Dewalt Radial Arm Saw purchase

Hi All,

I picked up a nice yard sale find today, an old Dewalt MBC 27 radial arm saw, 1/2 HP. Motor sounded great, and the saw slid along the the arm easily in both directions. It felt rigid, but I don't really have a basis for comparison. The table is essentially no good but it does have the hardware to bolt down another table. OK so I have a few questions.

1. Suggestions for a blade? 9" is the max rating, so I was thinking of a 8.5" or a 9" blade. Only planning on crosscutting with the saw. I don't have a great understanding yet on rake angles and such for a RAS. I have read about the Forrest woodworker I blade but was hoping for less expensive options.

2. Is this saw powerful enough to handle dado stacks?

3. I need to build a new top for it. I was reading about Mr. Sawdust book that depicts a sandwich top with some steel reinforcement. Is this needed, or can I get away with a double layer of 3/4" MDF? Any suggestions for top construction would be appreciated. For what it is worth, I have a 5' long cabinet to put on each side of the saw, and to have a continuous top to the whole station. Also looking for guidance on what to have for the back stop and how to know where to position the backstop in terms of depth (front to back).

4. I have read a little about these saw rebuilds. How will I know if I need to replace motor bearings and such? The motor sounds great, but I have not dialed it in to see how it cuts. The blade does spin for quite a while after power is shut off, is this a sign of worn bearings? I'd just assume use it as is, but wasn't sure how to diagnose the bearing condition and what impact worn bearings might have on the performance of the saw?

Sorry for so many questions, just diving in to my first radial arm saw. Thanks!

Get the Mr. Sawdust book. Well worth the money if you have a Dewalt RAS. It will tell you everything you ever wanted to know about these saws and more.

There is a DeWalt Radial Saw Discussion Forum available. The guys on the forum know everything possible about these saws and can help guide you through a rebuild. I've done it and it's not difficult unless your saw is really in rough shape. The nice thing about these old DeWalts is that they're really overbuilt, so they usually don't need much more than new bearings, some lube and proper adjustment.

As far as a blade, your MBC was designed for household power in the '50s, so doesn't pull a lot of watts. Any blade over 8" will probably over burden it. The guys at the forum will tell you to buy special Forrest "Mr Sawdust" blade, specifically designed for saws like yours. I tried one and didn't like it. I think people are just as happy with the Freud LU83R 8", a thin kerf blade which won't work your saw as hard and costs a lot less. Amazon has them for $40ish. You can definitely run a dado stack, but will be taking relatively shallow cuts.

Fun project!

Tony, I bought a Freud LU91R008 for my MBC. The negative rake is nice for it reduces the tendency to self-feed. I paid less than $52 delivered from routerbitworld. Sadly, I am going to have to sell my MBC. OSHA rules.

Tony,
As mentioned, you can run a small dado stack on this, but with 1/2 HP, I probably wouldn't think you'd be happy with it. The Freud negative hook blades are nice for Radial Arms, less climb and nice cuts. I use one on my Delta 30C with a 1 1/2 HP and it sings. The little DeWalts are nice saws and you can do a lot with them if set up and tuned properly.

Thanks all for the suggestions so far. I went ahead and bought the Mr. Sawdust book for a reference. I got a good deal on the saw at $30, but it will need some investment. I am going to order one of the negative hood saw blades referenced above (thanks for the suggestions).

I did have another question that came up, which is that the original switch/button to turn the motor on is not there anymore. Instead, seller described that the saw was wired so that if it is plugged in, it is on (hope that makes sense). As a result, he wired an electrical receptacle on a switch to turn the motor on and off. I am thinking about re-wiring this and having a paddle switch in the front of the workstation that this will be mounted. Does this seem like a reasonable thing to do? I found some on amazon such as this one ...

http://www.amazon.com/Woodstock-D415.../dp/B005W17FRS

Will that work?

Tony,
Mounting the switch up front shouldn't be a problem. DeWalt MBCs, MBFs, and GWIs mostly used a Klixon toggle type switch in the upper arm as a starting mechanism. Some were also mounted on the motor end bell. In some cases a key type switch was used. None of them ever seemed to be in a convenient location though, especially when a spinning blade was on the arbor. The larger DeWalts used a switch box on the back column such as the GP and the really bug ones I have seen had Mag starters on them. Where you mount the switch is entirely up to you, just take into account the wiring length you will need and make sure you use a proper switch rated for the application.

My RAS table is just a single piece of 3/4" melamine with a piece of 3/4" white oak screwed to it acting as the fence. I use mine exclusively for 90 degree cross cuts so the table and fence extend over both adjacent surfaces.

I wrote a post about it a few years back and posted a video of it in operation to show the under the table dust collection strategy I'm using. http://www.sawmillcreek.org/showthre...-Collector-yet

I've never been able to prevent a dado stack from walking into the cut on the pull stroke. You can get around this by pushing the blade into the cut, but that limits the width you can cut.

Good luck, and I hope you enjoy your new tool.