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Vans Capacitive senders

az_gila

Well Known Member
Guys.... I've decided to go with the Dynon FliteDek (I think this is the final panel configuration... :) ...) ... so I can now use capacitive senders instead of the mechanical ones that can't read the upper 25% or so of the tank.

I can't seem to find the kit on Vans web site... so...

A. Can someone point me to Vans kit location?

or
B. Do I need Vans kit, or is it so simple I can get the parts locally? If so, does anyone have drawings they can share?

...thanks

gil in Tucson - retiring in 2 weeks - should speed up building... :D
 
capacitive senders

Gil your going to love the accuracy of the system you've chosen. Yesterday I landed for some cheap gas and at the self serve set the pump for 16 gallons. When both tanks were full to the bottom of the filler necks the pump was showing 15.8 gallons. It is a confidence builder to have this happen at fillups and confirm what we hope to be true in flight when we look at the fuel guage.

Regards,
 
dynon panel

I was just talking to dynon at copperstate fly in and he said they were testing a rv with their converter box for the capacitive type sender.Unless I miss understood him the fuel gauges on dynon only work with float type rightnow. I have already installed capacitive type in mine and plan on using dynon.
 
dreamweaver said:
I was just talking to dynon at copperstate fly in and he said they were testing a rv with their converter box for the capacitive type sender.Unless I miss understood him the fuel gauges on dynon only work with float type rightnow. I have already installed capacitive type in mine and plan on using dynon.

Correct for a direct connection, but at present the Dynon can use a third party converter (Princeton?, EI?) that give a voltage signal from the capacitive plates...

However Dynon has the converters in beta test right now... should be OK for my schedule...


Still don't know where to get the kit onfo.... :)

gil in Tucson
 
az_gila said:
Correct for a direct connection, but at present the Dynon can use a third party converter (Princeton?, EI?) that give a voltage signal from the capacitive plates...

However Dynon has the converters in beta test right now... should be OK for my schedule...


Still don't know where to get the kit onfo.... :)

gil in Tucson
Gil, check this out.
http://www.vansaircraft.com/cgi-bin/catalog.cgi?ident=1163953389-454-612&action=search

-mike

PS They're pretty simple but the kit has some odd parts that may be worth having vans provide the works to you.
edit: Whoops! checking the link after posting, I see it doesn't go where I wanted.

Enter a search on capacitive probe and you should get there. Also, I believe the kit contains materials for both tanks. (at least it does for the 9)
 
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If I recall correctly, the QB comes with floating senders and capasitive senders aren't even option. How easily they can be install for a QB tanks?
 
float to capacitive

after finishing tanks not long ago, the only way you could put capacitive in is to take off the baffle off so i would say you cant.
 
Gil
It's in "the list" (IE CAPACITIVE PROBE A CAP. FUEL SENDER 4678 $60.00).
Or, I have a complete kit never been used,(I decided to go with float senders).
You can have it for $45. If your interested contact me offline.

Bill
 
Still confused

OK guys... I had already done the search of Vans web site and came up with this listing...

Capacitive probes for RV-4/6/7/8 tanks
Part Number = IE CAPACITIVE PROBE A
Price = $60.00


But it's under the Electronics International Instrumentation listing. Is this a special thing for the EI instruments, or is this the "generic" capacitive probe listing?

I thought the kit contained just 4 simple bent plates, a few nylon standoffs/washers and 2 BNC connectors.... Is this the same kit?

thanks gil in Tucson
 
az_gila said:
OK guys... I had already done the search of Vans web site and came up with this listing...

Capacitive probes for RV-4/6/7/8 tanks
Part Number = IE CAPACITIVE PROBE A
Price = $60.00

But it's under the Electronics International Instrumentation listing. Is this a special thing for the EI instruments, or is this the "generic" capacitive probe listing?

I thought the kit contained just 4 simple bent plates, a few nylon standoffs/washers and 2 BNC connectors.... Is this the same kit?

thanks gil in Tucson
Yep that's the 4 plates, a roll of wire and a bag of hardware etc. It's got nothing to do with the instrumentation for reading fuel level (other than it's the capacitance sensor itself).
capsendersubkitch8.jpg

I imagine the other kits are the same as the 9 with exception of the plate shape.
-mike
 
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Does anyone here know if the capacitive senders will work on Jet A as well? What is the exact mechanism they use to function? Dielectric capacitance changes?
 
airguy said:
Does anyone here know if the capacitive senders will work on Jet A as well? What is the exact mechanism they use to function? Dielectric capacitance changes?
They work on the change in capacitance brought about by changing the relative permittivity (dielectric constant?) between the plates. Air has a relative permittivity of ~1 and avgas is about 2. Jet A has a permittivity of about 2 as well so they should work perfectly and have nearly the same calibrations.

-mike
 
Thanks

mlw450802 said:
capsendersubkitch8.jpg

I imagine the other kits are the same as the 9 with exception of the plate shape.
-mike

Thanks Mike... that was exactly what I needed.

I'll see if I can get it without the T-411 plate....
I had to make that plate myself (very early -6A kit), so Vans pre-punched holes probably won't mate up... :)

gil in Tucson

PS when is the big move to AZ?
 
Another Option...

I don't personally know of anyone flying with this system, but I do know of a couple of RV's under construction that have it installed...
SkySports System
Aircraft Spruce carries it.
Maybe if someone is flying with it they could chime in with a review ;)
 
How do they solve the problem?

How do cap senders solve the problem of reading the upper 25% of the tank? From pictures, it looks like the plates only span the inboard bay, so would only measure the level in the inboard bay, anyway? Am i missing something?

Can those cap senders be installed with a completed SB tank, with the baffle yet to proseal into place?

I guess I am looking for reasons not to seal the baffle in place!

Jae

az_gila said:
Guys.... I've decided to go with the Dynon FliteDek (I think this is the final panel configuration... :) ...) ... so I can now use capacitive senders instead of the mechanical ones that can't read the upper 25% or so of the tank.

I can't seem to find the kit on Vans web site... so...

A. Can someone point me to Vans kit location?

or
B. Do I need Vans kit, or is it so simple I can get the parts locally? If so, does anyone have drawings they can share?

...thanks

gil in Tucson - retiring in 2 weeks - should speed up building... :D
 
The capacitance sender plates go to within about 1/4 inch of the top of the tank so it should measure the fuel quantity in just about the entire height of the tank. See the pic of my installation here: http://www.rjsflyer.com/rv9a/lefttank4.htm
Don't see why it wouldn't measure out to an extra bay. As far as installing after ribs are riveted and before the baffle is installed, should be no problem, just a little more difficult to get the mounting holes drilled in the ribs accurately.
 
jchang10 said:
How do cap senders solve the problem of reading the upper 25% of the tank? From pictures, it looks like the plates only span the inboard bay, so would only measure the level in the inboard bay, anyway? Am i missing something?
There are two plates per tank, one inboard, one outboard.
 
Can someone confirm

Davepar said:
There are two plates per tank, one inboard, one outboard.

OK... I made an assumption that the two plates were on the inboard and outboard ribs of the fuel tank, and thus have a different capacitance for all fuel levels.

Can someone confirm if this is how they are being installed?
And if not, which rib are the outboard plates being attached to?

The previous postings seem to have some variation.... :)

thanks gil in Tucson
 
Cap sender problems

I had good results with the Cap senders connected to my Efis/One for the first couple of years... but one side has been giving me fits recently.

The problem is the bulkhead BNC connector used to connect the "wire" to the tank. It leaks just ever so slightly though the center conductor and eventually gunks up to the point where it isn't very accurate anymore. I liberally sealed the back side of that connector with Proseal when I first built the tanks. I added more for good measure when I had the tanks open to put the safety wire on the pickup tube nut.

I'd seriously try to find a fuel-proof replacement for that connector.. and I might need to retrofit my tanks with one soon, too.

-Clay
 
Cap Senders in a -9

Here are some shots of how mine look...
060917e.jpg

060917f.jpg

060917b.jpg

The sender plates attach to the #2 and #6 ribs. Check out my website for more details.
 
This doesn't directly address Gil's original question, but thought somebody might benefit from this info.
I purchased the EI MVP-50 Engine Monitor, which handles 3-wire capacitance probe inputs. In order to interface it to the Van's 2-wire i/f you will need to purchase a EI P-300C 2-to-3 wire module, which I notice Van's now lists in the accessory catalog. You will need 1 for each tank.
 
az_gila said:
Correct for a direct connection, but at present the Dynon can use a third party converter (Princeton?, EI?) that give a voltage signal from the capacitive plates...

However Dynon has the converters in beta test right now... should be OK for my schedule...
Still don't know where to get the kit onfo.... :)

gil in Tucson

Gil,
Make your own. The kit is overpriced for what it is. It also suffers from "Dutchman's disease". The spacers are multi-piece nylon "hardware store" washers. They should be one piece units made from Delrin or Teflon. Only these two plastics are totally imprevious to the effects of gasoline over time. Do you really want to have to open those tanks back up, 5 or 10 years down the line?
Second, Vans supplies el cheapo import BNC bulkhead fittings for the electrical connection. Use only genuine Amphenol, or you risk getting a leak here. The sender plates are simply .025" sheet. I can email you a template to make them yourself. I can supply a CAD drawing of an improved design spacer and photos of my senders. They are very easy to make.
Charlie Kuss
PS Click on my user name at the top of this message to contact me via email.
 
Please post photos!

chaskuss said:
I can email you a template to make them yourself. I can supply a CAD drawing of an improved design spacer and photos of my senders. They are very easy to make.
Charlie Kuss
Charlie, could you post the information and photos you mention on this thread? I am interested in seeing what you have done. If it is something that can be fabricated I would be interested in doing so.
 
Vans capacitive plates + VM1000C

Hi,

Anybody using VM1000C + Vans capacitive proves ??? :eek:

I have the Vans capacitive probes built into the tanks in my RV7 also I have the VM1000C EMS I need to convert the capacitative signal to 0-5 Volts (same as the floats)

Has anyone installed Vans converters (Part Number= IE P-300C) with the VM100C??
Where can I find any working converters for the VM1000C??


Thanks for your help,
best flights
 
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Vans capacitive fuel plates + VM1000C

HI,

I post this information to share with anyother with same doubts about working with the Vans fuel capacitive plates.

Asking Vans about their Capacitive to voltage converter (Part Number = IE P-300C ) to use with VM1000C, told me: "suspect that they won't work"

Finally I have this answer from the Tech Support at Vision Microsystems :)

"We have converters for the Van's Capacitive plates that allow them to be used with The VM1000C. P/N 3010036 Vans Fuel level converter $98.00"
 
Spacers Specs

If anyone has specs on custom spacers they've made and are willing to share, that would be much appreciated. My father-in-law has offered to mill some for me next week when he has time.
 
If anyone has specs on custom spacers they've made and are willing to share, that would be much appreciated. My father-in-law has offered to mill some for me next week when he has time.

I don't think the standoff distance matters, as long as they don't contact any of the aluminum skin.
 
I was just starting to think about how to do the capacitance to voltage conversion. It seems that there are a variety of opinions on the converters and which are best. Maybe I'll make my own converters. Anyone have an idea of the range of capacitance for these?

Oh wait!!! Is this another side project. :D
 
I was just starting to think about how to do the capacitance to voltage conversion. It seems that there are a variety of opinions on the converters and which are best. Maybe I'll make my own converters. Anyone have an idea of the range of capacitance for these?

Oh wait!!! Is this another side project. :D
I just went with the Dynon senders. I was an early beta tester for them, long before they started selling them. I just replaced one a few months back, after 9 years and 750 hours. Buying them is much cheaper and easier then designing and making them.

The only issue is that the Van's BNC connector really isn't designed for a fuel tank. I really gooped on the proseal on the inside to keep them from leaking and haven't had an issue. Some of the early builders reported fuel leaking out of the center of the connector, and I was so worried that I made sure that wouldn't happen to me.

The senders are spot on and putting them in was a great choice! These senders are so accurate that if my EFIS tells me I need 10.2 gallons, it will take 10.2 gallons.


Those are very nice!
 
Hi Bjorn,
They're great. Do you have any specs or drawings you could share that I could send to my FIL?
Thanks.
Allen
 
Does it take 12 of the standoffs? 6 in each tank? They send 48 washers.
 
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The senders are spot on and putting them in was a great choice! These senders are so accurate that if my EFIS tells me I need 10.2 gallons, it will take 10.2 gallons.



Those are very nice!

I wish mine were accurate. They are only accurate when the tanks are full. As I use fuel they show more fuel than I actually have. After several calibrations I finally gave up and use the gauges for relative levels and rely on my totalizer for the actual total amount of fuel. I have a D180 and the sensors that Dynon sold me.
 
I wish mine were accurate. They are only accurate when the tanks are full. As I use fuel they show more fuel than I actually have. After several calibrations I finally gave up and use the gauges for relative levels and rely on my totalizer for the actual total amount of fuel. I have a D180 and the sensors that Dynon sold me.

That is really odd. Mine have worked extremely well with both the D10 EMS I had and the SkyView I currently fly with. Have you contacted Dynon?
 
The Dynon EMS box is expecting a 0.0 to 5.0 VDC input from whatever sensor you're using; the Princeton box does output 0-5 V, so it's compatible from that perspective. Dynon recommends to do any sensor calibration in the sender prior to doing additional cal in Skyview.
 
I just went with the Dynon senders. I was an early beta tester for them, long before they started selling them. I just replaced one a few months back, after 9 years and 750 hours. Buying them is much cheaper and easier then designing and making them.

The only issue is that the Van's BNC connector really isn't designed for a fuel tank. I really gooped on the proseal on the inside to keep them from leaking and haven't had an issue. Some of the early builders reported fuel leaking out of the center of the connector, and I was so worried that I made sure that wouldn't happen to me.

The senders are spot on and putting them in was a great choice! These senders are so accurate that if my EFIS tells me I need 10.2 gallons, it will take 10.2 gallons.



Those are very nice!

I had a bit of trouble with the Dynon senders, because the useful range of voltage was so narrow. The system was quite accurate for fuller or nearly empty tanks, but terrible in the mid-range. I ended up swapping them out for the Princeton C-to-V senders, which you can set up to use the full 0-5V for any tank size, and they work great...
 
Hi Bjorn,
They're great. Do you have any specs or drawings you could share that I could send to my FIL?
Thanks.
Allen

I do not have the measurement or drawing and now they are sealed inside the tanks.... I did it more or less 'freehand' anyways using a cheapo Harbor Freight mini-lathe.

I did it this way as I didn't believe the plastic tubing used in the Van's version would hold up over the years, ending up with a short between the plate and rib. This solution use a solid block of delrin as isolation.

Here's how (from memory and pictures) I made to two parts ('Rib insert' in the middle, and the 'Donut' shown on the left in the first picture in my log).

Both used a 1" delrin rod as raw material.

The dimensions were selected so I could use the screw, washers and nutplates described in the OP07 (AN509-8R14, A3135-017-24A, K1000-08).

Rib insert:
- Cut a piece 5/8" or longer (it's easier to cut back/sand later...)
- Drill a hole all the way for a AN509-8R14 screw (using the lathe is easiest).
- Reduce the diameter of one end to about 1/2", keeping about 3/8" as 1"
(The reduced diameter is the one going into the rib, the 3/8" width of 1" diameter, represent the 3 stacked rings used in Van's kit)

Donut:
Take a piece of 1" drill a 1/2" (using the lathe) hole all the way through.
Cut it into 3/16" thick slices. Lathe is best but waste material, I has plenty so I didn't care.

Now use some scrap with the same thickness as rib.
Drill a 1/2 hole in the rib-scrap
Sand the 'Rib insert' slightly to fit into the 1/2 hole. Alternatively scrape off a few 1/1000 in the lathe.
Insert the ehhh.. the 'Insert'. The donut fits around the insert (1/2" end), grabbing the rib-scrap between them.
I found it best to have the donut flush with the insert. Too thick and the washer gets deformed when tightening the screw. If you lack grabbing power, sand some off the insert. Finally countersink for the washer/screw.
 
Washer material

I'm planning on putting the no longer sold capacitive system in my tanks but need some expert advice on the materials for the washers. The plans that I have seen call out umhw or something like that. I'm not exactly sure I know what that material is even after a little google action. My first thought is just to turn a two piece setup out of Delrin rod instead of multiple washers and tubing. The aircraft spruce catalog mentions delrin is resistant to fuel. I just want to make sure I don't have a material slowly dissolving in my tanks. Any material experts that can lend some advice? Thanks in advance.
 
Not an expert. I think Delrin is a copyrighted name so it can't be used by everyone selling the same material. UHMW I think is the generic name for the same thing.
 
UHMW is ultra-high molecular weight polyethylene, and I believe it is the material Vans supplied in the capacitance sender kit in the form of thick washers stacked up to separate the cap plates from the tank ribs.

Delrin is another kind of plastic, a polyacetal, if anyone is chemistry curious.... ;) Delrin machines very nicely whereas UHMW seems to be really fussy if the tooling isn't sharp. Fuel resistance to gasoline and even gasoline/ethanol is good according to the manufacturer: http://www2.dupont.com/Plastics/en_US/assets/downloads/design/DELDGe.pdf
 
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Capacitive Plate Isolators

Has anyone got the CAD drawing of the capacitive plate Isolators?
I am going to need to make some.
 
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