Thread: Blast gate gallery

One other reason for wanting to move it was that it was PITA to get to the gate because it was against the back wall behind the saw table but as it was the only branch before, there was no real reason to move it. Now I've added another branch for the thicknesser, I thought it would be a good idea to move it.
Bit the bullet this morning and moved it - so much easier to get to.

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What glue do you use for MDF to PVC?

Originally Posted by Flintlock

What glue do you use for MDF to PVC?

I used a PU glue but even PVC cement should work. In both cases it pays to clean the PVC itself. When using the PU glue I lightly sanded the PVC but with the PVC cement using PVC cleaner would be the way to go.

Thanks BobL. Just starting on some pivoted blast gates. What is the c/c measurement from the duct to the pivot point?

Originally Posted by Flintlock

Thanks BobL. Just starting on some pivoted blast gates. What is the c/c measurement from the duct to the pivot point?

I posted the plans here Ducting update.

The plan for the sides of the rocker gates are posted as an image and the plan for the central rocker component is posted as an attachment
The way to draw up the plans does not use a measurement "from the duct to the pivot point" .
Instead the distance of the "centre of the duct" from the pivot is provided, and the the diameter of the duct is drawn along that circle.

Wanting to make some gates soon, tonight I started work on a CAD layout based on Bob's design and going to get some quotes on getting them laser cut out of acrylic or PVC. If that's not cost effective I'll print out the CAD layout and use it as a cutting template to save time. Pretty much got it all figured out, I might tinker around and add the stop cutouts but otherwise I'm pretty happy. The holes are all just 150mm at the moment too so I need to update that, going to need to go measure my stock of PVC pipe and couplers to see what I should be aiming for.



The flanges I'm going to have cut as well, they'll just be simple circles 4cm larger in diameter than the coupling. Then I'll stack a couple of those together on each side and glue them to the blast gate and coupling.

Nice drawings Dan.
Not sure about using acrylic for gates as they will eventually lose any transparency because wood dust (and the opening and closing action), will act as an abrasive.
Because you don't want the gate to flex and Acrylic is also more brittle than PVC the Acrylic will need to be quite thick so could be Exy?
If you were to use acrylic I would suggest physically supporting the gate, either from the ducting on at least one side of the gate or from the top centre of the gate
This will reduce gate flexying and makes it easier to open and close the gate.

If you do use a cutting service make sure you keep all the offcuts because 4" gates can be made out of these.
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Thanks for the suggestions mate, I hadn’t thought about the abrasive nature of the dust. I’ll see if anyone can do it in PVC, otherwise it will be down to templates and some time and effort [emoji846]

Originally Posted by bueller

Thanks for the suggestions mate, I hadn’t thought about the abrasive nature of the dust. I’ll see if anyone can do it in PVC, otherwise it will be down to templates and some time and effort [emoji846]

Having made a few from Bob's plans (and about to make some more), the only thing that is at all very time-consuming/tricky is cutting out the holes. Using the Dremel hole cutter attachment as Bob suggests makes that much easier and if you have a Dremel, I recommend acquiring that attachment..

Hi BobL
Just about to cut out a template for the blastgate from the link above, but something doesn't look right to me. You have got measurement 'd' the same on both parts. Shouldn't 'd' on the back and front be 25mm bigger than the rocker ie 325mm?
Thanks
Ian

Made some calls about laser cutting PVC and places that will do it are thin on the ground in Perth, just going to buy some PVC sheet and go the printed template route. About 80 bucks for a 2.4m x 1.2m of 3mm Rigid PVC, I reckon i can get about 20ish gates out of that if I keep the waste down.

If anyone is looking to print a template it looks like you can get Officeworks to print them on A2 plotting paper for under $2 bucks a template. I'll get a few of those printed to cover any mistakes and then I'll use the first blast gate as a template for the next run. Hoping to get this all sorted out tonight so I can get them started over the weekend, will let you guys know how it goes.

Originally Posted by Flintlock

Hi BobL
Just about to cut out a template for the blastgate from the link above, but something doesn't look right to me. You have got measurement 'd' the same on both parts. Shouldn't 'd' on the back and front be 25mm bigger than the rocker ie 325mm?
Thanks
Ian

The outermost radius for the the sides is prescribed not by "d", but by "e" which is 325 mm

Originally Posted by bueller

Made some calls about laser cutting PVC and places that will do it are thin on the ground in Perth, just going to buy some PVC sheet and go the printed template route. About 80 bucks for a 2.4m x 1.2m of 3mm Rigid PVC, I reckon i can get about 20ish gates out of that if I keep the waste down.

3mm is OK for the rocker but i'd be worried about using 3mm for the sides because they will flex too much. Id use at least 5 or preferably 6 mm for the sides.