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taydin
12-13-2010, 08:57 AM
Hi, I am in the process of building a dust collection system for my home shop and have been searching for pipe fittings for a long time. I have finally given up finding them, so I want to build them myself.

I first need a reduction from 150mm to 120mm. 150mm PVC pipe is already available, so that's taken care of. 120mm is not available (125mm is), so I bought 130mm round PVC stock and will turn a 120mm pipe on the lathe. I also bought 2mm thick PVC sheet stock. This will be used for the conical piece that joins the 150mm pipe to the 120mm pipe. I drew up the reduction as a sheet metal part on Alibre Design and have unbent the conical piece, so I know the dimensions that I have to cut out.

But how do I bend that PVC sheet to be the conical middle part? Do I need a special tool? Do I need to heat it? If so, how can I uniformly heat it?

Edit: There is a special glue available for PVC called Tangit, so joining the pieces will be no problem...

Lew Hartswick
12-13-2010, 09:03 AM
PVC forms well if heated appropiately. I would try it in some sort of
"toaster" oven BUT be careful to not get it too hot or it'll sag all all
over tjhe place. You will need to QUICKLY wrap it around a form and
hold it till it cools.
PVC cement is commonly available at all "big box" plumbing depts.
That still sound like a hard way to make the adaptor though.
...lew...

Boucher
12-13-2010, 09:51 AM
You might consider warming in a hot water bath on a plate to support it. This can achieve a uniform and controllable temperature.

Evan
12-13-2010, 09:53 AM
Some how I doubt they have a Home Depot in downtown Gebze.

Slit the end of the 150 mm pipe by cutting out 4 pie slices at 90 degrees around the end. Wrap something elastic such as electrical tape around the very end. Heat the points where they must bend and the elastic will draw the ends together. Slobber some glue on the part and you have a cone. You could just wrap it with electrical tape instead of using glue. Save the 2mm piece for something else.

JCHannum
12-13-2010, 09:58 AM
A hair drier will work and should be available. It would be best to form the cone around a blank, possibly turned up from wood.

taydin
12-13-2010, 10:50 AM
A hair drier will work and should be available. It would be best to form the cone around a blank, possibly turned up from wood.

If I understand correctly, this is the procedure you are talking about:

Turn a rough cone using wood. I could also use the PVC stock left over from the 120mm pipe. Then screw one end of the stripe to the cone. Using a heat gun, continue heating one spot, press it against the cone and go on until the stripe is fully wrapped around the cone. Fix the stripe to the cone using tape and let it cool. Is this correct?

taydin
12-13-2010, 10:52 AM
Some how I doubt they have a Home Depot in downtown Gebze.

Slit the end of the 150 mm pipe by cutting out 4 pie slices at 90 degrees around the end. Wrap something elastic such as electrical tape around the very end. Heat the points where they must bend and the elastic will draw the ends together. Slobber some glue on the part and you have a cone. You could just wrap it with electrical tape instead of using glue. Save the 2mm piece for something else.

After doing this, the 150mm will be touching the 120mm at 4 points. But how do I seal the 4 triangles that are left open? Do I use the cutoffs?

taydin
12-13-2010, 10:54 AM
You might consider warming in a hot water bath on a plate to support it. This can achieve a uniform and controllable temperature.

Hmm, if the PVC will sufficiently soften up using water, I could also use the kitchen oven for this purpose. I am wondering how much time I will have after opening the oven lid

taydin
12-13-2010, 10:58 AM
Actually, if I just use a 150mm OD, 120mm ID washer cut out of the 2mm PVC stock to join the two pipes, will I create too much of an air resistance? The saw requires about 550cfm and my dust collector is 1100cfm.

Would using such a washer be the difference between good dust collection and NO dust collection? The distance between the saw and the dust collector will be about 6m and there will be a flexible "accordeon" type of hose in between. Because of the structure of the hose, I am already creating a huge resistance...

Here is that hose:

http://www.burflex.com/YuklenenResimler/poliuretan_bakir.gif

914Wilhelm
12-13-2010, 11:07 AM
I soften pvc in the oven (it stinks and off gasses if too hot, don't use the wifes oven). After you remove the softened PVC from the oven, you will have about 30 seconds to form this. If you get it wrong, just pop it back in the oven and retry it. You get a few chances with this type of plastic. Typical PVC mets at 176F IIRC.

jkilroy
12-13-2010, 11:26 AM
Ok, I'm going to save you some cash here, google up PEP Plastics, they will fab up any kinda reducer you need. They do 12" to 4" and 6" for a product of mine, great people, super product.

taydin
12-13-2010, 11:30 AM
Ok, I'm going to save you some cash here, google up PEP Plastics, they will fab up any kinda reducer you need. They do 12" to 4" and 6" for a product of mine, great people, super product.

Thanks for the link, but I am in Turkey and ordering those products internationally will be either very expensive, or impossible, because if they are held up at the Turkish customs, that'll be the end of it :(

Rustybolt
12-13-2010, 11:46 AM
Actually, if I just use a 150mm OD, 120mm ID washer cut out of the 2mm PVC stock to join the two pipes, will I create too much of an air resistance? The saw requires about 550cfm and my dust collector is 1100cfm.

Would using such a washer be the difference between good dust collection and NO dust collection? The distance between the saw and the dust collector will be about 6m and there will be a flexible "accordeon" type of hose in between. Because of the structure of the hose, I am already creating a huge resistance...

Here is that hose:

http://www.burflex.com/YuklenenResimler/poliuretan_bakir.gif




Use the wire to ground that puppy unless you want a shock every time you touch your saw.

noah katz
12-13-2010, 12:16 PM
You could also go the other way and start with the smaller piece and expand one end.

I believe there are directions on how to heat form PVC on somewhere on Bill Pentz' web site http://billpentz.com/woodworking/cyclone/index.cfm

IIRC you can expand PVC about 20% before it tears.

I wouldn't worry too much about pressure drop if you're going to use a lot of that hose.

Bill's site also has a pressure drop calculator in Excel which will calculate the drop of various pipe and fittings.

I tried forming a piece once and it was pretty time consuming.

I like the idea of cutting out triangles; I'd probably do at least eight, and make them at least 8" long to make for a more gradual transition.

Evan
12-13-2010, 01:03 PM
After doing this, the 150mm will be touching the 120mm at 4 points. But how do I seal the 4 triangles that are left open? Do I use the cutoffs?


Correctly calculated the openings will close completely. Made long enough the angle will be gentle and the end of the reducer may be turned enough to present a proper round section of pipe at the desired diameter. Make the reducer section longer than required so that you will have a section that is the right diameter to work with. Turn to fit and cut off the excess.

You can also do this by simply making a lot of radial saw cuts with a circular saw. That will leave small openings at the root of each but wrapping with tape will fix that. It's under suction so the tape will seal just fine. No heat required to bend the small sections.

Boucher
12-13-2010, 02:03 PM
Running 550 CFM through a 5" hose id going to be whistling. You better have a good hold on it. If something breaks it will definately be thrashing around.

Guido
12-13-2010, 02:15 PM
Just passin' through, but starting at one end of tayden's system does not dust travel from his source (saw), via hose conduit to the bag house/dust collector, thence to the vacuum fan?

--G

The Artful Bodger
12-13-2010, 02:33 PM
Hi Taydin, you can reduce the diameter of PVC pipe by warming it and stretching the pipe lengthwise, this forms a 'neck' in the pipe. Of course you only heat it at the place you want to reduce the diameter. In your case where you are wanting to make a reducer this method will produce two reducers which you must saw apart when cooled.

I imagine, but I have never tried this, that you could heat the bigger diameter pipe then slide a piece of the smaller pipe inside, not heated. Then when you stretch the larger pipe it will reduce down to fit the smaller pipe.
John

Evan
12-13-2010, 03:08 PM
Not a bad idea. This would work best in a glass lathe which has driven chucks at both ends. Failing that stuff a tight fitting bearing in the right end (tape until it is tight) and fit the bearing over a large bit in the tail stock with something to prevent the bearing sliding off the bit. Then heat gently with a propane torch or a heat gun and draw it out with the tail stock all the while rotating in back gear. With practise you can even make a coupling feature after it cools by heating a small area of the reduced section and pushing it together to increase the diameter of that section. Glass blowing with plastic.

I shall have to try that before I die.

Boucher
12-13-2010, 06:45 PM
I use a 6 1/2 gal cast iron pot with water and use my IR thermometer to monitor temperature. I have used oil in it also for higher temperatures. For smaller fittings the hot air gun works. The IR therometer can be used to measure surface temperature. For forming sheet material it can be laid on a flat plate in the water bath to maintain the flat shape until ready to form. For something this size a cutoff 55 gal drum may be closer to the size needed.

The Artful Bodger
12-13-2010, 07:03 PM
Does PVC really soften at less than the boiling point of water?

If so, put a cap on one end of the pipe then fill with hottest possible water and put a cap on the other end. Now pull on the caps and if I am thinking right the atmospheric pressure will put a nice waist in the pipe!

Yes Evan, a lathe would have possibilities! I have only ever done it manually.

Evan
12-13-2010, 07:18 PM
The melting point of PVC is listed as between 80C and 260C. That really narrows it down... :rolleyes:

macona
12-13-2010, 07:43 PM
Use the wire to ground that puppy unless you want a shock every time you touch your saw.

Main thing is to run a bare copper wire down the tube through both ends to ground. This prevents static build up and lowers the chances of a atomized particle explosion.

darryl
12-13-2010, 08:39 PM
I soften pvc in my oven all the time. I set it for 275F, and I have a time chart (in my head) for different thicknesses. I haven't seen any pvc which would soften enough to form at less than 250F. These are figures from my particular oven, so it could vary. Forget the boiling water idea. I would allow the oven to heat up first so you're not dealing with temperature overshoots, then put the pvc in to be softened. It shouldn't take more than about 5-8 minutes for a piece of 3/16 thickness to heat through.

I would be tempted to enlarge the smaller pipe rather than try to neck down a larger pipe. Be aware that once you soften it and let it cool, the original diameter part will have changed size as well as the part that you expand. I would turn a wooden jig that has the larger ID to start with, then cone it down to the smaller ID and leave some straight at that size, then taper it down some more. When you shove that into the softened pipe piece, both ends will become the proper size. The pvc will shrink in diameter if you don't give it something to form to- plus it will go off round. The last part of the pipe section will be tapered down to a smaller size than the original pipe, but that part you just cut off. The last taper just lets you push the wooden form into the softened pipe easier and more quickly. Inserting the form into the pipe should take about one or two seconds- don't use too slow a push at this point. If I had the tool and the piece of pvc in my hands right now, I'd be done before I could finish this reply.

This is an easy job to do. It will take longer to turn the wooden form than to shape the pvc piece. Once you have formed it over the wooden tool, let it cool for maybe 1 or 2 minutes, then force the tool out. Be prepared with a way to do that quickly. If the pvc gets cooled too far, it will be tighter on the form. You would still be able to hammer it out, though.

I suppose other considerations might include getting the formed sizes just right. If anything, make the wooden tool a tad on the large side. You can always turn it down more, but it takes years to put wood back on. :)

Last thing to suggest is that pvc can and will exude a harmful gas. You can heat it all day to a lower temperature without problem, but as soon as you exceed a certain temperature it will begin to gas. You won't see it- you might smell it, but if the plastic starts to brown at all, you're too hot. For a piece the size you're working with it won't be a problem- I can heat a slab over an inch thick and 22x16 inches to forming temperature without having it cause me breathing problems or stinging my eyes, etc. But I can also let it overheat, and then the gas is very noticeable- and by then probably toxic.

Evan
12-13-2010, 09:15 PM
It's hydrochloric acid.

Gravy
12-13-2010, 09:20 PM
Playing Devil's advocate here: Does it really need to be PVC? If you are already modeling with sheet metal, why not just use sheet metal? Aluminum tape it together and get back to work.

ulav8r
12-13-2010, 09:37 PM
The washer should work fine if you are going in the right direction. I am assuming you are connecting the 120mm hose to the saw and adapting it to the collector hose of 150mm. There might be a slight build up of dust next to the washer that would need to be cleaned out occasionally but should not be much of a problem. Just make it easy to disconnect from the washer so it is easy to clean when needed.


[quote=taydin]Actually, if I just use a 150mm OD, 120mm ID washer cut out of the 2mm PVC stock to join the two pipes, will I create too much of an air resistance? The saw requires about 550cfm and my dust collector is 1100cfm.

darryl
12-13-2010, 09:41 PM
Thanks, Evan. I guess I never paid enough attention to what it was- I tried to prevent by not overheating, plus I use the exhaust fan all the while. I actually have to put the fan on about 10 minutes beforehand so it can heat up and come up to speed.

whitis
12-14-2010, 01:31 AM
The melting point of PVC is listed as between 80C and 260C. That really narrows it down... :rolleyes:

There are different kinds of PVC. Crosslinked PVC for example, has a higher melting point.

Schedule 40 PVC pipe has to be derated to about one fifth the pressure at a temperature of only 140degreesF. Even at 80 degreesF, it has to be derated by 12%.
http://www.harvel.com/tech-specs-pvc-pipe-40.asp

A graph of an unspecified rigid PVC shows the modulus of elasticity dropping to near zero at less than 100degreesC:
http://books.google.com/books?id=6qrEKgxeFEcC&pg=PA45
This particular PVC has lost about 40% of its elasticity going from 68degreesF (near the baseline for PVC pipe) to 140degreesF.

At the boiling point of water, even Schedule 80 CPVC has lost 84% of its pressure rating:
http://www.us.piping.georgefischer.com/go/0B9970F6199943D441223A15E88988AB?action=GF_Documen tDownload&doc_uuid=0B9970F6199943D441223A15E88988AB

I have personally seen PVC pipe "melt" when exposed to steam at near atmospheric pressure and the boiling point of water when the water level in a hot tub got low and the pump thrashed the remaining water in the pump into steam.

An interesting way to make the fitting would be to replace your knurls with rounded rollers, turn a wood mandrel, aim a heat gun at the pipe (larger size) and use "metal" spinning to reduce the diameter. Advance the cross slide by feel as you traverse the carriage.

Duffy
12-14-2010, 10:34 AM
Taydin, you are making FAR more of this "problem" than it deserves. I have an 1100 cfm dust collector. It has a 5" inlet to the fan which is actually a 4X4X5 wye. One 4" duct serves my table saw and is permanently connected. The other 4" outlet is connected to a length of PVC hose which I can connect to either a 6"X80" belt sander, a router table, a 6" jointer or a 12" planer. The planer collector hood has a 2" outlet to which I have fitted a 4" disc of wood with the 2" hole internally tangent to the edge. A 4" metal adapter is screwed to the disc.
This setup produces far and away the most shavings and/or dust of whole shop. It has NEVER clogged and I did not bother with an anti-static bonding system.
By the way, unless you can cobble up a workable over-blade pickup, you will STILL throw lots of sawdust in your face. And you might also want to put a couple of magnetic covers over the quadrant openings in the sides of the saw cabinet.
My system has been working for about 18 years, admittedly in a "hobby" environment, and I STILL have dust. It is a problem of woodwork, just like metal chips are a problem of metalwork.

noah katz
12-14-2010, 01:42 PM
How about chuck it up in a lathe, seal the ends except for a vacuum port, run slowly while heating the middle section, and connect a shop vac.


Does PVC really soften at less than the boiling point of water?

If so, put a cap on one end of the pipe then fill with hottest possible water and put a cap on the other end. Now pull on the caps and if I am thinking right the atmospheric pressure will put a nice waist in the pipe!

Yes Evan, a lathe would have possibilities! I have only ever done it manually.

taydin
12-14-2010, 02:07 PM
Taydin, you are making FAR more of this "problem" than it deserves. I have an 1100 cfm dust collector. It has a 5" inlet to the fan which is actually a 4X4X5 wye. One 4" duct serves my table saw and is permanently connected. The other 4" outlet is connected to a length of PVC hose which I can connect to either a 6"X80" belt sander, a router table, a 6" jointer or a 12" planer. The planer collector hood has a 2" outlet to which I have fitted a 4" disc of wood with the 2" hole internally tangent to the edge. A 4" metal adapter is screwed to the disc.
This setup produces far and away the most shavings and/or dust of whole shop. It has NEVER clogged and I did not bother with an anti-static bonding system.
By the way, unless you can cobble up a workable over-blade pickup, you will STILL throw lots of sawdust in your face. And you might also want to put a couple of magnetic covers over the quadrant openings in the sides of the saw cabinet.
My system has been working for about 18 years, admittedly in a "hobby" environment, and I STILL have dust. It is a problem of woodwork, just like metal chips are a problem of metalwork.

I have seen many commercial woodworking shops here and none of them had any provisions for dust collection. The machines weren't even designed with dust collection in mind. The guy does his sawing, planing, whatever, with enormous amounts of dust in the air. When he is done, he just dusts himself off using his compressor and calls it a day :) That's why air duct material is very difficult to find, so I definitely need to make them myself.

You probably have the same dust collector that I have. It is a Jet DC1100CK. The main outlet is 150mm, more than the 120mm I need. The wye that came with the machine converts the 150mm to 100mm, too little for the saw... The closest standart PVC pipe is 125mm. It doesn't fit the saw and it doesn't fit the dust collector...

As for the blade hood, it has a 50mm connection. I was going to make a 120mm pipe and glue a 50mm pipe to the side. So the saw and the blade hood will be serviced by the same 120mm hose.

Duffy
12-14-2010, 03:19 PM
!00 mm duct is LOTS big enough for a saw, up to about 16." Even a moulding head does not produce too much chip load for a 4" duct. The ASHRAE guides for duct system design are exactly that-Guides. Also, they are recommending for an indusrtrial setup, where down-time is BIG money. Your dust collector has more than enough oomp to handle anythinh you are likely to give it. CAUTION- do not let it pick up 3 1/4" nails. How do I know? ONE took out my impeller, (or unballanced it so badly that it AND THE BEARING were toast!)
One additional thought-pay very little attention to the recommended metal thickness. My system uses domestic forced air ducting which is about 26 gauge. It will last for years.

noah katz
12-14-2010, 05:13 PM
!00 mm duct is LOTS big enough for a saw, up to about 16." Even a moulding head does not produce too much chip load for a 4" duct.

I think these days the concern is less chip collection and more collecting dust to keep it out of lungs.

taydin
12-16-2010, 11:41 AM
!00 mm duct is LOTS big enough for a saw, up to about 16." Even a moulding head does not produce too much chip load for a 4" duct. The ASHRAE guides for duct system design are exactly that-Guides. Also, they are recommending for an indusrtrial setup, where down-time is BIG money. Your dust collector has more than enough oomp to handle anythinh you are likely to give it. CAUTION- do not let it pick up 3 1/4" nails. How do I know? ONE took out my impeller, (or unballanced it so badly that it AND THE BEARING were toast!)

I am really not insisting on using 120mm pipe. If I use 100mm, I don't need the reduction at the dust collector and I can use the wye supplied with the machine.

But then I need a reduction at the machine side :) The machine dust port is 120mm. There is also a 50mm port, which is the blade hood. I also need a wye to join the blade hood hose to the main hose, regardless of whether I use 100mm or 120mm hose.

taydin
12-16-2010, 11:44 AM
Inquired at a company that makes stove pipes. They are building the pipes and the fittings using a press and again, the standart sizes are 100 and 125mm :mad:

They said they can hand make the fittings to my specifications, but then it probably won't fit snugly to the dust port. I want to be able to disconnect the hose from the saw and use it with other machines if needed, so I can't clamp it to the port.

I bought a 150mm PVC pipe. Here is what I will try first:

I will chuck the 150mm PVC pipe to the lathe. Then I will turn the lathe at the slowest speed and start heating the edge with my heat gun. At the same time, I will press the edge using a bearing. Hopefully I will be able to bring the pipe down to 120mm OD.

Otherwise, it's plan B: I also bought small pieces of 130mm and 60mm PVC round stock, 2mm thick PVC sheet stock. I will turn the pipes myself. A good reason to go and buy a long boring bar :) I'll make a washer between the newly turned 120mm pipe and the 150mm pipe and glue them together. If the sucking performance is good, I'll just use it the way it is.

I will also try chucking the 120mm pipe to the lathe and try widening it with my heat gun. If that fails, too, I will cut the conical piece as I modeled and try to bend it under heat. Pictures to come soon!

Evan
12-16-2010, 12:31 PM
While you are taking pictures how about a couple of shots of down town Gebze? I'll bet I am not the only one that is curious.

dockrat
12-16-2010, 12:48 PM
While you are taking pictures how about a couple of shots of down town Gebze? I'll bet I am not the only one that is curious.

Evan, Google maps shows a lot of photos of Gebze

Duffy
12-16-2010, 01:24 PM
Taydin, Evan is absolutly right on the curiosity bit! For a pickup from the saw, again use a 120mm disc with a 100mm hole internally tangent to it. Insert the disc in the saw outlet, and a 100mm adapter, (maybe 100mm long?) inserted into that hole. Slp the hose over the adapter. As far as fit is concerned, dont sweat it-as long as the hose is snug enough NOT to slip off, you are good to go. If we DO have similar units, mine moves 1100 cfm and caims 9.5" of stat5ic suction. Trifling leakage like poorly assembled fittings just do not matter- they just act as localized dust pickups!
My saw is a 10" cabinet model, with a 100mm outlet. BUT the cabinet is really a glorified box with a 100mm hole in a removeable door in the side. After a few hours operation, the box contains a large amount of sawdust and fragments which are roughly formed into a sloping heap towards the hole-THAT is the limit of "streamlined design" for dust pickup.
Since you have an over-blade pickup, (50mm,) I suggest that you make an adapter fitting at the outlet. This can be as crude as a rectangular box covering the 120mm opening. It needs a 50mm nipple and a 100mm nipple for the two connections. This sounds clumsy and it IS crude, but it WILL work.
A nicely made up 120X100X50 wye would look better and cost more, but with the excess capacity of your dust collector, clumsy will work just fine.

taydin
12-17-2010, 08:11 AM
Duffy, the ring idea makes quite sense! I can take a 125mmm, 90 degree elbow and turn a ring with OD 125 and ID 120 and 40mm width and glue this ring into the elbow. This will effectively give me a 120mm elbow.

I can do the same thing for the reduction. turn a 150mm OD, 120mm ID, 40mm width ring and glue this into the standard 150mm PVC pipe. Then it's just a matter of turning a 120mm pipe and fitting this into the ring. That's a solid pipe reduction right there! I can also chamfer one side of the ring at 45 degrees so that there is no pocket where chips can accumulate.

Thanks to everybody for the wealth of ideas!

Here are a few pictures of Gebze, as seen from the location where I built my shop:

http://www.taydin.org/web/shop_surrounding/scaled_img_1389.jpg

http://www.taydin.org/web/shop_surrounding/scaled_img_1390.jpg

http://www.taydin.org/web/shop_surrounding/scaled_img_1396.jpg

http://www.taydin.org/web/shop_surrounding/scaled_img_1419.jpg

camdigger
12-17-2010, 09:55 AM
Nice pictures!

It looks like pretty country, Taydin.

There's a wild rumor afoot I may be in your neighborhood on business in the next few weeks - (Istanbul, actually).

I'm looking forward to it (it has to be better than the FSU), although SWMBO's not. She's trying to be brave about it, though.

Ironically, I've done enough travelling that it's lost some appeal. SWMBO, however has always wanted to travel and has not had anywhere near the opportunities. Who knows where this might lead...

P.S. to get back to the original subject, there is a series of youtube videos on assorted ground water ptojects around the world. One series from Germany shows building a pump from stock plastic pipe (White PVC?). The pipe was simply heated over a gas ring and shaped with wood blocks and gloved hands to make integral couplings and some necked down fittings. Might be worth a look...

Evan
12-17-2010, 10:22 AM
Nice shop. What I don't see in the background is very many vehicles on the road. Is that just me or is that an accurate interpretation? I assume it is a work day.

taydin
12-17-2010, 10:50 AM
Nice pictures!

It looks like pretty country, Taydin.

There's a wild rumor afoot I may be in your neighborhood on business in the next few weeks - (Istanbul, actually).

I'm looking forward to it (it has to be better than the FSU), although SWMBO's not. She's trying to be brave about it, though.

There are lots of historical places to visit in Istanbul. Make sure you take a boat tour of the Bosphorus. Way back when I was working in the US (Connecticut), I had a few business trips with American engineering colleagues. They all were blown away by the food :) So make sure to reserve some time for that.

Ian B
12-17-2010, 10:54 AM
Taydin,

Thanks for posting those pics - they take me back to when I had a 3 year posting in Diyarbakir, end of the 1980's.

Ian

taydin
12-17-2010, 10:56 AM
Nice shop. What I don't see in the background is very many vehicles on the road. Is that just me or is that an accurate interpretation? I assume it is a work day.

This is the suburban area of the city. But development is going at a very rapid pace. Pretty soon there will be many more apartments like the one that can be seen at a distance...

derekm
12-17-2010, 11:25 AM
bodge alert!

stick one pipe inside the other. Then fill the gap with polyurethane foam from an aersol can. finish with tank tape!

taydin
12-26-2010, 01:32 PM
Ok, finally made some progress...

Here are pictures of the pipe reduction, going from 150mm to 120mm:

Here I took a 160mm round stock and gutted it:

http://www.taydin.org/web/pipe_reduction/scaled_img_2402.jpg

http://www.taydin.org/web/pipe_reduction/scaled_img_2403.jpg

http://www.taydin.org/web/pipe_reduction/scaled_img_2404.jpg

taydin
12-26-2010, 01:33 PM
Then I made a ring which reduced the ID to the desired 120mm:

http://www.taydin.org/web/pipe_reduction/scaled_img_2405.jpg

http://www.taydin.org/web/pipe_reduction/scaled_img_2406.jpg


Now I glued the ring to the pipe:

http://www.taydin.org/web/pipe_reduction/scaled_img_2407.jpg

http://www.taydin.org/web/pipe_reduction/scaled_img_2408.jpg

taydin
12-26-2010, 01:37 PM
Then I turned a 120MM OD pipe, again from round stock and glued it to the ring:

http://www.taydin.org/web/pipe_reduction/scaled_img_2409.jpg

http://www.taydin.org/web/pipe_reduction/scaled_img_2410.jpg

http://www.taydin.org/web/pipe_reduction/scaled_img_2411.jpg

And finally, I attached the flexible hose to the reduction:

http://www.taydin.org/web/pipe_reduction/scaled_img_2412.jpg

taydin
12-26-2010, 01:40 PM
Now that the dust collector to hose connection was taken care of, I started on the piece that will be connected to the saw. This piece also needed a 50mm T so that the 50mm hose from the blade hood merges in. The saw side is 120mm ID, the other side is 120mm OD and the T is 50mm OD. As can be seen in the first picture here, the 120MM OD side is pretty rough. That's because I was too lazy to turn a piece to go inside that part so that I can chuck it properly. The pipe "escaped" from the chuck ...

http://www.taydin.org/web/pipe_reduction/scaled_img_2414.jpg

http://www.taydin.org/web/pipe_reduction/scaled_img_2415.jpg

http://www.taydin.org/web/pipe_reduction/scaled_img_2416.jpg

http://www.taydin.org/web/pipe_reduction/scaled_img_2417.jpg

taydin
12-26-2010, 01:47 PM
I still need to make another pipe that will connect to the one above with the T. The above will be permanently attached to the saw and this new pipe will be disconnected and moved over to other machines when required.

But first I gotta haul the chips out so that I can get to the lathe :)

http://www.taydin.org/web/pipe_reduction/scaled_img_2418.jpg

http://www.taydin.org/web/pipe_reduction/scaled_img_2419.jpg

http://www.taydin.org/web/pipe_reduction/scaled_img_2420.jpg

taydin
12-26-2010, 01:50 PM
One question though: When turning the pipes, I had to use some of my stock to make fillers so that I could reliably chuck the pipes. Now I am out of stock and couldn't finish everything this weekend :mad:

Is there a tool that can be used instead of a filler? I am thinking of something similar to a chuck. You basically adjust it so that it touches the pipe from the inside and then you chuck that together with the pipe. This way, I don't need to use stock for this :confused:

darryl
12-27-2010, 03:12 AM
Take a fairly large hex nut, drill and tap each flat. With a selection of bolts of various lengths, you'll be able to fit them in to get an outer distance from head to head equal to the pipe ID that you want to turn. You can use all six tapped holes at once if you need to (helps keep the pipe round) or use just three. The chuck jaws clamp the pipe at the spots where the bolt heads are. If you use a four jaw chuck, then a short section of square tubing drilled and tapped on all sides works the same way.

The diameter of the square tube section or the nut should be more than one inch. This lets you use a bolt set where the length differs by 1/2 inch, and there's enough adjustment range then to allow for any diameter of pipe from about 2 inch ID and up. Your kit would include at least three bolts of each size, starting at less than 1 inch, so you'd have 3/4 inch, 1 inch, 1 1/2, 2, 2 1/2, 3 inch, etc. A trio of 3 inch bolts for instance would work for pipe with an ID from about 6 1/2 inches to about 7 1/2 inches.

Your shop build is interesting- what are those wall sections made of?

The Artful Bodger
12-27-2010, 03:46 AM
One question though: When turning the pipes, I had to use some of my stock to make fillers so that I could reliably chuck the pipes. Now I am out of stock and couldn't finish everything this weekend :mad:

Is there a tool that can be used instead of a filler? I am thinking of something similar to a chuck. You basically adjust it so that it touches the pipe from the inside and then you chuck that together with the pipe. This way, I don't need to use stock for this :confused:


I think I would try a wooden plug in the pipe which would allow the chuck jaws to tighten without deforming the pipe much.

Maybe the chuck jaws could be used inside the end of the pipe, just tighten the jaws enough to touch the pipe without deforming it then put a tight metal band around the outside of the pipe, a big hose clip for instance, just a thought as I have never tried it.

John

taydin
12-27-2010, 05:20 AM
Thanks for the tip darryl, quite doable by a newbie like myself :)

Just to expand on that idea, if suitable gears are attached to the bolts at the inside, one can arrange for all bolts to turn simultaneously by turning a centrally mounted shaft.


Your shop build is interesting- what are those wall sections made of?

The walls are made out of U profile at the edges and sheets of a material called "fiber cement". It is like sheet rock, but harder. There is styrofoam between the sheets for heat isolation. But the walls are not suitable for mounting or hanging heavy stuff on. I have to drill the U profile and use sheet screws when I need to mount something.

The Artful Bodger
12-27-2010, 01:24 PM
Maybe the chuck jaws could be used inside the end of the pipe, just tighten the jaws enough to touch the pipe without deforming it then put a tight metal band around the outside of the pipe, a big hose clip for instance, just a thought as I have never tried it.

John

Nah, second thoughts, the hose clip will not work!

What would work would be a heavy ring that is a snug, no need to be really tight, fit over the end of the pipe with the chuck jaws expanding from the inside.

taydin
12-27-2010, 04:06 PM
Nah, second thoughts, the hose clip will not work!

What would work would be a heavy ring that is a snug, no need to be really tight, fit over the end of the pipe with the chuck jaws expanding from the inside.

But how would the diameter be made configurable, especially if it is a heavy ring like you say? What if it is a triangle with 3 equal sides? After all, the important thing is that it resists the chuck opening up so that the pipe is squeezed in between ...

darryl
12-28-2010, 03:22 AM
Not sure the gear idea will work, since the gears would ride in and out with the bolts, changing the drive gear requirements all the time. One thing I pictured as a way to pre-adjust each bolt for any particular diameter is to have a piece of wood as a base, mount a stub onto it that the central piece can center on, then an adjustable stop that you set for the radius of the tube you'd be clamping. The central nut or tubing section would be rotated so each bolt in turn could be backed out to touch the stop. You could use a locknut on each bolt if you wanted to. With this preliminary adjustment made, you'd insert the 'jig' into the pipe, then possibly back each nut out an equal amount to apply some internal pressure to the pipe- enough to hold the jig snugly, but not enough to distort the pipe away from round. Conversely, if the pipe is not round and you need it to be such for the machining process, the jig would be able to force that. All six bolts would be used in that case.

The Artful Bodger
12-28-2010, 03:38 AM
But how would the diameter be made configurable, especially if it is a heavy ring like you say? What if it is a triangle with 3 equal sides? After all, the important thing is that it resists the chuck opening up so that the pipe is squeezed in between ...

Hi Taydin, maybe you could make a heavy ring and tap three holes to take threads that would align with the chuck jaws?

taydin
01-01-2011, 02:16 PM
Here are the pictures of the finished dust collection setup :)

http://www.taydin.org/web/pipe_reduction/scaled_img_2421.jpg

http://www.taydin.org/web/pipe_reduction/scaled_img_2422.jpg

http://www.taydin.org/web/pipe_reduction/scaled_img_2423.jpg