Reel Repair by Alan Tani

I have an elcheapo bench grinder, how do I slow it down?

For my dc trolling motor, I use an inline PWM controller to control the speed.

What do you guys use for a/c motors to slow em down?

Well that's a Color of a Different Horse as some motors can not be (turned down by reducing Voltage ) it will burn the Windings  HOWEVER depending on the Motor you have there are a few options .

They make Step Controllers for this too.
My Router has  one . I will take a peak at the particulars on it and get back .
Meanwhile get the info off your motor plate if you can .

For my outer shop stationary grinder, I have a dual head single speed unit.

For the upstairs shop, directly to the right of my stool I have (3) grinders.

(2) are Mini-Grinders with a total of (4) 3" heads — fine wire, grinding stone, burnishing stone, fine grinding stone.

The larger Craftsman has (2) 6" heads — buffer and a wire wheel.

These are all hard mounted and accessible just by swiveling my stool — and they are far enough away from the bench so as to not throw dust or crud on the reel work.  They are all hard mounted on a rolling bottom toolbox — at bench level.

And all three have variable speed controls built in to the units — quick, easy, accessible, no fiddling with extra loose wiring, or taking a chance on heating up or ruining a motor not designed for variable speed work.

I keep a pair of safety glasses, clean and on top of the first grinder — and another backup pair on the reel bench pegboard to my lower left.  These are the types of safety glasses that go over my reading glasses — and have good side protection also.

Best, Fred

For my linisher, bench grinder/polisher, pillar drill, etc induction motor driven things I use something similar to this:

https://www.ebay.co.uk/itm/174822234137?_trkparms=ispr%3D1&hash=item28b4379819:g:9EcAAOSwT5tg3V60&amdata=enc%3AAQAGAAACwPYe5NmHp%252B2JMhMi7yxGiTJkPrKr5t53CooMSQt2orsSDAeS9EQtjPGVfKXTxF0%252BjhEz5RdsnkPWzgHFJd3csHALhoDufUNmmFQAdBqiMJOP%252BGSvv6uRFjpk82Bm%252FW5v%252B83lAr0tfJ10IPZ7GhvNEoUx6R%252BTFTknxSB3ARLX8w7a25NygyxDvEeGTV4LLu3AXy%252BJJY674sWecmdwAzmqt9N2eIgumosPQJdAJgubs5GvPl7D38856nLh3TwlxZBcFGBNxc%252F%252BcCGu8wTYNseVKTIhXFzO9aUl1i5IOksc%252FwcLXrLXjv4jt1FB9%252B0PBMOMQb2GySlXFBn35BCCtHt9Ydqf3UsMQ%252FQ88lA1%252BdidEv915Udf%252B4uUOTyffwTUumVbB7PCerv8rwIUJo3Vn%252FOvnKIhreF8QdBrpAzBpMIqHoWe4KvpOMao8MP2nHtIBs%252Buv0pj5UeY2uwrPL0yPdICeVAp3tiN80qT9aPklh3JwkydUeajj65tdUP%252Bon8bzpmjAiT2zOWysqsx8SYrZnAYZEmN56m%252Fwrh6Dwu%252BTlnOg6%252BeVRCyGLhd8apBVvOcgOW6nSsbyA39bxv2G5A99BZqV0ttDm9NkGm7G06fX6ws6qZcUZoTnJlM4rVopmYCRwM82hg%252BF%252FgOsmQRxE2VX9x4s%252BUcFIU%252FNXEUMZ8aQiGDX2eCq0IWSkhVmgj1%252FN4lGzPYT0iJddS4nPV4ni9gQEl4V0LqaQ267H25dES44yjGzB4s6OX9oxcsKbzDZf%252FcV1Kkgiq0kd8YO8XX2mjX%252FlFEY66vxOD9e9r2EFQvbwjD7HYrRJzwE6IgS%252BoAtf%252B5oj3atdqpyUX2sYzEVNtDzj%252FYkLDQnaRw9EBzeOZLWrYQVEOmnZ8X8Aech0SMyqklwyqfM0vg9mrciqdZERbPsXjxx4BTkDU%252Bz6aOpcJS6EcjFF1n%7Campid%3APL_CLK%7Cclp%3A2334524

I didn't buy this particular one, but they are all similar
I just used it in single phase mode - they can convert single to three phase if needed.

These things really work well There really isn't an alternative type of device! My one has been in service for a few years with no issues
Wire it for a mains plug input - fit an appropriate mains socket output - you can then use it for any induction motor device (just allow for power requirements )

I don't like the single phase/3 phase motor speed controllers, what I have installed on the header drive motors of the algae harvesters are below.  They plug in in between your power source and your load with standard 3 prong 120v plugs.


https://www.walkerindustrial.com/Dart-Controls-55AC15E-p/55AC15E.htm?gsn&gclid=Cj0KCQjwxdSHBhCdARIsAG6zhlUXpfS8IgVuafRWGQs2mV3hnsCqSH-wrlf3UFZquzkhnY1oyJN9V7oaAo9AEALw_wcB

https://www.harborfreight.com/router-speed-control-43060.html

The Harbor Freight one will work if the amp load is 8A or less., it says 15A on the controller but in the specs it says 8A.

" Plug any router into the control unit and get instant variable-speed control.  Works with any universal AC/DC brush type motor, 8 amps and under"

Check the amp load on your bench grinder.

$180 v $18 is a lot of $ and if the HF one does not work it is no big loss.

I try to not do Amazon but sometimes it can not be avoided, this one will work for up to 15A and under $26.00.

https://www.amazon.com/Universal-Variable-Voltage-Control-Controller/dp/B01M1I4NLX

Quote from: Wompus Cat on July 19, 2021, 03:20:59 PM
Well that's a Color of a Different Horse as some motors can not be (turned down by reducing Voltage ) it will burn the Windings  HOWEVER depending on the Motor you have there are a few options .

They make Step Controllers for this too.
My Router has  one . I will take a peak at the particulars on it and get back .
Meanwhile get the info off your motor plate if you can .

Yes, me do not want to burn the winding!
Pic of spec coming soon. Thanks,

Quote from: foakes on July 19, 2021, 04:02:46 PM


And all three have variable speed controls built in to the units — quick, easy, accessible, no fiddling with extra loose wiring, or taking a chance on heating up or ruining a motor not designed for variable speed work.

I keep a pair of safety glasses, clean and on top of the first grinder — and another backup pair on the reel bench pegboard to my lower left.  These are the types of safety glasses that go over my reading glasses — and have good side protection also.

Best, Fred

Nice setup Fred. Variable speed benchtop grinders, it would be nice to have 2 of them but I have space for one.

I had not idea that I needed one with variable speed when I picked mine up at lowes. :-)

Yes, I have a full face shield, freddie krugger style,

Quote from: Keta on July 19, 2021, 09:57:46 PM
I try to not do Amazon but sometimes it can not be avoided, this one will work for up to 15A and under $26.00.

https://www.amazon.com/Universal-Variable-Voltage-Control-Controller/dp/B01M1I4NLX

Quote from: thrasher on July 19, 2021, 09:44:15 PM
https://www.harborfreight.com/router-speed-control-43060.html

THanks guys, I will dig up the unit and post the specs first,

running a fast motor at slower speeds will result in heat?

If it's an induction motor do not use a universal/brush type motor speed controller.
To properly control the speed you need to vary the frequency of the supply not the voltage/duty cycle.
Use one similar to the one in my previous post.