Motor choice for Wadkin AGS10 restoration

[Goldfinger234]

I was just saying my experience after 30 years. Sorry to the Original Poster. I did follow up to say ignore me .

To get back on track if this chap does choose to go down the vfd route then IN MY OPINION it's worth checking Clough42 YouTube Playlist on the TECO LS510 unit. It may help.

Either way. I'll keep my thoughts to my self in future.

Be happy.

M.

Don’t have to keep it to yourself, overrunning motors is OK as long as it’s within the spec of the motor and you’re not putting undue load on it. Mainly it’s bearings you’ve got to be careful with, and whether the saw itself is OK to use at that speed.

 

[Spectric]

Don't forget that max torque will occur at 230 volts 50Hz and as you push the frequency higher the torque will decrease even with an increase in speed.

 

[Megaweasel]

Interesting discussion

Motor has arrived this afternoon. It is metric which does mean I need to drill new holes in the motor plate, but as it seems to have quite a few holes in it already I’ll probably weld those up and drill new. You are correct it’s a metric shaft so will need to machine the pulley/get a new pulley. I do have a mate who should be able to do that for me - or failing that I’ll get a new one. It should be the same size as the old 3-phase motor as it is a 2-pole motor, 2800 rpm 2HP. Given the sizes of the pulleys we should end up around 3500 rpm.

Cheers all and thanks for the advice. Perhaps I’ll post once I’ve got it going on my observations (although there are a lot of Wadkin AGS rebuilds here already - loved the BGS 10 rebuild BTW Deema)

Chris

 

[Fergie 307]

Don't forget that max torque will occur at 230 volts 50Hz and as you push the frequency higher the torque will decrease even with an increase in speed.

And likewise if you slow it down, often not a problem on something like a lathe. If it has a gearbox that can compensate for the loss of torque to an extent. On something like a saw it could be an issue and it might bog down. Im with others who have said you dont need variable speed, just get the correct motor to give the speed at the rim you are looking for.

 

[Fergie 307]

I presume you’re talking about an RS or something similar. They were 6 pole 900rpm motors originally and a very big lump of a thing. Hopefully changing the mount on the saw won’t be too bad, it won’t have had a motor like yours to begin with. I can’t remember exactly what mine was like internally, it was nearly 20 years ago, the belts on saws are usually short, therefore if the OP has got a 4 pole motor by accident he could be screwed to start with, as you’ll need a bigger pulley on the driven shaft to give you the same speed at the arbor as the saw was designed for. I hope he’s got the right one. This is where the minefield can start with these machines if you’re not very clued up on motors etc..

Mine was a 1.5 hp 1400, so presumably four pole. Still going strong as far as Im aware as i gave it to a guy to replace the faulty one on his lathe.

 

[Noel]

I’ve tidied up this thread. In fairness to the OP I hope it still makes sense.
But please note that if anybody cannot convey an opinion in a respectful and polite manner it’s best not to post, just move on elsewhere.

 

[Megaweasel]

Thanks to everyone for the advice - having purchased a single phase 2hp motor, thought it might be of interest to discuss how I fitted/tested it on the AGS 10. I’m just trying to fit it so that i can be sure that everything is ok and that it will work before I strip the machine and replace parts/ paint it etc.

Following the advice in the thread, i decide to go with a simple single-phase update rather than the VFD/three-phase. VFDs that work at 380 volts are now available and while expensive might have worked with the existing non-deltaable motor (is that a word?). However, i had no easy way of checking the motor before committing to the VFD and I’ve read a few things that suggest older motors insulation on the windings might not take well to using with a VFD. That left replacing with a delta-able 240v three-phase or a single phase motor. General consensus was that there was going to be little benefit in the VFD for a table saw - breaking and soft start might be nice, but reverse would be positively dangerous! Breaking would require some large resistors outside the VFD. In the end, single-phase would be cheaper and easier to do.

I got lucky and found a TEC motor on ebay being sold new-other by a company selling pumping gear that apparently overstocked during the pandemic. I got it for £50 quid plus £17 for postage - bargain! It’s 2hp (1.5KW) and 2860 RPM which by my calculation should end up around 3500 RPM - or thereabouts.

Once the Motor arrived, I lined it up with the existing one and was delighted to find that the distance from the mounting plate to the centre of the spindle was more-or-less the same. the old one had developed a bit of a lean but then it only had a pressed-steel foot

This would help keeping to the original belt size a lot easier if the motor can end up in the same place. I marked where the centre of the shaft came on the old motor when mounted on the plate ( when I got the saw, the motor wasn’t mounted so i placed it in roughly the right place, selecting what appeared to be the right set of holes from all the various ones in the plate)

Then i mounted the plate back on the saw and clamped the new motor to it to check the position:

There are quite a few holes in it now so i guess it’s had a few motors in the past. I might look to weld these up before I paint it, just to make it look a bit tidier. Once i got it roughly the right place, I clamped a straight edge to the spindle pulley and then jiggled the motor about until the straight edge sat straight against the shaft. Then I marked the motor position with masking tape (couldn’t get a straight line to the holes in the foot).

All good, so took it off and drilled the holes and mounted the motor to the plate with some new bolts and nyloc nuts.

Wired the motor with some new flex. Needed to change the wiring as it was going to be running backwards in its out-of-the-box configuration. Not a big problem as it had the diagram of how to re-arrange the plates in the lid of the connection box. I did find that I had to move the connection box a couple of times. as delivered the cable gland was facing the rear of the motor which wasn’t great and the box is wider than it is long. I unbolted it and moved it round so that the cable entry was towards the front (i.e towards the Switch box). However, with it in this position, it fouls against the lower cabinet. I swapped it 180 degrees as the connection box is not centred. It now does lower all the way. This is an important consideration as the motor is pretty huge - bigger than the 3-phase original (i.ve read that in general, 3-phase motors tend to be a bit smaller so that might be another consideration for the VFD/single phase debate).

I got a new SPZ three-way taperlock pulley to fit the new motor. Oddly, I had in my box of parts two 587 v belts and one 612 Which was odd. On the balance of probabilities I fitted the two 587s so I could at least test. Tensioning is actually pretty easy as simply letting the motor mount drop tensions the belts under the weight of the motor. Powered it from the wall with a 13amp fused plug to test and it ran great. Spindle bearings seemed ok but the blade rang a lot, but then its a pretty old simple blade on it. Starts quick and doesn’t seem to impose a particularly heavy load (lights don’t dim ) It also stops much quicker than I was expecting (quicker than my current saw in fact)

It’s odd watching it without the table top on - it looked really fast so thought I’d measure it. Used a strobing iPhone app that uses the camera and the flash. I scribbled some black sharpie on the blade and also stuck a strip of masking tape on the spindle. It did a great job and I found it was running at 3954 RPM. I guess the slight change was due to the slightly larger metric Pulley rather than the old imperial one on the old motor - i went for the nearest.

So really happy now - got a quiet motor installed and it works fine. I know the belt size so will get three new belts and a nice new blade.

I’ve stripped the saw down today which went very well indeed. Not a single stuck nut and no chipped teeth or broken/chipped cast iron. I’ll probably look to replace the spindle bearings and maybe get the face machined as its out by about 0.1 MM. Doesn’t sound a lot but at the top of the blade is considerably more, and while its in bits it seems sensible. Will probably change the bushings for the tilt while am at it as there is some play in there.

I also need to get a new NVR. There is evidence of some burning/Charing in the past to the front of the machine, but the inside of the switch box looks ok so I guess it was replaced. The controller on there is for the old three-phase (DOL?) so I don’t think.I can use it. Shame as it does look nice in its metal box - very ’period’. Perhaps I can adapt something From one of the ugly grey plastic boxes. Anyone ever done that?

Anyway, hope my ramblings may be useful to someone wanting to do this in the future, and thanks so much for all the comments and advice.

all done for 95 quid (So far…)

 

[Fitzroy]

Superb, it’s great when folks come back with an update on the outcome, £50+ postage you lucky blighter!

 

[Megaweasel]

cheers! - must admit I was chuffed to tiny bits when I got it. During lockdown I built one of Matthias’s belts sanders (the woodgears one) for something to do and had to find a motor. It was a real balance of how much is it / where is it/ how much will it cost to get it. Took ages to find one at a sensible price. This one (one or two available) just showed up on the day I needed it.

It is branded techTop rather than ‘tec’ - don’t know what the story is there, but it runs sweetly, stops fast, and goes round at the right speed so hey-ho..

Sometimes you just get lucky.

 

[Housey210]

Hi all,

I have a Record/ Minimax C26 universal but find I rarely use the sliding table these days, favouring my track saw for panels and Kapex for cross-cutting duties and i rarely use the Spindle moulder. I’d like a planer with a (quiet) helical cutter rather than the straight Tersa blades so started thinking about a change to a small table saw and a stand-alone planner/thickneser.

At least that was my logical reasoning - really, i think I just wanted an excuse to buy an ancient table saw as a restoration project - hence after watching a few on eBay and a good bit of negotiation and van hire, I have a nice Wadkin Bursgreen AGS 10 (or possibly AGS250) table saw of I think 1977 vintage.

looks terrible at the moment but its actually in pretty good nick - its complete, no cracks in the cast iron, no missing teeth, rise-and-fall works nicely, tilt works nicely, tops looks great, so all good. Had a large custom dust chute fitted (see pic) which I hope to remove and replace with something a bit more ‘modern’ around the blade.

Anyway, initially what I need to do is get a motor and fire it up. It came with a 2 hp, 2800 rpm 3 phase motor which seems to be of the same vintage as the saw (Newman). It’s 400V and not capable of being configured to Delta - at least not without stripping and doing scary wiring mods that I really don’t want to try myself.

So I need a motor and I’ve spent a good many hours researching and reading up on VFD’s etc. I get it for adapting a drill press or lathe to add variable speed and perhaps DC braking for rapid deceleration but given I’ve got to buy something, are there any real reasons why investing in a Delta 3-phase 240 v motor and VFD would be a better idea than buying a new single-phase motor?

I can get a ‘period’ 3-phase that will work for around 100 quid, or a new one for perhaps 150 quid. VFDs (Chinese) seem to be around 80 quid or so - so £180 to £230 or so for the VFD - then it needs mounting and wiring to use stop/start and emergency stop.

Lots of options for single phase motors - period one that looks nice or a new one. Simple to use and wire with a new NVR.

So - bit long and windy, but any reasons to go VFD for a table saw resto when buying from scratch?

HI,

I have this if you want it. Three phase, removed from my old wadkin boa thicknesser. I am keeping the pulley though!

 

[Megaweasel]

ha - would have been great to try the VFD thing - but I now got and fitted a single phase, stripped it down, welded the old holes and getting it all sand blasted! Would have looked nice and 'period' though..