SM4 Spindle moulder

[Sussex cabinet maker]

Hi everyone, ive just bought an SM4 Sedgwick spindle and it's been great. however its one big problem is the shaft doesn't lock for fitting tooling. I spoke to Sedgwick them selves and that said it does, but it 100% doesn't, and tbh i'm not surprised they thought it would, as the machine is so old I doubt they would know by now anyway as the guys making that machine will be long retired. I've bought the manual from S&S and it's not mentioned there either, and the chap I bought it from told me it doesn't lock.

9 times out of 10 I can jam I bit of wood in the block which makes enough friction to nip the top shaft nut up, but if a bit off surface rust starts (it always will for me as my workshop is an old cowshed) it becomes a nightmare to change cutters. My current thought is to get an M10 nut welded onto the top of the shaft so I can lock it with a spanner, however every part of me is screaming that thats a really bad idea. so has anyone else had this problem and got a work around?

the machine is solid and actually feels a lot safer that my pin router and old router table, but this often puts me off using it as getting it setup takes so long - fine when i'm running a whole kitchen out, a massive pain when its just one cut!

Many thanks,
Adam

 

[deema]

The SM4 spindle doesn’t lock, you use two spanner’s, one on the top of the spindle and the other on the nut.

 

[meccarroll]

The SM4 spindle doesn’t lock, you use two spanner’s, one on the top of the spindle and the other on the nut.

I have a Rojek spindle with no lock off but do as above mentioned except it works in a slightly different way.

The nut holds down the retaining rings and the top retaining ring is machined so you can hold it with a spanner.

To undo mine I hold the top retaining ring with the spanner then undo the nut.

 

[Sussex cabinet maker]

The SM4 spindle doesn’t lock, you use two spanner’s, one on the top of the spindle and the other on the nut.

which part of the top of the spindle? all I have is a threaded end?

 

[Sussex cabinet maker]

I have a Rojek spindle with no lock off but do as above mentioned except it works in a slightly different way.

The nut holds down the retaining rings and the top retaining ring is machined so you can hold it with a spanner.

To undo mine I hold the top retaining ring with the spanner then undo the nut.

View attachment 196862
View attachment 196863

this is basically how mine would work if I could get a nut welded on top

 

[meccarroll]

which part of the top of the spindle? all I have is a threaded end?

I have looked at some SC4 moulders online and don't see how that will work as they have nothing to hold the actual spindle. So long as you can hold the block in place you should be able to undo the retaining nut.

You should be able to use a piece of wood aganst the fence and slide it to lock the cutter from moving then undo the nut.

If you ever have a real extreme problem you can always hold the pully wheels and get someone to undo the nut.

 

[Sussex cabinet maker]

I have looked at some SC4 moulders online and don't see how that will work as they have nothing to hold the actual spindle. So long as you can hold the block in place you should be able to undo the retaining nut.

You should be able to use a piece of wood aganst the fence and slide it to lock the cutter from moving then undo the nut.

If you ever have a real extreme problem you can always hold the pully wheels and get someone to undo the nut.

thats a great point regarding the pulleys, however I need tis machine to be much faster for a set up ideally as currently just wedging wood in is taking forever. I wonder about threading a bolt into the top of the shaft with a weld to for maximum retention. last thing I want is a bolt flying off at 6k rpm.

Also on the subject, does anyone know how a set of accurate measurements could be marked onto thew cast bed? I wonder about contacting laser ingaveus or something?

 

[Sgian Dubh]

this is basically how mine would work if I could get a nut welded on top

It would helpful to include a photograph of the top of your spindle. The manual you have indicates there is no spindle lock, assuming you have the correct manual for your machine, and if there is a lock it will almost certainly be a fairly large knob and shaft sticking out probably on the right side of the machine as looked at from the front.

If there is no such knob/shaft as I've just described this strongly suggests the two spanner approach shown by meccarrol above is one option with the other likely option being a spanner plus an Allen key in the end of the spindle. All this talk of welding bolts and so on seems wrong. There will almost certainly be an existing method of locking the cutter block in place on the spindle, but I suspect you just haven't found it yet. Slainte.

 

[deema]

This is what the top of the spindle should look like. There should be two flats for a spanner.

 

[Sussex cabinet maker]

Hi guys, just I’ve just had a moment to get some photos. The hole on the top is not for an Allen key…

 

[Sgian Dubh]

Hi guys, just I’ve just had a moment to get some photos. The hole on the top is not for an Allen key…

That is interesting because, as you say, there seems to be no obvious means to use either a spanner or Allen key at the top of the spindle.

I can think of only two reasons for that:
1. That there is a spindle lock inside the cabinet at the bottom of the spindle and you just have to find it via some sort of hatch or similar.
2. At some point the original spindle (that did have provision for a spanner or Allen key at the top) has been replaced with one that doesn't.

Of the two options above, number 1 seems most likely because number 2 seems to be bonkers - who would think that was a good idea?

Sorry I can't help more than that, but I do now rather wish I was familiar with that particular spindle moulder model so that I could give you definitive guidance. Slainte.

 

[ChaiLatte]

Welding anything to that is a risky solution as the heat could cause distortion.

Is it correct to say that the main securing nut is standard right hand thread?

If that is so, the reaction force on any 'holding nut' will tend to tighten it when undoing the main nut.

An elegant solution would be to drill and tap the spindle and use as large a grub screw as would fit (M10 would be enough*), secured in place with loctite or JB Weld. You could dot peen the joint for extra mechanical security.

You have a huge expanse of cast iron that is square to the spindle in all directions so could rest a drill press on it to ensure the spindle is drilled coaxial. In other words, there is no excuse for drilling a wonky hole. The spindle has a centre drilled in already to locate the hole. All the work can be done without dismantling the machine.

* Being old, the machine likely uses imperial fasteners. If there are any places on it that require an allen key, I would pick an imperial grub screw such that an allen key from the machine's standard toolkit will work. It may be a CDO thing, but putting metric fasteners onto an imperial machine and having to have a special allen key for one purpose would bug me.

 

[deema]

The spindle is removable. Inside the cabinet under the pulley there is a long screw, you undo this a few turns, give it a tap with a copper hammer to release the taper on the spindle and then fully remove the bolt.
Now, the spindle you have is none standard. Maybe home made or the end been turned off. I suspect the former as it has a centring hole in the end. Anyway, I would either get it drilled and taped in a lathe for a screw, or buy a new spindle.

You can get top hat, router and main spindles. I have all three, which are useful but it’s a pain to change them over.

 

[Against_The_Grain]

Because they were made in very small batches there can be massive variances between batches as Sedgwick often changed things as they went along. That's the style of shaft you usually see on the SM3 spindle moulders, but they also did it on the very first SM4s (in the green livery, rather than the later white and blue ones which were the SM4-II), for locking those off you open the side door and there's a hole in the casting above the pulley in which you're supposed to stick a rod that's the exact same diameter as the hole (so not to marr the hole by using something smaller).

Here's a picture from a SM4 listing on eBay, you can see the hole in the casting above the pulley, it's best to make a rod that's long enough so that it locks into the hole but also projects out of the door, so the door cannot be closed and the door interlock engaged with the locking rod in place and the spindle started which could be catastropic.

 

[ChaiLatte]

...release the taper on the spindle ...I would either get it drilled and tapped in a lathe for a screw. I have all three...

Maybe I am making four from the one plus one plus one above, but if the machine end of the spindle is tapered, that might make it challenging to hold in a lathe to drill and tap the opposite end.

Perhaps you could look at or photograph one of the three you have and say if my arithmetic is at fault. That would also be useful as it would show the through bore necessary in any lathe to accommodate the spindle (plus possibly the through bore of any fixed steady needed to support the spindle). If the result of those observations make the lathe idea difficult, that would also give us chance to come up with alternative ways to achieve the goal.

 

[niall Y]

Some spindle moulders - my own included- have a hole towards the base of the spindle shaft. You pass an appropriately sized rod through this to hold the shaft still. And yes, you have to make doubly sure to remove this before switching the machine on.

When working with spindles it is always important to incorporate an "idiot run" into your routine to check for such stupid mistakes, before switching on.

 

[deema]

Yep, no worries I will photo when I pop into the workshop. The shaft is fairly short so no steady required. The end has a taper and then another length if straight shaft. Easy to grip in a lathe.

 

[Against_The_Grain]

Not wanting to be offensive or anything, but all this talk of machining shafts and work holding in the lathe is completely pointless if the locking pin hole is in the base.

 

[niall Y]

I maybe mistaken, but the top of the shaft that the OP posted of his machine might still be original, but just updated to allow for a flush-fitting, cutter-block. Having the thread go all the way to the top of the shaft, would allow for this.. One isn't then limited by the shaft getting in the way when passing work over the top of the block.

 

[Against_The_Grain]

I maybe mistaken, but the top of the shaft that the OP posted of his machine might still be original.

I believe this shaft design was an "in-between" design. Earlier Sedgwick spindle moulders including the first one they produced, the small GW, had dual-spanner operated spindle shafts, later ones like the SM3 and SM4 didn't have the dual-spanner operation but a locking pin that engaged in a hole in a casting in the base of the spindle moulder, they then later went back to dual-spanner operated shafts on the SM3-II and SM4-II and then onto Allen key screw locking shafts today in their SM210 and SM225T spindle moulders.

I don't think this particular design was very popular which may explain why they went back to dual-spanner operation, this particular style was quite time-consuming to use as an operator as you would need to open the side door for every tooling change which entailed having to undo a particularly long screw which was designed like that so you couldn't unscrew the screw to open the door faster than the machine could stop to prevent entanglement in the pulleys. The unfortunate truth is Sedgwick machines are quite poorly designed from an operator standpoint and quite roughly made, but they are strong and stand up to abuse and work well for the occasional user but will drive a constant user insane unless they are left set up and never changed.

Little effort has been made by Sedgwick over the years to make their machines more efficient to operate and they have reduced the quality significantly whilst adding superfluous features, the stop system on the newer morticing machines being an example of a completely useless feature in the real world which just adds unnecessary cost. It's quite clear that the designers of these machines have never had to use them in an industrial setting with time constraints, if they had they would realise where they could improve the machines significantly for little to no extra cost. However, I do believe Sedgwick's main market now is the education sector.