Centauro 700 CL Bandsaw - Questions

[Sal Kurban]

I recently acquired this beast in a bandsaw disguise. O boy, was it a challenge to unload it! Anyhow, I already have a SCMI 600 but could not resist this one after I saw it running. I have never seen as quiet and vibration free bandsaw but considering this beast is cast iron that weighs a ton or so, no wonder... had to pull the trigger.

The machine is running as is but I want to offer some affection to make it run better. The upper guide is a Carter but the lower one seems original. What is odd is that the lower guide is an aluminum alloy which was broken at some point and was welded. Needs replacement. The upper guide just needs jaws. First of all, attached are some pics of this machine. I understand this is the CL series and there are CO series and such; what is the difference?

I have several other questions:

1) First the guides. I came accros woodworkerstoolworks.com. Anybody has any experience with them? Would these work on Centauro 700 CL?
2) I already fit my SCMI 600 bandsaw with the Euro style guides from Grizzly, the T21973 and they work without issues. Would Grizzly roller guides such as H9565 with some modifications work on these larger machines? Some people swear by rollers including Mr Iturra, but I have not seen them on larger machines, why?
3) Now that I have more than one 3 phase machine, I am thinking perhaps about a rotary phase converter. The SCMI 600 has a 3 plus HP and the Centauro has a 4.3 HP motor, would a 5 HP RPC work on the latter machine if running by itself? Or should I go for a 7.5 HP, RPC?
4) If I go with replacing the motor on the Centauro, what frame is this? Would a 5 HP, TEFC 1725 RPM single phase such as the Leeson Motor #131537 work? What other motors would you recommend for these Italian machines such as the SCMI SC600 and the Centauro 700CL?
5) Considering the weight of the Centauro, I was thinking about putting casters on it as I did with the SCMI. But this machine has only three holes on the bottom base at three corners and the fourth one is missing (where the motor is located). The lip is to close to the frame and drilling a hole may be impractical. Any ideas?
6) If I need to paint these machines, would I need to strip the existing paint? I have never painted metal before so please be gentleCentauro CL700-1.jpgCentauro CL700-2.jpgCentauro CL700-3.jpgCentauro CL700-4.jpg

[David Kumm]

Bobby at Woodworkerstoolworks is a great guy. Melrose WI and the family has been in the machinery business forever. He will not steer you wrong. You will find that saw will tension really high which will cause much less reliance on guides. I have old Hanchett and Wright guides on my CI saws. Wright is still in business. Carter makes some big high end guides for that size saw as well. If you put a 1" Trimaster and tension to 25000lbs you don't need any guides touching the blade. You especially don't want the back bearing spinning when sawing with those blades. You want a larger RPC as that saw will be HARD starting given the mass of the wheels. The motor should be a large frame with a fair sized shaft and pretty good bearings given the torque needed to start the wheels. If you switch it out don't scrimp but three phase is way better, and you don't have to switch out the starter. Look for a used Phase Perfect. One just sold in WI for $1500 which is about the market for a 30 amp unit. RPC are cheaper but I still prefer the PP. I have an Oliver 217 on wheels and it is tough to move. I'd put it on a couple of 4x4 and find a pallet jack- they are about $350 to move it around.

[Jim Matthews]

There are multiple colors of enamel paint available for touch up on cast iron sinks. There should be some at your local Benny Moore or Sherwin's. Even the Borg stores carry some, but in fewer colors.

If it was my saw (and it isn't) I would give it a good cleaning, first. This paint was likely applied electrostatically and is well bonded to the iron. Year's of misting oil and pitch could be all that's coating the works.
I'm wondering if you might benefit from DIY blocks made from HDPE. Your alternative is the Walker Turner guides, which are near the same size. Those would need to go back to the factory for refitting.

I'm no fan of the rotating guides, but if this holds the kind of tension you recon, guides will rarely come into play.

Lastly, I considered a 36" Crescent that was near this size, and the best solution I had was a conveyor roller to sit underneath, while the saw was in storage.
I had ginned up a set of wedges to fit under the corners when the saw was "deployed" in the cutting position. Knock out the wedges, and the frame would settle back onto the conveyor to roll back out of the way.

SWMBO vetoed the purchase, so it was never tested.

Another possibility is using a skates to lift.

[Sal Kurban]

(...) If you put a 1" Trimaster and tension to 25000lbs you don't need any guides touching the blade. You especially don't want the back bearing spinning when sawing with those blades. [...].

Which brings another question; the Centauro does not have a tension gauge. How do I tension the blade without a tension gauge. Do I need a tension meter? Any recommendation?

Thanks for the input...

[David Kumm]

I use a Starrett but an Iturra is fine. Sam Layton just bought one and might let you know his thoughts. To me it is well worth the cost to experiment at what tension each type of blade performs best and to be able to repeat the setting. There are other methods but with multiple saws I find it the quick and easy way to get the best performance from these great saws. Dave

[Sam Layton]

Hi Sal,

That is a great looking saw. I wish one like that would find it way in my shop...

I just purchased the Itura tension gage. I am very happy with it. However, this is the only bandsaw gage I have ever used. I am still experimenting with the gage. Thanks to David Kumm, I am getting my technique down. I was disappointed with my saws ability to tension a 3/4" blade. I never knew... However, on 1/2" and below it will tension fine. I am still experimenting with stronger springs as time permits.

I was just not happy not knowing what the tension was. I am not good at plucking, my hearing is bad and I do not hear tones, and how much deflection is good, I don't know. After changing the tension spring, there goes the on board tension gage. Also, I can now always tension my blade to the same spot every time.

I still can not believe how much those tension gages cost. I considered making one, looks easy enough, but how do I calibrate it. So, for me the $160.00 was well spent. Louis Iturra is very nice dealing with. The Starrett, and Lennox are also nice gages, but a lot more money. So, I cried once, I am over it, and I am glad I purchased the gage. The Iturra appears very well made. If you have any questions, just let me know.

Sam

[James Heisbert]

Which brings another question; the Centauro does not have a tension gauge. How do I tension the blade without a tension gauge. Do I need a tension meter? Any recommendation?

Thanks for the input...

I have never used a band saw that doesn’t have a tension gauge. I don’t know how it works for other people with their saws like that, but I would strongly recommend you to install a tension gauge to that Centauro. I always achieve straight cuts and fine curves with the tension on.

[David Kumm]

I have never used a band saw that doesn’t have a tension gauge. I don’t know how it works for other people with their saws like that, but I would strongly recommend you to install a tension gauge to that Centauro. I always achieve straight cuts and fine curves with the tension on.

Sal, you want a gauge that attaches to the blade and not to the saw. Big saws run such a variation of blades that a gauge on the saw is almost meaningless unless you have a book to write down the references for the different blades. That is why many big saws don't bother. That saw will actually overtension a big blade which is pretty rare so bite the bullitt. Dave

[Stephen Cherry]

With such a big inertial load, I would think that the bigger the better for a rotary phase converter. When I start my 5 hp shaper with a big head, my 15 hp phase converter sounds like it's really doing something. If buying a rpc, I would deal with a good manufacturer, and call for a recommendation.

Or, drives warehouse sells a nice drive for not a ridiculous amount of dinero:
http://www.driveswarehouse.com/p-2134-x200-075lfu.aspx

[Sal Kurban]

[...]

Or, drives warehouse sells a nice drive for not a ridiculous amount of dinero:
http://www.driveswarehouse.com/p-2134-x200-075lfu.aspx

My understanding is that this drive is a 3 phase input. Am I correct?
Thanks to all who pitched in.

Sal.

[Stephen Cherry]

My understanding is that this drive is a 3 phase input. Am I correct?
Thanks to all who pitched in.

Sal.

I would reconfirm this with drives wharehouse, but the last I heard is that you could double the hp for the drive, then supply it with single phase input. They have a paper that explains this. I'm certainly not a drives expert, but these look like some pretty nice drives, with real documentation.

[Rick Fisher]

Nice saw.. That is a jump up from your 600 .. lol

Funny.. I read this post and realized I never connected my tension guide, I just wing it .. works fine.. One of the benefits of carbide blades is they last forever, so I set the tension and forgot about it some time ago..

I can only imagine how nice a saw that will be when its up and running ..

[James Heisbert]

I would reconfirm this with drives wharehouse, but the last I heard is that you could double the hp for the drive, then supply it with single phase input. They have a paper that explains this. I'm certainly not a drives expert, but these look like some pretty nice drives, with real documentation.

Can you explain how you would double the hp for the drive?

[David Kumm]

Can you explain how you would double the hp for the drive?

You need to look at the output amp ratings of the vfd. If it is marketed as single phase input it will likely say 5 hp with 13 amp three phase output and about twice that for input amperage. If listed as a three phase input you will need one that says 10 hp as you need 25-30 input amps at single phase to get 12-14 three phase output amps. You need a vfd - regardless of what size it is listed at- that accepts roughly double the input amps than you need on the output side. Almost all vfds that are listed as three phase input will accept single phase by connecting two of the three input terminals. That is really only relevant if you are buying used as it gives you lots more choices. Dave

[James Heisbert]

You need to look at the output amp ratings of the vfd. If it is marketed as single phase input it will likely say 5 hp with 13 amp three phase output and about twice that for input amperage. If listed as a three phase input you will need one that says 10 hp as you need 25-30 input amps at single phase to get 12-14 three phase output amps. You need a vfd - regardless of what size it is listed at- that accepts roughly double the input amps than you need on the output side. Almost all vfds that are listed as three phase input will accept single phase by connecting two of the three input terminals. That is really only relevant if you are buying used as it gives you lots more choices. Dave

Thanks for the reply. I guess most vfd’s in the market are three phase input as to industry standards, am I right?