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Jerry
01-27-2010, 10:53 PM
I will bet that I am not the only one who has one of these 4"X7" metal-cutting bandsaws, that are sold by Grizzly, Busy-Bee, and others. For years, I wished for refinments that my saw did not have such as - a hydralic adjustment for the down-feed, coolant system, better stand, and vise refinments. I finally decided to do something about it, and this is the bandsaw with included modifications. Another worthwhile mod, is to precisely adjust the back-vise-jaw to the angles you regularly cut, and with a scribing tool, precisly scribe the angles into the surface that the rear-vise-jaw rests on. I now have the bandsaw that I always wished it was.


http://www.pbase.com/stormchaser/image/121456189.jpg
http://www.pbase.com/stormchaser/image/121456190.jpg
http://www.pbase.com/stormchaser/image/121456192.jpg
http://www.pbase.com/stormchaser/image/121456191.jpg

Big T
01-27-2010, 11:15 PM
Nice job!! I am going to make the vice mod asap.
Thanks for posting

Sparky_NY
01-28-2010, 01:58 PM
A few questions about your hydraulic downfeed. I am about to do the same thing on my saw.

What did you use for oil?

The total volume of the cylinder is greater on the side without the pushrod than on the side with the rod. That means that the oil capacity is different on each side at full stroke. How do you handle that? Do you just underfill it to allow for the difference?

Approx what size cylinder did you use?

How happy are you with how it works?

I have a cylinder and flow control check valve on the way, just wondering about these couple points.

Thanks!

Doozer
01-28-2010, 02:12 PM
It is a double rod cylinder, so no air venting is required.
I am still not clear how the cylinder is mounted to the bracketry.
It looks like a lot if needless force in the system.

--Doozer

Sparky_NY
01-28-2010, 03:21 PM
your right, I totally missed that it was a double rod type cylinder. The one I have coming is a standard single rod type. Not sure how that is going to work out. I hate the idea of having to do a reservoir of some sort for the excess, that complicates things considerably.

Considering we only need metered flow in the one direction, maybe just being less than full with oil will do the trick.

I was just looking at a Jet bandsaw downfeed cylinder. It looks to be a standard single rod cylinder, with plumbing exactly like the pic in this thread. I wonder how they get away with no reservoir? Maybe there is a way to handle the different liquid volumes on each side of the piston afterall, other than a reservoir!

dexter
01-28-2010, 03:22 PM
Very nice job. Those mods really increase the capabilities of that saw.

Black_Moons
01-28-2010, 04:54 PM
On my bandsaw, it kinda looks like the cylinder is actualy siting in its own little resavor with an snap ring to hold the cylinder inside it.

farrviewsouth
01-28-2010, 05:05 PM
Nice job. And I agree, going out in the shop tonight to continue to work on building my stand:D

Jerry
01-28-2010, 08:56 PM
Hello everyone,
I happened to have this double rod cylinder lying around and used it. A double rod cylinder is not necessary for your saw. Use a standard single rod cylinder if you like. This cylinder should have piping between the two ports, and one path should have a check valve and nothing else. This will always allow the saw to be raised with little resistance. The other path should have a adjusting valve like the one on my cylinder that also shuts off to hold the saw up. Of course you will want to ask me where the second path is on my cylinder. I never bothered with the check valve, and while lifting the saw, I open the adjusting valve which allows the fluid to transfer over to the other end of the cylinder. I have used larger bandsaws (not real high end saws) that included a hydraulic cylinder and feel mine works equally well. As far as the amount of fluid that I am using, I filled the cylinder full, removing all the air from the cylinder. I then forced out enough fluid through a loose fitting for proper operation and called it done. I have not had to re-visit the amount of fluid since completing this conversion several years ago. I have been using automatic transmission fluid in the cylinder on my saw, for the past several years with good results. I removed the cylinder to show you how I mounted the cylinder. It is a 10 second job to remove the cylinder, as there is only a nut at the one end holding the cylinder in place.

http://www.pbase.com/stormchaser/image/121479681.jpg
http://www.pbase.com/stormchaser/image/121479683.jpg
http://www.pbase.com/stormchaser/image/121479682.jpg
http://www.pbase.com/stormchaser/image/121479684.jpg

sconisbee
01-29-2010, 01:30 PM
I would think that for a single rod cylinder, just go with one that's got more stroke/length than you need for the job and operate it with reduced stroke length thus effectively having a built in reservoir on the non rod side.

vpt
02-01-2010, 08:45 PM
I also did the jaw mod to my bandsaw today. Next I have to extend the other side of the jaw to come closer to the blade to match the rear jaw. Any ideas on how to do this? I would like it to be flush with the existing jaw. But if I have to I will bolt a longer plate to the existing jaw and make it full width.

http://img519.imageshack.us/img519/1214/qcgb024.jpg

darryl
02-01-2010, 10:51 PM
I have pretty much the same saw, looks like it anyway. I've done several mods- Making the swivel point of the jaw tighter so it repeats better is one. On my saw, the blade guide area was pitiful. I did a fair amount of remachining to get them straight, better fitting, and properly adjustable. One of the first things to do is make sure the blade angle doesn't change when you move the guides up and down. The rest of the alignment depends on it. I also had to machine the top surface of the lower guide so in vertical mode the table would sit level. I tossed that pos tin foil table that it came with and mounted a permanent one which is contoured to clear the base when it's lowered in horizontal mode. I ended up with a much smaller table, but it's solid. I'd like to continue and add some of the mods that you've done.

Sure does make it a nicer machine when it works right. Oh, I replaced the belt with a link belt- so much nicer now.

gzig5
02-01-2010, 11:39 PM
Hi Jerry,
Are the two adjustable blade guide support bars as issued or a modification?They look considerably different than the C-shaped cast abominations which run on the outside on my machine. Any chance of an inside shot to see how they run and attach to the blade guide heads?
Greg

Jerry
02-02-2010, 07:42 PM
I also did the jaw mod to my bandsaw today. Next I have to extend the other side of the jaw to come closer to the blade to match the rear jaw. Any ideas on how to do this? I would like it to be flush with the existing jaw. But if I have to I will bolt a longer plate to the existing jaw and make it full width.

http://img519.imageshack.us/img519/1214/qcgb024.jpg
The minimalist approach would be to cut a plate from 3/8ths material to match the rear jaw for size, and then with it clamped to the front jaw and in the proper position to mate with the rear jaw, drill and tap it in 4 places for counter-sunk machine screws. Or if your bored, you could make a complete new front jaw matching the rear. My saw is somewhat different from yours in respect to the front jaw. My saw front jaw has a slot that runs parallel to the jaw face, allowing the jaw to be positioned close in to the blade like the rear jaw.

Jerry
02-02-2010, 07:46 PM
Hi Jerry,
Are the two adjustable blade guide support bars as issued or a modification?They look considerably different than the C-shaped cast abominations which run on the outside on my machine. Any chance of an inside shot to see how they run and attach to the blade guide heads?
Greg
My saw is 30 years old and came with these castings in place as you see them. I did replace the guide bearings with a set of quality bearings, otherwise the saw makes a decent cut as you see it with the stock quide castings.
http://www.pbase.com/stormchaser/image/121631625.jpg
http://www.pbase.com/stormchaser/image/121631626.jpg
http://www.pbase.com/stormchaser/image/121631627.jpg

TRX
02-17-2010, 07:30 AM
When would you use the hydraulic downfeed control?

I've had my saw for 18 years now. I screwed the spring adjuster down to something that seemed reasonable, and I've never touched it since.

I guess a more precise question would be, "when would you need to vary the pressure of the blade against the workpiece?"

EVguru
02-17-2010, 08:02 AM
When would you use the hydraulic downfeed control?

I've had my saw for 18 years now. I screwed the spring adjuster down to something that seemed reasonable, and I've never touched it since.

I guess a more precise question would be, "when would you need to vary the pressure of the blade against the workpiece?"

It depends what you're cutting. Bar stock isn't a problem on my unmodified saw, but I also cut a lot of 16/18swg ERW sections.

Particularly on square section the cut starts off slow as it goes through the (typically) 1" wide horizontal top face, but would then rip through the vertical walls like 'a dose of salts through a short Grandmother'. If I let it do this, then at best the blade tends to wander and at worst the blade snags, bounces out of the cut and buckles. At the moment I deal with the problem by controlling the decent by hand, after all it doesn't take long to make a cut in such thin sections.

I've bought another similar saw and I'm planning to do the full works on it, stand, swarf tray, lubricant, and damper.

Jerry
02-17-2010, 08:53 AM
It depends what you're cutting. Bar stock isn't a problem on my unmodified saw, but I also cut a lot of 16/18swg ERW sections.

Particularly on square section the cut starts off slow as it goes through the (typically) 1" wide horizontal top face, but would then rip through the vertical walls like 'a dose of salts through a short Grandmother'. If I let it do this, then at best the blade tends to wander and at worst the blade snags, bounces out of the cut and buckles. At the moment I deal with the problem by controlling the decent by hand, after all it doesn't take long to make a cut in such thin sections.

I've bought another similar saw and I'm planning to do the full works on it, stand, swarf tray, lubricant, and damper.


This is one the situations as to why I added the hydraulic cylinder to my saw, as I now can make cuts that are much more precise (cut square) by controlling the descent when cutting through thin tubing for example.

hardtail
02-17-2010, 11:04 AM
Just looking at your website.........nice work!!!

Jerry
02-17-2010, 11:51 AM
Just looking at your website.........nice work!!!
Thanks, and I'm still in the shop!