New Delta 28-348G Metal / Wood Bandsaw up and running

[David Wambolt]

As some of you may have seen, Amazon discounted the 28-348G (3 Phase, LVC) along with the 28-348F (Single Phase, LVC). The price was $699 for the 3 Phase and $799 for the Single Phase. Usual street price for this saw was around $1,700.

I received it last week and it had a few blemished on it. I contacted Amazon and they refunded me $140. So my cost for this saw was $560. I spent another $250 on a Teco 2hp VFD so that I could use the 3 Phase unit. Amazon donated $100 to that cause right off the bat due to it's price being $100 cheaper than the single phase.

So with that said I purchased the 28-348G, Teco MA7200 2hp VFD, Kreg Bandsaw fence, Delta Riser Block, Delta Mobile Base and some SO cord. This is my first vertical bandsaw, I have two horizontal machines to cut metal. This saw also comes with poly-urethane tires. I also ordered the Carter tune-up kit which includes roller guides and the blade stabilizer. That has not arrived yet, so I'm running the stock guides for now.

I went ahead and assembled it per Delta's instructions. Nothing was missing and all went together the way it should. I broke the saw down and was able to lift the lower section with gear box to put it on the stand. I did everything by myself and by breaking the saw down it was still quite heavy, but doable. The riser kit went together without a hitch and I picked up a couple of 105" Olsen blades from Woodcraft yesterday just to play around with while my Timberwolf's are enroute from Suffolk.

Since this was my first experience with a VFD and 3-Phase, I screwed up at first. I tried using the VFD to supply power to Delta's heater/starter box that mounts inside of the saw base. It's a very nice set up if you had native 3 Phase and incorporates the LVC push button controls. I got the saw to run, but it would usually fault the VFD.

I went back into the box and bypassed the Delta starter assembly and wired the motor direct to the VFD. She came to life after that and purrs like a kitten. Well the saw isn't super smooth, but I think most of that has to do with the V-belts. I'll replace them with either higher quality belts or a link belt. The transmission works well and I can switch from 3000 SFM to 160 SFM with the pull of a handle. I have other speeds in which I can achieve if I switch the belts. But that's where the VFD comes into play, because I can not only decrease the speed of the motor without changing belts, but I can overdrive the motor past 60hz to increase my wood SFM to 3500+. I ran the saw up to 90hz and I'm not sure how the motor scales, but that should have been over 4000 SFM. The saw is kickin at that point, sounds like a monster! :) The motor in this saw is rated at 1-1/2hp and is made by Marathon Electric in the USA. I was expecting an import motor, but it's has a quality motor in it already.

I cut a piece of aluminum plate to mount the VFD. I used the two mounting studs from the Delta LVC switch to attach it to the throat. I used my metal brake to add a bend at the top to give it a bit more strength and also allows me to use rubber grommits to make a tool holder or mount a work light. The LVC controls are not hooked up and I'm going to see if I can make them work with my VFD. Originally I planned on mounting the VFD remotely and would have just installed the operator panel on the saw, but I didn't have a good place to mount the VFD. For now it will remain there until I sort out a better solution.

Overall, it was a killer deal. I'm sure once I get it all dialed in the saw will give me many years of service. I made some sawdust with it already and man it cuts great. It's so nice to be able to free form wood like that but also allows me to cut steel and aluminum with a blade change whenever I see fit. A true dual purpose saw that helps me save on space. It's cool pressing the VFD and the saw comes up to speed over a five second period (user configurable) and also brakes when you turn it off over a five second period (user configurable). There are so many options with this VFD that it will take weeks to get it figured out. :) Sorry bout the mess - my shop is not done yet so I'm having to work on machines where ever space permits.


http://www.dmwtech.com/gallery2/d/3316-2/CIMG0435.JPG

http://www.dmwtech.com/gallery2/d/3328-2/CIMG0430.JPG

More pictures here: http://www.dmwtech.com/gallery2/v/welding/wood/delta_348g/

[Tommy Emmons]

When was this deal on Amazon? I just checked and the model that you got is not even listed on Amazon. Did you get an email to notify you of the deal or does one just have to monitor Amazon's site to find these deals? I would appreciate your feed back. By the way, nice deal. I just wish I had run across such a deal.:)

[David Wambolt]

When was this deal on Amazon? I just checked and the model that you got is not even listed on Amazon. Did you get an email to notify you of the deal or does one just have to monitor Amazon's site to find these deals? I would appreciate your feed back. By the way, nice deal. I just wish I had run across such a deal.:)

The deal was at around the middle on January. I purchased on 01/18/07. They were doing a big clearance of certain Delta equipment and had a link from their main page. Mike on the fourm bought a Shaper and several others bought stuff too. I sat on the band saw and then they sold out of the single phase 28-348F. So I bought the 3-phase model for $699. I wish I would have bought the shaper too. They had a 5hp dust collector cheap, but it was too big for my shop.

I usually check Amazon every other day for deals. Here's the link to the saw on Amazon:

http://www.amazon.com/Delta-28-348G-14-Inch-Controls-260-Volt/dp/B0001LQZJS/sr=8-1/qid=1170648846/ref=sr_1_1/102-9816486-3548912?ie=UTF8&s=hi

The price went from $1700 something to $699 then to $899 the day after I bought it and now to $2187. Gotta love Amazon's price system.

["Gary Brewer"]

Hi Dave: Great deal on your band saw. How did you deal with the 3 phase issue? and what is a Teco MA7200 2hp VFD and exactly what is it used for? Is this because you got a 3 phase machine? Sorry if these sound like stupid questions but electricity is not my forte. Your thread peaked my curiosity.
Thanks,
Gary

[Alan Greene]

Tommy
Amazon has the Delta 28-475 x X5 saw on sale right now. for $999.00. It also comes with the riser, mobile base and a magnetic work light. There is also a Delta $100.00 rebate and free shipping. Seems like a decent deal.

http://www.amazon.com/Delta-28-475X-Horsepower-Woodworking-230-Volt/dp/rebates/B0000A25WT/ref=detail-conditional-rebates_1/105-7056347-3206045

Not affiliated etc.

[David Wambolt]

Hi Dave: Great deal on your band saw. How did you deal with the 3 phase issue? and what is a Teco MA7200 2hp VFD and exactly what is it used for? Is this because you got a 3 phase machine? Sorry if these sound like stupid questions but electricity is not my forte. Your thread peaked my curiosity.
Thanks,
Gary

Gary,

There are several ways to deal with 3-Phase. If you are at 3hp or under, I think the best way is with an inverter based Variable Frequency Drive. What this device does is takes in single or three phase power, converts it from AC -> DC -> AC and gives you three phase output with full control over the voltage and frequency. Standard three phase operates at 60hz, if you reduce the hertz, the motor will slow. If you increase the hertz past 60, the motor will exceed it's rated RPM. That's what nices about a VFD, you can fine tune the motor in ways you cannot do with single phase or with a static/rotary phase converter.

There are other options like static and rotary phase converters and you can Google either of them for a good read. The VFD is by far the most advanced, but it's power output ability is limited to about 3hp with single phase input. In this case the Teco MA7200 is a 2hp VFD and is perfectly matched to the 1-1/2hp motor in the band saw. Hoopefully that helps answer your questions. This was my first time experimenting with three phase and it worked well once I figured out that I should bypass the starter box. If the saw didn't have LVC controls, it would not have been a problem.

[Richard Butler]

David,

Where did you get the VFD? I might put the 3 phase Bullet motor back on my 1943 Unisaw assming I can get full rated power from the motor/VFD combination.

[David Wambolt]

David,

Where did you get the VFD? I might put the 3 phase Bullet motor back on my 1943 Unisaw assming I can get full rated power from the motor/VFD combination.

I got my AC Drive from http://www.factorymation.com . Another good source is http://www.automationdirect.com . Hitachi makes a good VFD as well. I liked the TECO because it had a dual line display and could be connected to a PC for programming. The only thing it didn't have was an analog dial to set the hertz, but the up and down arrows work just fine for that.

[Richard Butler]

David,

I see that Teco makes a FM50. Would that be good choice for a 2hp table saw since I don't really need speed controls nor do i need a reverse.

I have a 2hp motor. Should I get a 3hp rated VFD?

[David Wambolt]

I would get the 3hp rated VFD, and the FM50 would work fine. It still has adjustable frequency and braking. One neat thing is how quickly you can stop a 3 phase motor with braking. I can take my bandsaw from 3000 SFM to stopped in about 1.5 seconds. If I had it to do over again I'd probably buy the FM50 as well. It's cheap and does what I need. The MA7200 looks cooler and has more features, but the FM50 would get the job done.

Also Teco has very good customer service. I emailed them a question and they passed it along to about four people until it reached an engineer who could answer it. He replied with what I needed very promptly.

[Mike Heidrick]

Dave, awesome bandsaw setup.

I could not find a 1 phase in to 3 phase out VFD setup that would work with my 5hp shaper. Ended up changing the 3ph 5hp to a 1ph 5hp motor from Delta and got a 1ph LVC from a guy from ebay. Let me know if you do not end up using that set of LVC power buttons you have - I could use them on another project.

Here are some pics of the shaper if you want to see it.

http://i39.photobucket.com/albums/e169/BloomingtonMike/shaper11.jpg
http://i39.photobucket.com/albums/e169/BloomingtonMike/lvc.jpg
http://i39.photobucket.com/albums/e169/BloomingtonMike/upgrades.jpg

[Noah Katz]

"The only thing it didn't have was an analog dial to set the hertz"

A lot of drives can be set up to use an external potentiometer.

VFD HP is derated for 1-ph output by about 1/3, so if you want to run a 3 HP 1-ph motor you'll need a 5 HP drive.

[Richard Butler]

The VFD is perfect for adjusting the speed of a 3 phase motor, but what is a good solution for adjusting the speed of a single phase motor? I want to build a lapping machine and being able to vary the speed and have some reasonable torque is essential.

[Noah Katz]

How much power do you need?

VFD's won't work with capacitor-start motors, but I don't know about other types of 1-ph motors, like split-(I think) and shaded-pole motors.

There's also fan motors which you can get w/3 speeds.

[Richard Butler]

David! THANKS!!!!!

I was talking to my neighbor about your bandsaw and the 3 phase motor and the AC drive. He gave me an old Delta 1hp 3ph motor that came out of a sander. I replaced the bearings ($20), found a spare Unisaw pulley and bought the FM50 drive. After wiring it up I have to say that putting that motor and drive on was the single biggest improvment I have made to any of my tools and that includes "fork lift" upgrades. The saw is now amazingly quiet and smooth. Playing around with it last night I tried to stall it at 10rpm and could not. Furthermore I ran the speed up and got cuts that were almost as smooth as a 90 tooth crosscut blade on a tableaw. I can't wait to get that old Delta 3 phase motor back on my Unisaw and get it up and running.

The FM50 drive was amazingly easy to setup. Just wire it up and go. Now all I have to do is get some really cool start/stop controls for it. It would appear I have a few options in that area all of which are dirt cheap.


Anyway, thanks to you I now have a very spiffy bandsaw which is an gross understatement. I highly recommend going 3 phase with a AC drive. BTW the 2hp Teco drive was $140.00. Considering the fact that an adjustable pulley set will cost about $90 and is quite limited in terms of speed options, is a pain to change speeds, etc, the AC drive is a cheap upgrade. Just based on the time it would take to adjust the speed using pulleys it is clear that the AC Drive is a clear winner.

I read that some feel that a single phase motor does produce the hp that a 3 phase motor will. One fellow said that the single phase motor's true HP output is actually about 30-50% less than a 3 phase of the same HP rating.

Personally I think he may be right.

I am so pleased with the results that I am going to change my drill press motor to 3 phase with a AC Drive (VFD).

3 phase ROCKS!


Thanks again!

[David Wambolt]

Richard,

You're very welcome, but I can't take any of the credit. I just did my research on the forums and posted my completed project. Now I have not seen too many people use the TECO drives, but so far it works great. Can you adjust the ramp up and ramp down speeds on the FM50? I didn't catch if the FM50 had a built in braking resistor like the MA7200. That right there is a neat feature in that you can stop the saw very quickly. It sounds like if anything, my post inspired you to give something new a try and the results were something you really liked. That's what it's all about!

The only thing is that when running 3 phase motors at less than their rated speed, they can build heat due to lack of cooling. If you find yourself running at 40hz or less, I'd add a fan into the cabinet to blow on the 1hp Delta motor. Over running the motor shouldn't cause it to heat up. I ran mine at 90hz and it was barely warm after cutting some wood.

I'm still waiting on my Link Belts from Amazon. My saw is a bit 'rough' due to the belt drive system, so hopefully those will cure the case of the vibes my saw has.

I'm glad it worked out for you! It's nice finding this type of thread instead of someone telling me some of the tools I buy are way over priced. LOL :)

[Richard Butler]

Yes, you can adjust the acceleration and deceleration times on the FM50. It does not have a built in braking resistor but I am afraid that if you stopped the saw that fast it might not be very good for it.

Without a blade mounted it takes my saw 20 seconds to coast to a stop. With braking it takes 5 seconds and I could shorten that time but it probably isn't worth it.

The motor was free but the drive cost me $120. To make things fair we will include the cost of a 3 ph. motor which is about $50. If you tried to do the same thing with single phase you would need a pullley set from Iturra at $82 plus a single phase 1 motor which costs $100.00. I got the motor prices from Surplus Center.

Save 10 bucks and get the ability to change speeds on the fly. I think it is a no brainer.

[Richard Butler]

It just occurred to me that since the VFD uses low voltage to remotely turn it on and has a relay contact output, one could use the VFD to automatically turn on a DC. One solid state relay and a contactor and away you go. This is getting better and better all the time. Want multiple emergency stop switches? No problem! I think I will be having all sorts of fun in the near future. :grin:

[Don Bullock]

That is a super gloat. Very nice. Thanks for posting all the information on the set-up.

[Noah Katz]

"one could use the VFD to automatically turn on a DC. "

I'd think twice about that. Capacitor start motors are rated for only a certain number of starts/hour, IIRC something less than a dozen. And spinning up that big impeller reallyu puts a lot of stress on the caps.

I decided I'd just leave the DC running most of the time to avois that, and to clean my shop air as well.

At 13 cents/kW-h, running a 3 HP motor continuously costs 37 cents/hr.

[Mike Heidrick]

Noticed Wilton had their Metal/Wood multi speed bandsaw on sale at Amazon for about a grand in both single phase and 3 phase if anyone is interested.

[Richard Butler]

"one could use the VFD to automatically turn on a DC. "

I'd think twice about that. Capacitor start motors are rated for only a certain number of starts/hour, IIRC something less than a dozen. And spinning up that big impeller reallyu puts a lot of stress on the caps.



Here is what I found on the subject.

http://www.bhc.co.uk/pdf/MS_Cat.pdf

"[Motor Starting Capacitor] Duty Cycle

The standard rating is 1.67% or 1/60th full time and corresponds to a maximum duty of 20 starts, each of three seconds duration per hour. It is expressed following BS5267: 1967 and IEC 252 1975, as 3/1.67 (a 3 minute cycle with 1.67% duration during which the capacitor may be energised). If the same capacitor is to be used for a duty cycle of 60 starts
per hour the cycle duration will be 1 minute."

So how long is the cap actually on? I really doubt it is on for 1 second when used in a manufactured DC. So one could say that if the cap was on for .5 seconds (actually that is a fairly long time), then you are allowed 120 starts per hour. All of the cap start motors I have had experience with have had cap-on times in the sub-second range. I do admit that I have not had the opportunity to work with a really large DC that used a cap-start motor.

If this was a production shop then I would agree with you. This is a hobby shop where in all truthfullness the machines sit idle most of the time. Of course the DC is a different beast having much more mass to spin up so the start windings and cap are on for a longer period of time. I did a quick search and found this little tidbit.

----------------------
"I was going through the mounds of stuff on my desk this afternoon and
came across a memo published by a major motor capacitor manufacturer who I won't mention (the report was marked 'proprietary' and was distributed for use by another motor manufacturer). Capacitor Failures in Single Phase Fractional to 5 hp motors. Date codes greater than 5 years - 91.2% failed"
----------------
http://groups.google.com/group/alt.hvac/browse_thread/thread/11a31cb5ea24cb05/d4cf5dba4da0495f%23d4cf5dba4da0495f

It seems that there are some motor caps out there that are prone to failure.

Short version?

I think I am good to go. I will let you know for sure when I measure my cap-on times for my DC but I have a feeling that the actual on times will be in the 1/4 second range.

[Noah Katz]

Richard, thanks for that info, which is the most definitive I've seen.

On the one hand it does seem to indicate that it's a nonissue for hobbyist use, though that statistic is sobering.

I'd say the Leeson 5 HP motor 14" impeller I had (switched to a 15" but haven't mounted it yet) took between 2 and 3 sec to come up to speed.

[Michael O'Sullivan]

Has anyone tried attaching the height extension to the 28-348F? Mine does not fit together particularly well. First off, the upper blade guard attachment is a nightmare and really doesn't work at all. Second, the blade is no longer perpendicular to the ground, the upper arm extends out slightly further than it should. As a result, even after adjusting the table, the blade almost touches the insert.

Anyone else seeing this?

[David Wambolt]

I put the extension on my 28-348G and it seemed to work out well. I did notice the blade was somewhat close to the insert, but it was that way without the riser. The blade guard parts work just fine and I was actually surprised how easily it went together.

My saw runs a bit rough though, but I have a lot of vibration in the belts. At 40hz on my power, it smooths out and at 90hz it again smooths out. the pullies are alligned well, but I think the belts are just junk. If the Power Twists would only come back into stock on Amazon, I could finish up the saw. I'm also waiting on the Carter guides to come in.

[Richard Butler]

Most of the references say that the cap in on from 0-75% of the rated rpm. I think it is on for much less. Probably something like 0-20% Onc way to find out is to listen for the centrifical switch to close as it spins down and note the rpm using the higly accurate SWAG method. (:>)

[Noah Katz]

I don't think the kickin speed is the same as kickoff.

[Richard Butler]

You are likely correct but since it is a centrifical switch it won't be too far off.

[Noah Katz]

Listening to what I have, it sounds like it stays connected til about 3/4 speed and doesn't kick out til less than 1/4 speed.

[Richard Butler]

Noah,

Sorry for the delay in responding. I believe you are correct in that most stay on until 75% of full speed is reached. My perception was wrong. On most of the motors I have dealt with that have cap start, they reach full speed almost instantaneously.

I have completed my Unisaw and 14" Delta bandsaw conversions. All I can say is that it has been really fun to add variable speed capabilities and additional power to both machines. I doubt I will be running the Unisaw any faster than stock. My limited experiments indicate that there is no advantage to spinning the blade faster other than slightly faster cuts.

I will be converting my drill press over to 3 phase with a VFD next. I will have to buy a 3 phase motor for it unless I happen to come across someone that will give me a one.

I decided to splurge and bought two 10K linear pots from Radio Shack. Mounted them in a 2x4 handy-box along with a solid state relay. I have not wired the relays as I don't have a DC yet but my tests indicate that they work. Even my neighbor was impressed with the speed controls and that is hard to do.

[Noah Katz]

No problem.

I have one on my old Craftsman TS (long story), thought the speed control would be handy but never changed it.

Could be good with a sanding disc, slowed down for control sanding to a line.

The blade decel is really nice though.

[Mike Heidrick]

Want to bring up the VFD topic again. FM50 just showed up for the jointer. I want to discuss the wiring of it and how I can power it up and down. Any advice from those that own a VFD??

[Richard Butler]

One of the fellows asked if would draw up a schematic so that the stock controls and contactor would work with his FM50 VFD. For your amusement I attached the drawing.