The 9-15 - Open Source Vacuum Project

[Brady Watson]

OK...here's the deal. 2yrs ago Bill Palumbo & and I came across a great source for vacuum motors that exceeded the performance of a Fein T3 @ 25% the cost. There were 2 models...One did 10.5" Hg & 95 CFM and the other did 9.5" Hg & 95 CFM but this 2nd one was a bypass motor, meaning that it could be used in series with the another motor of the same model...meaning that you could have one vac sucking thru the other to get a higher Hg" rating. There are many projects that I have worked on in my own R&D department & this is one project that is ripe for exposure to this group...so I am letting it out there for the good of the community. I briefly shared some of this information at the Jamboree this year, for those who attended. Before I get into technical aspects of this project, I want to make a few things clear, that you must intrinsically accept if you choose to undertake this project for yourself:

1) If you are not good with electricity, spend a few bucks and get an electrician.
2) If you are really, really lazy and you want every little thing spelled out for you every step of the way, this is not for you.
3) This is as much a learning process as it is a means to an end. You will learn much as you build this setup, and be rewarded with a powerful vacuum powerplant for your effort.
4) This is NOT a replacement for a professional vacuum system made for production work, although it's performance approaches some of these units.
5) Do your homework, your OWN research and use your own ingenuity to make YOUR version better than what I have come up with.
6) If you build a system using any of these motors, please post a picture to the group to inspire others.


593
Here's a single VBTST6460VM being tested


594
Single motor vacuum performance via Summit Racing gauge

OK...the name...the 9-15 stands for 9" Hg or 15" Hg from 2 vacuum motors. I will be talking about the bypass motors only. These motors have gone up about $10 since I bought them, but they are right about $100 each. You can purchase them through the very nice & knowledgable gentleman @ http://www.lighthouseenterprises.us/imperial.htm I believe that the model number is: VBTST6460VM They do 94 CFM & 130" H2O (about 9.5" Hg) each. Each motor is a 3 stage unit that compresses the air 3X to get higher suction. By having one motor sucking thru the 2nd motor, you essentially double the suction, and loose a tiny bit of CFM in the process. In my testing, I found that running both motors in parallel, both motors together pulled about 9.5 to 10" Hg with about 180 CFM (I have no way of verifying CFM, but it moved a lot of air). These are industrial grade units by the way, not some Eureka replacement piece of junk. Running the motors in series (one sucking thru the other) I measured 15 Hg" with about 1/2 the airflow. Probably about 90-100 CFM if my math is correct.

Being the kinda guy who 'wants it all' I didn't want to create a system that was either only 9" Hg or 15" Hg...what if I could do BOTH? Depending on the job, one may need more CFM and less suction & another might need that whole 15" HG to hold down small parts. I wanted to be able to switch as I needed to. Enter the 9-15...I started with the idea of housing each motor individually in a pod of sorts that could be tied into another pod by unplugging and plugging in tubing. I made a plywood box just for testing the concept, complete with automotive type filtration, and 'exhaust pipe'. Entire box was dadoed and cut courtesy of the Bot...and holes drilled in the RIGHT spots for the motor to mount mid-ship. Don't ya just love having a bot around?
This box with ZERO sealant, tape etc, with one quick-grip clamp pulled 7" Hg which is not too shabby for a non sealed box. It was a good little unit, but not quite what I wanted...


595
Plywood 'pod' created on Bot with only one clamp to hold it together while running tests


596
This pic for you nudges that are going to ask if it did 7" Hg with the lid off!

Here's the drum vac or the 'Typhoon'...This was based on a 15gallon steel drum and the housings were sealed into the lid allowing easy access to the filter...The only problem was that there really was no easy or elegant way to switch between 9 and 15" Hg with the drum configuration:


597
2 motor Typhoon concept


598
Single motor Typhoon test assembly

Several months went by working on & off on the project, still not arriving where I wanted to on it...After a good intense 'strong coffee thinking session' and about 47 sheets of paper scratched out, I finally came up with a theoreticaly system that would 'do it all'. A trip to HD and a pile of PVC parts later, I cobbled together a working model of the 9-15:


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Downright ugly, ain't she?
...yes I am aware that the top tube is not connected...wise guys!

By opening and closing valves the vacuum is directed in either parallel or series, yeilding 9" Hg & 200 CFM or 15" Hg & 100 CFM. Pretty neat, huh? You guys can figure out a more eloquent way of packaging the entire assembly. This config was really just setup to prove the concepts (and they DO work as planned!) As it is one motor sits lower than the other...You can do better....


600
The 9-15 in 9" & 200 CFM mode

Doing small parts and need some extra oomph over the 9" Hg setup? No problem. Turn a few valves with the motors off, and in seconds you're ready to go:


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9-15 in 15" Hg & 100 CFM mode

Examine the photos carefully to get the full concept. It's pretty simple once you understand what is going on. I know that many of you can improve on my design & concepts, so if you build one of these, post it up for the good of the community...and to keep me interested in sharing projects like this...it's nice to see my 'babies' come into existence
I'd love to have the time to fully document each step, create plans or a kit...but I just don't have the time to do that or walk someone thru start to finish (read my 6 requirements in the beginning). This is a really worthwhile project for you guys that like to tinker and do clever things on a shoestring budget. I'd much rather have my R&D be used than shelved or saved for my book.

I've since moved on to a new vacuum system that is more suited for production work. Meet 'Becky', a Becker VTLF250SK 25" Hg & 175 CFM!:


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Warning...small animals and loose appendages may get sucked in without notice!


-B

[paco]

Cool! Perfect timing! Thanks a bunch for sharing Brady!

I could use one detail; fittings for the motor intake and out to the PVC plumbing...? I can see you've use cast iron flange for the intake (are they glued?) and a PVC reducer for the motor #1 out (fit readily?)... in other words; are the plumbing connections standard size(s)?

Noisy?

[Brady Watson]

Thanks Paco.

You are correct. The motor mounts against a cast iron flange, but there is a silicone 'vacuum gasket' in between. Lighthouse should have an appropriate gasket, or get a hi temp silicone O-ring from McMaster, MSC etc. The flange is attached/sealed via C-clamps for my demonstration, but If you really want to do it right, machine a 3/8" AL disc/donut on the bot & tap holes to bolt the cast iron flange to it. Then use that AL disc for mounting & clamping it together. The motors DO get toasty, so you need something that won't melt.

In open air, they are as loud as any other shopvac. Add a little foam bedding material to the enclosure & exhuast baffle and it quiets down substantially. You can see a pic of the bedding material (some call it egg crate foam) in the wooden box pic.



-B

[rhfurniture]

I like Becky best... but how many amps, how many dollars?
R (:

[Brady Watson]

ShopBot sells the Becker pump. Check out their price list. It is much cheaper than buying directly from Becker and you get all of the plumbing etc. It's a 10hp 3ph 230v motor.

-B

[scott_smith]

Hmm, My pool plumbing has a 2” pvc 3-way valve for the skimmer / main drain selection. If they work with vacuum you’d only need 1 valve between the pumps. Google “Jandy valve”. Looks like Jandy also makes a check valve for the pool industry. Might get it down to one 3-way valve and a check valve.

Just some thoughts,
Great gob Brady,
Scott

[scott_smith]

Scrap the check valve idea. Don’t think that would work.
Scott

[Brady Watson]

The plumbing works...and I doubt there is a simpler way to plumb it than what I did. Your job is to make it look all pretty...or not. It works as is...that's the important part. The check valve can be used for something else...which is an entirely new thread & project altogether.

-B

[paco]

Brady?

It still need a filter at the intake right?

Is that a 2" to 1-1/2" reducer at the exhaust motor #1 to motor #2?

Roughly, what size is that setup (above)?

You said it get somewhat hot; how does the PVC plumbing take the air temperature from the exhaust?

Why this particular motor?

I know you mentioned you don't want to hold my hand for the tinkering of this project but I can't order the motors if I'm unsure about the fittings... I believe you're the one to answer for that since you built one. Thanks a bunch in advance!
603

I was just about the order a second Fein T3 (still shopping) but this could be better.

[Brady Watson]

Paco,
Yes...1.5 to 2". It gets hot @ the exhaust, but it didn't melt the PVC...but I didn't run it all day long in 90° heat in a production environment. It might not be a bad idea to take a stroll down to the automotive store & get a length of 1.5" exhaust pipe. That stub you see in the wooden box pic shows a 1.5" automotive stubby fitting. It slips right on & a hose clamp seals it off nicely. By putting a longer metal tube there instead of going right to PVC, it will act as a buffer zone for the heat. Of course doing this changes the route of the tubing. Do not let the tubing keep you from doing the project. Hi-temp Silicone tubing can be used for those 'hot connections' and slight differences between metal & plastic diameters...here I am...doin' your R&D for you again...LOL!


If I had to guess (disassembled right now) it is about 24" tall or so.

The motors are CHEAP for the performance they give AND made for series operation. You cannot do what is being done with the 9-15 with just any old motors...they have to be BYPASS motors and both should be identical.

-B

[Brady Watson]

Paco,
Yes...1.5 to 2". It gets hot @ the exhaust, but it didn't melt the PVC...but I didn't run it all day long in 90° heat in a production environment. It might not be a bad idea to take a stroll down to the automotive store & get a length of 1.5" exhaust pipe. That stub you see in the wooden box pic shows a 1.5" automotive stubby fitting. It slips right on & a hose clamp seals it off nicely. By putting a longer metal tube there instead of going right to PVC, it will act as a buffer zone for the heat. Of course doing this changes the route of the tubing. Do not let the tubing keep you from doing the project. Hi-temp Silicone tubing can be used for those 'hot connections' and slight differences between metal & plastic diameters...here I am...doin' your R&D for you again...LOL!


If I had to guess (disassembled right now) it is about 24" tall or so.

The motors are CHEAP for the performance they give AND made for series operation. You cannot do what is being done with the 9-15 with just any old motors...they have to be BYPASS motors and both should be identical.

-B

[harryball]

I may have missed it but are these motors single phase? I do wish I have 3ph power but alas it is still 8 miles from me.

This looks very promising. I could see using 4 of these to build a serious system for less than $1000 which for many shopbotters would be the holy grail. I agree, for commercial production standards just pay the price of admission and get a big pump, for the rest of us there does seem to be hope!

Robert

[Brady Watson]

Robert - Yes...110v single phase. I believe around 12A.

"I could see using 4 of these to build a serious system for less than $1000 which for many shopbotters would be the holy grail." ...Yes Robert...now you are starting to see the WHOLE picture


-B

[richards]

Brady,
You've come up with another winner!

I visited the www.lighthouseenterprises.us/imperial.htm (http://www.lighthouseenterprises.us/imperial.htm) site that you referenced and was impressed with both the extent of their product line and their prices. Since there was no detailed product information on that site, I looked up a similar motor at Grainger. That motor had about the same specs at greater price ($171). But, the Grainger specs gave a life expectancy of the motor of 500 hours. So far I haven't gotten an answer whether 500 hours means 500 hours for the brushes or 500 hours for the vacuum head. Do you have any information?

Edited: Also the listed current requirement is about 13A. Is that mostly surge or would I have to run two 15A lines if I wanted to run two motors?

[Brady Watson]

Mike - thanks.

I really don't know durability on one of these motors, but the way I look at it is, if it saves you money on the front end so that you can become more productive in your business, then even if they burnt out once a year, it would have paid for itself many times over. Hours running = hours cutting = hours making money. You have to put money back into the 'shop pot' for maintaining and upgrading your equipment. How else do you expect to grow your business? It is not designed for doing 50 sheets a day, day in & day out, but it is a way for people to get into the game cheap & with something that really works. I clearly stated that it does not replace an industrial vacuum system...but it WILL get you going until you make enough money and business to both afford & really need an industrial setup. You won't find a cheaper solution using new motors with the same specs anywhere...

General rant: Put a filter on your vacuum motors and pumps! I see many examples with zero filtration...while this isn't a huge deal if you run a sealed bleeder, the minute you start using pods, pucks and custom jigs, dust will get into the motor. Filters are cheap...

A 4 motor Fein setup is pretty good, but this setup gives you 1 more full pound per square inch of downforce with 2 motors running in parallel for 1/2 the price...Or about 4.5 pounds extra, per square inch downforce when running in '15-mode'. The Feins do move more CFM than these units, but if you have a good seal, the suction & downforce is what you want more than the CFM.

I won't give advice on electrical, as I am not a certified electrician outside my own shop.

For those who haven't brainstormed the possibilities of this unit yet, it is ideally suited in '15-mode' for vacuum bagging, veneering, fiberglass vac bagging construction, vacuum infusion and of course, thermoforming...The real idea behind this unit was a "universal vacuum power supply" that could be used throughout the shop for various tasks. Unlike those little high vaccum/low CFM surplus pumps, this puppy puts out 15" Hg which is more than enough for any of the applications mentioned, BUT it's got about 100 CFM compared to 4-6 CFM of the little pumps.

In the same line of reasoning, your professional vacuum system should have a 'vacuum power take-off' port on it, for use with custom jigs, vacuum bagging etc. A bleeder alone isn't going to 'do it all', no matter how big & bad your pump is. Purpose built jigs made specifically for the job at hand, beat out universal bleeders big time.

-B

[john_l]

I am still trying to learn the basics of this. Regarding the 4 motor setup mentioned... would that mean 4 motors all hooked in a, valvable, series arrangement (like the example of 2 shown above. Or do you mean 2 sets of 2, with each set serving half the table?

Sorry for the stupid question.

[Brady Watson]

John,
You can run any combination you wish, but the original idea was to have several sets of 2 motors working in unison to create a system on par with the specs of a professional unit. Of course there are some unique challenges like wiring up everything for 110v, but generally you can use as many as you need. You should really start with 2 motors, experiment and see what you really need.

There is quite a lack of vacuum knowledge & know-how in this sector of the CNC market...If you use vacuum efficiently, you can get buy with a lot less than you think you can. I've used just ONE Fein T3 for years to do 4X8 sheets, cut all the way through. It's more about how you use the vacuum than anything else.

If you really want a hot setup comparable to 4 Feins, then just use the VBTST13431AEAD model which CANNOT be used in series, but puts out about 10" Hg by itself. That's about 2.5" Hg more than the Fein...but about 25% less CFM. If you use 4 of this model, then you will have a 400CFM system capable of 10"Hg+.

-B

[geneb]

Brady, according to Ward the VM6460 motor is no longer available. He's substituting (for my order anyway) the VBTST13431AEAD motor which is listed at 94CFM and 140".

Since my vac plumbing is set up for two Fein Turbo III's, not being able to run these motors in series won't hurt me, but it may affect others planning on using them that way.

BTW, thanks for the great vac ideas!

[paco]

Gene, Brady,

what make it so that the VM6460 can be used in series while the VBTST13431AEAD cannot. I mean from the listing on lighthouseenterprises, I personally couldn't tell which one can or cannot...? What's the magic spec.? This is not enough for me to shop another model that could do the same as the VM6460. (http://www.talkshopbot.com/forum/show.cgi?tpc=28&post=53910#POST53910)(bottom of Brady's post) Would Ward help me with that?...!

It's just that I hate it to not know and it may be something that other are wondering about... and I may just have to replace the one I got someday right?!

[Brady Watson]

Gene,
Thanks for the update. Now that I've posted the terminology (EG - Series operation needs bypass rated motors) you guys should be well on your way to create your own one-off experiments. If you want to make your own dual-motor setup similar to the 9-15, you've got all the engineering done for you (except packaging) and you'll just have to find bypass-rated motors.

The motor you list pumps out a little over 10" Hg, which is pretty good all by itself. When SB gets the time to post my latest column, you'll see how you can squeeze out more from whatever vac setup you are using...allowing you to take on jobs you never thought your little shop (or big shop) could do before...and the column after that will talk about some other vacuum goodies that you can employ 'on the cheap'.

EDIT: Paco...you slipped in there...These are BYPASS motors...that is the 'magic spec' that you want. They are made to withstand another motor connected to it in series. The other model, while it does 10+" by itself, is not made to this spec. What's different mechanically? I have no idea...I have one of the non-bypss motors and it looks absolutely identical to the bypass motor on the outside. If you run the bypass motors in parallel, you'll have over 9" Hg and nearly 200 CFM. Worst case if you fry one, just run them in parallel.

-B

[geneb]

It should be fairly easy to test the "AEAD" motor to see if it will work properly in series with another of it's type. You'll either get a big number on your gauge, or you won't.


Brady, was the "AEAD" motor specifically listed as being incompatible with series operation? I didn't see anything on the website about it.

tnx!

g.

[Brady Watson]

Gene,
No it wasn't. In fact that was the motor I was originally going to buy, but after speaking with Ward, he told me that I could set the motors in series if I used the VBTST6460VM model. I wouldn't have known this without his recommendation.

In hindsight, 2 of the AEAD's running in parallel would be adequate for most things you are going to want to do on the Bot. It boils down to how efficiently you can use your vacuum source. I'm not going to spoil the 'Tips & Tricks' column that will be out soon, but I will tell you that I machined over 5,000 parts last week (averaging 30 parts per 4X8 sheet) using just one 3yr old Fein Turbo III. Parts were cut around 6-7 IPS. Something for y'all to think about...

If you look at the numbers, 10.5" Hg + @ 190 CFM is not too shabby for a pair of motors that cost about $200. That's 60 more CFM than a single Fein T3, and a whopping 30% more vacuum suction than any combination of Fein vacs can muster. So by the numbers, a Fein will hold a best of about 3.5 pounds per square inch of downforce, and the Imperial will do 4.5 pounds per square inch....or 504 & 648 lbs per square foot respectively. You'll be down about 25% less than a Fein with just one of the Imperial motors, but up a full 140 lbs more than a Fein per square foot of holding power. That is a HUGE difference when it comes to part holding!

-B

[paco]

quote:...but after speaking with Ward, he told me that I could set the motors in series if I used the VBTST6460VM model. I wouldn't have known this without his recommendation.Ah ah! There it is! I knew there was a trick about all that knowledge!

Kidding you Braby! Thanks a lot for all this informations and photos and everything.

I think it would fair and advisable to say that buying those motor is not then end of the bill nor the designing of the vacuum rig, right? One still need air filter and plumbing whatever the end concept. In other words, it's not as plug and play as a Fein but it can be done... with some generous help!


I believe that it still a good way to go but time will tell... I'll be doing mine this weekend.

If I could only get my hand on some Trupan or similar...
604

[Brady Watson]

Yes Paco...it's called RESEARCH...Let's your fingers do the walking


Yes...it does require some actual work on the builder's behalf and a few more bucks than just the vac motor, like a $20 (or less) automotive air filter, a box to house the filter (can be bits of scrap you have in the shop) and some PVC fittings. If you want to make a PVC filter, you can use 6" PVC/Sch40 & a hot tub filter element + some bot-cut parts cemented together. Not as cheap as the wooden box, but it's all PVC. You'll have to do your own R&D on what filter to implement.

Don't give up...remember the pioneers of great innovation and achievement such as Edison, Tesla, Fred Sanford & Angus MacGyver. Here's a pic for inspiration:


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Fred and Angus circa 1985, developing the 'K9 Attractor Beacon'

[harold_weber]

Here are a few items to consider before running two vacuum blowers in series:

http://www.rossbrownsales.com.au/page/motors.html#Operation

http://www.i-boards.com/ics/messages.asp?MsgID=824913&ThreadID=84102

In the first reference, scroll down to the item titled "operation of vacuum motors in series" They outline the thermal problems you will have with the motors. If I were going to attempt such a project, at the very least I would make sure that the second stage motor had NO plastic parts in the air flowpath (especially the impeller and the tangential volute or scroll).

The second reference has a comment from a person who has run a two stage system and they note that the second stage motor has short life. Anything that can be done to reduce the air temperature at the second stage inlet will help the thermal problem. An air-to-air aftercooler from a small car turbocharging system may work, but then again the tubes or headers may collapse since they are designed to withstand pressure instead of vacuum. Unfortunately, heat exchangers are not cheap, and they will introduce a flow loss, reducing the vacuum you can pull.

Finally, Brady is correct when he says the two units need to be exactly the same if you run them in parallel. HOWEVER, I disagree with Brady that the two units should be the exact same size when you are running the series arrangement. The first stage (lowest absolute pressure or highest vacuum stage) will match much better if it is about 30 to 40% larger than the second stage. These remarks are based on my 32 years experience with HD diesel engine turbocharging at a Fortune 500 company.

[paco]

Along that, here what a friend sent me yesterday (http://www.canavac.com/page2.htm).

I wouldn't say don't do it but be aware of potential problem...

[Brady Watson]

Yes the motors get hot and you should consider running the motors in parallel 1st to see if you really need 15" Hg - and for the majority of setups and parts you don't need that much. While running an aftercooler & 30-40% larger vacuum motors is a nice idea from an engineering standpoint, it's simply not realistic on a low-buck solution like this. We all want the proverbial Ferrari at 1983 used Camaro prices...but the fact of the matter is, good components cost money. One of these motors, less a filter and plumbing is 25% the cost of a Fein. It doesn't come with a warranty, and you have to fill in the gaps. As stated earlier, you will learn much about vacuum if you participate in this project.

As I clearly stated in the beginning, this project is not meant to be on par with a professional vacuum pump. Not in performance or durability, and I have not done extensive durability testing - but it can be used to help you make more money, generate more business etc so that you can afford a professional setup later on. That's the key...get this in operation & take on jobs that you wouldn't be able to do otherwise. Build your business on a shoestring & set aside some of the profit to buy better equipment to keep you on the cutting edge and in the game.

The project is dubbed 'open source' for a reason. Anyone and everyone is welcome to participate, do their own experimentation and share it with the community. Harold, if you are an air-flow engineer of sorts, you should be dispensing this knowledge to the group, showing examples of projects/methods that you have created. I only know what I know by doing, using Fred & MacGyver as inspiration.


-B

[geneb]

I got a call last night from Ward at Lighthouse Enterprises. He was curious as to what we needed all these motors for and was surprised at the sudden demand.
He's read the thread and has quite enjoyed it. I'm pretty sure he thinks we're all nuts. *laughs*

g.
*waves at Ward*

[harold_weber]

Brady, I thought I WAS dispensing knowledge to the group. If you want it said more concisely: IF SOMETHING IS NOT DONE TO COOL THE AIR GOING INTO THE SECOND STAGE, ITS GOING TO HAVE SHORT LIFE.

As for the expense, two suggestions:
1. Right now there is a mustang cobra charge air cooler on EBAY for $30.00. Folks tend to discard these in favor of larger coolers. If one installs this cooler in fabbed-up enclosure that directs the air through what is normally the outside of the core, it should work fine. The "research" needed is to simply find something that will work from a junkyard or from EBAY.

2. Yes I did say the low pressure stage needs to be 30-40% larger for the best performance. That was mis-leading, sorry. I'll reword that to say if we start with your proposed system where both stages are identical, the second stage should be 30-40% SMALLER for the best performance (this has to do with the placement of the operating point in the map of the stages). Since the air with the lowest density is going into the first stage, its size is setting the flow of the system (unless the second stage is really small). So there is no need to go to a larger more expen$ive low pressure stage.

[conceptmachine]

Brady,
I guess we can now call you Brady "G" Watson

[Brady Watson]

Gene,
That's great. Maybe he can suggest something in leiu of the motor that is now discontinued for running in series. Now that he knows the application, he might also keep his eyes peeled for something even better than the units I suggested.

Harold,
I totally got what you were saying the 1st time, and I didn't mean to imply that your suggestions were anything less than valuable. It would be interesting to see what others come up with using your suggestions. One thing that I do know is that you take a small hit in performance when you add an aftercooler. I know when I had my Buick Grand National that the intercooler gave up 1-2 PSI. We might be splitting hairs here, but it's worthy to note that it may affect performance. It would be interesting to get some real data testing series with & without a secondary cooling device.

Shawn,
Not sure what you mean with the 'G' reference. Please clarify.

-B

[conceptmachine]

You know, Fred "G" Sanford.It's been a while since i saw an episode of sanford and son,but the G always stands for something different depending on the situation.

[harold_weber]

Brady, yes, that makes sense that you lost boost at wide open throttle on a Buick engine. The problem is that you have to plot where the operating point moves to on the compressor characteristics in order to understand WHY you lost boost. When you add the aftercooler, the downstream positive displacement device (the Buick engine) is able to swallow more of the colder air, and at high engine speeds this throws the existing compressor into "choke"- the compressor runs at a much less efficient operating point. So the simple answer is that you need a larger (higher flow) compressor when you add an aftercooler to a turbocharged engine system.

The above information is not useful here because we don't have an engine downstream of the blowers and coolers, so there is no positive displacement device that will consume a greater mass flow rate of the colder air.

Sorry, this is getting a little off the thread topic.

[srwtlc]

There's been a lot of discussion on vac setups lately and I was wondering if anyone has done some tinkering with this setup. Anything to report, availability of the bypass model of these motors, aftercooling, etc.?

[evan]

Bump

[Brady Watson]

Where's PACO???

[paco]

Québec, Canada.

Not much work on the vacuum lately. I still desperately search for bleeder board material around here. Without it, the filter canister design will need to accommodate room for dust collection and clean up.

Right now, I'm cutting right on the grid... picture how fast I lose the hold... and how often I need to clean up the Fein T3... With simple filter canister design with a bleeder board system, the whole thing will give me a p'etty good saving.

I don't plan on series usage since my readings (along with my tests) caution about overheat issue. It'll be either parallel or one per zone. With the CFM from three pump (one Fein T3 and two VBTST6460VM), I think I'll be happy with 7-9 Hg. I may end up selling the FT3 and get two more bare pumps; 4 zone, 4 pumps.

The few tests I made with the pump (VBTST6460VM) are very encouraging.

I'll keep you posted when it's done.

[joenagel]

I'll chime in with what little info I have on this set-up, I purchased 2 VBTST13431AEAD vacs and built a plenum box with shopvac filters on each pump and run them in parallel, I have a gridded table that I use inboard gasketing and fixtures with and I'm able to pull a solid 9"hg at the holes on the table. With gasketed fixtures I can hold 5" x 7" pieces of cedar with no problem if I don't get too aggressive with my cuts. I also have a bleeder/spoil board of regular mdf that I can place on the gridded table and draw through it to cut sheet goods, again with proper feeds and speeds the vacs hold down the sheet goods with no problem.

I just wanted to say thanks to Brady for the Idea. (it really sucks!)

[Brady Watson]

My pleasure, Joe. I'm glad that someone is using this info to their benefit!


-B

[ckurak]

Brady,

Sorry I am late to this thread. A fellow shopbotter just told me about this a few days ago.

Anyway, I was looking over your PVC piping. From my experience with water flow in pipes, it looks like both of the two Wyes that you have should be flipped 180 degrees. It appears that in the 15 mode there would be excessive turbulence since the airflow would need to change direction drastically. Flipping both of the Wyes around should make for a smoother air pattern, followed by higher CFM.

Mostly, thanks for sharing this idea.

Charles

[Brady Watson]

You bet, Charles. The pics shown were obviously just dry fit - as indicated by some missing fittings. I'd be interested to see what improvements you or others make to the design.

-B

[bud31069]

Hi Brady & Group,
I have built a "Brady Vac" for my bot, and thought I should post some pictures as a way of thanking Brady, and to support the forum.

I created my system with 5 zones so I could use the small zone(8"x8") to carve smaller items. The other zones are standard 2'x4'(except for the one that had the small zone amputated from it). I used VCarve to lay out my plenum.

I used two small petroleum barrels as containers for the motors. This setup works great, but I can see a point in the future where I will have to replace them due to the bottoms flexing when the vacuum is turned on. Over time I am sure they will fail due to this.


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The plumbing was laid out in such a way that will allow me to use either motor to pull any of the five zones, or will allow me to run the motors in series to increase my vacuum. I can also split the vacuum duty between the two motors and pull 2 and 3 zones respectively.


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Here are some pics of the system running 1 motor on the small 8"x8" zone.


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Here is my setup for running the motors in series on the small zone.


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As you can see from the pictures I am pulling 9-10" when I use one motor to pull the small zone and 15-16" when I run the motors in series on the small zone.

I still need to go back and seal the edges of plywood and MDF, but I am very pleased with the results I have achieved.

Total cost of the system was less than $500.
Thanks again Brady, your idea really sucks...

James (Bud) Simpson

[paco]

James,

thanks for taking the time to post the details and the pictures. Your setup look good!

I keep wondering about overheating issue with running the motors in series... what your thoughts and finding about this?

As for me, I haven't yet found a supply for usable bleeder board so the motors are still on the shelf.
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[bud31069]

Hi Paco,
I am using plain MDF I got from Lowes for my bleeder.
I dont have an accurate way to measure the exhaust temperature, having said that, I have a digital indoor themometer that I placed in front of the exhaust. It was reading about 130deg. after 15 minutes of runtime.

Bud

[Brady Watson]

Looks like a great setup, James! Thanks for posting to the group!

-Brady

[paco]

James,

what's your vacuum reading with the MDF bleeder board WITHOUT anything on it (sheet good)?

15 minutes is relatively short usage time considering I can run vacuum hold down for hours (2-10 hours). Please, keep us post on this as it's pretty relevant issue on a such vacuum design.

[bud31069]

Paco,
With nothing on my table and all zones open I am reading less than 2" vacuum running both motors in series.
I will take a reading the next time I have full sheet on the table and let you know what I am getting.

James

[paco]

Hmmm... that's pretty amazing with standard MDF sheet good!?

Thanks!

[evan]

James,

Thanks for the post! Your setup looks great! I've been thinking of upgrading from my two Feins T3 setup, but haven't been able to justify the price of a roots (I don't have three phase for a Regen. Setup) but even a couple more inches of mercury would be great and at $500, well know I have to find the time. Thanks again.

Edited to add: And of course a Big Thank you to Brady.

[bearcat]

James,

Which vacuum motor model are you using?

Thanks,

Ed

[bud31069]

Hi Ed,
I am running two VBTST13431AEAD motors.

James

[ward]

This is Ward at Lighthouse Enterprises. I have updated some of the information on my webpage regarding the Imperial motors. The only motor where there have been warrantee issues when running the vacuum motors in series is the VBDST13431AEAD. They will not warrantee this motor if run in series, all the other motors - there is no problem running in series. Also, the VBDST13431AEAD does not always fail when run in series - it is your risk - at least buy an extra if you are going to depend up this motor.

Also, note that all the prices are going to go up 10 to 25% in the next few days. The warehouse just has not had time to update my prices yet.

Have fun saving money!

[Brady Watson]

Ward,
Thanks for chiming in & clarifying. We all appreciate your input.

Thanks!
-Brady

[ward]

One more thing! I just started carrying mufflers for central vacuum systems. They might be of value to you also??? They are 15.5" long, 4.5" in diameter and have a 2" hole in each end?? They are supposed to cut the noise level by up to 50% especially when vented to the outside??? I can give special pricing to someone who might want to try one?

[ward]

I just ordered half a pallet of the good series Imperial motors VBTST6460VM and my Texas warehouse will have the other half. We will have them in about 3 weeks!

[david]

Ward what the difference between the Imperial,Domell and Lamb motors in quality.

[stargategfx]

Ha HA Haaaa...Got a good laugh at that picture of my boss, R.D.A., aka MacGyver!
But seriously, thanks for posting this Brady!
I'm going to try putting one of these systems together on one of my Bots before we resume work for next season.
If I get stuck, I'll call the boss!

[Brady Watson]

My pleasure, Boyd. Post up some pics when you get your setup going.

-B

[ward]

Ametek is vague on series use!
Domel engineering says this "Using two motors in series could always cause heat problems. Not on the windings but on the impeller side. Working air temperature rises due to compression and also the impeller temperature. If you close inlet the
impeller temperature rises dramatically.

When you have two motors in series you get worm air into second motor. The simplest solution is to make "bypass opening" to secure some cold air for second motor. You'll lose some air flow and pressure of the system but you'll save second impeller."
The Domel is supposed to last 20% to 30% longer than the Ametek of the same spec. They have a different design in their brush - much more brush in contact with the armature - probably less arching and less wear. I will take a picture soon! Maybe today
The Imperial seems to be the only motor that will stand up to this kind of abuse? The All-Metal horn really helps.

[ward]

I was wrong, this Domel brush doesn't look like the one I was thinking of. I still need to find out why the Domel motors are supposed to last longer. One other note - I have never been asked for brushes for Imperial motors and I sell a lot of vacuum motors.
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[john_l]

Any Updates?