New digital carb sync board

[tz89]

VideoArizona, Your processor arrived and is loaded.

 

[Great adVENTURE]

I just finished my diy monometer and came across this... I want one! Great minds create great things.

[videoarizona]

VideoArizona, Your processor arrived and is loaded.

 

http://www.venturerider.org/forum/attachment.php?attachmentid=110961

 

Hi Tom,

 

I re-directed the address of the sync board from Phx to my Green Valley home as I came down here unexpectedly. My sync board came in today.

 

I want to thank you for the great job you did on making the sync board for me! Looks like a "PRO" did the work!

 

I would say you are very good at building electronic stuff!

 

Again, my thanks for your efforts!

 

And if anyone wants an electronic digital sync board for their Ventures, I highly recommend Tom and his board!

 

david

[tz89]

Thanks. Since I loaded the newest test version of the software, I added a jumper and header to act as a switch to turn on (default) or off the self-calibration step. You should leave it on, but some board builds display better with it off. Use whatever looks best to you. The simple math in the calibration can introduce rounding errors because the display has whole numbers only due to space restrictions. I turn it off on one of my six sensor boards that I use. Thanks again.

Edited December 2, 2017 by tz89

[Rotten]

These look very interesting

Are you selling these as complete units and ready for work? If so how much?

[tz89]

Thanks. There are 4 (and 6) cylinder units at https://digitalcarbsync.com/product/xtra4-assembled-kit-4-cylinder/.

 

I have enough parts on hand because I ordered a few extra when I built VideoArizona's.

 

 

These look very interesting

Are you selling these as complete units and ready for work? If so how much?

[Rotten]

Cool Ill take a look

[tz89]

My first sync on my 2009 RSTD using my DigitalCarbSync.com gadget. Photo a little jittery plus the protective layer is still on the lcd. I don't think it had ever been done before. Hoses were really stuck on and the sync was off by more than the equivalent of a half inch of mercury old school.

 

Took it out for a ride and it is nice and tight - that little raggedy feeling is gone.

 

Pulled this snippet from an old post by goose: Just for future reference, the shop manual specifies 280 mmHg at idle, and variation between carbs of no more than 10 mmHg or .4 inHg.

 

Mine are now within 0.1 inHg of each other.

 

In theory, the 152 reading implies 320 mmHg at idle but without a tach on to set the idle - and other minor variations due to test conditions (old 9v battery, temperature, altitude, atmospheric pressure, etc) - I would not bet on it. I would bet that the idle is higher than spec. That's something for my next version. I have the software built-in but it has never been adequately tested and developed.

 

 

Edited May 1, 2018 by tz89

[tz89]

Better pictures....

 

 

 

 

[Patch]

I have used the vac mate for many years now, I really enjoy the experience each time I pull it out.

 

You likely know it has an additional feature which permits guessing at valve seating or pressure leaks.

 

Nice to see you have continue to develop this tool. Long term what are you thinking, if that not a marketing secret?

 

Patch

[videoarizona]

Thanks for the link, Tom.

 

I've been looking for an enclosure and found one that was mentioned in following that thread!

 

The board works great, BTW. I synced up the RSV before the trip and it purred like a kitten the entire trip...over 4K miles!

 

And you are correct...the board is far more accurate than the screws on the carbs for making the adjustments!!

 

Thanks Again for an excellent product!

[tz89]

I have used the vac mate for many years now, I really enjoy the experience each time I pull it out.

 

You likely know it has an additional feature which permits guessing at valve seating or pressure leaks.

 

Nice to see you have continue to develop this tool. Long term what are you thinking, if that not a marketing secret?

 

Patch

 

I would really like to find a way to make cases in small batches. Setting up for injection molding is so expensive.

 

3D printing I think, but that is outside my wheelhouse. Any experts on this site?

 

Software-wise I'm tinkering with the tach. I want to find the right balance between responsiveness and stability.

 

Thanks for asking.

[Patch]

Funny thing about casings these days is, we forget how simple it can be to just use metal plate!

 

So not knowing how to soft switch, essentially you are looking at counting pulse on #1 ?

 

Funny thing is, when I use tach side of the VM I do so only if I'm tuning for a range. Say If I need a band at a set rpm, or suspect issues at x rpm.

 

That said I really don't see it as a very important feature!

[tz89]

 

 

That said I really don't see it as a very important feature!

 

Good feedback. I don't use it either. Someone asked about it early on and I liked the engineering challenge. Since my RSTD doesn't have a tach I can set my idle by ear - most of us can I bet. You just have to listen to a few.

[Patch]

Pouring a coffee while thinking through the question... I went to reform school but... Trade schools look for projects, usually they ask for cost of material and a description, then send the problem up to drafting and in the above post, it would then go to the Tin Bashers trade classes!

 

Think about it, its easy to make the phone call

Patch

[tz89]

Pouring a coffee while thinking through the question... I went to reform school but... Trade schools look for projects, usually they ask for cost of material and a description, then send the problem up to drafting and in the above post, it would then go to the Tin Bashers trade classes!

 

Think about it, its easy to make the phone call

Patch

 

Good suggestion. I'm building a strong relationship with our local community college because of my day job. I'll explore that idea.

[Patch]

will your display flux say by .5 back and forth or up/down to signal to look past the sync????

[tz89]

will your display flux say by .5 back and forth or up/down to signal to look past the sync????

 

Not entirely sure what you mean.

 

Some other products try to tell you what to do. I figured that for guys syncing their own carbs they would just want the data reading - not a nanny.

 

If it was just being used on a Venture I could maybe get to a close approximation of the required adjustment. But this thing can be used on a lot of different engines including those old six carb Valkeyies. I wouldn't want to try to figure that out!

Edited June 16, 2018 by tz89

[Patch]

Of course you could use it on just about any vacuum sync.

 

I guess I should have put the question this way: is the reading dampened or will (as the pic shows above) pulse say 25.3 .5...? Does it round up or down to the nearest full number?

[tz89]

is the reading dampened or will (as the pic shows above) pulse say 25.3 .5...? Does it round up or down to the nearest full number?

 

Oh, gotcha. I'll give the long answer.

 

The sensor reads vacuum from 0 to -115 kPa and returns a voltage of 0 to 5 volts (actually 5 to 0 volts).

 

The board reads the voltage and converts that to an integer value of 0 to 1023.

 

I keep an array of readings and extract the peak value.

 

I display integer values to save display space, and because using something past the decimal point would suggest a false level of accuracy.

 

I use a little math to change that range into something useful. By default, I use each point equals 1/10th-inch mercury. You can go into the software and change it to a different range. There are a few. One of my European customers asked for millibars for example.

 

So - to answer your question - it is not rounded in the usual sense. It is smoothed by keeping an array of integers and extracting the peak.

 

Hope that makes sense!

Edited December 23, 2018 by tz89

[Patch]

"I use a little math to change that range into something useful." That is what I was asking, thanks for taking the time.

 

So I see "your focus market" would benefit from the tach; in the end after sync we do need to set final rpm.

 

So I get that there has to be something to the time writing in code.

 

In my minds eye I have a picture of what the unit "should" look like and I'd want the tach and all small enough to pack in my toolkit - not something I would do with my VM.

 

Keeping it simple I found an option, and would require a simple clip to ignition cable for field....

 

Cheap too, just riveted to the casing! I haven't looked in the MFG but you should before branding with your name..

 

https://www.ebay.com/itm/New-Hour-Meter-Tachometer-Small-Engine-Spark-For-Motorcycle-Boat-Bike-US-STOCK-/331086473062

 

Patch

 

[Patch]

I'm just going to throw this in as well... I would likely want to know if I am reading any positive pulses. The thing is it should be easy to understand if there exists some hint of high pressure in the circuit I am measuring, such as spring float or seating!

 

Back to VM, I can tell (allowing for VM cal or lack of) if the strobe is high scale or below scale this will indicate issues outside of carb sync..

 

Just a thought

 

Patch

[tz89]

 

The board works great, BTW. I synced up the RSV before the trip and it purred like a kitten the entire trip...over 4K miles!

 

And you are correct...the board is far more accurate than the screws on the carbs for making the adjustments!!

 

Thanks Again for an excellent product!

 

Thanks. I'm glad your trip went well.

[tz89]

The new 3-D printed case is coming along. Many thanks to Stephan in Quebec Province!

 

Edited December 23, 2018 by tz89

[videoarizona]

Hmmm...think I want one...