybe after 50 or so years (or however old these saws are) that tensioning spring has taken on some "sag"! And further along those lines, the .025" blade may need more tension that the .020" blade the recommendations are provided for.

I think I'm going to try ordering a new tensioning spring and see if it's different than the used one!

Just *feeling* the tension of the blade (by grabbing it and giving it a wiggle - purely subjectively) it sure seems to me to be a little on the loose side. When I set up say my hacksaw, I set it up a lot tighter (so tight I can "twang" it.)

The more I think about it, the more it makes sense! It wouldn't surprise me if Hooda has only tried setting up his blade tension with the owner's manual 1/4" spring distance, and probably is on his original spring like me also.

Are there are generic guidelines for bandsaws as to how much tension to set up their blades with?

I think I'll try measuring the force on the original tensioning spring in it's "as installed" position.

Sorry Jakeru, I forgot to mention the most important part of the tune up... blade tension,,,most people have difficulty with the tension,,,rule of thumb tighten uptil you think it is right then give it another half turn and it is probably still loose...a properly adjusted blade will loose tension over night or during a cut that heats the blade,,also when cutting flat bar or anything,,how you place it in the vise will determine the cut ,,,flat bar on edge will produce poorer resuts than flatbar on the flat,,
not too many people get right into tuning their band saws etc,,,those that do get the best results..

[jakeru]

Sorry Jakeru, I forgot to mention the most important part of the tune up... blade tension,,,most people have difficulty with the tension,,,rule of thumb tighten uptil you think it is right then give it another half turn and it is probably still loose...a properly adjusted blade will loose tension over night or during a cut that heats the blade,,also when cutting flat bar or anything,,how you place it in the vise will determine the cut ,,,flat bar on edge will produce poorer resuts than flatbar on the flat,,
not too many people get right into tuning their band saws etc,,,those that do get the best results..

When I first got my bandsaw the blade would not even stay put. And it was missing some hardware. Pretty much nonfunctional. So I've tuned it the best that I can. Problem is making it cut straight consistently. I think we might be onto something with the blade tension though.

I went ahead and got what I feel to be an accurate measure of the tension on the blade, by measuring the spring rate of the tensioning spring, and measuring it's installed length. I determined that it has a 700pound/inch rate, and a .25" deflection (from its .875" free length to its .625" installed length) gives it 175 lbs of force total on the idler wheel, so that's 87 lbs per each of the two straight bands.

At .5" wide x .025" thick per band, that would be 7000psi on the blade material. That seems on the low side, compared to what I've read it should be.

(If I had the .020" blade on there, I figure the same tension would be 8750psi.)

If I cranked down the tensioning spring until coil bound (it binds at .575" height) it would have 105 lbs per each of the two straight bands. That would be 8,400 psi on the .025" blade or 10,500 psi on the .020". I could keep cranking it even after coil bind even, I suppose. It seems like this experiment may be in order.

I expect a new spring might some more pressure at installed pressure as well as at coil bind, but it's hard to say how much. It might not even be able to put out more force at coil bind than the original spring.

I am not sure how much tension the saw is good for though; one concern is it has rubber tires which are a little bit soft. Another concern is the capacity of the cast iron arm structure itself. Yet another concern is wear on the bronze bushings on the wheel axles. I have replaced the idler bushing. It is not exactly "bullet proof." design. It does seem like the most of the original oiling points failed because someone packed grease in there instead of oil, which overheated and solidified and prevented further lubrication without some severe cleaning (digging that solid grease cake out of those little roller oilers was a very tough job, but I finally got them all freed up, and the oiling system is all pretty much functional now! I'm also feeding it proper hydraulic oil now (which won't attack bronze bushings), too, and it doesn't seem to need very much either which I'm happy about.) I guess I'll just have to proceed with caution and monitor how it goes.

Another thing that affects straight cuts, is the distance between the roller guides front and back. It is good to have them set no wider than necessary to cut the size metal. There is more tension in the blade when having a smaller distance from front and back guides. The problem with adjusting that distance from work piece to piece, is that the blade angle changes. The blade guides have to twist the blade as it comes off the drive wheel to get it perpendicular to the saw table. Not sure I am clear about this. The blade guide closer to the drive wheel has to twist the blade more, the closer it is to the wheel. The blade guide at the idler side should also be adjusted in toward the work vise to narrow the gap, and alleviate blade wander.

on mine, I normally cut smaller pieces, so I have the distance between front and back guides set in the area so I don't have to move them. That way I can adjust the rollers (bearings in my case) accurately to maintain a vertical cut.

ken

Well no matter how close together I set the roller guides, it won't make it cut straight reliably. Sure, i can tune it so it cuts straight on the same shape and orientation with the same feed rate. Not too useful though, when it cuts crooked on a different workpiece. It needs versatility and reliably cutting straight to be really useful. That setting up process take a lot of trial and error... not something worthwhile going through with each different piece I want to cut. And probably Hooda is in the same camp.

Also, on the old craftsman bandsaw, only the guide rollers near the idler wheel is adjustable in lateral position, although this adjustment can be made very easily, just twist a knurled knob, slide, and tighten the knurled knob again. Both sets of guide rollers can be rotated with a screwdriver, fairly easy as long as the screwdriver is handy. The position of the pairs of rollers with respect to each other can be adjusted with difficulty (best to remove them from the bandsaw, or remove blade from bandsaw to do so accurately) e.g., the pairs of rollers can made closer together (tighter on the blade) or further apart. You can even splay one of the rollers to be ahead of another. It's something that I wish to "set and forget" but I'm not confident that I've found the optimal setting yet.

There's a ton of information on 4x6 bandsaws on this forum http://groups.yahoo.com/group/4x6ban...yguid=81201657 Helped me alot in setting up my new Harbor Freight 4x6. I have seen many on the forum mention tightening the blade tensioner as tight as they can, to get straight cuts, and also to use low feed pressure. I don't need to tighten that much, to get straight cuts, but some do.

Yep I've checked that group out, am a member. I think at one point I went through many of the posts in it. The trouble is my bandsaw is not the typical imported 4x6 so it is hard to find relevant information about how to set it up. It does seem to have its own (different set of) quirks than the traditional 4x6. In fact, this saw is not even a 4x6... it's more along the lines of a 3"x6" (or soemthing along those lines.) I did find an atlas-craftsman yahoo group that has more relevant information about it. But I've already read everything that it has to offer also.

In one of your pics earlier in this thread you show a homemade felt oiler. In the pics, it looks like the roller is actually touching the teeth of the blade. Maybe just a camera perspective problem. But that can cause the teeth on one side of the blade to get damaged/flattened. Unless the teeth are the same quality on each side of the blade, the blade cannot cut straight. Damaged teeth on one side will cause the blade to cut at an angle.

The roller have chamfered ("barrel shaped") bottoms, which do not touch the blade teeth. However if the blade slips down off the rubber tires of the wheels, the bottom edge of the wheel has a slightly protruding hard metal edge that can bend or damage the teeth. I had this happen on a previous blade before I got some other problems with the saw worked out (namely, replaced the idler wheel bushing to bring the wheels much more closely into alignment, and got the blade to track straight without falling down off the wheels.) Usually now, the blade rides just above this metal ridge. It doesn't seem to be damaging or bending the blade/teeth anymore.

Also, the rollers are not the same comparing the front rollers to the rear rollers. The rear rollers have a shoulder on the top that provides a thrust surface for the blade.

Also, even a brand new blade would not reliably cut straight, so the problem is not with the blade.

You mentioning tightening until it twangs: here's a post from Practical Machinist that includes a link to a calculator for tightening the blade, along with MIDI files of what the blade should sound like when you twang it. I was surprised to learn that blades are tightened 15,000 to 30,000 pounds.
http://www.practicalmachinist.com/vb...htness-211224/

How cool would it be if Hooda could get the use of his saw back, just by replacing a spring!

Interesting thread there, Dave, thanks for the link. My bandsaw is twanging right at 55Hz. But I went through the calculation and it is coming off in a much higher psi ballpark that I anticipated; I think I fed it the wrong weight number.

Interestingly, I did just check the twang of my hacksaw the way I like to tension it, and above their highest tone of 250Hz... I'd guesstimate maybe it's at 300hz. That hacksaw cuts straight with good control.

I'm definitely going to try cranking the tension up on this thing. It's just one thing that I've never tried. I hope it will be able to handle it.

[posixPilot]

WOW. We have lowes here and I never shop there, they are a little out of the way.

So, I was just on the Lowe's site and I noticed they dropped the price for the RAGE3 from $249 to $224 ... no shipping, local pickup. Maybe that means it's a wicked hunk of crap, but I decided to buy one anyways. I'll let you guys know how good or bad it is when I get it home.

Cheers
Mike

[everlastsupport]

So, I was just on the Lowe's site and I noticed they dropped the price for the RAGE3 from $249 to $224 ... no shipping, local pickup. Maybe that means it's a wicked hunk of crap, but I decided to buy one anyways. I'll let you guys know how good or bad it is when I get it home.

Cheers
Mike

Let me know. I have many other means of cutting, so it would be lite use for me. And with Fathers day, little short notice. Might just run over there this weekend.

[posixPilot]

Let me know. I have many other means of cutting, so it would be lite use for me. And with Fathers day, little short notice. Might just run over there this weekend.

It will probably be Sunday before I get a chance to pick it up ... I'm having to work on Saturday to meet a dead line.

Cheers
Mike

[everlastsupport]

It will probably be Sunday before I get a chance to pick it up ... I'm having to work on Saturday to meet a dead line.

Cheers
Mike

Hey Mike,

I might pop over there later today (Sat). In Florida you have to pray they have some tools. Wanted to try one (from the videos) for some time. Will let you know. Thanks for the update on the price.

[posixPilot]

Hey Mike,

I might pop over there later today (Sat). In Florida you have to pray they have some tools. Wanted to try one (from the videos) for some time. Will let you know. Thanks for the update on the price.

Well, I picked mine up last night, but it was too late to cut anything. So I just set it up and compound-mitered (45/45) some 1.75" galvanized sq tube:

First cut:


Not so great. The blade wandered all over the place. I stopped half way through when I saw what a mess I was making. The big gouge on the right is nearly a blade width. The saw isn't very smooth at the top of the rotation, so I probably jammed the blade into the work piece on the first cut.

Second cut, better, but not great as well:


I was more careful to keep the saw steady, but there are some small gouges 1/16" or less. The saw seems to eat a lot with each tooth, so the saw marks are very coarse, even if you take it slow. A straight mitre cut might be cleaner, as the compound puts some unusual loads on the saw.

The saw does throw big, yet cold chips. I did not see any sparks, but I won't be cutting with it again until I find my full face shield. The work piece was only a bit warm after the cut, and I was able to handle the cut end with bare hands as soon as the blade stopped spinning. There was also some burr on the trailing edge of the cut that flaked off with a gloved hand.

Over all, not that impressed with the saw; I will be keeping it however, as it's my only means for cutting metal, and its adequate for my needs. But I certainly won't be throwing out my 12" wood cutting Delta.

Cheers
Mike

[Rambozo]

Is that the sliding miter version?
I was thinking I would go with the 14" chop version. It's a lot easier to make those right, plus it can handle larger material. Does anyone here have that model?
I was spoiled by access to a nice cold saw where I used to work, but way outside my budget, and no room for something that big. I'm really getting tired of the mess from my abrasive chop saw, and the occasional burns from being impatient.

[Rodsmachineshop]

if i bought a cold saw for the price and well made tools with a good warranty would buy the one from northern tools . looks very well made and has a 2 year warranty http://www.northerntool.com/shop/too...6857_200326857 264 dollars

[posixPilot]

Is that the sliding miter version?.

Yes, it is the RAGE3, the sliding mitre version. However, at the max miter and compound capacity, the side was fully collapsed when I made that cut ... in other words, the cut was really bad without the slide extended.

Cheers
Mike

[Rambozo]

Yes, it is the RAGE3, the sliding mitre version. However, at the max miter and compound capacity, the side was fully collapsed when I made that cut ... in other words, the cut was really bad without the slide extended.

Thanks, that's all I need to know. I'll pass on that. I have been looking at that Northern Tool model, too. I missed a great one on craigslist, but I'm not in a hurry. At least for now.