FREE - RC Heli Optical Tachometer DIY - HeliFreak
Fun, Learning, Friendship and Mutual Respect START  HERE


Unregistered
Go Back   HeliFreak > R/C Helicopters > Finless Bob's Helifreak Tech Room


Finless Bob's Helifreak Tech Room Finless Bob's Helifreak Tech Room - Tips and how-To Videos


Reply
 
LinkBack Thread Tools Display Modes
Old 05-07-2008, 02:00 PM   #1 (permalink)
Team Taco VP
 
Posts: 34,492
 
My HF Map location
Join Date: Nov 2005
Location: Stanton, Ca. USA
Default FREE - RC Heli Optical Tachometer DIY

OK Helifreak user mikef had posted about this home made optical tach some time ago. Many asked for plans and instructions for how to make one. Mike has now made that available for download here on Helifreak.

I myself have not built this myself but looking at the plans / design it looks very sound. It works just like many RC Heli tachs where you look through a view finder and adjust until you see the blades stop. This is a PROPER heli tach design not a airplane prop tach design.

Mike agreed to answer any questions you all have on the design or building it.

Thanks Mike! You Rock!

Here is the link to download the plans and code.

NEW FILE UPDATED 6/6/2008
Download Link -> RC Heli Tach (1 Megs)


Bob

Last edited by Finless; 06-06-2008 at 10:56 AM..
Finless is offline        Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 05-07-2008, 02:36 PM   #2 (permalink)
HF Support
 
Posts: 39,875
 
My HF Map location
Join Date: Jul 2007
Location: McKinney, TX
Default

I agree that the concept is sound and, being an EE by degree and a software engineer by trade, I don't see any glaring errors. It's pretty ambitious, though, meaning that I probably couldn't make the time to build one.
__________________
Alan (just call me "Bum"; no need to be so formal)
HeliFreak Support
Protos Max Evo 700 (Brain 2), Protos Max V2 770 (iKON 2), Synergy 516 (Brain 2), DT520Ev2 (VBar)
Graupner MZ-24 Pro

Experience is something you gain only after you need it.
I wouldn't mind social media so much if it didn't involve people.
TheBum is online now        Reply With Quote Quick reply to this message
Old 05-07-2008, 02:47 PM   #3 (permalink)
The Capi
 
Posts: 25,121
 
My HF Map location
Join Date: Oct 2006
Location: Toronto
Default

Nice idea ! BTW i doubt many people have or have access to a PIC programmer however i have found an easy and CHEAP solution. RCD PIC programmer (Google it) only uses passive parts and costs about $10 to make. Here is the one i throw together (yes iam aware its very ugly but it works).


__________________
Spreading capibara awareness since 2006
DominicD is online now        Reply With Quote Quick reply to this message
Old 05-07-2008, 03:04 PM   #4 (permalink)
Registered Users
 
Posts: 7,692
 
My HF Map location
Join Date: May 2006
Location: McKinney TX
Default

__________________
Just a guy and his heli....
LITHIUMSTATIC is offline        Reply With Quote Quick reply to this message
Old 05-07-2008, 03:28 PM   #5 (permalink)
Registered Users
 
Posts: 1,166
 
My HF Map location
Join Date: Apr 2007
Location: Clarksville, TN
Default

Would Mike or anyone else be willing to pre-program the PIC Micro Chip and mail out to us Freakers? For a fee of course...say $8-12 with chip and shipping.

I would really like to build one of these as I'm always looking for a project. However, buying a programmer seems to kill the cost benefit of buying a tach outright. Plus, I have no use for the programmer afterwards.
__________________
Jesse
T700N FBL - V-Bar w/ 3DX Head
T250 Super Pro - HS-5084MG Tail Servo
X9303
HELINHAWAII is offline        Reply With Quote Quick reply to this message
Old 05-07-2008, 03:35 PM   #6 (permalink)
HF Support
 
Posts: 39,875
 
My HF Map location
Join Date: Jul 2007
Location: McKinney, TX
Default

Quote:
Originally Posted by HFG View Post
BTW i doubt many people have or have access to a PIC programmer however i have found an easy and CHEAP solution. RCD PIC programmer (Google it) only uses passive parts and costs about $10 to make. Here is the one i throw together (yes iam aware its very ugly but it works).
Is this it? It looks like the parts count is about the same. I agree with your $10 assessment.

http://feng3.cool.ne.jp/en/rcd.html
__________________
Alan (just call me "Bum"; no need to be so formal)
HeliFreak Support
Protos Max Evo 700 (Brain 2), Protos Max V2 770 (iKON 2), Synergy 516 (Brain 2), DT520Ev2 (VBar)
Graupner MZ-24 Pro

Experience is something you gain only after you need it.
I wouldn't mind social media so much if it didn't involve people.
TheBum is online now        Reply With Quote Quick reply to this message
Old 05-07-2008, 03:42 PM   #7 (permalink)
Registered Users
 
Posts: 1,166
 
My HF Map location
Join Date: Apr 2007
Location: Clarksville, TN
Default

Quote:
Originally Posted by HFG View Post
Nice idea ! BTW i doubt many people have or have access to a PIC programmer however i have found an easy and CHEAP solution. RCD PIC programmer (Google it) only uses passive parts and costs about $10 to make. Here is the one i throw together (yes iam aware its very ugly but it works).
Great idea...but I'm stupid when it comes to any programming type stuff. Is the code for the chip hard to write?
__________________
Jesse
T700N FBL - V-Bar w/ 3DX Head
T250 Super Pro - HS-5084MG Tail Servo
X9303
HELINHAWAII is offline        Reply With Quote Quick reply to this message
Old 05-07-2008, 03:52 PM   #8 (permalink)
The Capi
 
Posts: 25,121
 
My HF Map location
Join Date: Oct 2006
Location: Toronto
Default

Yes thats the RCD programmer i used. Nice thing about it is that it generates the 12V required to program the PIC directly from the serial port. Jesse there is NO reason to write any code. Inside the files provided by MikeF is a file called TACH.HEX. The hex file is what you program to the PIC.

Programming a PIC is its MAJOR disadvantage for hobby use IMO. This is why i have started using Atmel controllers which you can use USB to program them.
__________________
Spreading capibara awareness since 2006
DominicD is online now        Reply With Quote Quick reply to this message
Old 05-07-2008, 03:59 PM   #9 (permalink)
Registered Users
 
Posts: 1,166
 
My HF Map location
Join Date: Apr 2007
Location: Clarksville, TN
Default

Quote:
Originally Posted by HFG View Post
Yes thats the RCD programmer i used. Nice thing about it is that it generates the 12V required to program the PIC directly from the serial port. Jesse there is NO reason to write any code. Inside the files provided by MikeF is a file called TACH.HEX. The hex file is what you program to the PIC.

Programming a PIC is its MAJOR disadvantage for hobby use IMO. This is why i have started using Atmel controllers which you can use USB to program them.
Ohhhh yeeeaaah, It's still early here in HI and I worked late last night. I got so excited, I didn't look at the rest of the files in the zip. Thanks man! But still, rather than build a programmer too, I'd rather just buy a chip from someone if at all possible...
__________________
Jesse
T700N FBL - V-Bar w/ 3DX Head
T250 Super Pro - HS-5084MG Tail Servo
X9303
HELINHAWAII is offline        Reply With Quote Quick reply to this message
Old 05-07-2008, 04:32 PM   #10 (permalink)
Registered Users
 

Join Date: Mar 2004
Location: Mid Michigan
Default

I would be willing to program the chip for you freaks if you have no way of doing it yourself. You guys buy your own chip and just mail it to me. I would program it for free and you just cover the cost of all shipping. I will test it before I send it back. I would think you could ship this via US postal for $1 or less? How does that sound? You can PM me or email me when you get your chip and I will send you my address. ZIP is 48453 if you guys want to calculate shipping. That $10 programmer looks pretty cool HFG. I might build one just to have an extra programmer around.

I also apologize for the half year it took to get this info out. I get side tracked easily and have multi projects going all the time….. If you guys have trouble with the write-up please let me know. I wrote it from memory and it could have typos (I hope not however). Also if anyone has a suggestion for improvement let me know and I would gladly add it to the write-up. The code I used was just what I came up with and since I am not an expert programmer, there might be a better way. So far the prototype is still working fine. (Rond is the current owner).

Thanks,

Mike
mikef is offline        Reply With Quote Quick reply to this message
Old 05-07-2008, 04:44 PM   #11 (permalink)
Registered Users
 
Posts: 1,166
 
My HF Map location
Join Date: Apr 2007
Location: Clarksville, TN
Default

You got it Mike. I'm placing my order for parts today! Thanks man!
__________________
Jesse
T700N FBL - V-Bar w/ 3DX Head
T250 Super Pro - HS-5084MG Tail Servo
X9303
HELINHAWAII is offline        Reply With Quote Quick reply to this message
Old 05-07-2008, 10:29 PM   #12 (permalink)
Registered Users
 
Posts: 309
 

Join Date: Mar 2004
Location: Michigan
Default

This tach works awesome. Mike calibrated it for a range of up to just over 4,000 rpm!! The first time I took it out at the field and used it on my T-Rex 450 V2, one of the guys with his new MinAir 3000 rpm heli tach still couldn't get my Rexy, but this one locked it in easily.

This is not the only cool thing Mike has made either, he has a shop full of cool stuff like this, not to mention an awesome altimeter. Look at post number 27 of this thread

https://www.helifreak.com/showthread.php?t=61615&page=3

for a pic of the altimeter that was actually made by mikef and flown by me and Jason.

Ron
rond is offline        Reply With Quote Quick reply to this message
Old 05-07-2008, 10:49 PM   #13 (permalink)
The Capi
 
Posts: 25,121
 
My HF Map location
Join Date: Oct 2006
Location: Toronto
Default

Nice to see there is some interest in DIY electronics.... its inspiring
__________________
Spreading capibara awareness since 2006
DominicD is online now        Reply With Quote Quick reply to this message
Old 05-08-2008, 11:27 AM   #14 (permalink)
Registered Users
 
Posts: 660
 
My HF Map location
Join Date: Apr 2007
Location: USA
Default

Ok I think I'm going to have a go at this. Should be fun.
jared_of_atlanta is offline        Reply With Quote Quick reply to this message
Old 05-08-2008, 11:36 AM   #15 (permalink)
Registered Users
 
My HF Map location
Join Date: May 2006
Location: essex
Default

The circuit for the hold button is missing!!!!
heliphil is offline        Reply With Quote Quick reply to this message
Old 05-08-2008, 11:46 AM   #16 (permalink)
Team Taco VP
 
Posts: 34,492
Thread Starter Thread Starter
 
My HF Map location
Join Date: Nov 2005
Location: Stanton, Ca. USA
Default

Yep it sure is... It doesn't show you where the memory button should hook to on the PIC.

Mike?

Bob
Finless is offline        Reply With Quote Quick reply to this message
Old 05-08-2008, 12:04 PM   #17 (permalink)
Registered Users
 

Join Date: Mar 2004
Location: Mid Michigan
Default

I am at work right now but when I get home today I will check that out. It just connects to one of the pins on the PIC chip.
mikef is offline        Reply With Quote Quick reply to this message
Old 05-08-2008, 12:18 PM   #18 (permalink)
The Capi
 
Posts: 25,121
 
My HF Map location
Join Date: Oct 2006
Location: Toronto
Default

Looks like Pin 15 on the photo (don't feel like following your ASM code). Should just be a button and a pull up resistor (this goes from the pin to VDD).
__________________
Spreading capibara awareness since 2006
DominicD is online now        Reply With Quote Quick reply to this message
Old 05-08-2008, 01:58 PM   #19 (permalink)
Registered Users
 
Posts: 1,166
 
My HF Map location
Join Date: Apr 2007
Location: Clarksville, TN
Default

I'm having trouble finding a 2.5K Ohm precision pot. Will any 10 turn pot do?
__________________
Jesse
T700N FBL - V-Bar w/ 3DX Head
T250 Super Pro - HS-5084MG Tail Servo
X9303
HELINHAWAII is offline        Reply With Quote Quick reply to this message
Old 05-08-2008, 02:05 PM   #20 (permalink)
The Capi
 
Posts: 25,121
 
My HF Map location
Join Date: Oct 2006
Location: Toronto
Default

Dont think i have EVER heard of a precision pot More turns the better. a 20 or 25 turn pot will work, its just a voltage divider.
__________________
Spreading capibara awareness since 2006
DominicD is online now        Reply With Quote Quick reply to this message
Reply




Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the HeliFreak forums, you must first register.
Please enter your desired user name, your REAL and WORKING email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself. Use a real email address or you will not be granted access to the site. Thank you.
Email Address:
Location
Where do you live? ie: Country, State, City or General Geographic Location please.
Name and Lastname
Enter name and last name here. (This information is not shown to the general public. Optional)
Helicopter #1
Enter Helicopter #1 type and equipment.
Insurance
Please select your insurance company (Optional)
Helicopter #2
Enter Helicopter #2 type and equipment.
Helicopter #3
Enter Helicopter #3 type and equipment.
Helicopter #4
Enter Helicopter #4 type and equipment.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On




Copyright © Website Acquisitions Inc. All rights reserved.
 

SEO by vBSEO 3.6.1