SCM Minimax S45 Bandsaw Teardown & Overhaul

[Sideways]

This thread is to share a (hopefully quick) overhaul of a secondhand Minimax S45 bandsaw in real time.
I'm working on this with my buddy Deema and our aim for the saw is to give it a good clean, a thorough mechanical overhaul and ensure the electrics are safe and robust.

We both share the view that the Minimax bandsaws are a quality tool. Simple and robust.
The S45 is the smallest in this range.
Minimax were founded in the 70's and offered innovative machines aimed at advanced amateurs and small professionals. They have been very successful from the early days and since 1986 as part of SCM.

Here are a bunch of images of this used saw as we were getting started. Maybe Deema will be able to chip in a full length shot but I was more interested in recording details for reassembly....

The saw has a stong frame

Plenty of paint, resin and sawdust coating the machine

but trunnions are very solid

and dust extraction is concentrated where it will do most good - as the blade enters the lower wheel case

.
Love the improvised brush

Solid cast band wheels

And simple substantial guides

 

[Sideways]

We stripped the machine down to the frame and put in the hours to clean it. Under the dirt, the paintwork is in very good condition overall. It's a quality white enamel so it would be a waste to strip it and repaint. The top left corner of the saw has however taken a knock at some point and the upper door has a dent. It's fully functional still so we will have to decide whether this is acceptable or if we can improve it.
All bearings will be replaced. The wheels have been pulled off and the motor disassembled so that we can identify the bearings and order replacements. New belt will be fitted. Everything cleaned, reassembled and adjusted.
Here is the inside of the motor. It's in excellent condition.

The front bearing where the spindle is loaded : some wear can just be felt compared to the rear bearing which always lasts longer in normal use but it has a lot of life left. We'll replace both as routine.
Originals were good branded NSK bearings. The replacements will be SKF from choice but NSK, ***, and the other big name brands are all safe choices.
The rotor is nicely made and you can see the balancing. The rotor is cast with projections front and back. Washers are placed over these to add weight where it is needed and the stems swaged over to keep them permanantly in place. Like car wheel balancing but these are never intended to come off.

The spindle looks brown but this is just rust, resin and sawdust. Easily cleaned before the new bearings are fitted.

Here is the frame of the saw after cleaning and with the doors popped back on for safekeeping

 

[deema]

The paint used on these saws is IMO excellent, the reason for starting off with this statement is because the saw looks rather sorry for itself. However, we know what a few hours work can do, and this saw will look great again without a repaint. So, this is the saw in it’s as purchased spleder.

The ‘trick’ of cleaning tge paint is finding solvents to remove the black permanent marker and sprayed on red identifier as well as any over sprayed paint without stripping the original paint. the SCM paint is very robust, and makes it relatively easy to remove the ‘graffit’.

 

[deema]

Whilst Sideways took the saw apart, every nut and bolt removed, I was busy taking the motor apart. The fan is usually the most tricky bit to remove. It’s incredibly easy to break them, and they must be intact to correctly cool the motor. We usuallt gently warm up just the centre of the plastic fan to make it ever so slightly soft and to expand the plastic. A little gently plying usually gets them off. You can source new fans when occasionally they don’t want to play.

A puller is needed to remove the pulley after first extracting tge locking grub screw.

I mark the front and rear motor caps and their respective locations on the motor housing using a centre punch. This is to ensure I put them back together in the exact same orientation and alignment.

The motor bearings will be replaced with new SKF bearings and the whole thing will be cleaned. The paint is in excelkent condition, nothing a bit of elbow grease won’t sort out. Hopefully the bearings will arrive quickly, I have some others that should have been on next day delivery that I’m still waiting for over a week later.

 

[Ttrees]

@Sideways and @deema
Love looking at the details which you folks put into your threads.
A question if I may, as I haven't got a good look at the wheels of a Centauro to see if the bore of the wheels was non shouldered, like on my machine.
I have to make a new spacer for mine, and was wondering if the s45 has the same setup as this, as in
Whether the spacer is made of plastic or metal, if it's as deep,
if it fits snugly on the shaft, and if it's the thickness is matching the inner race.

Thanks
Tom

 

[deema]

Hi Ttrees, the S45 doest have a spacer, it uses two circlips to act as hard stops for the two bearings in each wheel hub,
Here is the schematic

 

[deema]

The tyres on this saw look virtually brand new, it’s been sat for a long time without being used as the belt was literally triangular having taken a set. A new A37 best us now in order. The A signifies the belt section, which is 13mm wide and 8mm deep, it’s a v section.

The pictures are all from the ’original’ condition. It’s only by completely disassembling the saw can you verify the condition of everything, make sure everything is working properly so that you can set it back up correctly to ‘as new’ condition. Clearly there is going to be some ‘patina‘ from it being use.

Bottom driven wheel.

Top wheel.

 

[Sideways]

I snapped these as the wheels sat on the floor after removal.
Both were pulled forwards off their shafts with a a three legged puller.
The rims have been part drilled to remove weight as required to balance them.
One photo is down into the hub of (possibly) the top wheel. You can see the two circlips and the ball bearing at the bottom
One photo shows the spindle of the lower wheel with a bearing remaining after the wheel was pulled off.
Last shot is the belt code ...

 

[Ollie78]

Looks like a good one.

 

[ndbrown]

My first bandsaw was a Minimax S45, a truly excellent machine. The earlier white machines had a 250mm depth of cut (my one), later ones had 300mm before they went to the MK2 current shape. These are at the lighter end of industrial so they are really at the heavy end of hobby. Often go for a lot less than they are worth as they are overlooked by the hobbiest in favour of the much lighter build Startrite range. Agree, the epoxy powder coated paint is extremely durable. All the bandsaw most hobbiest will ever need in a fairly compact footprint. Hugely rigid frame for its size.
Nigel

 

[mindthatwhatouch]

What perfect timing, watching with interest.

I lucked out on one a few years ago (really cheap) that had motor issues. A little time with some wire and a soldering iron fixed that, and I've been using it since.
I've finally got round to trying to clean it up a bit and improve the dust collection and guides. Unlike yours, on mine the factory fitted dust extraction is at the base of the cabinet which really does nothing other than catch a bit of dust. The previous owner has added a port near the top which is better but still feel I can improve it further. Really like to change the guides for rollers. particularly the lower one which has cool blocks type of holder, still has the pieces of wood that the last owner fitted!

Not convinced the brush is improvised, mine is identical.

 

[Sideways]

Some less dramatic progress today.

First the door interlock. This little hinged section sits between the top and bottom doors. It overlaps tabs on both and has a tongue that goes into a locking solenoid. This is wired up so that the saw won't run with the the doors to the bandsaw wheels open.

A wire brush in the drill press it good for removing surface rust and grime from components, so several pieces have been brushed, subjected to diesel and scotchbrite to loosen resin, etc.
Here are the trunnion castings after a good clean.

And fitted

It is very easy to disassemble a "Kipp" or Bristol locking lever handle, so they get opened up and the sawdust removed with a fine wire brush

 

[Sideways]

The lower guide set is badly encrusted in resin. This has had a partial clean but I'm going to try CMT Orange spray on it.

The upper guide wasn't so crusty so that has already come up very nicely
I'm deliberately showing several views so that you can see how these are put together, mounted, easily dismantled and adjusted.

In the image below, we are looking vertically downward between the side guides. You can see how the outer part of the rear guide's face will stop the back of the blade from moving rearward.

With flash off the gap between the blade guides is more obvious. The guides are set just a paper thickness from the side of the blade when it use. We'll set these up once the saw is reassembled with a blade.

 

[Sideways]

Last parts to show today are parts of the rack + upper blade guard. I'm loosely assembling these on the bench as they are cleaned.
The rack is in perfect condition and has been left bolted to the support tube.
The two adjacent parts bolt to it and are part of the upper blade guard. See the slot where the blade slides in.
Two pairs of holes are lined up, this is how these components are bolted together. The smaller of the sliding pieces remains inside the upper band wheel box at all times. The rack and blade guard wind down when cutting thinner stock
This view is from the side as if I were are the spine of the saw looking out at the blade

Here the same pieces with the blade guides added and seen from operators position

The rack is wound up and down by a pinion. This is screwed onto the knob spindle and locked with a grubscrew.

All for now. Time to go soak those lower guides overnight ...

 

[FlatlandsF7a]

What perfect timing, watching with interest.

I lucked out on one a few years ago (really cheap) that had motor issues. A little time with some wire and a soldering iron fixed that, and I've been using it since.
I've finally got round to trying to clean it up a bit and improve the dust collection and guides. Unlike yours, on mine the factory fitted dust extraction is at the base of the cabinet which really does nothing other than catch a bit of dust. The previous owner has added a port near the top which is better but still feel I can improve it further. Really like to change the guides for rollers. particularly the lower one which has cool blocks type of holder, still has the pieces of wood that the last owner fitted!

Not convinced the brush is improvised, mine is identical.

Perfect for me too, very interested to see this thread develop. Just to second that it would be great to see clear details of the lower guides, as mine are also the 'cool block' and single rear thrust bearing version (yellow S45, Pre 1995 is all I know, as it has a dealer sticker phone number without the extra '1' in the number!), and I'd be intersted to upgrade if that would be worthwhile (although I'm not sure there's space.

Also to confirm that my brush is identical as well, so definitely not improvised. My dust collection port is in the ideal location though, and a wee bit of plywood makes the extraction excellent, except for large blade rip cuts where the grid can get clogged.

 

[Hornbeam]

The GL456 guides work really well and are very simple to set up. N=My only issue is that you cant buy just the wear parts but have to buy the guide sub assembly

 

[Ttrees]

Could make your own if you felt the replacement shaft and rollers were too costly.
https://www.ncwoodworker.net/forums/index.php?threads/centauro-classico-band-saw.61462/

 

[Sideways]

Interesting thread there Ttrees, thanks.
The lower guide here is really well gummed up. CMT orange didn't do a lot to unglue it, not really any better than diesel. It may be cellulose thinners next at this rate.
Nevertheless, the guides I can get hold of are very little worn on this saw. No slop. A little axial movement. I can't pull them apart by hand though Deema says the similar looking ones on his Felder bandsaw do dismantle.
You can clearly see the bronze bush looking at the join between barrel and disc

 

[FlatlandsF7a]

Interesting thread there Ttrees, thanks.
The lower guide here is really well gummed up. CMT orange didn't do a lot to unglue it, not really any better than diesel. It may be cellulose thinners next at this rate.
Nevertheless, the guides I can get hold of are very little worn on this saw. No slop. A little axial movement. I can't pull them apart by hand though Deema says the similar looking ones on his Felder bandsaw do dismantle.
You can clearly see the bronze bush looking at the join between barrel and disc
View attachment 127330

Do you happen to have a figure for the clearance below the table for the lower guides on your machine?

Mine (the cool-block type) seem to be pretty squeezed in, so I wonder if the clearance below the table and above the machine frame is the same. My upper side guides feel pretty chunky, and it would be a challenge to squeeze them in under the table I think!

 

[Sideways]

It was a little tricky to maneouver the lower guides out after unbolting them.
When I reassemble, i'll take you some photos with a rule in the frame so we can see the clearances.