Motor type identification help please

[Taf_PembsParticipant @taf_pembs]

Morning all,

My old .. ok .. very old Clarke wood worker belt sander has only gone and let the blue smoke out of the motor.

To be fair to it, it has had a serious amount of use more so in recent years as a reasonable (but slow and very under powered) belt grinder.

Perfect opportunity for me to give her a make over.. or should I say re design but need a motor first.

Machine Mart have a VAT free sale on at the moment so could any one tell me the difference between these 2 1.5kw motors please – 1 obviously has Start & Run Cap’s but the other more expensive one is I presume centrifugal switch but according to their blurb they only do permanent Caps. So I’m not sure and I don’t know enough about them to make the choice.

https://www.machinemart.co.uk/p/2hp-single-phase-2-pole-motor-3/

https://www.machinemart.co.uk/p/2hp-single-phase-2-pole-motor/

 

Would the cheaper one be plenty good enough for a grinder motor or would the more expensive protected one be a better option?

 

Cheers,

Taf

[Clive FosterParticipant @clivefoster55965]

Presumably you have already checked that a 2,800 (nominal) RPM motor will give a suitable belt speed.

3,000 surface feet per minute seems to be generally accepted as a maximum safe speed for a belt.

Personally I prefer things a bit slower, especially if it’s a horizontal belt. A friend swopped a 2,800 rpm motor for a broken 1,440 rpm motor on his and it was a bit scary. If not held really tight things would get launched across the shop. Also difficult to get flat results so the right speed motor was quickly found.

Generally permanent capacitor motors have less starting torque than capacitor start or capacitor start and run ones. Permanent capacitor motors tend to have a smaller load range too. They work best, and most efficiently, on fixed loads like fans. Before I knew about such things I tried to used what turned out to be a motor designed specifically for fan use on a drill. It got very hot if run off load for anything other than the shortest of periods and soon burnt out. A general purpose permanent capacitor motor wouldn’t be so sensitive but the useful load range is always less.

Capacitor start, capacitor run motors give both best starting torque and running load variation capability so its generally worth paying extra to be sure it will work fine.

Clive

[noel shelleyParticipant @noelshelley55608]

Hey Taf, Questions ! is the speed right, 2 pole will be about 2850rpm a 4 pole 1425rpm. The blurb indicates a better insulation on the dearer one, this matters if the motor runs hot or for stop start use. The MOST important point and will void the guarantee is not using an overload protection device (DOL) This appears to add another £44, you must use the right range unit AND set it to the full load amps as shown on the spec plate. IF the sander already has this that’s fine, I DO NOT mean a NO VOLT release ! A fuse is NO USE in this case. Good Luck. Noel.

[Taf_PembsParticipant @taf_pembs]

Cheers Clive, thanks for that..

Makes sense now, bench grinder (permanent cap I believe) takes a bit of spinning up but compressor motor (Start & Run Cap) in virtually instant.

I’m going to keep it belt drive, new base and use the current mounting casting at it seems pretty good. I’m also planning of using some stepped pulleys so I can change the sanding belt speed if required. That’s the current plan anyway!

Cheers again!

Taf

[Clive Brown 1Participant @clivebrown1]

It might be worth considering a 3 phase motor and VFD. Probably a bit more total cost but compact, better motor characteristics and very convenient speed variation.

[Taf_PembsParticipant @taf_pembs]

Sorry Noel, I think we replied at the same time so didn’t see yours.

Reading the PDF advertising on them it indicates that they all have the spec of the dearer one so I have already ordered the Start & Run Cap one.

https://dccf75d8gej24.cloudfront.net/documents/ClarkeElectricMotors.pdf

I’ve also ordered the correct range motor starter (DOL) but from my local supplier where I have a trade account so somewhat cheaper and better buttons (not that it makes much difference!).

I did think about going 3 phase and VFD Clive but I need to keep it as cheap as possible and use what I have where I can, only need a motor, starter and a couple of pulleys.

The driving roller has a diameter of 2 1/2 inches (64mm) so as best as I could work out with a 1:1 ratio on the pulleys for a 2 pole motor that would give a belt surface speed of around 1900 Feet/min. The plan was to get 2 x 3 groove pulleys so I have plenty of adjustment depending on what I’m doing. A bit of a pain to swap but I’ll see how I can put it together to keep it as simple to change a possible.

🍻

[EmgeeParticipant @emgee]

If you ordered the 2HP did you check with the supplier the motor voltage as on the motor list it states 110v for that size motor, but clearly either the voltage or the current is not correct, at 110v current would be far greater than what’s stated.

Emgee

[Taf_PembsParticipant @taf_pembs]

You had me worried then, had to find and check the order! 😲😁

I’ve definitely ordered the 240v,  sorry, 230v version. The blurb on the sheet is incorrect 👍

Hunting pulleys now.. plenty about but want to keep the diameter of both pulleys as large as feasible for what it is as it’s pushing the boundaries of v-belt transmission with 2hp on a single belt on small pulleys. Its looking like 2″ to 6″ pulleys.

But as they say down this way… ‘she’ll be right ..!’

[Michael GilliganParticipant @michaelgilligan61133]

Poly-V

MichaelG.

.

Edit: __ Loads of information around, but this is a reasonable place to start:

https://www.transdev.co.uk/rubber-belts/poly-vee-drive-belts/

[Taf_PembsParticipant @taf_pembs]

Would be much better Michael but I cant find any stepped / pagoda pulleys to suit, not sure if they even do them.

I would like to be able to change the surface speed of the belt so that fairly limits it I think.

 

[Michael GilliganParticipant @michaelgilligan61133]

It’s comparatively easy to produce suitable grooves with a simple tool … it just requires careful setting of both the depth and the pitch.

From the work you have shown us so far, that should be a doddle for you,  Taf

MichaelG.

.

P.S. __ Record woodworking lathes use them

http://aroundthewoods.com/woodturningbasics/lathes/woodturninglathe04.html

 

 

[Ian PParticipant @ianp]

I was going to reply earlier and recommend you go down the 3 phase and VFD route but I realise now that you have already bought a new motor so its too late. For interest then, converted my belt sander (linisher) with a motor and  VFD and its been TRANSFORMED, into a totally different and multipurpose machine! I have it set up to run on frequencies between 4Hz and 150Hz. The motor is off an old Boxford lathe 0.75HP and as the sander is small (100mm x 900mm belt) the motor does not even get warm. I find the ability to place the work on a stationary belt and switch on at a very low belt speed very useful.

However one of the biggest improvements I made was to use a PolyVee belt direct from the motor to the sander pulley which is smaller in diameter than the sander drive roller. This allows clear workspace large workpieces. (my motor is mounted below the sander, more accurately the sander is mounted off the motor)

I realise every user has different requirements for the type of work they do and also have no idea what size of belt or machine you have but using a PolyVee pulley smaller than the drive roller is a practical solution that would be harder and less power efficient than with conventional Vee belts.

Ian P

 

 

 

[Taf_PembsParticipant @taf_pembs]

Cheers for the comments folks, I do like that lathe set up Michael, very nice. certainly something to consider when I get some chunks of metal suitable to make some pulleys.

You are all of course correct in that how I’ve decided to do it is really not the most ideal way but there is method in the madness!

Clive Brown suggested the VFD route earlier in the thread but I had already discounted it really. 2 reasons, firstly I simply had just enough to but the motor while it was on sale and didn’t fancy hunting for a used motor really to cut cost that way. I deliberately went for something more than powerful enough so if I do get round to making a proper 2 x 48 belt grinder or the like then I already had the motor (appreciate that a 3 phase and VFD would be far better for that).

The other reason is I need it to be as portable as possible to take to other places so needed it to be simple so I opted for a single phase and try to make the best of it with the ability to alter the surface speed with pulleys.

Cheers folks, appreciate the input!..🍻

[noel shelleyParticipant @noelshelley55608]

For what it’s worth Taf, I have a Axminster belt sander 6″ wide that runs on a 3/4Hp single phase motor, this was bought to flatten brass castings . It never got hot and is 27 years old now, I doubt you will need 2Hp, or even 1Hp. So power transmission on a single belt will not be a problem.  Good Luck. Noel.

[Taf_PembsParticipant @taf_pembs]

Cheers Noel, good to know!!

The original motor was a 1/3 hp and anything other than very light pressure would stall it (what killed the low speed windings I suppose 🙄) but as I said, it is very very old, I think its the first version they ever did.

Only reason for the 2hp was all the decent linishers / belt grinders I’ve looked at had at least 2hp so it was stuck in my head. May get a bit of belt slippage but I doubt very much I’ll be stalling it now!!

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