Clarke 6x4 Bandsaw Restoration

[Dr.Al]

Lots and lots and lots of progress today; not sure I'll get it all posted on here today, but I'll see how far I get.

First of all I took all the painted bits outside for some photography:

There are definitely some blemishes in the paint - it's much easier to see now that I can look at all the bits in daylight. However, I decided not to do anything about any of them until it's closer to being put together. I'm sure I'm going to scratch the paint in a few places trying to reassemble it, so I might as well do all the touching up in one go.

Here are the worst examples:

After taking the photos, I removed all the fasteners and used an old chisel a knife to get rid of all the masking tape.

 

[Dr.Al]

The masking around the saw-cut area didn't work as well as I'd hoped:

So I guess that will need some attention later. Most of the rest of it seemed to do the job adequately. I guess if I'd wanted it to look properly professional, it would have been better to paint everything and then re-machine all the critical surfaces afterwards. Sounds too much like hard work though...

Next job was to assemble the motor:

Shiny!

I used a counterbore to do an initial cut on the two main earth points (one inside the motor and one that gets hidden behind the switch housing):

The counterbore was just turned by hand. After those photos I cleaned them both up with a little hand scraping tool.

I tested the motor and swore loudly: it wouldn't start properly. So I took it apart and found I'd somehow managed to get paint onto the contacts for the centrifugal switch. Given where they are, I'm not sure I could have got paint on them if I'd tried, but somehow it got there. I got some more synstrip on a cotton bud and applied it, then cleaned with acetone, then used a needle file to sort the contacts out once and for all. After reassembly it ran and sounded really good. Phew!

There was a little dribble of primer that made its way down into one of the bearing bores:

That came off with just a bit of careful scraping with a knife.

Next job for the upper casting was to reassemble the gearbox.

First up was the worm shaft. Here are the bits (including two new bearings and a new oil seal):

I don't have a press of any sort, nor do I have a vice that will open far enough to be useful for this sort of thing. I therefore had to resort to a hammer, which I really wanted to avoid, but I just couldn't figure out an alternative. I made sure I was supporting the inner races of the bearings using the vice jaws and tapped each bearing home with a soft-jawed hammer. First up was the ZZ bearing:

and here's the assembled worm shaft:

 

[Dr.Al]

Now I was faced with the considerable challenge of getting the worm shaft into the gearbox. I wanted to be sure I was pushing on the bearing and not on the shaft (so the shaft didn't come back out of the bearings), so I took the head of my ER32 slide hammer and slid it onto the end of the shaft. The nut was up against the outer race. I then hit it repeatedly with a soft-jawed hammer.

and it seems to have worked:

The worm wheel shaft was originally fitted with two bearings, a spacer and an o-ring. The on-line manual I found showed it fitted with an oil seal like the worm shaft and this seemed a much better idea, so I went with that. I first fitted the retaining plate:

Then the various parts went in, first the 2RS bearing, then the oil seal, then the spacer:

and finally the ZZ bearing:

Then it was just a case of tapping the worm wheel home:

That face on the top of the gearbox is another important oil seal and it looked pretty shabby, so I attacked it with a 2nd-cut file:

and that's the gearbox back together.

 

[Dr.Al]

Next job was a slightly scary one. I plan to make a cut-off table, a bit like the one that @drmico60 has on his website. It's essential that the table is removable extremely quickly. If it isn't, I'll leave it on and it'll get in the way as I walk past, probably taking chunks out of my leg in the process.

I don't have the end-stop for the bandsaw (it didn't come with the saw when I bought it). As the bandsaw is in pieces, I decided to make some modifications to the casting to make it easy to mount something onto the end face when I get a chance to make it.

First of all, I got an angle plate and bolted it to the casting:

Then it was off to the milling machine to mount it on the table and clock it true.

I zeroed the Y-axis very carefully on the machined face of the saw, then zeroed the X-axis approximately on the right-hand side (in these photos) of the machined faces.

A 12 mm centre-cutting end mill was then used to produce four flat faces that can be used as references when mounting the cut-off table (when I make it):

I then drilled them out 6 mm (with a centre-cutting end-mill for a good finish). Finally, I drilled and tapped M8 a middle point that will be used for a mounting screw. This was quite a challenge: I used my ER chuck rather than the drill chuck, but even in that configuration and the drill bit pushed as far up into the chuck as I could get away with, there was only just enough room:

Here's the top of the milling machine showing how much travel was left in the Z-axis:

and here's the finished face of the casting:

The big tapped hole just down and right from the central one was for my previous attempt at an end stop - based on some M12 threaded rod. Given that was in an entirely arbitrary location (drilled with a battery drill by hand), I decided to ignore that and make a new one in a controlled location.

Hopefully this idea will work, I guess we shall see..

 

[Dr.Al]

Final job for the day was starting to assemble everything.

Here's the shelves on the base frame:

and the t-nut saver in place on the bottom of the lower casting:

It occurred to me at this point that the brackets that support the spring arm are held in place with nuts. In order to be sure I didn't need to take the lower casting off the base frame again, I decided to change the way these are mounted. Too late for welded nuts (and I doubt I could weld cast iron anyway), so I used a "v-coil" kit to turn the holes into threads:

The coils I had were way too long for the thickness of the casting, so they protrude out into the underside of the lower casting, but I don't think that will matter:

Next I fitted the vice screw (after a quick clean up with a wire brush on the angle grinder) and noticed that it operates up against an angled face of the casting:

I'm not sure if I've lost an important piece or what, but this just looked wrong to me. Off to the lathe & mill I went and made this little washer:

It's 18 mm diameter with a 13 mm hole through the middle. 5 mm thick at the thicker side but one face is angled at 5°. Here it is in place:

Got the length spot on:

and that's basically it for this weekend. The lower casting is now in place on the base frame and hopefully I won't have to take it back off again:

The vice jaws are just temporarily in place for now. I want to replace the screws with new ones soon, but they'll need making first. I also realised after mounting the casting and taking the photo that the motor cable needs to run all the way through from behind the hinge to where the switch housing sits. I've managed to thread it through for now, but I need to have a look again in case it's getting anywhere near the vice screw, in which case it'll need to be restrained and that means the casting will have to come off again. Not the end of the world as long as the top casting isn't fitted (at which point it'll be too heavy for me!).

I doubt much more will happen until next weekend, but I might get little jobs done in the evenings.

The end is in sight!

 

[Turbo]

Looking good so far but I have spotted a problem - you appear to have fitted the oil seal backwards on the 'worm gear' shaft. The lip on the oil seal should be nearest to the liquid you are trying to keep in! It probably won't leak with the thick oil & low pressure but if it does you know why!

Is that British racing green you used & is that a standard tractol colour?

 

[Dr.Al]

Looking good so far but I have spotted a problem - you appear to have fitted the oil seal backwards on the 'worm gear' shaft. The lip on the oil seal should be nearest to the liquid you are trying to keep in! It probably won't leak with the thick oil & low pressure but if it does you know why!

Oh sugar. I must admit I had no idea which way round it was supposed to go and wasn't sure it made a difference. I can't remember which way round I put it on the worm shaft and didn't take any photos that would give it away. Hopefully that one's the right way round (I think it probably would have been to be honest, I think I put the "open" end towards the bearing in both cases (as it seemed a reasonable assumption) - in the case of the worm shaft that's the side closest to the oil.

I guess I'll put my hopes in thick oil and low pressure; worst case the worm gear shaft is the easier one to get out! I might order a spare oil seal just in case...

Is that British racing green you used & is that a standard tractol colour?

It is British Racing Green, yes. I don't know what classes as a standard Tractol colour: Smith & Allan list every colour under the sun. Having said that, most colours seem to be on a listing of "All Colours", whereas British Racing Green has its own page.

 

[Johnnybravo]

That oil seal is the wrong way round. Also, be careful with what oil you use in that gearbox. Modern Ep90 gearoils contain additives that are not kind to the bronze/ brass worm wheel. I think it was Doubleboost who pumped his full with cv joint grease,but I stand to be corrected .

 

[Hog-Rider]

Many years ago the worm drive oil seal let go on mine and I would loose the Oil, I filled the box with grease and put a grease nipple in the top plate and every so often I will pump a bit of Grease in there and it has been working great ever since, ( No more Oil on the floor) Must have been like it now for many years well about 8 years plus.

 

[Dr.Al]

Amazing progress today: I successfully undid some of the work I did yesterday:

Yes, the worm gear shaft is back out. Ah well... thanks to @Turbo and @Johnnybravo for putting me right about the oil seal. I need to have a careful look at all the bits and decide whether to replace them with different ones or put the same ones back in again. Decision for another day.

I also used the work laser cutter to laser cut a 5 mm acrylic blank to use as a new gearbox cover:

It's clear acrylic: the blue-y colour is the protective film, which I haven't removed yet. I'd forgotten to measure the locations of the screw holes, so I just cut it as an outline then modified some grub screws for use as transfer screws:

Transferred the holes:

and then drilled them out on the drill press (I haven't taken photos yet, but I'm sure you can imagine a bit of plastic with four holes in it). The eagle-eyed among you will notice only three transfer screws: I didn't have enough grub screws, so I did the transferring in two goes.

Also turned up this blank from a bit of aluminium:

More on that another day.

 

[Dr.Al]

Finished off the switch housing today with two M16×1.5 tapped holes in the side:

The nuts on the conduit entries go in the bin and the glands go straight into the side of the switch housing:

I also made a modification to the top casting. The motor hinge plate has an adjustment screw that goes in the hole you can see in the top-left of this picture:

The screw bears down on the casting and will very quickly mash the paint into oblivion. I took an offcut of 3 mm steel plate, milled a chunk out of it and drilled holes for a couple of M5 countersunk screws. The plate fits here:

Slightly ironic putting a plate to protect the paint job given the number of times I knocked the casting (and damaged the paint) manoeuvring it to drill and tap the holes.

The number of areas that are going to need the paint touching up is increasing rapidly!

I've made the plate a lot bigger than would be needed if it were just for the hinge screw (I could have protected against the hinge screw just by fitting a screw to the casting in the right place). The reason for this is so that I can move the location of the hinge screw to make it more accessible. I did this fairly early on after having the bandsaw by adding an extra little bit of plate with two holes in it (one threaded) - it got screwed to the hinge plate and then a socket-head cap screw went in the other hole to provide the function of the hinge screw.

That was a lot better than the original design as I could easily get a ball-end t-handle hex key in there to adjust the belt tension rather than scrabbling around in a really restricted area with a spanner.

I haven't decided what to do with the re-build yet. Initially I'll probably just re-fit the offset plate with the cap screw, but I might remake the whole hinge plate at some point so I can have a long tommy bar (it'll have to be much further out to get past the motor). Anything like that is going to make me more likely to change the speed of the bandsaw rather than being lazy and leaving it at one speed all the time.

Anyway, the plate I've fitted should allow me to put the hinge screw wherever I want.

 

[Dr.Al]

Couldn't be bothered to update this thread last night, so I've got an evening and an afternoon's worth of updates. I may be some time...

Started off yesterday sorting out some wiring. First, the cables went into the switch box:

Then the earth connections were screwed to the body and the switch attached to the lower casting. I then machined a couple of nylon (I think) screws to act as grommets where the cables go through the holes in the body. I made the thread to match the conduit entries as I had two nuts left after threading them directly into the switch housing. Made a bit of a pigs ear of cutting the threads: I don't think the threading tool was sharp enough and it was tending to deform the plastic rather than cutting it:

and here's the two cables (to switch and from switch) coming through the bottom casting:

and they make their way over to the back end of the bottom casting:

I bought an aluminium die cast box to use as a connection box. I wanted to make it relatively straightforward to remove the motor in future (without taking the lower casting off the base) and also wanted the option to add a light powered from the same plug. I fitted the rest of the conduit entries from the pack on the sides and drilled two holes in the back:

One of the conduit entries won't be used until I fit a light, but it was a lot easier to drill the hole and fit the gland now rather than when it's needed. Here it is in place (with some "chocolate block" for live and neutral pre- and post-switch and a screw to attach earth):

It mounts firmly to the lower casting with the M8 cap head that is attached to the base frame. The plastic screw (with the cables going through) has a washer between the aluminium box and the base casting and the nut isn't especially tight (as I couldn't be bothered to put the taper on it to match the draft angle of the casting).

I also refitted the oil seal. Hopefully it's the right way up this time!

 

[Dr.Al]

Today I've mostly been assembling stuff.

First to go on was the hinge. I fitted a roll pin through the hole in the hinge bar:

added some grease

and slid it into place

the hinge bracket was then fitted

You can see in that photo that paint is showing some damage. I had foolishly put the motor on the base casting to keep it out the way. I'd put a bit of "elephant bog roll" under it to "protect the paint", but the weight of the motor has imprinted the paint with the pattern from the blue paper. I'm going to leave it for now, but once it's all back together I'll probably hand sand it down and then put some more paint on. There's loads of other touching up that needs doing. I suspect the pattern means I should have left it in the warm dining room for more than two days, but I guess it's possible the paint just doesn't dry as hard as I was expecting?

Here's the top casting fitted before I realised that you have to fit the drive wheel before to the top casting before fitting the top casting.

Corrected:

Next up was the spring. One of the spring handle brackets was very bent:

No idea why, but I put it in the vice and "persuaded" it to be at 90° again. Then it and the other one got mounted, along with the spring and the handle:

I had to use hex head screws rather than cap-heads for the spring brackets: there isn't enough clearance from the bar and I don't have any low-head M8 cap screws.

 

[Dr.Al]

Next job on the assembly line was fitting the idler wheel (if that's the right name for it).

I hadn't taken the idler mount piece apart as it seemed to be well adjusted, so fitting it was simply a case of cleaning it up with a wire brush and replacing the mounting hex heads with cap heads:

Inside view:

Then the idler wheel went on, but for some reason I didn't take a photo of that.

Next up were the blade guide arms. If you look closely at the previous photo, you'll notice I hadn't taken the masking tape off the side surfaces that the blade guide arms run against. A quick run of a chisel down the edge sorted that out and then I put some white lithium grease on the running surface as I figured it couldn't hurt:

The blade guide arms went in next:

Just mounted with cap screws at the moment, although these are likely to be replaced with custom screws:

Next up was the blade guides themselves. I seem to have completely lost all the photos I took as I was dismantling the bandsaw (which is *really* annoying). It looks to me like I've lost some parts. This is one of the blade guides with a bearing placed roughly in its home:

That gap is too big for the bearing and it seems to me like there should a spacer either side. Can anyone else with this saw let me know what theirs looks like? It probably doesn't matter, but I decided to make some spacers. The gap was conveniently about twice the thickness of an M8 washer, so I got some M8 washers and drilled them out 9.1 mm.

Looks better to me.

The eccentrics went on next; here they are fitted with the bearings all ready to be added:

and bearings fitted:

and one of the blade guides on its arm:

 

[Dr.Al]

Last job of the day was sorting out the drive train.

I fitted the motor with the standard mounting plate; I'll decide whether to replace that later:

End view:

Here's the little hinge screw extender plate I use to allow me to use a cap screw to adjust the tension:

Pulleys fitted:

I then got some hypoid gear oil and filled the gearbox. I know next-to-nothing about oil, but I looked through the various bottles I had and that one had "gear" in the name, so it seemed reasonable!

Finally I added a laser-cut flexoid gasket and a piece of 5 mm acrylic to try to keep the oil in and so that I can see if the level goes down.

It'll be interesting to see how much of that oil is left in the gearbox when I go back tomorrow morning (and where it's leaked from)!

Really starting to look like a bandsaw now...

 

[Screwdriver]

Be interesting to see your painting technique, never seen it done with a trowel before.

 

[Dr.Al]

Be interesting to see your painting technique, never seen it done with a trowel before.

I never said I was good at painting...

 

[roofman]

Great thread..

 

[zx9]

I also nicked an idea from @Wallace and added some markers on the eccentric bearing mounts to make it more obvious what orientation they're in. I cleaned up the surface with some sandpaper, gave it coat of black Tractol and a centre punch mark and then found an old tiny little tin of yellow Humbrol enamel from a decades old Airfix kit:

There are four of them, but I only bothered photographing two.

That reminds me, my Sealey only has one eccentric bolt per guide arm. When it has been mentioned in the past that some saws have two per guide I have been envious so I suppose now I have a lathe I should make another couple of eccentric bolts, though thinking about it blade alignment has not been a problem so perhaps I should leave alone.

 

[Screwdriver]

Great thread..

It is an awesome rebuild. I love doing stuff like this as much as I like to see others do the same.