UTMC

So my CR is way too peaky. I almost ate it several times today because that thing hits the pipe like a bat out of hell. Not so hot for trail riding.

I took the cover off and looked, and the bike has no flywheel weight.

So I went shopping for one, and this is what I found:

http://tinyurl.com/4dnnfw2

That's $109 plus any applicable tax and shipping fees, for eleven ounces of stainless steel that has been put on a lathe, and turned into a disc with a hole in the middle.

What the fuck am I missing here?

My "I'm not made of money" side says fuck that, I will wait until I have free range of the school's machine shop, and make my goddamned own.

Hell, it would take me maybe five minutes to design in Pro/E, and about a minute to actually fabricate on the CNC lathe.

Unfortunately, I won't have free range for another two months, which makes my "I don't want to die on my new motorcycle" side want to pony up the bucks.

Ack!

WeAintFoundShit wrote:
Unfortunately, I won't have free range for another two months, which makes my "I don't want to die on my new motorcycle" side want to pony up the bucks.

Ack!

And that's what you pay $ 109 for.

Also their tooling, R&D, raw materials, labor, quality control, warehousing, advertising, distribution, taxes and, finally, liability if it breaks. All that should at least account for around $ 29.

The rest is just the free market in a situation with limited demand, hence limited suppliers and, consequently, limited competition.

If you can do it yourself, I think you probably should do it yourself, just for bragging rights.

Yeah, step one is to try and just do it myself.
Step two is to buy the steel, and send to my friend Daniel, who will do it for me should I be barred from completing step one by the power tripping douchebag who runs the UC Davis machine shop.

That part, with overhead and profit, should cost no more than fifty bucks. The rest is just a big fat price gouge.

WeAintFoundShit wrote: That part, with overhead and profit, should cost no more than fifty bucks. The rest is just a big fat price gouge.

Really? Someone had to design it, prototype and test it, buy the materials and make 'em in a facility with machine tools that need to be paid for not to mention the facility itself plus the operators, then they sit on the shelf tying up operating captial until someone purchases it retail. The facility, the operators and the business itself all need to be insured as well.

If it's not sold direct by the manufacturer (and judging from your link it's not), then there may be another intermediate step or two, from manufacturer to wholesaler/distributor then to retailer. Every such middleman involves a profit margin.

All this goes double for low-volume parts where the manufacturer cannot spread the fixed costs over many parts sold.

You've got it easy; all you've got to do is design it and build it for one specific year of one specific model and you don't need to pay for the design program, the computer it is on, the machine shop, the machine operator or the tools in the shop and you already own the bike in question - you don't need to buy, rent or borrow one of those either.

If you want a better idea of costs, call a local fab shop and ask the price to design and build one from scratch to finished product. I can all but guarantee it'll be a lot more than $109 plus shipping.

In all fairness, it's unlikely that whoever came up with this product owns their own fabrication facilities. If all you need is a limited number production run of a simple item, you outsource that to someone who provides such services with their machine shop and can spread their costs for machines and the facility around many customers.

I agree with Stiles. But, if you think you can do it, do it yourself. There are waterjet cutting places that do CNC machining as well. A lot of them do one-off parts, so gather your measurements and call them up for a quote to see if you can get it done for less than asking plus shipping. I'd be curious to see.
If you can can email them a CAD drawing it'd be easier for them to give you an accurate price.
Look up onlinemetals.com; they have a no-minimum order on materials.

The only reason to make the part yourself, would be if you actually wanted to make the part yourself. You're kidding yourself if you think it is justified by economics. You will spend a lot of effort chasing materials and machinery, and it won't be as simple as you think. I spend my whole life doing things the hard way, so I know of which I speak.

I just need to see if I can get access to the CNC lathe, or the bench lathe if I need to do it by hand.

If I can't get that access, I already talked to a friend who is a machinist. His quote was "Yeah, that seems WAY overpriced. If they make these in any sort of quantity, they can turn them out for less than the price of a small latte."

I will let you all know if I turn out to be delusional, and end up buying the part.

My calipers and I are heading out to the garage.

Designed.

All I need is a thread template so I can figure out what pitch the crank bolt is, and it's done.

Looks like I wouldn't even need the CNC, and it could just be done on the bench lathe.
The only part I was thinking of "needing" a CNC lathe for was the taper on the face so the weight would fit inside the flywheel cover.
Turns out that the flywheel cover is basically flat, so there is plenty of room, and no need for a taper.

If I make it out of 303 stainless, the steel will cost me about $15 from onlinemetals.com, and I will check the local steel mill tomorrow, since I need to go there for materials, anyway.

WeAintFoundShit wrote:I just need to see if I can get access to the CNC lathe, or the bench lathe if I need to do it by hand.

If I can't get that access, I already talked to a friend who is a machinist. His quote was "Yeah, that seems WAY overpriced. If they make these in any sort of quantity, they can turn them out for less than the price of a small latte."

I will let you all know if I turn out to be delusional, and end up buying the part.

My calipers and I are heading out to the garage.

I'd be curious how "any sort of quantity" would be defined. How many of these do you think they sell? If they sold them at a price that seemed reasonable to a DIY-type like yourself, they would probably not make enough money for it to be worth their while.

Besides, an item is worth what someone is willing to pay for it. How much it cost to make the item is almost completely irrelevant.

Rabbit_Fighter wrote: Besides, an item is worth what someone is willing to pay for it. How much it cost to make the item is almost completely irrelevant.

True story.

Still, this part is so ridiculously simple to design and fabricate that I'm failing to see where the huge overhead comes from. Now there are certain bikes where they have to provide a new stator cover for the weight to fit, and with that I can see the higher dollar value, but in comparing the price of this to the price of some much more complicated, much more technical parts that I've priced and purchased in the past, I'm just not seeing it.

However, it's just like you said...

What is the planned weight of your self made one? Thought of making a few w/ incremental weight increases?

It's just a teeny bit less than eleven ounces.
And I am buying two blanks, so I can go up or down a step as needed.
Also, I am scavenging for connections at school for plain old, mild steel blanks. One of our classes uses 3" round bar, which would put the weight somewhere right about 9.5 oz at the current, main body thickness.

WeAintFoundShit wrote:

WeAintFoundShit wrote:It's just a teeny bit less than eleven ounces.

And the funny part is....?

Anyway, I talked to the OTHER shop lead today, and he said he'd work with me to get some time on the machines, as well as some three inch round stock of mild steel.
He was dubious of their available tooling being able to cope with the metal I was planning on, and since the stuff he has is also free, I will be switching to that.

Since the original design is a skosh under three and a quarter, I will have to get more accurate measurements of my clearance between the rotor and the stator cover, and see how thick I can make the part in order to hit my target weight.

Oh wait, you're probably laughing at my exacting specs in contrast to my vague estimate.
Got it.

Mild steel is probably good enough. Stainless can be hard on tooling, and increases time involved because of the speed at which it has to be cut. Glad to see someone doing something neat.
Someday I'm gonna get me a lathe.

I just took a better measurement of the clearance, and there are acres of space in there.
Really, I need some sort of modeling clay to stick in there and take a quick casting to actually measure. I can make that thing way, way thicker.
The only things that had me thinking stainless was the fact that I don't want the part rusting in there, and that the stuff I was looking at was higher density than mild.
Paying for materials, and tapping stainless threads doesn't sound like a treat.

Redesign for new materials in 3... 2... 1...

Oh, how I miss the days when I had a whole fab facility to play with. Could make any part we needed. Those were the days.

Now I'm in a hell where I have to talk to vendors and sales reps who dont know their own product, and lord help us if we plan to use product off label....

Just to have a Bridgeport, and a Lathe again

JoJoLesh wrote:Oh, how I miss the days when I had a whole fab facility to play with. Could make any part we needed. Those were the days.

Now I'm in a hell where I have to talk to vendors and sales reps who dont know their own product, and lord help us if we plan to use product off label....

Just to have a Bridgeport, and a Lathe again

It's true, I am currently spoiled with my options.
Were it not for the fact that I have all of this at my disposal, my bank account would be ~$100 lighter, and my bike would be eleven ounces heavier. This conversation would have stopped at "Damn, I can't believe I had to spend that much. Oh well."

Thankfully, I have hybrid bridgeports and lathes, as well as fully CNC mills and lathes at my disposal.

Made (by hand on a bench lathe).



Installed.



Took me a while to get into the shop and do it, but that's fine, coz I haven't exactly been out riding lately, either. I got snowed out the few times I tried.

ossum!!

Well? Does the cover fit?

kick ass!!!

The cover fits just fine, with room to spare.

I was going to drill two more holes, and run screws through them into two matching holes in the rotor. The idea was that, since the part replaces the nut holding that holds the rotor on, I would use the two screws to make sure it wouldn't work loose.
All of the mills were full, though, and it didn't look like any of them were going to clear up, so I just decided to loctite the hell out of it, and tighten it down as much as I could.

I'll be sure to post up if the thing works loose, and causes any havoc. I'm not too worried about it, though.

My assertion still stands, though, that this part is overpriced.
It took maybe ten minutes to design, and a couple of hours for me to tool up and make. Most of that time was spent facing the stock material to the appropriate thickness, because someone was hogging the band saw. It also went more slowly because the shop has very conservative limits on material removal and tool speed.

An actual manufacturing company, that has a CNC lathe with an automated workpiece carousel, could knock this part out at a rate of about one per minute, plus whatever time it takes to tap the hole.

I really think it all boils down to the fact that most folks, even the DIY types, don't have access to this type of metal working equipment, so they can charge at the very upper bounds of reasonability and get away with it.

That's pretty effin cool. When I win the lottery I'm getting a lathe and mill, among other things, and learn how to use them.

Just went and kicked the bike over.
It wasn't hard to start before, but it's MUCH easier now.

It started up with one, pretty lazy kick.

One week, and I can go ride it!

Wooot!