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cybor462
07-04-2007, 01:54 AM
Ok I have this slot to cut with a non standard radius. I need to do it with my mill BP clone and I do have a rotary table. take a peak at this pic and notice I have to cut the slot it is deeper on the one side than the other and it does not have an even radius. I hope to be able to cut this without cnc. I made this on my lathe and the end milling on my mill.

http://mywebpages.comcast.net/cybor462/peg.jpg
http://mywebpages.comcast.net/cybor462/peg1.jpg
I know the pics are not that good. What I need to do is cut the slot on one end .400 from the edge and the other end .100 The curve of the slot is not gradual or even. It starts very small then ends with a very aggressive radius.

Ok have at it.

Tony
07-04-2007, 03:01 AM
some sort of flip-up foot peg for a bike?

how many do you need to make?
how did you make this one?

its difficult to tell from the pictures and your description the
exact requirements of the slot.. can you post simple hand
sketches?

generally speaking, do it in steps.
use the smallest endmill available to rough the slot out.
repeat the same setup and cut on the the piece you need
to make.

switch to your next size endmill, adjust the angle of the
part in the vice and make your second cut. again, do
this to all your parts. of course, set them up all exactly
the same on the mill table.

you basically want to get closer and closer to your
final slot dimensions in these small steps, using various
size mills.

its sort of like cutting a ball in the lathe without a radius
cutter.. small calculated changes in X and Y until you
approximate the shape.. then clean with a file, paper,
whatever. a "human" CNC.

if you can post a sketch of the slot maybe we can help
you with most specific information.

-tony

NickH
07-04-2007, 06:56 AM
Forget the rotary table, cut the slot in one with a carbide ripper leaving only the area requiring your curve.
Cut curve in small steps with a ball end mill, use calculator & trig to work out your moves in steps small enough to give you the finish you require.
If your DRO has a curve function like mine you could approximate the required curve with a series of short radius cuts,
Regards,
Nick

Mcgyver
07-04-2007, 07:07 AM
what is it? or rather what tolerances does it need?

I've made odd ball curves using the step approach Nick refers to. Made a cam once in the index head and did the profile by raising and lowering the mill table. move the index index, change table height, take a cut, stop, repeat This manual numerical control is painstakingly tedious and will take a bunch of math but can get you out of bind.

Evan
07-04-2007, 07:39 AM
Are you sure about the changing radius? Perhaps it is just a section of a circle from a circular cutter centered on one side of the peg.

Like this:

http://vts.bc.ca/pics2/peg.gif

cybor462
07-04-2007, 09:50 AM
I know the pic is bad and my description is worse. Yes I am making extended foot pegs for my Honda 1100 as they are not available aftermarket. At least I have not found any. My foot hangs over the edge on the stock pegs about 2" so I made this larger.

I made this with my lathe and mill. Was rather easy until I came to this radius.

To answer the question about how many I need... I hope to test these when I have them made and then plan on marketing them as I have not seen any for sale. I will send them off to the cnc shop as I have done with the other tools I have made but I need to get the first ones made to test them. Getting back to the problem..

Next..I do not have a drawing program I do not think so I guess I will have to explain it. If you picture the peg with the cut slot as in Evan's drawing the curve I need looks more like a (J) except the radius at the start of the curve is less aggressive and then gets more aggressive as it finishes up at the end. Sorta like 3/4 of a hook at the end.

If any of you guys know of a drawing program I might find I would try to draw it for you.

Thanks


Jim

PS I have Corel Draw but it is not for Windows so it does not work anymore. I am sure that would have worked.

japcas
07-04-2007, 10:10 AM
cybor462, most of us here can still read an old fashioned hand drawn sketch. Can you sketch up something with some dimensions to help us understand a little better. Once were on the same page as you are, I'm sure somebody will be able to come up with a solution to help you.

cybor462
07-04-2007, 10:21 AM
I am not a draftsmen and I have not been successful in drawing this thing. The problem is the slot has to be cut that shape. It is internal and has to be cut within the slotted area. I will try to get a pic of the orig. peg so you guys can see the shape.

micrometer50
07-04-2007, 01:18 PM
Is it really necessary to duplicate the radius exactly? Would a simpler shape do the job.

dalee100
07-04-2007, 01:55 PM
Hi,

I too wonder if a simpler profile might not do as good. Otherwise, to make a proto-type pair, I'd simply do as NickH suggests and rough mill out most of the material with a rougher, then use a die-grinder with the appropriate burr to "blend" in the radius as needed. I do this alot on onesie-twosie items simply because I can't always justify the time and money to do it "right".

dalee

cybor462
07-04-2007, 04:12 PM
Yes it needs to be the same as a pin rides inside the slot. It has a spring so if the peg hits the ground it will swing up. The spring keeps it out normally.

I guess I can use the die grinder method. The original pegs are cast so that is how they were able to make the curve readily. A cnc could do it as well.

What type of die grinder cutter would work on 6061 without loading up? I do not use them much and only have stones for them.

lane
07-04-2007, 05:39 PM
I went out and looked at my wife`s shadow 1100. Cut the slot back to the short dimension from the end . Drill the cross hole for the pin. Put back in vise at an angle and using a ball end mill cutting down and out work radius in until it will fit and work like it is suppose to. You may have to try on bike a few times until you get it.

pntrbl
07-04-2007, 11:21 PM
Cybor, is this a folding footpeg and part of the radius forms the stop? Folding footpegs are fine .... but floppy ones wouldn't be much use. :D

SP

gizmo2
07-05-2007, 08:50 AM
I'd swipe the business ends from the old pegs, turn a threaded stub, and make the new pegs thread onto the stub. A little thread lock and go for a ride. Lazy is good.

cybor462
07-05-2007, 07:08 PM
Cybor, is this a folding footpeg and part of the radius forms the stop? Folding footpegs are fine .... but floppy ones wouldn't be much use. :D

SP

It is not floppy per say. There is a stiff spring that holds it out. The stop is the outside face of the milled area not the slot. It is based like the original peg just 2" longer so my foot fits on it without hanging over the end. I like my design better as the knurled peg looks and works better. I need to get the slot the right shape and I will test it. I know it will work as good or better than the original.

cybor462
07-05-2007, 07:12 PM
I went out and looked at my wife`s shadow 1100. Cut the slot back to the short dimension from the end . Drill the cross hole for the pin. Put back in vise at an angle and using a ball end mill cutting down and out work radius in until it will fit and work like it is suppose to. You may have to try on bike a few times until you get it.
That is how I planned on doing it just hoped there would be a smarter way. I guess the answer was close to what I expected. I have the slot milled to the far end now all I need to do is mill the close end and work it in.

Thanks for all the suggestions. I learned that lane's wife has the same bike I do. She must be a real women if she rides that thing. I think they weigh close to 700 lbs. At least mine does. That is without the rider.;)

speedsport
07-05-2007, 07:59 PM
wouldn't it be easier to just move your foot in until it sits on the peg like it's supposed to?, or isn't that "cool" enough?

cybor462
07-06-2007, 12:59 AM
wouldn't it be easier to just move your foot in until it sits on the peg like it's supposed to?, or isn't that "cool" enough?

Not sure how cool or uncool but the exhaust pipe and brake pedal are at the left side so you can't move your foot any further left, it has to go to the outside. :rolleyes:

That is why it is very uncomfortable since you can't go any further left my foot hangs off the outside of the peg. Having size 12 EEE feet I guess does not help any either!:)

Bill Pace
07-06-2007, 07:55 AM
V
I learned that lane's wife has the same bike I do. She must be a real women if she rides that thing. I think they weigh close to 700 lbs. At least mine does. That is without the rider.;)


Hah!! As you might of guessed, Lanes wife (Nell) is bout big as a minute, ...... and she wont wait on Lane to go out riding either, if hes got his nose in some project in the shop she'll just fire 'er up and take off anyway.

cybor462
07-09-2007, 10:04 AM
Well Tin was up for the BBQ and you know we had to sneak away for a trip to the shop. He looked at the peg and said "This defiantly poses a challenge".
So as I thought it will not be easy. I have decided to use a die grinder but wonder what type of tool would do the job without galling the alum? I have several die grinders but do not use them much, mostly for light small grinding work.

I seem to only have stones so I will need to get some other cutters for this job.

Which cutters would you guys get?

Joel
07-09-2007, 01:27 PM
A carbide burr, double cut:

http://www.amazon.com/Astro-Pneumatic-2181-Double-Carbide/dp/B00061SFKK

cybor462
07-09-2007, 03:10 PM
Thanks I will get a few. I think I did have some of those if I can find them.

cybor462
07-11-2007, 07:48 AM
I wonder how many of you guys have the same thing in your shop. I did not have the burrs I need to manually hog out the stock for this peg. It was suggested I get the burrs listed on the previous post.
I was working in the shop yesterday and was searching for a pin to use on a fixture I just made. I had a bin with all odds and ends I got from an ebay auction. As I was digging I saw not 1 not 2 not...ok 9 of those burrs all different types almost equal to the set listed previous that I was going to buy. I had them all! :( Just to think I was going to waste money on something I already had but had no clue I had them.
I wonder how many of you guys run into that same thing.

Just to think I have more of these ebay odd and ends I have not really looked through yet. May have a small treasure! :cool:

cybor462
07-15-2007, 10:58 PM
Finally got the groove cut. Put it on the bike and went for a 60 mile ride. Wow why didn't I make that before? What a treat. My foot no longer falls off the peg.

I ended up stepping out the slot with an EM and finished it up with a small drum sander for the die grinder. Not the prettiest but will be good for the cnc guy to run them. He will be able to produce a smoother curve.

Now to find Honda Shadow owners that are tired of their small pegs!:)