I am a small time 2 blade Broadhead maker(Australia) and for the past 3 years have been trying to make a machine to sharpen 6 heads at a time.
I have had some success but all in all it wont get the edge as sharp as I would like.
I have tried belts, wheels and die grinders with cutting bits all with varied success.
So short of giving up completly I thought I might as well ask for help.
Is there such a machine in the world ?
Has anyone made one that works?
How do the big companies do it ?
Tusker,
Sent you a PM.
Ron
Thanks Sharpster, but i am after info on any mechanical machines eg- self driven that can do 5 - 10 heads at a time.
John
John,
I wont tell you how I do it, but I will give you some clues, lol.
You need a surface grinding wheel ( the white ones) and lubricate them with a water soluble cutting compound.
A lubricant catching tank and recirculating pump.
The motor driving the grinding wheel needs to be able to change speeds to keep cutting speed the same as the wheel wears down.
I use an electronic variable frequency drive to do this.
You will need an adjustable "depth of cut" system to adjust for wheel wear.
A digital grain scale to check blade weights.
Its easier to move the grinding wheel across the blades clamped to a "foot print"base form. ( toggle clamps or magnetic chucks)
I bevel blades before fitting the ferrules( easier to clamp)
Straight edge blades are easier to bevel than curved designs.
Curved designs would probably require a seperate machine with a radial sweep to the cut.
The machine I'm alluding to, is pretty much my old one. I have a better machine on the go which will be ready soon.
It may be easier for you to buy a cnc surface grinding machine from an engineering supply. If you go this way, I would suggest a neomicro fine pole magnetic chucks, mounted on sine tables, to hold the blades down.
Google is your friend for looking at machinery
Whichever option you go for it will cost some serious money to set up.
Woody.
G'Day Woody
Thanks for your reply, I will have a look around on the net.
I was wondering if you were working on sharpening, never a dull moment is there!
John
It keeps me entertained....lol.
When are you going to make a single beveled, tanto tipped Concorde, I reckon you could sell a few of those.
Single bevels seem to be more and more popular, and are easier to make, for a machine beveling process .
And which was do you do the bevel? for left or right wing,and is ther any difference.
There is never an easy answer, and then there will be some other way to sharpen.
John,
If the magnetic chuck that holds the blades has a "form" to precisely locate the blades, by flipping it over, you can do either style just as easy.
This is one of the features my new grinder will have.
Most people seem to prefer right wing single bevels, but it depends on what fletch style is available in the customers area.
I believe in Europe, that left wing feathers predominate.
One of the challenges when designing a machine is to make it adaptable, so that you can follow what the customer wants.