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sconisbee
01-29-2008, 01:11 PM
After reciveing a great amount of excelent advice on my last problem with the large radiused acetal part, i figured it would be an idea to put this one out there to see what comes back.

I recived a request for the part below and the part is fine other than the hole through the middle, edm's not an option for this part, i figured i would mill the hole sides then the radius on each end using the rotary table, then file out the "sharp" corners to fit the mating part..... oh yea and to make this more troublesome its in 316 SS so any ideas that might speed things up a little?

http://i59.photobucket.com/albums/g290/synoguy/RudderClamp.jpg

Mark McGrath
01-29-2008, 04:58 PM
Simon,the pic didn`t load for me,and,I don`t know about the others but I find your website layout of black writing on a dark blue background very hard to read.
Mark.

IOWOLF
01-29-2008, 05:29 PM
About that website, and the Business you have .....

You want us here to figure out your problems so you can use them and get paid well for it?
I think you want the PM site. :)

topct
01-29-2008, 05:49 PM
You want us here to figure out your problems so you can use them and get paid well for it?


What's wrong with that?

Rustybolt
01-29-2008, 05:50 PM
Depending on the amount,it might be a good idea to broach these.

mochinist
01-29-2008, 05:58 PM
why isnt edm an option?

Carld
01-29-2008, 06:42 PM
You'll not get the square corners with an endmill on a rotary table. Your wasting your time and ours on such a simple job as this. You know what you have to do and your fudging your way out of it.

Wire EDM.

boslab
01-29-2008, 07:31 PM
laser, try dragon lasers
mark

mayfieldtm
01-29-2008, 07:53 PM
I would think that undercutting the corners with as small a mill or drill, as possible, should be ok with the customer.

I looks like it's just a clamp collar after all.

Tom M.

jimsehr
01-29-2008, 08:15 PM
Before I finished any of the out side of this part I would drill the biggest hole
in center I could and saw a kerf thru the slot area and plan on having part
pinch together. And be ready for it. Even if you wire cut it I think slot will close some. Maybe better to saw first then drill hole . But the drill or saw blade is going to get pinched.
jims

IOWOLF
01-29-2008, 08:31 PM
A shaper would do it.

mochinist
01-29-2008, 09:55 PM
Sawing would be the last thing you would do on that part, doing it first or even doing it before you finish the outside would cause nothing but problems with finish and tolerances. If you're that worried about pinching, turn or mill a slug out of some aluminum that is a nice slip fit for the hole, then it cant collapse on your saw blade.

J Tiers
01-29-2008, 11:30 PM
Sawing would be the last thing you would do on that part, doing it first or even doing it before you finish the outside would cause nothing but problems with finish and tolerances. If you're that worried about pinching, turn or mill a slug out of some aluminum that is a nice slip fit for the hole, then it cant collapse on your saw blade.

I know why you said that, but.................

How about roughing out, sawing, letting it spring, re-sawing to size, filling the cut with a distance piece, clamping, and then finishing out the part?

Seems like that would be better than sawing at the end.......... if the part is supposed to be "on" dimension when relaxed.

sconisbee
01-30-2008, 04:22 AM
Mark, the website isnt black on dark blue when its properly loaded, but my host is having server troubles and thus the site isnt loading properly, which is also why the pic didnt load for you.

Edm isnt an option because there is no-one locally that can do it within the timescale i have and its a one-off part.

Carld and as for waisting your time? A) if im wasting your time, dont post afterall nobody forced you, and B) EDM isnt an option, i already have a couple of ideas but was just seeing as theres so much knowledge on this board i woudl see if anyone had a suggestion as they might have done something similar. And im perfectly aware i wont get square corners with an end mill and a rotary table afterall endmills are round:rolleyes:.

It was my full intention of following up with details and a pic so that if anyone had anything similar in the future they could use the same method, and i know im not the only one here that makes some money with parts. This is more the welcome that i would expect to recieve at pm after posting about something chinese, and i surely didnt expect such a reaction here....

with that said, thankyou to J Tiers, boslab and mayfield and anyone i missed that actually offered ideas.

Your Old Dog
01-30-2008, 07:37 AM
sconisbee, sorry you ran into such a rough crowd. I for one would be very interested in how you accomplish the hole with the tools at hand. You can PM me with the results so as not to bother some of the others with such trivial information! Good luck.

ahidley
01-30-2008, 08:21 AM
Heres a round about way. Make the hole as big as possible with the mill (R20) and then make 2 additional pieces (half moons) and weld them in. Then machine the outside.

Bill Pace
01-30-2008, 08:28 AM
I knew those responses had a familar ring to it..... they were copied and pasted from over at the PM site!!

I cant offer any suggestions, but I'll be looking to see what you come up with....

Carld
01-30-2008, 09:32 AM
:D :rolleyes:

lazlo
01-30-2008, 09:38 AM
About that website, and the Business you have .....

You want us here to figure out your problems so you can use them and get paid well for it?


Your wasting your time and ours on such a simple job as this.

I'm really surprised by the nasty responses. Simon has contributed an amazing amount in the 79 posts since he's been here. He even drew and posted CAD drawings for a shop-made rotary broach for us.

With all the b!tching you two do about PracticalMachinist, why are you trying to send him over there?

Simon: maybe they're right in a way -- you'll probably get more professional responses on PracticalMachinist...

Peter Neill
01-30-2008, 10:27 AM
Well said Robert.

Peter

pcarpenter
01-30-2008, 10:55 AM
Yeah...whiny dissenters be damned. Don't take your question elsewhere and do let the rest of us know what you settled on and how it works--especially with concerns regarding stresses closing the saw cut. Let those with attitude problems continue to be angry little people--you didn't cause their depressive grumpiness. Likely some of them will continue to be hateful until they find the right combination of medications.

Given that its a one-off job and that its a sort of make-do with regard to finding a workable solution, I would have thought that the question was better asked here than over at PM.


paul

John Stevenson
01-30-2008, 11:01 AM
Make it in two halves.

.

mochinist
01-30-2008, 11:06 AM
Mark, the website isnt black on dark blue when its properly loaded, but my host is having server troubles and thus the site isnt loading properly, which is also why the pic didnt load for you.

Edm isnt an option because there is no-one locally that can do it within the timescale i have and its a one-off part.

Carld and as for waisting your time? A) if im wasting your time, dont post afterall nobody forced you, and B) EDM isnt an option, i already have a couple of ideas but was just seeing as theres so much knowledge on this board i woudl see if anyone had a suggestion as they might have done something similar. And im perfectly aware i wont get square corners with an end mill and a rotary table afterall endmills are round:rolleyes:.

It was my full intention of following up with details and a pic so that if anyone had anything similar in the future they could use the same method, and i know im not the only one here that makes some money with parts. This is more the welcome that i would expect to recieve at pm after posting about something chinese, and i surely didnt expect such a reaction here....

with that said, thankyou to J Tiers, boslab and mayfield and anyone i missed that actually offered ideas.Honestly I wouldn't get that butt hurt over it, it's just the internet. Personally I could careless that you are asking a question for a part that you will make money with, but I can kinda see how some might be insulted, since when your site worked it advertised machining and engineering problems and letting you solve them, then you come here with your problems for us to solve. I have a machining and machine repair business, if I advertised it in my signature and then came here asking how to repair a Bridgeport, I'm guessing someone would give me a reaming.

As for your part I would give a good idea if I had one but honestly I have an wire edm guy down the street that would do that for cheaper than I could do it messing around with tiny drills and files and it would look nicer. Maybe you could make up a custom broaching tool and do it that way, regardless it is going to cost a lot, do it time and material and make sure the customer knows it is going to cost him/her.



I know why you said that, but.................

How about roughing out, sawing, letting it spring, re-sawing to size, filling the cut with a distance piece, clamping, and then finishing out the part?

Seems like that would be better than sawing at the end.......... if the part is supposed to be "on" dimension when relaxed.Well as it is the part print doesn't have a lot of details, but I have made hundreds of similar parts(minus the funky shaped hole) and have yet to see a call out stating that in its relaxed form a part like that needs to be to size. You make them to size and then saw them, I have done this in aluminum, steels and stainless and I have had them spring closed and open, honestly never had one spring so far that it was a problem though and when the part is clamped on the mating part it should be to pretty close to size unless were talking some extreme tolerances on the part. On parts like this I add a tapped hole next to the clamp hole when allowed, you can use it to jack the part open so you can slide the part in easier.

sconisbee
01-30-2008, 11:12 AM
Thankyou to lazlo, peter, bill, yod and paul.. last thing i wanted was to start an argument, in fact the only reason i posted in the firstplace is because there is really a vast amount of smart people that have thier little tricks and tips to get by. Yes i also posted on pm, but that was for one reason and one reason only, and thats because i know that there are talented people there that dont come here, and vice versa.

ahidley, i'm saving that one as a backup as the customer is kinda picky and was insisting on a one part piece, having said that due to its final use i can understand why.

John i suggested that to my customer originally and he was umming and erring over it then said no had to be one piece even tho it will cost more.... The clamp its self is for the top of a rudderstock on a racing yacht and these things take a real beating so cant risk faliure during a race hence why the customer wants it in one piece.

I've been playing with the drawing in cad a little more and i think ive come up with a simple enough idea that should work, ill post on that after the part is finished.

The original was made of aluminium and had a round bore that was almost out to the edges with a wall of around 3mm each side, the tiller pivots on the 10mm hole at the back and comes down over the top, the aluminium part was slipping and also there was a fair amount of galvanic corrosion on it, which is the other reason for using 316 because the rudder stock is also 316 and the customer didnt want bronze (which at current prices doesnt surprise me).

sconisbee
01-30-2008, 11:26 AM
Personally I could careless that you are asking a question for a part that you will make money with, but I can kinda see how some might be insulted, since when your site worked it advertised machining and engineering problems and letting you solve them, then you come here with your problems for us to solve.


Granted i can see that, but i work all the time i can right now and i am the very first person to admit i dont know everything, localy there is a small group of us that routinly end up sharing advice if one persons idea didnt work out or whatever. As everyone has thier speciallity and everyone has thier opinion/wat of doing something and this works out because there comes a time where the person you ask for advice in turn needs a solution to a problem that they have in future, or one of my customers comes to me asking for something i might not be able to do but say one of the others would be able to do at which point i give the customer the other guys phone number. Its the same on here, today i need a little help, but tommorow someone may ask something that i know about so i will do my level best to help.

I'm all for sharing ideas and if someone came to me while i wasnt too busy and asked me something like "how can i make this work" then i'll gladly tell them and if its something simple ill either offer to do it for free or help them do it themselves. Afterall the only way knowledge can expand is by the sharing of idea's. I'm under no illusion that i do something that others cant, i know for a fact that anybody can do what I/we/you do if they were given the time to learn and had the tools, people pay me because i have the machines to do the work not because im able to do something they cant. Now i could and would have solved this on my own and live would have gone on, but i thought that its possible that someone else had done something the same or very similar in the past and had a way to do it that they didnt mind sharing, that way its a little less like re-inventing the wheel over and over.

On the EDM note, i've had calls back from 4 other shops further away that cant do it quick enough, but for now i think i've come up with a solution.

I'm not one for confrontations and i try to help where i can, but im far from perfect and i dont know everything. I have the upmost respect for the talented people on here that obviously have alot more talent than i do but either dont want to or cant do it for a living. John S for example i would love to have the knowledge and experiance that he has to solve things but simply put i dont, so i am glad there are places like this where ideas can be shared which is infact the original idea of the internet.

Chipslinger
01-30-2008, 12:14 PM
Actually,Wolf was correct , a shaper would do it. If you had one and not a wire EDM.

3jaw
01-30-2008, 12:19 PM
If it is just a clamp for a rudder then why not ask your customer if you can drill clearance holes centered in the corners before machining the shaped hole? Say 3/16" or 1/4"?

pcarpenter
01-30-2008, 01:01 PM
The holes at the corners could help with drainback. My intuition says it may reduce stress pileups at the corners too, but I think it would take a real stress analysis to know whether it would reduce opportunities for failures at that point or not. My guess is that its going to be so over-engineered given the original items design that loss of material at the corners would be no problem. However, always remember the engineers' motto:

Never use a 1/4" bolt where a 1/2" bolt will do.:D

I do tend to wonder what a shop with a shaper would charge you just to clean up the corners after you handled the rest of the internal details using an end mill. It seems it would be a small job at that point.

Paul

3jaw
01-30-2008, 01:19 PM
pcarpenter,

Point taken about stress concentrations but according to Scosinbee the original part was made of aluminum.

Greg

sconisbee
01-30-2008, 01:21 PM
I do tend to wonder what a shop with a shaper would charge you just to clean up the corners after you handled the rest of the internal details using an end mill. It seems it would be a small job at that point.

Paul


Called the customer again to re-double check about the holes in the corners and he firmly said no, no way, no how:rolleyes: however i know a guy with a slotter that (if its working its notoriously unreliable) might be able to fit it in as a quick job over the weekend, hes gunna let me know. Next up is re-suggesting to him that its done in two parts. Theres something to be said about some boat owners in this area of the world , but its too rude to post:D most are alright though. Just about to email the file over to a buddy with the complete pro, or office? i forget which version of solidworks with cosmos in it and he'll do me a quick stress check, might win me those holes in the corner:P

sconisbee
01-30-2008, 01:22 PM
Point taken about stress concentrations but according to Scosinbee the original part was made of aluminum.
Greg

The original part also had a round hole, so pcarpenter has a good point on that.

Your Old Dog
01-30-2008, 01:28 PM
pcarpenter,

Point taken about stress concentrations but according to Scosinbee the original part was made of aluminum.

Greg

That's correct, and it worked for a period of time before failure. Made in 316 it should last forever. I would sell it to the customer as a stress-reliever and not a easier way for you to accomplish the part ! Charge him extra for it and all will be wll !!

Mark McGrath
01-30-2008, 03:53 PM
My old friend Hood has a name for yacht owners. WAFI`s.
Mark.

sconisbee
01-30-2008, 04:03 PM
My old friend Hood has a name for yacht owners. WAFI`s.
Mark.

WAFI's?

now i wanna know! lol, im sure we have a similar name some of them can be seriously picky:rolleyes:

3jaw
01-30-2008, 05:05 PM
YOD,

I would sell it to the customer as a stress-reliever and not a easier way for you to accomplish the part ! Charge him extra for it and all will be wll !!

I like the way you think!!!:D

Rustybolt
01-30-2008, 05:20 PM
Since you're not making that many. Make it as you originally intended and clean up the corners with a die filer. Quick and cheap.

You'll recieve my consulting invoice by post.

Mcgyver
01-30-2008, 06:02 PM
since it's a one of, and edm doesn't seem to work (all though with the miracle of fedex it'd be there a back by now) why not just mill it as close as you can with the RT and then blue & file in the corners? you can do that to high level of accuracy as follows: make a make D shaped male part, say roughly half the hole's profile so you can insert it and then slide it toward the curved end. blue the male part, slide toward the curve and with a file, small half round file start removing the blue. grind a safe edge on the file if you like. it'll come out perfect. a bit tedious maybe but it never leaves your shop and boat owners expect to pay.

oldtiffie
01-30-2008, 06:10 PM
My old friend Hood has a name for yacht owners. WAFI`s.
Mark.



WAFI's?

now i wanna know! lol, im sure we have a similar name some of them can be seriously picky:rolleyes:

Try this.

http://www.urbandictionary.com/define.php?term=Wafi

Mark McGrath
01-30-2008, 06:32 PM
Oldtiffie,you got it in one.
Mark.