Author Topic: Please yourself  (Read 5054 times)

Offline John-Som

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Please yourself
« on: February 13, 2009, 04:20:35 AM »

I have just spent two days making a base plate for my next project, a beam engine.
The base plate or chassis is a fairly complicated piece with cut out rectangles,
curved areas, many holes with quite a few requiring counter boring. First a small error crept in, then another.

I was able to hide these to some degree but I knew it wasn't right and I could see that
bodging it up to make do would eat away at me and hang like a cloud during the rest of the build.

In our hobby we are our own quality control engineers and if we chose we could get away with all manner of inaccuracies. But where do we draw the line ?  I decided, during a restless night, that I just wasn't happy with my work and the only option was to resign the part to the scrap bin and start afresh.

We must all be victims of self criticism and I am curious to know how others handle situations like this. Anyway I have given myself the day off today and shall start afresh tomorrow. No way am I going to tackle a restart today – not on Friday the 13th !

JohnS
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Offline Bernd

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Re: Please yourself
« Reply #1 on: February 13, 2009, 04:30:31 AM »
Same here JohnS. Trouble is I keep winding up with smaller and smaller parts in the recycle bin. I'm trying Bogs method of recycling the parts into other projects. If I keep that up I'm going to wind up making very small tools or machine parts that will take magnifying glasses to see. :lol:

Ah, then the mistakes won't be so big and you won't seem them.

But I'll still know they are there. :doh:  :bang:

Bernd
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bogstandard

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Re: Please yourself
« Reply #2 on: February 13, 2009, 05:59:35 AM »
Oh, dear me John, and you were getting on with it so well.

It is all part of the learning experience, and I usually learn something new each day I am in the shop.

But always remember my old saying.

If it looks right, feels right, and runs right, then it is right.

Plans are for guidance only, if the holes are in the right places, make what is left into whatever shape you want.


John

Offline John-Som

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Re: Please yourself
« Reply #3 on: February 13, 2009, 06:58:54 AM »
Despite my earlier resolution not to start it today I have got my Mk 2 version under way. To avoid washing off my marking out lines with WD40 I have taken the trouble to give the surface a coat of aerosol paint.  I feel better already.

Bernd - in contrast to you, the bits in my scrap box are actually getting bigger. There's a lesson there somewhere but I can't work out what it is !

John - this situation is comparable to Eric Morecambe's piano performance when he insisted he was playing all the right notes - but not necesarily in the right order. It's similar to me, I have made all the right holes but not necesarily in the right place - in fact four of them moved while I was having a coffee break.

Ah well, my paint should be dry so time for marking out.

JohnS
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Offline rleete

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Re: Please yourself
« Reply #4 on: February 13, 2009, 07:29:03 AM »
I run into this all the time, with every project I do.  I'm my own worst critic.  It may look okay to others, but it eats at me if it isn't 100%. 
Creating scrap, one part at a time

bogstandard

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Re: Please yourself
« Reply #5 on: February 13, 2009, 10:20:25 AM »
Ah! yes, the dreaded moving hole syndrome.

There are a couple of ways to cure that phenomenon.

The first one, is as soon as you have drilled them, smear superglue all around 'em, so they can't get up and move somewhere else.
Or if that doesn't work, try using close fitting nails thru the holes, and nail them to a bit of wood at the back.

Refer to C-o-C.

Just don't come visiting me until you have cured them all, I don't want my workshop infecting.

Bogs.

Offline John-Som

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Re: Please yourself
« Reply #6 on: February 13, 2009, 12:53:00 PM »
yes John, the three nail knockit seems to work..... I saw the holes wiggling when they thought I wasn't looking but the little b******s were well and truly stuck. I am now back on track. I'll try not to sneeze next time I am in your workshop so you should be OK.

JohnS
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bogstandard

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Re: Please yourself
« Reply #7 on: February 13, 2009, 01:32:03 PM »
John,

I know exactly how you feel, I have been there many times.

The main thing is, the only thing hurt is your pride and pocket, so shrug your shoulders, say 'Ah! well', try to think of the smiley side, and carry on.

And of course, the world hasn't come to an end, just because you have made a mistake.

As you know, I use marking out as a safety feature, from now on, I will be pop marking where the holes go as well. It just might help to make sure they stay where they are put.

John

Offline sbwhart

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Re: Please yourself
« Reply #8 on: February 13, 2009, 03:44:14 PM »
Ah! yes, the dreaded moving hole syndrome.

There are a couple of ways to cure that phenomenon.

Just don't come visiting me until you have cured them all, I don't want my workshop infecting.

Bogs.

I catch the little devils In traps baited with the holes from polo mints very effective they are too
 
:lol:

Cheers
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Stew

A little bit of clearance never got in the road
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Offline SPiN Racing

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Re: Please yourself
« Reply #9 on: February 15, 2009, 03:51:43 AM »
Welding...

I keep it near by, and throw a bead on them to keep them from getting away.

Even works on plastic... set it on metal, weld around the plastic and the plastic gets scared and sorta melts onto the steel and wont come back off. /nod
SPiN Racing

Offline John Stevenson

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Re: Please yourself
« Reply #10 on: February 15, 2009, 07:16:15 AM »
I'm not saying I make many mistakes but I get thru about three 15 Kilo reels of MiG wire a year  :scratch:

This is just on turning and milling jobs, no fabrication.

Before.



After.



JS.
John Stevenson

Offline Darren

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Re: Please yourself
« Reply #11 on: February 15, 2009, 07:19:58 AM »
John,

Did I understand that correctly, you built up the shaft dimeter with mig welding and then turned it down to size?

What's the weld like to turn?

Thanks
Darren
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bogstandard

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Re: Please yourself
« Reply #12 on: February 15, 2009, 08:20:52 AM »
Wonderful rescue job John.

It is so nice to see the old methods being used rather than just buying brand new parts.

The jobbing workshop, now sadly declining in this day and age of redundancy being built into everything.
But for the people in the know, it can save them a fortune in replacement parts.

John

Offline John Stevenson

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Re: Please yourself
« Reply #13 on: February 15, 2009, 08:36:40 AM »
MiG weld turn nice once you have an uninterrupted surface, because it's pure wire and gas there are no inclusions like you get from the flux on stick welding.
You can get different grades, some which can be heat treated but the standard common or garden stuff works well.

I always turn undersize before welding so the transition layer is under the final size as often you can get 'smear' marks where the two join.

This one was a bad one in that the bearing diameter and the shaft diameter were toast and you always have to juggle to get it running true again.
A good selection of steadies, both normal and cathead are needed and also a good rotary 4 jaw in the tailstock is handy.

JS.
John Stevenson

Offline sbwhart

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Re: Please yourself
« Reply #14 on: February 15, 2009, 09:35:19 AM »
Nice one John
 :wave:

In the good old days before the "Bean Counters" took over our company, we had a tool room and maintainance shop where we had a metal spray kit for building up shafts like this. There wasn't much we couldn't do on site, now we can do next to nothing.

Cheers Stew

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Offline Darren

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Re: Please yourself
« Reply #15 on: February 15, 2009, 12:56:54 PM »
Thanks for sharing that John, could come in handy in a later plan..... :thumbup:
You will find it a distinct help… if you know and look as if you know what you are doing. (IRS training manual)

Offline Jadecy

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Re: Please yourself
« Reply #16 on: February 16, 2009, 01:37:31 PM »
On the initial topic - I had all kinds of walking hole problems until I got a DRO. Dial indicator with magnetic base was my old method and man did the error multiply as I went along! My bidder problem is the need to get new screws and nut for my mill. It is a 196? mill and the screws show it. Lots-o-spin in the wheels before anything moves!  :ddb:

Without the DRO with that much backlash it is almost impossible.

My bigger problem is brain lapses or whatever ya call em. Study the page, mark out the part, look at the drawing again, drill the holes. Everything looks great....wait a cotton pickin minute! DOH! DOH! DOOOH! I was looking at the wrong hole on the drawing when I picked my drill bit and now the perfectly positioned holes are way too big. Fortunately on that one I was able to make inserts to fix it. I could have welded it up but with that particular casting I didn't want to take additional unnecessary chances. A half hour at the lathe and all is good. I have plenty of others that ended up in the bin.

 :D

Offline kellswaterri

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Re: Please yourself
« Reply #17 on: February 16, 2009, 02:33:44 PM »


I'm not saying I make many mistakes but I get thru about three 15 Kilo reels of MiG wire a year  :scratch:

This is just on turning and milling jobs, no fabrication.

Before.



After.



JS.

Hello John, can I ask you how you keep the weld heat from affecting the rotor windings...or perhaps it does not harm them?
All the best for now,
                          John.