Excessive dust release from table saw

[Presh]

Hi All,
Fired up the new table saw with a record Power DX4000 twin motor filter and somewhat disappointed at the amount of dust that is released from beneath the saw table - see attached pic. I understand that this high pressure low volume filter is bit of a compromise (when compared to a low pressure high volume dedicated chip collector) but wanted a filter/vac that I could also use effectively on hand tools / routers / sanders etc. I was/am keen to avoid any dust hazard issues and hence purchased what I thought was a bigger (twin motor) unit than I reasonably thought necessary for my small workshop but this doesn't appear to be the case. It appears that the air displaced by the high rotating speed of the saw blade is a greater force / volume than the extraction from the vacuum unit connected to the collection box/shroud under the saw and the 'windage' from the blade throws the dust around with it. As you can see from the pic, quite a lot also comes out of the slot for the saw angle hand-wheel. Any ideas on how I can fix this? Thanks all.

 

[Bodgers]

Looks like you have a Ts200 or ts250.

I have the ts200 and I have a cheap setup with a 2000w VAX vacuum cleaner attached to a cyclone and a bucket and I don't have dust coming out of what looks like the blade angle adjustment slot at the front.

Do you have both the main port, and the blade guard extractor port connected on your saw?

The blade guard one should pick up some stuff that circulates above the table.

I do still end up with a bit on the floor, but I find the majority of it exists through the main dust port at the back.

I assume you have checked everything for leaks and the extractor isn't clogged anywhere?

It looks like you have a new mk2 model there - how are you finding the fence?

 

[Presh]

Yes I've checked all of the connections - saw shroud to the top of the table, the 100mm to the rear of the table and the short internal hose from the table body to the internal blade enclosure - all is tight without splits. The filters on the vac are also all new and it is pulling properly. The saw blade runs within a fabricated spot welded semi-circular shroud within the body of the saw and has a dust extract connection from this. I just wonder if this is adequate. Clearly the vac is not pulling sufficient air from around the saw blade. I will check this to see if it can be adjusted closer to saw. There is certainly more dust coming out of the bottom of the saw than os getting onto the filter body. I cut with a 60T blade on MDF so not sure if this is likely to create more of a burden for the vac i.e. a finer lighter dust and more of it? Will also consider a reduced bore duct to increase air velocity with a fixed volume

 

[stuartpaul]

I've always found table saws an absolute pig to extract from and have almost given up. Extracting as much of the finer stuff as I can and then clearing up afterwards.

That does seem like a hefty pile, - how much timber have you cut? Don't expect to collect everything, there will always be something on the floor.

 

[AndyT]

I've no idea if this is the answer, but it's something you could try.

I have a similar (older) basic table saw and when in use just connect the fitted extraction port to an ordinary workshop vacuum - it's about a 30mm connection I think. It's not perfect but I don't get that much dust on the floor.

The saw came with a piece of sheet metal fitted underneath it, which had a few slots in. I've removed this and mounted the saw on top of a B&D Workmate. Some sawdust does pile up on the jaws of the Workmate and needs to be vacuumed out from time to time.

You could experiment with using / removing the steel sheet, if your saw has one, or with blocking up the underneath entirely. (Obviously you'd need to keep an eye on how much sawdust was accumulating inside and clear it out from time to time.) I'm guessing that the whole underneath box is so leaky that the airflow is all over the place and not fast enough to pick up the dust.

 

[Silverbirch]

I have a Bosch table saw which has a similar problem. I found one or two articles online showing how to enclose similar saws and direct the dust to a take off point for extraction. I think perhaps Fine Woodworking published one of them.
It seemed like it would involve a fair bit of work and some head scratching to adapt it to my saw, so in the end I decided life was too short. I have it sitting on a box like stand, open at the top. I removed the perforated metal sheet from underneath the saw, like Andy, so a lot of the dust falls into the box for cleaning out later.I just use this in conjunction with a single motor Camvac, which works OK for the intermittent use I give it.

 

[paulm]

I used the same extractor on my sip table saw (before I sold it) and it worked pretty well, not much escaped at all, so I suspect it may well be the design of your saw and inadequate shrouding or design that is the problem.

Cheers, Paul

 

[doctor Bob]

I had an extractor like that, rubbish. Ok on a biscuit jointer or domino but not on a table saw.

 

[Presh]

Thanks for your thoughts.
stuartpaul - you ask how much did I cut? Only 8 cuts of 18mm MDF say 1250mm long each - so not a lot at all.
This particular saw is totally open underneath the blade so there are no plates to remove. I did think that this was possibly an issue in itself and that if I boxed in the saw body it would increase the air velocity at the remaining smaller gaps (slot for the blade angle hand-wheel etc) and may well draw air into the body of the saw and not force it out as is currently the case? Seems like its another trial and error job. I simply though that a vac with a 4" connector pulling 381cu.m/hr from a single source table saw would more than do the job! I could reduce the flex to say 2" to increase the velocity though this would add more burden on the vacuum motors. Will have another think and let you know if I fix or improve it.

 

[Presh]

I had an extractor like that, rubbish. Ok on a biscuit jointer or domino but not on a table saw.

So what do you use on a table saw then DrB?

 

[Bodgers]

I've no idea if this is the answer, but it's something you could try.

I have a similar (older) basic table saw and when in use just connect the fitted extraction port to an ordinary workshop vacuum - it's about a 30mm connection I think. It's not perfect but I don't get that much dust on the floor.

The saw came with a piece of sheet metal fitted underneath it, which had a few slots in. I've removed this and mounted the saw on top of a B&D Workmate. Some sawdust does pile up on the jaws of the Workmate and needs to be vacuumed out from time to time.

You could experiment with using / removing the steel sheet, if your saw has one, or with blocking up the underneath entirely. (Obviously you'd need to keep an eye on how much sawdust was accumulating inside and clear it out from time to time.) I'm guessing that the whole underneath box is so leaky that the airflow is all over the place and not fast enough to pick up the dust.

I think, like the TS200 it has a wire mesh at the base rather than a plate.

If I take all the extraction hoses away, I would estimate that 60% ends up being literally shot out the main dust port half a meter from the back, 20% on the top and the rest on the floor directly below.

Maybe the 250 dust shroud underneath the table is just different.

I don't think the extractor is the problem either.

 

[jolly1]

This maybe a wee bit of the wall, you say it is pulling properly. Have you checked both motors are running? Are the both rotating in the same direction. I am assuming the motor are brush motors, a brush motor speed is dependant on the load. If you cover the inlet, the motor will speed up.
If one of them is running in the wrong direction it will add little to the suction. Like I said a wee bit of the wall, but I would run them for test purposes with the bags removed and observe the direction of rotation, of course not sucking any debris or dust

edit please please have eye protection on and keep the digits away from the impellers

 

[Bodgers]

This maybe a wee bit of the wall, you say it is pulling properly. Have you checked both motors are running? Are the both rotating in the same direction. I am assuming the motor are brush motors, a brush motor speed is dependant on the load. If you cover the inlet, the motor will speed up.
If one of them is running in the wrong direction it will add little to the suction. Like I said a wee bit of the wall, but I would run them for test purposes with the bags removed and observe the direction of rotation, of course not sucking any debris or dust

edit please please have eye protection on and keep the digits away from the impellers

TS200 and 250 have induction motors on belts. That and the cast iron top are the two things that separate it from the cheapies.

 

[jolly1]

I am talking about the dust extractor motor on the "record Power DX4000 twin motor " not the table saw, apologies if I did not make that clear.

 

[doctor Bob]

I had an extractor like that, rubbish. Ok on a biscuit jointer or domino but not on a table saw.

So what do you use on a table saw then DrB?

Bit overkill for you I think

 

[Willy]

According to Axminster's info the saw requires a minimum of 500m^3 per hour of extraction. Perhaps the extractor just isn't up to it?

 

[Presh]

I had an extractor like that, rubbish. Ok on a biscuit jointer or domino but not on a table saw.

So what do you use on a table saw then DrB?

Bit overkill for you I think

You're not kidding! LOL. I'm working up to one of those. :wink:

 

[Presh]

According to Axminster's info the saw requires a minimum of 500m^3 per hour of extraction. Perhaps the extractor just isn't up to it?

Yes as I mentioned earlier this low volume extractor is a compromise and, were money no object, I'd have both a high volume chip extractor for the saw and the low volume unit for routers, hand tools etc. but reasonably thought a twin motor vacuum would do a better job than it currently is. I have noticed though that the base of the saw knife partially obstructs the dust collection port in the saw blade shroud. I intend to cut the bottom portion off this and it should improve. Both vacuum motors are pulling air correctly and actually drags the filter towards the table saw under the power of the vacuum if not restrained.

 

[woodfarmer]

I didn't have any problems with dust until I got modern saw with all the safety features. One of which was to enclose the lower part of the blade. Problem is the sawdust "wants" to exit from the back of the bottom of this enclosure, but because it can't is forced up again out the top. I got around it by angle grinding a hole at the back of the bottom now I dont get facefulls of sawdust etc.

 

[Myfordman]

Several people have written up mods to Ts200 saws to improve the dust collection over the years.

Do a thorough search of the archives and you will find them.