4x6 metal bandsaw stand/base and mods ...

[wquiles]

I have had this HF 4x6 probably since 2007 or so. Right when I got it, I discarded the flimsy folding "legs", and made a wood base for it. I later added a hydraulic piston to replace the spring, and for the most part that has been it until last fall (2013). But now that I am starting to do/learn more welding, and cutting metal more often, I decided to "attack" the many weak points, including the over-heating motor (which is obviously too small for the job - some of these actually catch on fire!). I also wanted to add cooling to it, so I decided to do a complete overhaul of the bandsaw. This took about 3 months (on and off), and several purchases spread over the 3 months (I am on a budget, like most people), but now that it is 99% complete, I wanted to share my project.


I of course over-built the base/stand, but I figured I can fairly easily re-use the base with another bandsaw if this one totally needs a replacement later on. I used 1-1/4" (1/8" wall) squared hot rolled steel, and 1-1/4" (1/4" wall) angle iron for the top. Everything was MIG welded with my MIG200 using 0.035" solid wire with about 25cfpm of 75%/35% shielding gas.


Here is the "before" picture - I am checking the size of the new top (notice size of stock motor):





Here is the "raw" new welded base:





Previous wood base next to new base:





Preliminary picture showing the hydraulic piston in place:





Finished bandsaw after all mods:
- new steel base (2 coats of flat black paint)
- replaced 1/3 HP (Chinese rating!) SP motor with USA-made, Baldor 3/4HP 3P motor (using TECO VFD for variable speed and safety switch)
- new clamping "system" (more on that later)
- making new "arm" for hydraulic system
- adjustable coolant system (running













A little bit more background on the "why" I upgraded the bandsaw with a hydraulic piston, since this is a popular mod for 4x6 bandsaws .....


The stock bandsaw comes with this stupid spring, which is meant to "try" to counterbalance the weight of the horizontal mass, in order to "try" to control how fast that mass (and thus the blade) moves down. You basically have a screw that you move in and out to change the tension on the spring against the moving mass. The problem is that it is nearly impossible to get the spring to perfectly balance the weight AND control how fast the whole assembly moves down. Bottom line: the spring does not allow fine-tuning the speed to accommodate a variety of materials.


The hydraulic piston controls how fast the whole assembly moves down, by letting hydraulic fluid slowly escape via the adjustment valve. You can also completely stop the movement at any position along the travel angle, which comes handy to align the cut with the blade. This adjustment made available by the valve is "very" wide, thus you have almost infinite control on how fast the blade moves down into the work, so that you can adjust to the material type, thickness, number of pieces being cut, etc.. This flexibility is why ALL of the larger bandsaws have a hydraulic piston on them. The 4x6 don't have one (and have the stupid spring) not because it is not needed, but because cost - it is the only way to keep the saw cheap and available to the hobby machinist. Here are two Grizzly bandsaws showing a hydraulic piston on them:








These videos I took 3-years ago, but clearly show the adjustment range I have in my bandsaw:
- Video 1: This is the fastest down travel, fully opening the valve very fast. It you watch closely, you can clearly see the speed increasing as I open the valve:
http://www.youtube.com/watch?v=c6imAX3KnQ4




- Video 2: This is a slightly slower down travel speed. You could probably cut wood this fast, or a thin walled metal part:
http://www.youtube.com/watch?v=NEVeIn5Bv2Y




- Video 3: This is an example of a very slow, controlled downward speed obtainable with the hydraulic piston. This range of speed (or a tad faster) is typically what I use when cutting most metals:
http://www.youtube.com/watch?v=u-TpwCDG_5k




If you look at the 4x6 Yahoo group, you will see that this hydraulic conversion is one of the most popular upgrades. Lots of ingenuity in how folks have added a hydraulic piston to their 4x6 bandsaw, and it was from that group that I got the idea to do mine back 3 years ago.


Will

 

[xalky]

Nice mods. I love the Hydraulic piston mod. Where did you get the piston and how much was it?

I have the Delta version of this saw, bought in 1990 and it's still going strong. I don't have the motor overheating problem on mine, Delta must have used a better motor back then.

 

[wrmiller]

I recently bought a Griz 4x6 and have similar complaints about it as well. Except the motor doesn't appear to be overheating. (not sure why everyone is stuck in the 1800s though as in why doesn't this have a variable speed BLDC motor on it instead of belts and pulleys)

I am not a welder, but I think one of my neighbors is, so maybe I can coax him into building me a better stand than what came with it. And a misting system. Then I need to do something about this vise. Not complaining too much, as this just gives me more projects.

Edit: What type and size motor did you put on it?

Bill

 

[RandyM]

Excellent! Very nice up grade on the stand and cylinder. Thank you for posting.

 

[wquiles]

Nice mods. I love the Hydraulic piston mod. Where did you get the piston and how much was it?

I have the Delta version of this saw, bought in 1990 and it's still going strong. I don't have the motor overheating problem on mine, Delta must have used a better motor back then.

That piston and valve I bought 3+ years ago, so I don't remember the specific source. I do remember it being new, but surplus - probably $30-40 or so.

I recently bought a Griz 4x6 and have similar complaints about it as well. Except the motor doesn't appear to be overheating. (not sure why everyone is stuck in the 1800s though as in why doesn't this have a variable speed BLDC motor on it instead of belts and pulleys)

I am not a welder, but I think one of my neighbors is, so maybe I can coax him into building me a better stand than what came with it. And a misting system. Then I need to do something about this vise. Not complaining too much, as this just gives me more projects.

Edit: What type and size motor did you put on it?

Bill

Bill, I posted this earlier:

Finished bandsaw after all mods:
- new steel base (2 coats of flat black paint)
- replaced 1/3 HP (Chinese rating!) SP motor with USA-made, Baldor 3/4HP 3P motor (using TECO VFD for variable speed and safety switch)
- new clamping "system" (more on that later)
- making new "arm" for hydraulic system
- adjustable coolant system (running

If you need additional information on the specific model, I will be posting that soon as I have additional photos on the motor/VFD conversion.

Will

 

[Rbeckett]

Bill,
That stand for your Bandsaw is a beaut!!!! Did you find that it was heavy enough to not be top heavy any longer when it is upright? Mine fell over on me the day I brought it home and since I am disabled I was pinned to the floor till my wife showed up and helped me get untangled from that OE flimsy base. I replaced the base with a two drawer file cabinet with spare parts and tools in the top drawer and I plan to add a flood coolant reservoir in addition to a small concrete slab in the bottom drawer to enhance the stability. I always keep a brand new in package 10-14 tooth bimetal blade and the original HF blade that I took off immediately upon arrival at it's new home just in case I break a blade on a weekend and do not feel like driving to the big box store and fighting the crowd... Keep up the great work, your welds look really good from what I could see.

Bob

 

[wquiles]

Bill,
That stand for your Bandsaw is a beaut!!!! Did you find that it was heavy enough to not be top heavy any longer when it is upright? Mine fell over on me the day I brought it home and since I am disabled I was pinned to the floor till my wife showed up and helped me get untangled from that OE flimsy base. I replaced the base with a two drawer file cabinet with spare parts and tools in the top drawer and I plan to add a flood coolant reservoir in addition to a small concrete slab in the bottom drawer to enhance the stability. I always keep a brand new in package 10-14 tooth bimetal blade and the original HF blade that I took off immediately upon arrival at it's new home just in case I break a blade on a weekend and do not feel like driving to the big box store and fighting the crowd... Keep up the great work, your welds look really good from what I could see.

Bob

Not even close to tipping. Not only the center of gravity is inside the wheelbase, but the 3 gallons of water right in the middle (and very low) make for a very solid and stable stand.


As to welding, thanks. This is my second project, but already having fun.

Will

- - - Updated - - -

More pictures of the building process ....

I started cutting it to "fit" - the idea being that it had to extend past the current "base" in order to allow me to clamp pieces to be cut to this new base:





Fast forward to having everything drilled and tapped:





I then started work on the first of two fences (one for each side of the blade):





After some more work, and drilling and tapping, I now have one of the two fences ready:





I then cut the fence flush, and allow the blade to go through the surface of the base, without going completely through it:










Now, to align that fence, I align it to the cut/groove on the base:








So now to cut something, I camp the piece to the base, using the fence for alignment:










Or use another piece of angle iron to clamp the piece to be cut to the rigid fence (similar to the stock clamping system):





I then worked on the other fix fence, for the other side, which will only be used to make 45 deg cuts:







With the hydraulic piston, I can get the blade to within a small distance of the piece, and measure accurately:



So using the new "system", I cut the pieces, and checked the basic design by stacking the pieces - surprisingly it could stand on its own!





Since the casters were going to be offset, I added re-reinforcements to the design:








Since the design I came up with had the weight of the bandsaw not aligned with the main support, I also added reinforcements there:





And since I can now cut accurate 45 deg, I prepared all of the pieces:








So I then started to clean up, prepare, bevel, etc. all of the LEGO pieces:

















As with my prior project, I practiced and fine-tuned the MIG200 settings with the same size pieces I was going to be welding:














I actually measured the approx. wire speed to have an idea on where to start:





I then started to weld (finally!):

















After grinding (to allow welding of other parts, casters, etc..













That LED light that I made, that I showed earlier works great. Here is the before and after photos, with and without it:








More welding:

















Basic frame is complete:





I then started work on the two "arms" that hold the bandsaw above the drain:




















So now I have the two arms ready:





After grinding:





This is why I have that bevel cut on the bottom (facing the angle iron):





To weld them, I added some "weight" I had laying around, which keeps them aligned and flat:














I then made (from scrap pieces) the "ears" which will bolt to the actual bandsaw. If I ever have to replace the bandsaw, these would be the ones to cut away and make new ones to fit the "new" bandsaw, thus reusing most of the base/stand:











And after grinding:








Test fit:





Then drill the holes in the ears:








Then I moved to "make" an arm, that would tie the upper bandsaw assembly to the base/stand. But I wanted something stronger, since it has to be offset a couple of inches outward. In order to make sure I would not crack the arm, I came up with an additional bolting point:








I also wanted this new arm to be removable, so it is offset backwards a little:





This was all done with basically scrap pieces:

















I then welded the extended piece which ties to the hydraulic piston:

















Final "arm":

 

[wquiles]

Bill,
That stand for your Bandsaw is a beaut!!!! Did you find that it was heavy enough to not be top heavy any longer when it is upright? Mine fell over on me the day I brought it home and since I am disabled I was pinned to the floor till my wife showed up and helped me get untangled from that OE flimsy base. I replaced the base with a two drawer file cabinet with spare parts and tools in the top drawer and I plan to add a flood coolant reservoir in addition to a small concrete slab in the bottom drawer to enhance the stability. I always keep a brand new in package 10-14 tooth bimetal blade and the original HF blade that I took off immediately upon arrival at it's new home just in case I break a blade on a weekend and do not feel like driving to the big box store and fighting the crowd... Keep up the great work, your welds look really good from what I could see.

Bob

Forgot, as to the blade, I am using:

64 1/2" x 1/2" x 14T Bimetal Bands $13.41 each

An I ordered them from (no affiliation):


Kenny Schmidt
Industrial Saw & Grinding, Inc.
3920 Rufe Snow Dr.
N. Richland Hills, TX 76180
(817) 284-7416
Industrialsaws@aol.com
www.industrialsawandgrinding.com



Will

 

[wquiles]

For the VFD, following my mentor's advice, I put it away from swarf, but I also wanted an external enclosure to protect the unit and wiring. I found a scrap metal box in my "shop", which was almost the right size:








I then made a steel support for it:











The box bolts to the support "T" with two bolts (and silicone in between), and the VFD bolts to the box at 4x places:








This whole assembly is then welded under the pan, ensuring that the VFD/electronics will remain free of debris and coolant:








I then gave everything two coats of flat black paint:








For the pan, I used galvanized steel, which I cut to size, to fit inside the angle iron top:





I then applied silicone to the whole thing, to ensure a good seal - no screws needed - the surface tension along that much surface area is more than plenty:





I then applied weight in the middle, to bow down the metal, thus ensuring coolant will flow towards the middle:





After the top dried, I went back and applied another thick bead of silicone to make sure everything was plenty well sealed. I then moved to work on the bottom "shelf". Again, used galvanized steel, and epoxy:














I then moved to make the drain hole:










Siicone sealed on both sides:





then found the perfect strainer for large debris:





This is how it looked at that point in time:





I then got another plumbing piece (with a larger inside diameter than the drain tube), to make the connection. The fit is such I can slide the white piece up and town to "make" the connection, thus allowing me an easy way to remove the 5-gallon if/when needed:








And after testing, it worked like I hoped (note the extra heavy silicone against the angle iron!):





I even found use for the cap:





And for those interested, this is the coolant I am using (at 10% concentration with distilled water):

 

[wquiles]

Now that the electrical wiring is protected from coolant, I can assemble and wire the new VFD and 3-phase motor. I started by installing a grommet to protect the single phase power coming into the VFD:








Since I needed to have the right length for the 3-phase motor wire, I installed the new Baldor 3/4HP motor. Look how much larger it is compared to the "1/3" HP factory unit (would get so hot I could barely touch it!):





I of course used the low voltage wiring as my VFD outputs 220V 3-phase:








Then tie everything together and test - I got lucky (50-50 chance) that the motor started turning in the direction I wanted!:





I then wired the switch for the coolant pump (inside the 5-gallon, with the inlet a few inches from the bottom, so it does not suck in much debris), tie-wrap everything securely, and that is all:





The only thing to note/add, is that the original ON/OFF switch on the bandsaw is now a logical signal to the VFD. The switch is re-wired as an E-STOP (emergency stop), so now I have an extra safety step to get the motor running, as it takes two steps:
- E-STOP has to be UP
- I can only start the motor by pressing the START/STOP button on the VFD (which is recessed on purpose, so nearly impossible to hit/press by accident).
- Moving this E-STOP switch UP will never start the motor, but it has to be up for the START/STOP on the VFD to work at all.




The small dial on the VFD (also recessed) controls the speed of the motor, so I never have to change belts again to adjust speed to material, thickness, number of pieces, etc.. The coolant switch is independent of the motor, so I can choose and adjust the output flow if/when needed.




Will