Posting screenshot to rails api with curl - ruby-on-rails

Question

I am trying to post a screenshot via my api to my admin site using curl....I have tried so many different things but nothing is working. I was able to post data using the following command
curl -X POST -d "data[device][test]=test" http://localhost:9000/api/v1/diagnostics -H 'Authorization: Token token="1212"
I know posting an image takes a slightly different approach and i have tried various but still had no joy....I have put some of these below!
curl -X POST -f "filedata[screenshot][test]=#/Users/Desktop/image_test.png" http://localhost:9000/api/v1/diagnostics -H 'Authorization:Token token="1212"'
curl -v -H 'Content-Type: multipart/form-data' -H 'Accept: application/json' -H 'x-api-key:1212' -F "filedata[screenshot][test]=#/Users/Desktop/image_test.png" http://localhost:9000/api/v1/diagnostics
The errors i am getting are 400
* About to connect() to 192.168.33.11 port 80 (#0)
* Trying 192.168.33.11...
* Adding handle: conn: 0x7fcd4b004400
* Adding handle: send: 0
* Adding handle: recv: 0
* Curl_addHandleToPipeline: length: 1
* - Conn 0 (0x7fcd4b004400) send_pipe: 1, recv_pipe: 0
* Connected to 192.168.33.11 (192.168.33.11) port 80 (#0)
> POST /api/v1/diagnostics HTTP/1.1
> User-Agent: curl/7.30.0
> Host: 192.168.33.11
> Accept: */*
> Authorization: Token token=1234
> Content-Length: 34655
> Expect: 100-continue
> Content-Type: multipart/form-data; boundary=----------------------------83266d811bad
>
< HTTP/1.1 100 Continue
< HTTP/1.1 400 Bad Request
< Content-Type: application/json; charset=utf-8
< Transfer-Encoding: chunked
< Connection: keep-alive
< Status: 400 Bad Request
< X-UA-Compatible: IE=Edge
< Cache-Control: no-cache
< X-Request-Id: 6231c398ff48566500e4aee2f101186b
< X-Runtime: 0.009898
< X-Powered-By: Phusion Passenger 4.0.5
< Date: Tue, 31 Mar 2015 11:09:31 UTC
* Server nginx/1.4.1 + Phusion Passenger 4.0.5 is not blacklisted
< Server: nginx/1.4.1 + Phusion Passenger 4.0.5
* HTTP error before end of send, stop sending
<
* Closing connection 0
log output:
Started POST "/api/v1/diagnostics" for 192.168.33.1 at 2015-03-31 13:14:19 +0000
Processing by Api::V1::DiagnosticsController#create as */*
Parameters: {"filedata"=>{"screenshot"=>{"test"=>#<ActionDispatch::Http::UploadedFile:0x000000059d16d8 #original_filename="image_test.png", #content_type="application/octet-stream", #headers="Content-Disposition: form-data; name=\"filedata[screenshot][test]\"; filename=\"image_test.png\"\r\nContent-Type: application/octet-stream\r\n", #tempfile=#<File:/tmp/RackMultipart20150331-14827-7454c3>>}}}
Filter chain halted as :validate_payload rendered or redirected
Completed 400 Bad Request in 2.9ms (Views: 0.2ms)