Electric motor for Dewalt

[mikekaminsky]

Hi!
I have DeWalt DWE7491RS. What type of motor can you recommend for it? I purchased it second used.. the motor stopped working after one week of usage.
Thanks for any suggestions.

[dewaltdisney]

Have you tried changing the brushes? The motor can get choked with saw dust over time so it might be worth doing a few basic things first

DWD

[Job and Knock]

As far as I'm aware that model is a US/N.America market model, so not sold here. in the UK, the models being offered here being the DWE7491-LX (110 volt) and DWE7491-GB (230 volt).

deWalt DWE7491RS.JPG (42.32 KiB) Viewed 10168 times

Above: deWalt DWE7491-RS portable table saw with mobile base

I understand that apart from the blade guard/riving knife the other main difference is that the -RS model has a longer arbor to accommodate trenching tooling (which is in breach of CE regs). In terms of the motor, though, it is a proprietory universal motor and is built-in, so the chances of obtaining an aftermarket replacement other than from a DW agent is effectively nil. Even there, DW will probably regard the item as a grey import and be rather uncooperative. If the brushes and switch gear are all working OK it may be worth talking with an electrical motor rewind firm to see if they can assist

[mikekaminsky]

Guys, I am from Hampshire, but currently I work in Texas, USA.
It seems like I have to purchase a new motor. I showed the old one to a mechanic and he said that it is better to replace the motor.

If to buy a new motor, I want to choose a reliable thing. Please, help me with the specifications. Do I need TEFC? Single or Three phase motor? I consider this one Link removed as possible spam. Mod 2.

[big-all]

you go to the local dewalt repair center and replace like for like
anything else would require adaption that may or may not be within your capabilities

[Job and Knock]

Agreed. The motor is a universal motor and is specific to that saw - third party induction motors just won't fit and even if you can shoe horn one in you'll probably need to replace the switch gear and the wiring for the run capacitor

[jaeger]

If you can't get a DeWalt replacement as spare part, maybe look to
having it rewound, I've heard of old DeWalt radial arm saws having their
motors rewound.

If you need a replacement, look up a motors frame dimensions table, they are made to industry
standards, although yours might be purpose made.
http://www.engineeringtoolbox.com/nema- ... _1504.html

[Job and Knock]

.......although yours might be purpose made.

But that was the point I was labouring to make - the link you provide is for induction motors - the DW7491 and other portable table saws of the same ilk use OEM-made non-standard universal motors. Universal motors are used in portable tools mainly because they are far lighter for a given power output - and weight is the key to portability........ However, they aren't long-lived

[jaeger]

Can you have a universal non standard?

The link was to supply dimensions that might aid selection of another motor should the
original be unavailable, something to work from.
A problem could be if it's direct drive.
That table has been used to select replacement motors for those cheap Chinese
pillar drills.
if an OEM is available all well and good*, after that I'd try for a repair at a professional
motor repair workshop.
If all else failed and it was a case of scraping then I'd look for a replacement.
An off the shelf motor should need no special wiring, motors I've purchased
to repair/modify machines are 'plug and go'

*I have a 1970's Dewalt RAS and they still supplied me with spares for that so I'd be surprised
if it wasn't available

[Dave54]

Universals usually are "non-standard" as they are often made literally as part of the machine, with the motor frame incorporated into one "drive housing" with a motor, gearbox, and arbor for the blade, rather than a completely separate unit like the induction motors given in the link.
Universals have a higher starting torque, and generally run at a higher speed. The biggest problem though is that they are smaller than an equivalently powerful induction motor, meaning that there usually isn't the room for a different type of replacement.

I'd get the right part(s) if available, which they should be as the OP is in Texas. Failing that get it rewound, although that may be an expensive alternative.

[BillyGoat]

Ahhh, the great thing about standards is that there are so many to choose from

[powersawtools]

I also have this tool. I purchased this 2 year ago and still working good.