Startrite 351E bandsaw motor swap

[Farmer Giles]

My ageing bandsaw motor started to give up the ghost a couple of days ago. I intend to replace the motor so I thought I would post it on here in case somebody else wants to do it, or somebody already has so I can make sure I don't fall into any avoidable issues.

I had the saw from new, it's about 15 years old and hasn't had a hard life. It has a 1.5hp single phase motor, it started to struggle getting going a while ago so swapped the start capacitor for an identically rated one. This worked for a while but it was still struggling to get up to speed but the saw spins nicely by hand so it's not binding on the guides etc. I detected the faintest electrical smell the other day and suspect it is on its way out, I was only gently feeding 15mm oak through it so not pushing it. Before I condemn it to the scrap yard I will take the bottom blade wheel off, remove the belt and start the motor with no load, but I think its dying.

Given I always thought it was a tad under-powered, and I now have a 10hp 240v single phase to 415v 3 phase converter, I am thinking of changing it from single to three phase and upping it to at least 2 if not 3hp.

Modifications I can foresee is the motor shaft may increase in diameter so the pulley may need a new taper bush and possibly pulley. Also the NVR switch will need swapping. Apart from that as long as I can get the same frame mount on the new motor it should be relatively easy - famous last words!

Existing motor is a invensys compton made in Doncaster, its a big old lump for 1.1kw, its 2850rpm at 50hz but other than that the motor plate doesn't give any info on flange mounting type etc. and the motor code on the plate doesn't turn up in searches so I will have to take it off and measure it. It's probably a B5 flange mount, the flange measures 200mm diameter with probably a 165mm PCD, but I can't measure the register without taking it off but probably 130mm diameter. There are 3HP 3 phase motors for just over £100 with a B5 flange so with a bit of luck this will be the one, the shaft diameter will go up from probably 19mm to 24mm.

Three phase NVR switches are about 30 quid, so total with VAT for both switch and motor will be about 160 quid, with pulley shaft bushes and cabling I'm budgeting about 200 quid.

I shall post some pictures when I get down to it. I may still get tempted by a larger bandsaw, if so I will still replace the motor but will probably keep it to 2HP single phase so I can sell the saw more easily.

Cheers
Andy

 

[mbartlett99]

Why don't you take it to your local motor guy and have it rewound. Afraid I don't know anyone in your area but the guys I deal with are old school and really know their business - might be worth taking their advice on your options.

 

[carbo]

Take it to Doncaster rewinds...

 

[acewoodturner]

I have a startrite 352 and went from 3 phase to single phase many years ago. Not too difficult a job once Startrite had faxed me a wiring diagram. A few time it has cut out due to overheating. Although I use a good extractor some fine sawdust does get inside the motor. I usually just strip the motor down and give a good blast of air from the compressor and put it back together again. Good to go for another few years anyway. Maybe its worth doing the same.

 

[Farmer Giles]

I did consider a rewind however even when new its was a bit under-powered so I looked at this as an opportunity to upgrade it. However I guess the motor could always been a bad 'un and is unrepresentative of a 1.5hp motor.

Interestingly I have an Elektra Beckum spindle moulder with a burnt out motor, it is not a standard motor fitting so will be the answer for that. I didn't do it as other priorities became apparent but I should blow the dust off that while I'm at it.

Food for thought, I grew up in Doncaster, I can see a drinking opportunity with old mates coming up.

 

[carbo]

Tell them mark Davies sent ya... they may be able to advise you on what other options are available. Just across from the range.

 

[paulm]

Another possibility for you perhaps for-sale-brook-crompton-electric-motor-single-phase-t83308.html

 

[Farmer Giles]

Thanks Paul, given somebody may search and find this thread and be disappointed that it is curtailed by buying your identical motor, I shall post a couple of pictures of the replacement.

I had my eye on a bigger bandsaw, but didn't want to buy yet so this will give me a bit of breathing space to save up and get the shop tidier

 

[paulm]

You're a gentleman to do business with Farmer Giles, very happy it's going to be put to good use

 

[Farmer Giles]

I eventually got around to fitting the new motor today, many thanks Paul, works a dream It took a while as I had to clear a route through the workshop to it so welded up a stock stand first which takes all my long wood and metal stock which was on the floor in front of my woodworking machines, the workshop floor has never been so clean. Plus my wife broke her leg while we were skiing last week so I am working from home whilst looking after her and the kids, dog etc.

So after the motor I thought I would change the blade, I had forgotten how much of a PITA the guide block adjustment is on old startrites. They work absolutely fine when adjusted, you could say keep it simple, and it is, however they are so basic they are backward. My judgement on this is not clouded at all because I also managed to bang my head on the open upper pulley door, honest! :roll: Who decided to hinge the doors on the right anyway? stupid idea, the back of the bandsaw is usually towards the side of the shop so why not hinge them on the left so the door opens towards the side?

So now the guide blocks. Rant in order of annoyance.

Firstly they twist as you tighten them, yep, you can grip them after eating 4 shredded wheat, make a jig, do a jig all sorts of ways. But why should you? It wouldn't have been difficult to make them so they slide horizontally but can't twist.

Secondly, the fore and aft movement of the lower guide, the bolt that adjusts this is in a place where you get about 5 degrees of spanner movement. I had to hunt around for my 13mm ratchet spanner. Must have been designed by the same bloke who gets paid a fortune to make the bolts on cars a sod to get to.

Thirdly, the bolt that adjust the for and aft movement of the upper lateral guides also adjust the rear guide. So you adjust the lateral guide location so you get them nicely behind the teeth, them move the rear guide and screw up the lateral guide location. It can be done, it's just fiddly, and seeing as I only do it once a year, I don't get used to it, I just invent new swear words each time.

Fourthly will have to wait as I ran out of time due to the bash on the bonce, as a follicly challenged gentlemen, I always have at least one head scab and it took a while to stem the bleeding - both literally and verbally!

I still think they are great bandsaws, and not having tinkered with other makes I suspect these are a PITA to swap blades too. It should be a doddle and it isn't difficult to engineer it that way, it annoys me when I'm sodding around with half engineered products when I could be making something.

My finger hovered over the ALT saws roller guides for the Startrite bandsaws, not because they guide better but they promise to be easier to adjust but at 200 quid for the pair to save swearing and a yearly head scab is a bit steep!

 

[Harbo]

You can change the guides to roller bearings quite cheaply.
Been posted on here before,

Rod

 

[Farmer Giles]

You can change the guides to roller bearings quite cheaply.
Been posted on here before,

Rod

I've looked at a few old posts, I think the axminster guides are the cheapest however I don't want to swap one fiddly design for another so I shall persevere for now, muttering under my breath until I get chance to look at some in the flesh. I'm tempted to make my own, I've got the means to do this but I have other priorities at the moment. I might go to a woodworking show and look at a few bandsaws to see if there is a good design out there I can build on for when I do get chance.

Cheers
Andy

 

[Farmer Giles]

After a good nights kip and without having a pressing deadline or a throbbing bonce bump, I attacked the guides again this morning, still a PITA but they are nicely aligned now and have a 80 gm paper gap between blade and guide. Yesterday I did manage to align the blade in the centre of the wheel OK however again the saw hasn't been designed to help you. The wheel is 27mm thick so the gullet wants be around 13.5mm. As you can't see it straight on because there is no sight hole, the best way is to take a picture and look at it on the PC. Looks about right to me. I might check out the tyre brushes before I close the lid, now time for dad's taxi.....

 

[andersonec]

I bought 8 roller bearings from "Bearing Brothers" and just put them on with a bolt.

Are you sure it's the motor going or is it the drive belt slipping when it is slow to start up? I know the belt is toothed but if it is loose or worn it will slip.

Andy

 

[Farmer Giles]

I bought 8 roller bearings from "Bearing Brothers" and just put them on with a bolt.

Are you sure it's the motor going or is it the drive belt slipping when it is slow to start up? I know the belt is toothed but if it is loose or worn it will slip.

Andy

The new motor is fine and I had changed the run/start capacitors on the old motor before it let out its smoke so the old motor was defo knackered. Whether the old motor's life ( it was 17 YO) was shortened by bad guide block alignment is possible, I haven't always been as patient with fiddly tools when I had a lot of stuff to do.

I have my dads' old stash of bearings, hundreds of 'em so for the lateral ones I could replace relatively easily but would reuse existing adjustment system. The benefit would be the lack of tilt when tightening the bolts, but at the cost of the amount of support the old guides gave. Given my initial rant is over and I now have a nicely adjusted blade in use, I will contemplate the options for future use.

Cheers
Andy

 

[paulm]

Glad you're up and running again FG

The guides are quite quick and simple to set once you have done it a few times, honestly !

 

[Farmer Giles]

Glad you're up and running again FG

The guides are quite quick and simple to set once you have done it a few times, honestly !

Thanks Paul

As I said, bashing my bonce on the upper wheel door had no bearing on my comments on the guides at all! :lol:

 

[paulm]

Yes, I can see that bashing your head while doing it wouldn't help at all !!!

What might help though is that the doors just lift off the hinge pins, on mine anyway and hopefully on yours, so if in the way I just lift them off and put to one side.

No idea why they can't just hinge them on the other side though as you say, which would be easier still !

 

[Farmer Giles]

I will be taking the top door off next time Paul, I have enough craters in my head!,

Here's the motor swap, pretty simple, not much too it, only a couple of points where a hand from somebody else make it easier, there was a guy repairing a dry stone wall that I managed to coerce with a mug of tea to help, although he was a bit reticent when I told him I wanted him to hold my nuts while I tighten them :shock:

Here's the motor in question, notice the old wooden planes on the floor, I used to find them down the tip along with all sorts of other useful stuff before the council outsourced the dump and the thought police moved in :roll:

I always take a picture of the electrics before dismantling. Of course remove the power before you do this. Remove the power lead before moving on.

Taking it off is a bit of a pig as the lower two bolts are impeded by the saw frame and even with stubby spanners its a pain. I tried to replace the motor without taking the lower wheel off so undid the nuts, in the end I had to take the lower wheel off anyway so its easier to undo the bolts from the other side.

Here's the motor off, you can see the pulley at the bottom. The bolts aren't captive and have four washers on you have to take the lower wheel off to get the motor back on otherwise the bolts just push through and the washers fall off. Ideally this is where help is needed for a couple of minutes. The lower right bolt is fixed, the other two slide in slots to adjust belt tension.

Taking the lower wheel off is easy however you have to wedge the wheel while you undo the bolts. I got a couple of soft wood wedges and wedge them between the wheel and the frame, Sorry, I forgeot to picture this, be careful as you don't want to damage the tyre or wheel. Here's the bolts out, before I took the wheel off I marked the wheel and one of the holes. I doubt very much if the wheel is balanced in situ however if it ran OK before, putting it back the same way isn't going to hurt.

Here's the wheel removed, you can see the marker about 1 o'clock. I checked the belt, it was fine so went back on, I did take a picture of the code on it but it came out blurred I was going to order a spare. I took the blade off at this point and gave the machine a good vacuum.

The rest is simple, just in reverse, For belt tensioning I just used the weight of the motor and tightened the bolts up with assistance of the dry stone walling guy and a second mug of tea, interestingly when it came to putting the cable back on, it appears the motor was wired incorrectly from new with the live and neutral reversed. it isn't going to make any real difference being AC however I put it straight. On the diagram on the back of the lid of the terminal box, live should be on U1 and neutral on U2, as you can see from the first photo, they are reversed.

Once I had tested the motor without a blade, I put the blade back on and set up the guides, tensioned the blade and did some test cuts for squareness. I did have a 5/8" blade on which is pushing it for this saw, I didn't have a 1/2" in stock so it ended up being a 3/8" 3 tpi skip blade, no drift and nice and square, no fence adjustment needed.

Last thing I did was order an A4 magnetic dry wipe board so I can put it on the door. I can use this to write down which blade is in use and what blades/belts etc. I need to order.

Cheers
Andy