Cirrus Spray Bar

[bobden72]

OK chaps I am now on the last stretch of building my 1/4 scale Cirrus, which is the carburettor. The drawings for the spray bar show a .005" thick slit in it. What have other builder done to achieve this, is it possible to get a slitting saw that size. Or could I drill a row of holes, which would be hard in its self. Has any one any ideals please.

 

[mcostello]

Could You mill a .005 groove in a piece and solder the pieces together and turn them down?

 

[stevehuckss396]

Yes you can get a saw in that size. Just tried a google search and found a few sources.

 

[lantain1982]

Hello bobden72
I was faced with the same problem with such a narrow slot on my Cirrus project. The fix I came up with was to use the blade of a "ridgid back razor blade". These blades have a thickness of 0.005" . Do not know the correct turn but they have a folded back along the top. These blades have slot on the flat face. I removed the ridge, opened the slot up with a Dremal and gained a hole 0.200" in diam. I mounted the then rectangular blade on a mandrel and having a cutter grinder generated a diam. of 0.650" [largest diam. from the plain rectangle] plus a number of cutting teeth. I tried to back the teeth off with a diamond stick but may have had some effect on cutting. However I plunged the cutter in from both sides of the bar and produced a slot. From memory it raised a bit of a burr and the slot was a little less in lenght than specified. Hope this may be of help.
Cheers, lantain1982

 

[petertha]

Have you seen Paz's build?
http://modelicengine.la.coocan.jp/c0512.htm

 

[bobden72]

Would you like to share the information, bearing in mind that I am in the UK.

 

[bobden72]

Thanks for the very good informative pictures, no I have not seen them before. Thats the road I will be going down I should have thought of it myself but I suppose I was looking for the easy way out. Thanks again Bob

 

[bobden72]

Hi I am still waiting.

 

[bobden72]

First thanks for all the reply's I received, from these I was able to resolve my problem.
I found I had some small 3/4" diam saws in my Dremel box, but were too thick. So I just mounted one on a mandrel in my lathe, then using my tool post grinder I slowly ground the cutting blade to .005". I used it yesterday with some trepidation and it worked just great. Spray bar now done and the carb almost finished. Thanks for the inspiration, I have attached some pictures of the finished cutter.