Crown Guard Extraction

[MikeJhn]

This one cost only pence to make:

 

[MikeJhn]

And this one is much better and cost about £80.00 in total.

 

[doctor Bob]

One mistake is to take a branch pipe from your big extractor and attach that to the crown guard. You just reduce pull below and get more dust above, so it looks like it's doing something but isn't.

I'd rather have a big suction below and some above than just strong below. It's standard practice to branch pipes in industry, however we have to pay to test our extraction annually to check performance, I'd fail without top extraction.

Here is mine, could be easily copied with some already posting examples, use metal pipe to support it.

 

[hlvd]

This is the modification done on our crown guard at work done by P&J Dust Extraction when we had our system fitted. There’s also an extraction point below the saw through a 100mm pipe.
We’ve just had our yearly Dust Extraction test, so working perfectly.

 

[eribaMotters]

P&J did similar on the Startrite that I used at school. This was plumbed in like yours to a large and efficient extraction unit in the store room.
I "acquired" one of the fabricated galvanised steel bits you see attached to the yellow crown guard. I have my Numatic cleaner plumbed in to this and use my large JET bag extractor with fine paper cartridge filter on the bottom of the saw cabinet. I've found this works very well and would not be without the top extraction.

Colin

 

[Ttrees]

I'd rather have a big suction below and some above than just strong below. It's standard practice to branch pipes in industry, however we have to pay to test our extraction annually to check performance, I'd fail without top extraction.

Here is mine, could be easily copied with some already posting examples, use metal pipe to support it.

Have you used one of these with a normal cabinet saw?
Still waiting to find some good sized pipe(s) for the job, as it seems it makes sense
to have the pipe running through, maybe not the case at all?

There's possibly a lot more to it than you make out, (if using in a compact environment with non sliding cabinet saw)
Being a newbie to the use of the machine, and all the possible tenon jigs and such
one could make, I can't decide if a movable swing arm is a want.
Maybe not made anymore or for UK market due to it being removable from the blade.

What kind of a seal is on the telescopic part, is there a pipe inside?
Was/is it designed for the HPLV system, and a trailing/affixed HVLP system going to the machine?
Then there's the Altendorf crown guard assembly, a seemingly sprung cog or something of that nature.

What's faff and what's not is the question, which I'm not posing for anyone.

Love to hear of any downsides to any of these designs from the folks who use them.

Member Hiemlaga has made some worth looking at
https://www.ukworkshop.co.uk/threads/overhead-table-saw-blade-guard.115782/#post-1268044Thanks
Tom

 

[Phill05]

I have an Axminster Axminster Trade AT254SB cabinet saw with the Record Power 3000 dust extractor attached. I cut the riving knife down as I was doing a lot of work with a cross cut sled and thus have no crown guard mounting point for the original.

I was watching my son rip some poplar yesterday and sawe the dust flying up from the blade. The extractor takes a lot of stuff but not the dust.

Well my thinking is if dust is coming up then there has to be something not quite right either not enough main suction to take it away or riving knife is thinner than the blade so is back cutting on the up as well, I had replaceable wooden bed plates cut by the blade that was in the saw inc for the riving knife and when suction was on there was no dust or very very little on the table.

But my first opinion to the OP was that price is outlandish and not needed if the saw is properly setup in the first place.
Everybody has their own opinion mine is from years of experience.

 

[Lard]

Apologies, I’m not trying to hijack the post but here’s a somewhat related question I’ve been waiting to ask….

My record power TS has several ‘holes’ around the base and so I must be losing a considerable amount of suction from my 100mm hose. This did result in the making of my own ‘over the blade’ extraction that does pick up a fair bit of ‘sprayed’ dust.

Does anyone have any thoughts on whether I can block up some/all of these holes? I’m got concerns about the motor overheating ie ventilation for the motor - am I over thinking it?

ta

 

[Sideways]

I have an Axminster Axminster Trade AT254SB cabinet saw with the Record Power 3000 dust extractor attached. I cut the riving knife down as I was doing a lot of work with a cross cut sled and thus have no crown guard mounting point for the original.

I was watching my son rip some poplar yesterday and sawe the dust flying up from the blade. The extractor takes a lot of stuff but not the dust.

I agree that an overarm crown guard would be an excellent addition.
The advantages of having a riving knife no higher than the top of the blade are real. I've done just the same for similar reasons, but the crown guard is still needed. It is a vital piece of safety equipment in the evet of kickbacks and it needs to be robustly supported to keep your hands away from the blade. Some types of kickback will pull your hand into the blade before you even realise what is happening. It's your choice to compromise safety for yourself but you told us you're letting your son use this machine. You may not realise the potential hazards but please spare yourself the risk of a lifetime's regret if this takes his fingers off. Just because it's popular among the amateurs who post youtube videos about their TS sleds doesn't make it safe to dispense with the crown guard that was a legal requirement for good reason when your saw was sold to you.
Now, it would be better still if the crown guard were attached to a shop vac not the main extractor. A bag collector connected via a long, narrow (50mm ?) spiral type hose makes pitifully little suction at the crown guard where it needs to deflect and trap dust that's being thrown off at 140km/ hour.
But regardless of all else. Your saw recommends an extraction of 1000 m3/hour. The Record extractor claims 1200, however it has only a 550W output motor. There are numerous posts on this forum that point out that dust extractor specs are typically quoted with no hose attached, a clean bag, etc etc. Real world performance of most extractors is closer to half of what their specs claim.
You would reasonably see an improvement in dust collection if you stepped up to a dust extractor with more like 1.1kW or a 1.5kW input motor which is as big as you can reliably run off a 13A plug.

 

[Ttrees]

Apologies, I’m not trying to hijack the post but here’s a somewhat related question I’ve been waiting to ask….

My record power TS has several ‘holes’ around the base and so I must be losing a considerable amount of suction from my 100mm hose. This did result in the making of my own ‘over the blade’ extraction that does pick up a fair bit of ‘sprayed’ dust.

Does anyone have any thoughts on whether I can block up some/all of these holes? I’m got concerns about the motor overheating ie ventilation for the motor - am I over thinking it?

ta

This thread might be of interest
https://www.ukworkshop.co.uk/threads/harvey-table-saw-refurbishment.116812/page-2#post-1358577

 

[MikeK]

When my saw was commissioned, the dealer included the OEM overhead guard at no cost. The technician found it in the warehouse, but no one could remember why they had it or how long it had been there, so they loaded it on the truck with the saw. The shroud connects to the 120mm overhead dust collection ducting with an 80mm flex hose and worked very well. It came with two clear shields. One was for the blade at 90-degrees and the other was used when the blade was angled up to 45-degrees.

The fixed vertical support beam on the right corner of the saw kept getting in my way, so I removed it and used the standard guard that attaches to the riving knife. I used the same 80mm hose, but had to build up the 60mm port on the guard so the hose would seal.

Here is the saw in the cluttered shop soon after commissioning with the OEM overhead guard. The square support tubing hinges at about the mid point of the horizontal piece so the guard can be moved out of the way. Once I built the miter saw workstation, it was difficult to move the bandsaw and router table between the saw and workstation.

Here is the current configuration showing the smaller OEM guard attached to the riving knife. When not being used, the bandsaw and router table are stored against the wall next to the saw accessories and do not interfere with the slider operation.

This is a closeup of the 80mm flexible hose connection to the 120mm ducting. All flexible hose connections have a blast gate.

 

[Doug71]

It's a funny old world, I'm looking for an overhead guard for my Minimax panel saw while @MikeK has one for his but chooses not to use it,
shame you aren't a bit closer I would happily look after it for you

 

[MikeK]

It's a funny old world, I'm looking for an overhead guard for my Minimax panel saw while @MikeK has one for his but chooses not to use it,
shame you aren't a bit closer I would happily look after it for you

I would be happy to give it to you as it is cluttering up my dust collection closet. It is a heavy lump of steel, but if you can make arrangements to collect it, you can have it.

 

[Doug71]

I would be happy to give it to you as it is cluttering up my dust collection closet. It is a heavy lump of steel, but if you can make arrangements to collect it, you can have it.

Thank you Mike that is very kind, unfortunately it looks like the shipping costs would be prohibitive

 

[Gary_S]

It's your choice to compromise safety for yourself but you told us you're letting your son use this machine.

My son is a 3rd year student furniture maker. Ge is safety first second and last but the knife was simply too high. Rather than remove it, we elected to cut it down. The crown guard is useful as a safety feature but we needed the cross cut sled. That is why I am now looking to replace it with something better than the one that requires the original knife. I will if I have to replace the knife and reinstall the guard but my original question was regarding an over arm version, not one attached to the crap design of the knife.

 

[MikeK]

Thank you Mike that is very kind, unfortunately it looks like the shipping costs would be prohibitive

I'll throw in a Holzmann HOB260NL P/T if it helps sweeten the deal! However, you must promise you won't bring it back.

 

[MikeJhn]

The first page of this thread may be of interest to those wanting decent extraction from their table saw may give some ideas's if nothing else: Axminster TS250-2 modifications.

 

[MikeJhn]

I don't see the point of this as the blade deposits most if not all dust below the blade as it cuts downwards, I would say this is an expensive gimmick.

Have a look on U-Tube there is a high speed film showing the dust caught in the gullet of the saw blade and being thrown forward.

 

[Spectric]

I'll throw in a Holzmann HOB260NL P/T if it helps sweeten the deal!

Mike, have you got your new one yet ?

 

[MikeK]

Mike, have you got your new one yet ?

The Christmas and New Year holiday schedule stopped all deliveries until the second week of January. It's at the warehouse near Munich and I offered to drive there and pick it up myself, but those Grinches declined.