Sedgwick MB Planer Thicknesser Full Refurbishment

[yetloh]

My Swedish Moretens P/T (great machine with some very clever ideas) has this black aluminium extrusion

Height controlled by this Bristol lever locking int0 a slot on the front panel

It has nibbled the powder coating a bit but is a very smooth and effective design.

Jim

 

[deema]

Progress, Sideways and I have ventured back into the workshop to start the part we both really love. The assembly of the refurbishment. It’s always brilliant and a wonderful feeling to see the ‘butterfly’ emerge from what we start with.

The first job was to sort out the oil in the gear reduction box that is used to step down the motor that drives the infeed and outfeed rollers. Usually, the oil hasn’t ever been changed or topped up since the machine left Sedgwick factory. The gearbox is designed to work in one orientation, it has a pressure relieve valve in its upmost surface which also acts as the fill port. If the gearbox is not kept with the red coloured bolt vertical it will piddle oil everywhere.

With the red coloured bolt removed an oil level can be seen, oil needs to be added up to this point. The gearbox when we took it out was about half empty to where it should have been.

And with oil added to the level

 

[deema]

We usually sort out the oil level with the motor / gearbox mounted into the base. It stops any accidental spills due to the assembly tipping. We also mount the motor into the base as one of the first steps.

In the photo you can see the fill port open on top of the gear box.

In the next photo you can see the red coloured bolt reinserted. The relief valve is part of this bolt.

The main spindle drive motor mounts on a metal bar via two bolts through its upper foot. A third bolt is attached to the lower motor foot and clamps to the base through the side. This is what rotates the motor and tensions the belt. The motor /gearbox doesn’t have a tensioning system as it drives a chain, it uses instead an idler sprocket to tension the belt.

 

[deema]

The base casting is next, first off the thicknesser table rise and fall, mechanism needs to be assembled into it.

I’m not sure what the technical term for this form or worm drive is, but it’s a form of worm drive, which means that loading the thicknesser table cannot back drive the system and change the height of the table when in use. Originally, grease was used in these parts, and for maintenance grease nipples are located on the upper surface. However, we clean all the grease out of the system and instead coat everything in white grease. White grease drys, it doesn’t pick up sawdust and create a very effective grinding paste. We will put the grease nipples back only to stop dust getting down the holes. However, they should not be used to for lubricating.

The horizontal gear is grub screw located and the pinned to the shaft. The vertical shaft in the photo has a locking collar on the upper surface of the base casting.

The gears as can be seen look like new with no discernible wear. This is what we find on these machines.

 

[deema]

The base casting is very heavy, a two man lift really. Before putting it on top of the base we run a tap through all holes. This ensures that no shot / paint or anything else remains in the threads. The castings on this vintage of machine are thicker in my opinion than the more modern machines. Cast iron is a superb vibration reducer, that’s why it’s used today on top end machines. It’s expensive to have castings made versus fabrication, but is far superior for vibration reduction. You can always spot a value engineered machined by the amount of cast iron there is versus fabrication / aluminium extrusion.

The cast base sits on top of rubber washers to further reduce vibration transmission from the motors in the base. It’s held to the base by four M16 bolts inserted from underneath. These were fiddly to out back, getting everything lined up as the through holes have very little allowance. Hopefully Sideways might have photos of the rubber washers.

The cast iron hand wheel is attached by a grub screw, the column for the thicknesser table is inserted and bolted to the riser mechanism with three bolts. The column is lubricated with white grease.

The thicknesser column is attached to another casting, which runs in the Acme threaded rod. Another property of cast iron is that the graphite in it makes it a good bearing surface.

 

[deema]

The rear side casting is next to be bolted to the cast base. It’s again held by M16 bolts (22mm spanner / socket) at this stage you only attach the rear side casting. A lot of parts need to be built into this casting before the front side casting is attached.

 

[Sideways]

Iso 100 for the gearbox oil. It was perfectly clean so only needed a top up.

Wide rubber washers between the base casting and the steel cabinet

You can see both the grub screw and the roll pin in this view of the helical gear

And the two lubricating holes for the rise and fall spindle as Deema mentioned.

 

[robump]

Great write up guys. Thank you for taking the time to document the project! Might come in handy for the future.

Where did you source all you new bearings/bushings from.

 

[deema]

I buy bearings and stuff from lots of places, however BearingsRus, 4bearings and simplybearings are some of my more frequent visits

 

[robump]

I buy bearings and stuff from lots of places, however BearingsRus, 4bearings and simplybearings are some of my more frequent visits

Thank you! Do you know the colour codes for the new Sedgwick blue and white? I assume they are RAL colours are they?

 

[Inspector]

The white grease you mention for assembly. The only white grease I am familiar with is a Lithium grease. Same stuff?

Pete

 

[deema]

@Inspector Hi, Pete, there are two white greases we use, lithium and calcium. You can mix the two as they are compatible with each other. I understand that calcium grease has a better water and rust restrictive properties than lithium, but has a lower working temperature (about 120C). Not an issue for wood working machines. Another alternative is Dry Moly Lubricant, however moly and white grease are not compatible, and it’s harder to find to buy. So, we use white grease as you can pick it up just about anywhere here in the UK.

Silicone based lubricant spray would also be a good alternative, however, if the spray gets onto a table top and stuff is passed over it, it ruins the ability to add a finish. We don’t use it for wood working machines for this reason.

 

[deema]

Soooooo, it’s been a while since we did any work to this machine. I’ve been out of action for just over three weeks with some bug, still nit right, but there is only so much day time TV I can stomach! Today we made a little progress.

The two bearings were pressed into either end of the main cutter spindle. These are both new sealed for life bearings (SKF and FAG), including the self aligning bearing. Although we are leaving the grease nipples in place for these bearings, they will never need to be used.

The bearings had a collar made for them so that the press only acted on the inner race.

 

[deema]

We reassembled the spindle into the body of the plane, it runs really smoothly.

 

[deema]

To get the spindle back into the saw I didn’t describe the process. Firstly the two bearings need to be pressed back onto either end of the spindle. A press is ideal, however, warming the bearings up to say 80C (never at or above 100C) and cooling the spindle is also another way, they should then slide on without any pressure. The larger bearing is first pushed into the casting, gentle tapping is usually required, we usually create a temperature difference to allow them to pop in very easily. Next, the other cast side is presented and again very gently tapped on. There is a bolt that must not be forgotten in the end of the spindle on the none driven end. This is stop the bearing moving in use (see picture). The two threaded rods, one of which has the anti kick back fingers attached to it also need a nut adding before the final casting is added to the spindle.

 

[deema]

Next to assemble are the two planing tables, these are needed to set up the alignment of the whole machine. These are lifted on, with a good squirt of white grease on the moving surfaces. For this machine both tables are adjustable…..something I really like in a machine. Each has a proper adjuster rod. This is an old machine when they made proper adjusters. The threads on these are square threads, huge capacity and won’t get stripped due to saw dust build up. This happens on the more modern Sedgwick machines that use a standard screw thread rather than a trapezoidal, acme of square thread.

 

[Sideways]

The bearings sit inside the side castings and the cutter block is machined just slightly smaller than the bearing housings. Net result is a small clearance that helps to keep prevent the ingress of dust and chips out even when using open bearings. The sealed for life bearings we fit are well protected.

 

[deema]

The tables are coplanar with each other, using a straight edge there is only a few spots where light can be seen across both tables. Now, light can get through the smallest gap, the gaps are less than my thinnest feeler gauges. That’s very impressive for a machine of this age. Looking at the tables, there is very little evidence of any wear at all. We have to align the tables properly with the spindle……but that’s for another day, it had arrived at gin o’clock!

The photos are of both tables with a torch behind the straight edge.

 

[deema]

The next task was to verify the exact alignment of the tables to each other. This is done by setting the clock to zero on one table and checking the clock when checking the other table.

You measure the table at either end, the clock is in thousands of an inch. Reading the clock you can see that there is actually about half a division of variance, so about 1/2 thou in old money or circa 12 microns for the metric people. That’s about as good as it gets over a distance of 12” or circa 305mm.

This is not how it started out, the tables were approximately 12 thou twisted. To adjust what seems to be a PT with no adjustment you slacken the bolts holding one of the side castings and either push or pull it in the direction of the tables. As the tables are running on angled beds, this moves the elevation of one table and decreases the elevation of the other table on that side as the other side remains fixed and bolted down. We do this usually with a rubber mallet and tap the castings to get them perfectly aligned. We again verified that the tables were perfectly coplaner using a straight edge.

 

[deema]

Next is to verify the alignment of the tables to the spindle. Often they aren’t perfectly aligned, which isn’t a big deal. As this can be adjusted by the blades. However, the same misalignment needs to be set up with the thicknesser table otherwise when thicknessing it will produce a wedge shaped finished part. There are ways of shimming the tables if perfect alignment is needed for instance if a Tersa head is mounted.

This PT after our adjustments was virtually perfectly aligned to the cutter spindle.

Unfortunately I didn’t properly zero the clock, but if you read the clock you can see that again there is about 1/2 thou or 12 microns variation, which reflects the tables. Again, over 12” / 305mm that’s about as good as it gets.