[tauscnc]

Hey Kong,
Thanks! I finished my set and it came out rather good! Much easier to cut the carbon fiber (CF) then I thought it would be. The cuts where clean also with that carbide "fishtail router" bit. Of course everything was going well untill the LAST pass! It was the LAST pass when the mount let loose I was using my "famous" Scotch double-side tape to hold a piece of wood to the table and the CF to the wood. Its amazing how well this double-side tape works! If you have not tried it really do.

Anway, I caught it before any major damage. To make a long story short I cut into a spare piece and took the dust and superglued (CAed) it into the "mistake." It's in the larger fin toward the front but hard to see. I think the spread of the CA makes the fin look worse then it is. I will need to use a de-bonder to remove the extra CA.

Here are pics of the complete set:
https://home.insightbb.com/~kristaus/raptorv2.htm

For pics of the acutal heli and my "real" site:
http://www.cuttingedgecnc.com/raptor.htm

For all other info as my cnc setup, rc helis etc, check out my site
http://www.cuttingedgecnc.com/index.html

Thanks again!
I think I might make a carbon servo mount for the tail rotor next!

taus
www.cuttingedgecnc.com

[kong]

Gotta love that CF, not only is it strong and light, but on your heli's it looks GREAT! I'm just getting into the rc world with my first car arriving just after xmas. I now seem to spend a lot of time drooling over other peoples models! I already saw your site ages ago, and there is plenty of useful info there. Good job!

[Mr.Chips]

Kong
I'm ready to make my anatibacklash nuts for the lead screw.

Could you explain the bicture in a little more detail, they seen to be 2 piece and one has pins on the side.
Thanks

Also what size did you drill the material before tapping? The dia. I found was 0.401", wanted to make sure that this was correct.

I'v red that some people freeze the delrin before tapping did you do that?
Hager

[motordude]

Just a small warning. A friend did some work on a home made aeroplane involving carbonfiber lamination. He used electric handtools to finish the product. The dust, which is electrically conductive, got into the machine and the current found its path via the dust into him.
Obviously it was quite unpleasant. He now only uses pnumatic tools.

Regards

John

[kong]

Mr Chips, you can download the plans for that nut in this thread. It is a metric nut for 18mm acme with 4mm pitch, so I drilled a 14mm hole before tapping.
Yes, they are 2 piece, the second section can slide over the first to remove backlash, then those grub screws lock the two halves together. No, I never froze the delrin first. Hope it helps.

[Mr.Chips]

Kong,
I understand. The metal that I thought was pins, is actually set screws to lock the two pieces together after taking up the slack.
Thanks

[nick999]

A few small questions:

1. I tried using a router with a vacuum table, but have found that it holds the dust to the table instead of up the dust collection. Is it preferred to not use a vacuum table?

2. I used a drill bit to drill a few holes, instead of using the router to do it. I have found that the holes were being dimpled, both at the entrance and the exit. Should I decrease my feed rate, or will using a router bit always give me better results?

3. Using the type of router bit that MLINDER had suggested on the first page of this thread, I am getting a rough edge on both the top layer and bottom layers (in some places). Is this just the nature of the bit or should I be changing the speed of something?

4. After cutting the parts, I found that they were very difficult to remove from the spoil board, almost like if I had left the vacuum on. Is it that the dust was so compacted that it held the parts to the table or could it actually be that the dust is heating up to the point to where the resin is 're-gluing' the parts into place?

Thank you in advance for your help. I hope that I will not need to be killed for having read this thread

[mlinder]

Nick999,

You need good vacuum for dust removal. Also, my spindles are spinning at between 13K to 18K depending on the material thickness, with a feed rate of about 30 in./min.

Also the type of laminate makes a difference. Vacuum bagged manufactured laminates do not seem to hold together as tightly as pressed laminates which use heat and presssure when produced.

Hope this helps.

[nick999]

MLINDER,

Thank you for your help. I am cutting 1/8" material that has been pressed, not vacuum bagged. My spindle speed is the same as yours, but I need to run a feed rate of around 24in/min to keep from breaking a 1/8" diameter bit. I can not imagine how you get away with anything smaller.

My dust removal is great, it will suck my hand up if I got it too close But, I am beginning to think that the table suction too strong. It is holding the dust in the kerf, and maybe that is the cause of my problems. I still do not know what could be causing the flare on the top and bottom edge, but one problam at a time.

Thanks again for your help,
Nick

[nick999]

MLINDER

I tried it again with less table suction, worked better. I guess it could be the material quality that I am getting, but it looks like I may need to go back over it for a final finish pass. The cut is pretty rough in some places.

One more question, do you have a cleaning proccess that you send the parts through?

[mlinder]

Nick999,

We use what is called "medium duty" Scotch brite pads. They are green colored and you can find them at Smart & Final. Do you have S&F in texas?

Of course, we get pretty good edges righ toff the routers, so the Scotch Brite isn't really "deburring" anything. Nust a quick swipe and the parts are good to go.

Mark

[nick999]

MLINDER,

I have some of the green colored scotch brite pads. It never even entered my mind, I would think that it would scratch the surface. I was thinking about an ultrasonic cleaner, because everything I do is small. I will try the pads first, as it is a lot cheaper. I think I may still need the ultrasonic cleaner for all of the small cut outs in the parts. I can't imagine standing at a sink for hours cleaning the parts with my roommate's tooth brush .

I ran another set of parts, this time doing a finish pass with a 1/16" diameter bit. The parts came out pretty good, but still need some sort of cleaning due to the compacted dust.

Thanks again for your help.

[millmore]

Is there a place to buy that "fishtail" carbide burr? We cut fiberglass circuit boards and small shapes and would like to try that type of tool.

We have a router with no vacuum table.... looking for alternative ideas to holding down our panels of fiberglass. Our panels are about 2 x 4 and we cut fully through them. Trouble is ... some of the small parts get sucked up in the dust collector. Some cut out and hit the bit and go flying.

We are considering double sided tape.... but I worry about trying to get the panels apart... again any ideas would be helpful.

[tauscnc]

Hey millmore,

I just did a search for fishtail routers on google.com and it came out with a lot of links. Here are some:

http://www.drilltechnology.com/router/diamondfc.html

http://www.timbecon.com.au/products/...els-353_3.aspx

http://www.discount-tools.com/fiberglassindexmain1.htm

Hope that helps. O yeah, I got mine from harborfreighttools.com and you can get sets of many reground carbide cutters for like $5.99. You could also see about the diamond cutters that are sold under Dremel at your local hardware store for tile cutting.

taus
www.cuttingedgecnc.com

[Blazze]

mlinder

I am also having trouble with bits while cutting carbon fiber. I have not tried the "fishtail" router you recomend. I found a company called Drill Technology. (from this thread) Which of their bits would you recomend? I was looking at the diamond point (G point) down cut routers.
I cut mostly between 1.0 mm to 2.0 mm, but I also cut 3.0 mm and 5.0 mm. I cut through the 1-2mm sheet in one pass. I am using a Hasse 23x39 router table. My product line will be R/C Helicopter parts so they need to have a nice cut. Could you please give examples of what happens if the spindle speed is too fast/slow? Also would like the same for feed speed. As you can see I am very new to this and Any info would be a big help.

Mike

[tauscnc]

Hey Mike,

I found the fishtail routers to work the best. I think if you use a down cut or up cut bit like an endmill it will fray the edges of the carbon fiber as it will split the layers. I am not sure if this is true though. When I first cut my tail fins out of 2 mm CF plate I used a 1/16" carbide endmill and it worked well but the finish need much sanding.

With a fishtail router I needed to sand it very little. Also, I found cutting it in one pass to be better then 2.

As for speed of cut...ummmm ??? The way I learned (taught myself) was to manually machine though a piece and see how fast you can move though the work and how much strain your putting on the machine. You get a lot of good feedback on everything manually machining. That way you can judge what speed to put into the cnc code. Once you have done this a few times in different material and with different endmill then you can judge if the feedrate with cnc is to quick or not fast enough.

Hope that helps.

[Blazze]

Hello

That is a good way to judge feed. The only problem is I dont have a manual mill. I am cutting carbon with an ok edge. I get a few "hairs" on the top and bottom weave. These are easily knocked off with a few swipes of 400 grit wet. (the carbon I am cutting is uni in the middle and weave on the outsides) It seems when I was using the bits that came with the router, I was getting an edge with no hairs, No sanding.
I ordered a few of the bits that came with the router. They are expensive, about $7.00 each. I will post a picture of the bit tomorrow, mabey someone can tell me what it is.
The newer bits that leave the "hairs" are more coarse that the original bits. The fishtail bits from drill technology are much cheaper about $2.50, mabey I will order some of them tomorrow.

Thank you for your time
Mike

[tyrc racing]

I know this is an old topic, but i dont to mess with the forusm so Im will just ask me question here LOL

Is it possible to cut carbon fibre with a fret saw/ hegna saw? If so, which one should I buy LOL? I have about £100 or $200 to spend

[racecomp]

Yes you can cut carbon with a fret saw but it will get blunt very quickly.

www.racecomp.com.au