Davis and Wells 20" Bandsaw Restoration

[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/documen...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

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 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.