Scratch wheel

[Turnthetables]

The bearing is a good Idea... I'm going to see what I can do...

[matt_kronik]

After reading the Skratchworx article, I sought out this project.  I'd like to build one, but I've got a few questions:

• I have a laptop, hence, no MIDI card.  Do I need a USB to MIDI or Firewire to MIDI adapter if I want to connect this device to my PC?
  
• I have no background in programing (but I'm not a fool!).  How difficult would it be for me to get a device like this working
  
• For rasteri: is this device connected to a more sophisticated piece of hardware, like FinalScratch or Native Instruments Traktor Scratch, or is it fully independent?
  

That's all I can think of for now.

Later!

[ademir]

Those HD motors make great bearings though - you could attach an encoder wheel to it perhaps?

Well, i harvested a motor from a 40 Gb old Samsung HD today. It looked like this:

http://img515.imageshack.us/my.php?image=dsc02630qy8.jpg

It's cool because you can attach a shaft on that screw. I was able to take another 2 rings off, like this:

http://img240.imageshack.us/my.php?image=dsc02631fq0.jpg

NOW, you see that little circle on top? Check this out:

http://img101.imageshack.us/my.php?image=dsc02634tf1.jpg

(rainbows not included)

Cool, huh? :D

I'll get an encoder out of this motor just like that one, some posts back :)

- a

[rasteri]

I have a laptop, hence, no MIDI card.  Do I need a USB to MIDI or Firewire to MIDI adapter if I want to connect this device to my PC?

Yup. They're not too expensive, I got my USB->MIDI adapter on ebay for under £10.

I have no background in programing (but I'm not a fool!).  How difficult would it be for me to get a device like this working

You won't need to do any programming. All you need is a midibox core module kit (buy from smashtv, get one with a preprogrammed PIC18F4620) and a soldering iron.

For rasteri: is this device connected to a more sophisticated piece of hardware, like FinalScratch or Native Instruments Traktor Scratch, or is it fully independent?

It's connected to a PC running Traktor. I have built a prototype version that is completely standalone and is powered by batteries, but I'm in the middle of porting it to a dsPIC (for lower power consumption and cost) and that will take another month at least. Rest assured I will make details available (including source code) when I'm done.

[rasteri]

And ademir, that's very cool. Those things would make amazing jog wheels.

[Turnthetables]

ademir,

Can you read Minds? I'm actually posting pictures of hdd jog wheel mount... I grinded (ground isn't a word in this sense, right?) the base of the enclosure to be flat and I'm going to mount the encoder wheel on the base of the HDD spindle, use that cool little spacer to give me some space ;) and mount the jog wheel (CD) on top. now rasteri, If i were to connect the touch sensor wire to the spindle with a conductive jog wheel on top would it work? The spindle is aluminum I believe, But don't quote me on that...

[ademir]

ademir,

Can you read Minds?

actually, i'ts a natural gift. And a curse... :P

I'm actually posting pictures of hdd jog wheel mount... I grinded (ground isn't a word in this sense, right?) the base of the enclosure to be flat and I'm going to mount the encoder wheel on the base of the HDD spindle, use that cool little spacer to give me some space ;) and mount the jog wheel (CD) on top.

I gave up of this idea early today. Don't get me wrong, it's gonna work that way, but i'll use some bearings and a shaft and make an encoder from scratch. from scratch, get it? :P

I think that it'll be better if you get as little connections as possible between the jog wheel and the encoder disc.

now rasteri, If i were to connect the touch sensor wire to the spindle with a conductive jog wheel on top would it work? The spindle is aluminum I believe, But don't quote me on that...

Get a multimeter (if you're going to build a midibox, it's good to have one around anyway) and do a continuity test. If it works, go ahead.

About the touch sensor, you guys are aware of the QT113 IC? it's a touch sensor itself. it can work as a proximity sensor, too. attach some caps and a wire would do the trick. Here in Brazil, i can get one of these for about 10 euros. You guys can get it cheap.

later,

- a

[cimo]

.. check out skate/inlines bearings, they can be found anywhere iirc there is a 6mm hole

[ademir]

.. check out skate/inlines bearings, they can be found anywhere iirc there is a 6mm hole

the nsk 608 bearing has a 8mm hole, which is very close of a real turntable platter shaft (i don't have any turntables or discs here right now). it's used on skates/inlines, too ;D

as soon as i get some drawing on, i'll post it here, to see what you guys think.

later,

-a

[cimo]

plus metal tie zip (those with a screw to tighten) and 3 screws pointing downward.An 8 mm bolt with some washers and nuts to fix the cd/disk.

[matt_kronik]

Thanks for the info, rasteri!

One more question and a quick comment:

Do I need (sould I use) an external soundcard? The one on my laptop has four outs, but two are digital signal only.  Could I just buy a USB surround sound card and get Traktor to assign one deck to the front and the other deck to the rear outputs?

Instead on gutting my Vestax PCV-275, I think I'll order 45mm Infinium fader.  I know the Rodec Scratchbox uses a beefed up version of the Infinium fader.  I think they'll work, they have analog outputs.

[rasteri]

Do I need (sould I use) an external soundcard? The one on my laptop has four outs, but two are digital signal only.  Could I just buy a USB surround sound card and get Traktor to assign one deck to the front and the other deck to the rear outputs?

You don't NEED an external soundcard - I use my laptop's internal soundcard all the time. Get hold of a program called ASIO4ALL, and set traktor to use it for output instead of directsound or whatever.

External soundcards are a good idea in general though. I wouldn't get a surround card, they're mostly for home cinemas and stuff and might not come with ASIO drivers. I suggest you get one with four discreet outputs that you're sure will come with ASIO drivers. M-audio make some pretty good ones.

Instead on gutting my Vestax PCV-275, I think I'll order 45mm Infinium fader.  I know the Rodec Scratchbox uses a beefed up version of the Infinium fader.  I think they'll work, they have analog outputs.

The infinium looks like a GREAT option, I encourage you to try it out - I haven't had a chance yet. The only problem is it wants a 3.3v power supply, so you'll need to add a 3.3v regulator. Also the code will need to be modified slightly, but that's an easy job (I'll do it for you if you give me some ADC readings). In the long term I'll look at interfacing with the infinium's SPI port.

Also infinium make a retrofit version of the product, which costs slightly more but should just drop straight in without a new regulator or code modification. http://www.infiniumtechnologies.com/downloads/20070330_3/download - maybe give that a go?

[matt_kronik]

Also infinium make a retrofit version of the product, which costs slightly more but should just drop straight in without a new regulator or code modification. http://www.infiniumtechnologies.com/downloads/20070330_3/download - maybe give that a go?

Yeah, yeah!  I forgot about this option.  I wanted to upgrade my PCV-275 crossfader only to find out it wasn't a VCA mixer to begin with.  Maybe I'll put the infinium in my AEM-100i, put the Pro-X-Fade in my PCV-275 and get the CF-PCV into the scratch wheel...or not.

I'll work with that ASIO4ALL, as of right now, it look like it was just what I needed.

Thanks again.  I can't wait until I get my stuff ordered and I can get started on building my own!

I'll be in touch.

[dantheman]

Hello there,

I am extremely impressed with all the ingenuity and hard work put into this project.  :)

I was looking to buy a numark total control but where is the fun in that!? This scratch

wheel seems to be hundreds of times better and you get the fun of creating it yourself.

So you have inspired me to come up with a little project of my own....

The idea is to have a nice flight case setup for my dj'ing.

I want to use the scratch wheel with a m audio x-session midi mixer.

It seems to get rave reviews and is nicely priced at 64 quid.

Also thinking of adding additional midi buttons for kill switches and effect switches (extra space in case)

I want to keep all expenses to a minimum.

also came up with another iteration, possibly two scratchers either side of the m audio leaving

some space for extra buttons above each scratcher;

Let me know what you guys think, i am a bit of a novice when it comes to things like this

but i love dj'ing!

[rasteri]

That's an unbelievably cool idea, I especially like the second picture. I was going to say that the x-session's crossfader sucks for scratching, but as long as you keep the crossfaders builtin to the scratch devices, that won't matter at all.

I think I'll build myself one now :)

[dantheman]

That's an unbelievably cool idea, I especially like the second picture. I was going to say that the x-session's crossfader sucks for scratching, but as long as you keep the crossfaders builtin to the scratch devices, that won't matter at all.

I think I'll build myself one now :)

I forgot to mention that the diagram is all drawn to scale with the containing box representing the inside dimensions of the flight case. Actually found a cheap enough flight case on ebay which is the one i am doing my measurements on. The cool thing about this case is that you can whip off the lid completely as its a guitar effects rig case. This means the lid won't get in the way when you are dj'in!

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=370104230503

The interior dimensions of the flight case are 688mm x 296mm  (area 203648)

dimensions of the x session - 215mm x 264mm ( area  56760)

dimension of scratch wheel - 250mm x 200mm (area 50000)

so 203648 (flight case) - 2x 50000 (scratchwheel) - 56760(xsession)

= 46888mm case area left, equating to a 216mm x 216mm area left overall for extra buttons (spaced over unused spaces)

costs so far are;

case = £37(ebay)

x session = £64 (amazon.co.uk)

2 x cost of scratch wheel

so if the cost of building the scratch wheel is less that say £25 in total (each) then i think this setup would be much cooler and better value than the numark total control priced at £155 (amazon.co.uk)

p.s do you think the xsessions crossfader will be good enough for mixing?

[Mudo]

...

Hi,

I give you a sysex with my mcs3 jog 360 sysex messages.

It is usefull?

...

360.syx.zip

360.syx.zip

[rasteri]

I forgot to mention that the diagram is all drawn to scale with the containing box representing the inside dimensions of the flight case. Actually found a cheap enough flight case on ebay which is the one i am doing my measurements on. The cool thing about this case is that you can whip off the lid completely as its a guitar effects rig case. This means the lid won't get in the way when you are dj'in!

Sweeeet.

so if the cost of building the scratch wheel is less that say £25 in total (each) then i think this setup would be much cooler and better value than the numark total control priced at £155 (amazon.co.uk)

Well the cost of each scratch wheel is probably a bit more like £50 by the time you add buttons and shit. But you can't scratch with the numark total control.

p.s do you think the xsessions crossfader will be good enough for mixing?

Yup. Faders don't need to be very good for mixing.

[dantheman]

Well i definitely think that the scratch wheel is worth 50 bucks, so its time to start building!

ok so i have the following things;

-- multimeter

-- soldering iron

-- old hard drives

-- 7" vinyl

-- buttons

-- crap fader

-- old mouse

I need;

-- project box case

-- midibox circuits ( core module)

-- conductive paint

-- good fader (innofade looks nice) 

-- brass bush

i am also not sure about a couple of things;

how to wire everything up to the midi core module ( i have looked at the schematic but still not sure)

is the picture of the circuit enough to go on? Are all the components on the circuit the ones included in the midibox core kit?

best place to buy everything

p.s - if you can think of anything i have missed i would love to hear it

Dan

[rasteri]

I've attached a schematic showing how to hook it up to the midibox core module. Youll also need to make the change mentioned in this post - http://www.midibox.org/forum/index.php/topic,11167.msg102850.html#msg102850

(that potentiometer is the crossfader, by the way.)

scheme.PNG

scheme.PNG

[dantheman]

Thanks for that!  :)

[matt_kronik]

Okay, guys.  Before I get started, I wanted to make sure I have everything straight.

I whipped up an assembly view over the past few lunch breaks.  I didn't bother to lable a few components, and it's not dimensioned, either, but it'll help me get things straight in my mind.

Lemme know if I missed anything.

SCRATCH WHEEL Layout1 (1).pdf

SCRATCH WHEEL Layout1 (1).pdf

[dantheman]

what a beautiful diagram, very clear and concise - well done.

The only (trivially minor) fault i can see is you have mixed up labels 6 and 8.

[matt_kronik]

Heh, thanks dantheman.

I've got too much freedom here.  I need supervision!

Yeah, so nobody download the old one any more.  Get this new one.

SCRATCH WHEEL Layout1 (1).pdf

SCRATCH WHEEL Layout1 (1).pdf

[dantheman]

no problems!

I am thinking i will do a project video of everything i do to help others.

will post it on a youtube as episodes.

Ok i am about to order my midibox core module and pic

and i have a couple of questions;

1) what pic do i need (want to be sure)

2) I am in the UK, should i buy from mike's or smashtv?

3) is there anything else i should/need order?

Thanks

Dan