Davis and Wells 20" Bandsaw Restoration

[Jeff Carmi]

Hello everyone! Please see my first thread (http://www.sawmillcreek.org/showthread.php?197107-Davis-and-Wells-Getting-it-home!) to bring you up to speed.

So it's taken a few months to get back around to restoring this old boy. I still don't quite have the funds I'd like, but I think I'm going to go for it. I'm going to be moving at the end of this month and figure it's a good excuse to take the saw apart. .

Here's what I'm thinking (and in the order that I'm thinking it):

- Wheels off. Send for volcanizing/balancing
- Take saw apart. Consider repainting. If so, sandblast (have never done this).
- Order all replacement parts. Definitely need new guide blocks and bearings.
- Repair hole below table (see pics above). Hopefully my metalworker buddy can do this for me.
- Possibly regrind/flatten table and repair pitting in mitre slot.
- Paint (have a spray gun, but never used it. My compressor is small but should suffice)
- Moving. Re-assemble saw at new garage.
- 3hp 3ph motor and VFD. Unsure about matching frame types and shaft diameters. Also not sure if motor RPM is a concern if I'll be using a VFD. Also considering a 5hp setup as per Dan at D&W recommends. Can't seem to find these things as cheap as people say. . .
- Driftmaster fence system, or an original if I can find one.
- Carbide blade(s)
- Make much dust!

PLEASE let me know what you guys think! This will be my first full restoration and I've got a commission to start building mid-May, so this has to happen quickly. Your thoughts and suggestions are greatly appreciated!

-Jeff

[Jeff Carmi]

I'm concerned about the CLASS B rating on a new 5 HP Baldor 3 PH. Could be a good deal, but is it worth waiting for a CLASS F? I'm definitely going with a VFD and am hoping that the overload protection will keep me safe from overheating. I realize it's also about longevity but I think 10's of 1000's of hours, when kept at proper temps, should be enough :)

http://en.wikipedia.org/wiki/Insulation_system

http://www.engineeringtoolbox.com/nema-insulation-classes-d_734.html

[Robert Boyd]

I would check on the price of a VFD that is rated for 5hp before you choose a motor. VFD's up to 3hp are cheap if you are running single phase input. IF you want to run a VFD for a 5hp with single phase input the price goes way up.

Start with bearings and tires and go from there. Everything else can be done at a later time.

[Rod Sheridan]

Hi, the class B insulation is an indication that it's a cool running motor, as the insulation is chosen to match the temperatures expected.

Class F is higher, however the motor will probably be a hotter running motor.

With a VFD, motor overheating is possible even if the motor doesn't run at more than rated current, if the motor is run at low speeds for a significant time period. This is because the amount of air the fan forces over/through the motor for cooling is significantly reduced.

For a bandsaw, you're probably just using the VFD as a single to three phase converter and will run the motor at rated speed, so no cooling issues.

3HP is a lot of power for a bandsaw, I would stick with the existing 3 HP motor and gain some experience as to whether it's enough.

Regards, Rod.

P.s. Last year I made a bandsaw mill with an electric motor, 3 HP was plenty for up to 20 inch deep cuts.

[Jamie Buxton]

5 hp is likely more than you need. I've got an older Laguna LT16HD with a 2 hp motor. The resaw height is 12". I use it a lot, in hardwood, and it has never bogged down. I resaw with carbide blades, which make kerfs that are .05" wide or less. You're just not removing much material with a kerf that thin, so big power isn't necessary.

[Jeff Carmi]

Thanks for the replies!

So I sealed the deal on a brand new 5 HP Baldor for $150. After several conversations with Dan at D&W I started leaning towards a more hefty motor. I know it's overkill but I'll be happy knowing my saw will never bog down.

The Teco VFD's are well priced. (http://www.factorymation.com/Products/7300CV_230V/). Considering the difference in price between a 3 HP and 10 HP VFD (which I would need to run 1 phase in/3 phase out) is fairly proportionate to their respective power ratings, I don't think the power jump is unreasonably expensive.

For the time being though, I may try to build a rotary converter and live without the VFD for a while. That way, when the time comes, I can get a 5 HP VFD and have 3 PH power available for other machines. If anyone knows good resources for building a rotary phase converter please let me know!


Will be breaking the saw down today and making a trip to see Dan at D&W. He's really helpful and has offered to give me a "lesson" on this saw. I'm having him vulcanize and balance the wheels, so he's also offered to lend me his puller.

Stay tuned for pics and updates. STOKED!

-Jeff

[Robert Boyd]

For the Factorymation VFD anything over 3hp requires three phase input. Just an Fyi. There is another company that will sell a higher hp single phase input VFD and the information is in the Moak bandsaw thread I believe.

The cool thing is you have Dan to help you out if you have any questions.

[Jeff Carmi]

So many phone calls. . .

AC Tech makes a 1/3 PH IN, 5 HP VFD for about $520 (SCF250Y (http://www.lenzeamericas.com/documents/saleslit/CB-SM-0412-e1.pdf)). Not too bad. However. . .

After talking with Don at Lenze Americas (http://www.lenzeamericas.com/cgi-bin/library.pl?submicro|97319|null) I am convinced that the Class B rating of this 5 HP Baldor is not a good choice when run through an inverter (VFD or other). I also spoke with tech support at Baldor and they said the same thing. The Class B won't tolerate voltage spikes and variances in RPM that a Class F will when using a VFD, even if I keep it at constant speed, but especially when slowing it down.

I won't' be buying that motor now, but I may still stick with 5 HP. I guess it's back to craigslist/ebay for me. . .

[Robert Boyd]

Jeff,

If you have time visit Vintagemachinery.org for pictures in the photo index. Another option is to join Owwm.org and place in add in the Boyd section for a 5hp motor.

[Jeff Carmi]

Thanks, Robert!

Those sites have been in my bookmarks for a while now, but never used them for trade. I'll give it a shot.

[Steven Satur]

Dear Jeff: I have the same saw as you, I never thought 3hp was not enough. What are you cutting that you think you need more?
As for the org. fence, my saw came with one and I sold it last year, just wasn't what I was looking for, plus you had to remove the rail to change the blade. The Laguna might be a good choice.

Steve

[Jeff Carmi]

Hi Steve,

At this point I'm sort-of letting fate decide what motor I go with. 5HP is overkill and almost cost-prohibitive (because of the VFD), so I'll probably end up with 3HP. I'm having trouble finding 3 phase motors for cheap. I was under the impression that industrial shops let these thing go for practically free. . .

As far as the fence goes I'm still leaning towards the Laguna, despite their reputation. What fence system are you using, and how happy are you with it?

Thanks!

[Dennis Ford]

If you are not planning to use the variable speed; why go to 3ph and VFD? A single phase motor may do what you want. I recently did a band-saw rebuild and wound up with a 5hp single phase motor (I have been unable to bog it down even when I tried). 3 hp would probably be plenty. I had planned to use 3hp and a VFD but found a good deal on a Baldor 5hp single phase motor.

[Jeff Carmi]

Hey Dennis,

This saw is the biggest machine in my shop. I've got a Powermatic 1500vs drill press and an RBI 26 Scroll saw, as well as an array of Festool power tools. (I get by with a lot of handwork). All of these are variable speed and I've come to appreciate this feature for different operations and woods. Even if the speed adjustment is subtle I can completely eliminate burning and improve cut quality. I also like the VFD for its efficiency and other features.

Admittedly, I'm stuck on the idea but am not sure I can afford the 5 HP w/ VFD arrangement and will probably go with 3 HP and a VFD. I've looked at many other similar sized saw currently available on the new market and most are closer to 5 HP than 3 HP. Like I said previously, chance will play a big part in making this decision for me. Like you, I could see myself settling for a 5 HP/1 PH if a good deal came along.

Cheers!

[Sam Layton]

Hi Jeff,

Good luck on your motor search. You have talked about HP, but what about RPM's. What RPM range are you going to get? Did Dan at Davis and Wells recommend one over the other? I guess with the VHD you have variable speed. If you get a single phase, will it be 1700, or 3500 RPM?

Sam

[Jeff Carmi]

Hey Sam, and all!

The motor search is over and, yup, I went with the 5HP, 3PH Baldor motor. Until a week ago I knew practically nothing about AC motors (or any electric motor for that matter) and feel I've now got at least a narrow understanding - at least for what my purposes are.

Concerning RPM: I believe the lower RPM delivers more torque and will therefor get wheel momentum going much more easily than a higher RPM motor. I think 1750 is very common across most woodworking machinery I've seen. Dan at D&W certainly agreed and really got me stuck on higher horsepower as well.

Concerning Class: It seems most old motors out there are Class B. My understanding is that this is fine for shops not running a given machine all day. However, when it comes to using a VFD this is not the case - an "inverter rated" or Class F motor is necessary. (In any case, though, Class F is a better choice because it will work many more hours in its life than the former.) I don't understand this entirely, but even if one were always running a VFD at the same speed it would still be best to have a Class F due to the way current is delivered from the inverter to the motor.

Other must-have specs: TEFC (totally enclosed fan cooled), proper voltage for your power, and a frame type size appropriate for the given machine - mine, and many other, are good with a 182 to 184 and others still. I didn't see bigger frames until higher power ratings (7.5HP+).

Hope that info helps anyone who's curious!

. . . Onward!

At this point the saw is completely disassembled. I'll upload some photos asap.

VFD: Now I'm shopping for an appropriate VFD and having little luck on the used market. I'm not expecting to find a 5HP, 1PH unit, so I'm looking for 10HP, 3PH and derating. However, this seems like more trouble than it's worth as these much higher power inverters are about as much as a new 5HP, 1PH drive from AC Tech (about $500). They (7.5Hp+ VFD's) also tend to be 440v and would require a transformer and higher amperage just to bring in 1PH power. This additional stage also means potential for power loss (although probably not too much). If I can't find a good enough deal in the next week or two I"ll probably end up biting the bullet and getting the AC Tech drive SF250Y (http://www.lenzeamericas.com/documents/saleslit/CB-SM-0412-e1.pdf).

Paint: Also looking at paint options. I'll probably go with an enamel. I'm still doing some research but this seems like the best balance of protection and ease of application. I'm looking at Benjamin Moore paints formulated specifically for adhesion to metal. This is nice too, because there is a huge selection of colors.

Fence: I'm still leaning towards the Laguna Driftmaster (ugh) despite their reputation - too many horror stories, but still the best option. However, I am considering ordering the fence off the PM1800. It's similar to a Biesemeyer fence but with an aluminum 2-postion extrusion, like on the Laguna. It comes out to roughly the same price (if anyone wants the part #'s just message me) but doesn't offer the features (on-the-fly drift adjustment and micro adjustment, especially) the Driftmaster does. Also, and this may seem trivial, the Powermatic fence is yellow. I'm not painting my saw Powermatic yellow, and I'm not going to completely restore and repaint this thing and then slap a yellow fence on it. . . But I do like the fence :p

I'll be stripping the finish and prepping for paint the next two days. I also was unable to pull the bearing from the lower wheel pulley. Hopefully I can find a local machine/auto place to punch it out for me. Please let me know if you all have any tips or suggestions. Any and all words are appreciated!

Pics will be up soon!

[Sam Layton]

Hi Jeff,

Sounds like you are well on your way. I am glad you have your motor situation figured out. I often see smaller rotary phase converters on Craig's List. I don't know if that would fit your needs, or if you want a VFD specifically.

What color are you going to paint the saw?

From everything I have heard the Laguna Driftmaster is a good choice for the fence. Hopefully you can go through the purchase process without any problems. I would also not want to buy a new fence, and have to paint it right away... I think the micro adjust would be a great feature.

How are you going to strip the paint?

Could Dan at D and W's give you any tips on how to pull the bearing? Are you purchasing the bearings from D and W's?

I am excited for you. Looking forward to the photo's. Sorry for all the questions...

Sam

[Steven Satur]

One side of the Driftmaster fence will have to be removed to change the blades, plus I do not not of there is enough meat in the side of the table for the brackets.
Get your bearings from Dan, also he can also tell you the brand of paint to use to get to the org. color. It was not cheep but you won't have to strip it down.

Steve

[Jeff Carmi]

Here are some pictures.

A few things to note:

Hole in casting near/under trunnion frame-base: turns out this is part of the casting process and not a hack-job with a torch. After going to D&W the other day I noticed other saws with the same hole, at which Dan elaborately explained the casting process and why this hole is there. He also mentioned that my Comet saw is pretty rare. Almost the entire cabinet is cast into the saw frame, as opposed to Rankin Bro's saws where the cabinet door is the majority of the cabinet.

Guides and Guide Posts: My lower guide was cracked as well as the lower guide post (see photo). The circumference of the post should be complete and not broken as is pictured. The keyway (slot in the post) is meant to engage the steel key and positively lock the guide to the post. I'll be replacing the entire lower guide assembly.

Wheel Puller: Dan lent me his puller (with a deposit) and it worked very well. It's critical to get a good hold with the jaws on the rim of the wheel and secure them with a c/f-clamp. I was unable to remove the lower wheel shaft from the pulley wheel and had to make another trip to D&W so Dan could punch it out for me. Took him all of 2 minutes. . .

Comments/Questions welcome!

[Jeff Carmi]

Sam,

The great thing about VFD's is they're about 98-99% efficient (supposedly). Phase converters are not, and power loss can be great. A rotary converter is basically a static phase converter with a motor implemented to regain some of the loss. This means powering another motor to make up for lost power. . . doesn't make sense at all when a VFD, which is comparable in price, can convert with little/no power loss and do a whole lot of other great stuff.

I'm going with some relative of black (onyx or something) for paint and considering red accents to match the Comet placard. The paint will be a self-priming satin enamel formulated for painting metal from Benjamin Moore. This paint will paint over existing finishes, so I don't need to strip, but I want a pretty flat finish and so need to strip to remove the texture of the old paint. I'll be stripping with purple degreaser (from the home centers) as recommended by Dan - the "poor man's stripper." It works well but is pretty toxic stuff. It needs to stay wet until it is eventually rinsed of the surface. Small parts will soak. I'll spray the frame with a bottle every 5 mins or so. After the cleaning/stripping I'll hit it with sand paper to smooth everything.

Still debating on the fence setup. Like the motor, this may just depend on what I can find for a good price. I'll keep you informed.

See the pictures I just posted for some info on pulling the wheels/bearings. I'm happy to answer any questions. I was nervous about this operation, but it was much easier than I thought it would be. You just have to have the right puller and jaws. I will be replacing all the bearings on the saw, and Dan will seat them for me.

I'm also going to be welding up a mobile base next week and ordered casters (http://www.needcasters.com/footmaster-leveling-casters-GD-series.htm) from needcasters.com. Here's the info from my receipt:
FOOTMASTER 550 lb Capacity Leveling Caster
Product Code: GD-60F
[Choose Wheel Type: Standard Nylon Wheel]
[Choose Color: BLK - Black]
[Choose Leveling Pad: Standard Rubber Pad]
Qty: 4 @ $30.00 = $120.00


Steve,

I'm confused as to why removing part of the fence is necessary for changing blades. It looks like the rail stands off quite a bit from the table and/or can be mounted just to the left of the blade access slot. Can you elaborate?

The table on the saw is a little thin compared to some others. I imagine the bolts for the Laguna fence can't be more than 1/2" though, and hope it will mount securely. I'll have to look into that - good looking out!



Thanks for your thoughts, guys! Stay tuned!

[Steven Satur]

Well if you put a 1" blade in the saw you might have a problem hitting the fence tube, plus it woud depend on if you just mount the fence to theleft of the slot. My thougts are that the two mounting brackets would need to be a little farther apart.
My saw has a sheet metal cover for the motor and was heavy enough to get down the basement. Your saw must weigh another 200lbs.

Steve

[Jeff Carmi]

So it's been a while. . . I got the saw together and working a few months back. Here's a link to it starting up the first day I had it ready: http://www.youtube.com/watch?v=vLP2eTepezA.

I've since gotten the saw way more dialed in and have installed the Driftmaster but have yet to get the new motor in. I'll write more in-depth about the whole experience soon and will have a way more action-packed video to share.