What did you do today? (2013)

[Luke GrahamParticipant @lukegraham30014]

I've been doing electronics-oriented things over Christmas. I made a pen holder for the mill, which will hold a pen that can draw acid-resistant traces on copper circuit board. This means I don't need to use a UV light box or developer. I also made a fixture that will hold the PCBs for drilling and marking. It uses home-made 1/8" taper pins to align the fixture and board to the mill table, and is tapped M3 to hold the boards down.

I've also built a data-logging Arduino setup. It records light, temp, humidity and if the shed door has been opened. It writes all this to a SD card, and can replay the information to a PC when/if one connects via USB.

Oh, and I also wound a coil around 15mm copper pipe using magnet wire. It works well as a solenoid, using a simple steel slug I turned up. I have great plans for this thing…

Edited By Luke Graham on 28/12/2013 23:43:32

[Boiler BriParticipant @boilerbri]

Prestons is one of my most visited web sites.

Bri

[jason udallParticipant @jasonudall57142]

Luke..you might find copper is not good choice for a coil former..eddy current loses…btw good luck with the rail gun

[John Stevenson 1Participant @johnstevenson1]

Sorting the design out for a job.

Oh how things have progressed. Did the design work and drawing yesterday.

'Made' 4 gears today on the 3D printer to prove the concept on a simple jig. Two seperate gears and one double pinion made all in one.

The production gears will be separate gears pressed on a shaft but easier to print together.

OK doesn't look anything special but the ratio needed has to be accurate to 3 decimal places, no plus or minus.

100 year old gear book gave me the ratios

Gearotic gave me the options using two different pitches. Now here is where it gets fancy. None of the 4 gears are standard, the two finer teeth ones are corrected so they fit fixed centres that are written in stone.

Of the two courser gears one is standard for the pitch, one is corrected but both have the pitch corrected to fit the same centres.

Anyone know where I can get a 44.53 DP gear cutter ?

[Ian PParticipant @ianp]

JS

Can't help with the gear cutter but presume you will grind your own anyway.

If I understand your description correctly you are calling the smaller gears 'pinions' and they are fixed together the two larger gears are separate items just laid on top of each other for the picture?

In the end product there are two parallel shafts with one of the large gears driven and the other being the output gear?

If that is the case then the overall ratio is fairly close but not exactly to 1:1

It looks to be in the range of 1:1024 to 1:1016

Ian P

[blowlampParticipant @blowlamp]

Posted by John Stevenson on 29/12/2013 21:32:01:

Sorting the design out for a job.

Oh how things have progressed. Did the design work and drawing yesterday.

'Made' 4 gears today on the 3D printer to prove the concept on a simple jig. Two seperate gears and one double pinion made all in one.

The production gears will be separate gears pressed on a shaft but easier to print together.

OK doesn't look anything special but the ratio needed has to be accurate to 3 decimal places, no plus or minus.

100 year old gear book gave me the ratios

Gearotic gave me the options using two different pitches. Now here is where it gets fancy. None of the 4 gears are standard, the two finer teeth ones are corrected so they fit fixed centres that are written in stone.

Of the two courser gears one is standard for the pitch, one is corrected but both have the pitch corrected to fit the same centres.

Anyone know where I can get a 44.53 DP gear cutter ?

Use your laser machine to cut one out

Martin.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by John Stevenson on 29/12/2013 21:32:01:

Anyone know where I can get a 44.53 DP gear cutter ?

.

Make a single-point tool & cut 'em on a shaper !

… Maybe not; you hate shapers don't you.

MichaelG.

[John Stevenson 1Participant @johnstevenson1]

Actually I could cut them in Gearotic on the CNC mill using a 15 thou slitting saw but it would be a slow job.

My laser won't cut metal, a big one will but they can't get this accuracy in small parts without burning.

Most cost effective way is to either grind one up or get a single point cutter cut on a wire eroder.

[quote]

It looks to be in the range of 1:1024 to 1:1016

Ian P [/quote]

I think someone has been looking at the pictures name

[Ian PParticipant @ianp]

The 1024 was a guess as I did not look at the image title until you mentioned it. I have some image analysis software which counted the hidden teeth (incorrectly) and it came out at 1:1017352 so I took a guess.

What diameter are the gears about and what will you do about backlash?

Ian P

[John Stevenson 1Participant @johnstevenson1]

Ian,

Large gears are about 38mm, backlash won't be a problem as it's a slow moving shaft and always in one direction so a simple brake will do.

Final gears will be in steel and brass, the plastic is only a rough trial.

[JasonBModerator @jasonb]

Finished the Galloway Cart.

J

[Jeff DaymanParticipant @jeffdayman43397]

Lovely job Jason, well done. JD

One of the holes on the frame is .000128" oversize though….

(just kidding, and taking cover!)

[Nicholas FarrParticipant @nicholasfarr14254]

Hi Jason, as Jeff says nice job. I like the contrast between the yellow and the red.

Regards Nick.

Edited By Nicholas Farr on 30/12/2013 14:30:05

[John Stevenson 1Participant @johnstevenson1]

Your going to get 12 points on your licence with those tyres………….

[Sub MandrelParticipant @submandrel]

Very neat. Makes the rough-hewn sled my Suffolk is on look a bit sickly…

Neil

[Oompa LumpaParticipant @oompalumpa34302]

Well, not so much what I did today as more "what I learned". Learning is good, right?

I learned to keep my mouth shut and not gawp whilst milling because those flying bits of very hot material coming off the flycutter, well they will go anywhere!

Owwwwww!

[Sub MandrelParticipant @submandrel]

I learnt not to guide drywall screws into plasterboard with my fingers. The darn Wickes screws left well over a dozen little steel splinters in my left index finger and thumb

Neil

[JasonBModerator @jasonb]

The Knauf ones are like that too, I much prefer Gyproc or screwfix BZP ones and you don't get those nasty rust stains grinning through

[Oompa LumpaParticipant @oompalumpa34302]

Posted by Stub Mandrel on 30/12/2013 20:34:49:

I learnt not to guide drywall screws into plasterboard with my fingers. The darn Wickes screws left well over a dozen little steel splinters in my left index finger and thumb

Neil

It's the cheap Chinese ones, I learned to buy the better quality ones long since

[John Stevenson 1Participant @johnstevenson1]

Posted by Oompa Lumpa on 30/12/2013 21:15:11:

Posted by Stub Mandrel on 30/12/2013 20:34:49:

I learnt not to guide drywall screws into plasterboard with my fingers. The darn Wickes screws left well over a dozen little steel splinters in my left index finger and thumb

Neil

It's the cheap Chinese ones, I learned to buy the better quality ones long since

No it's the cheap English ones who buy the even cheaper Chinese ones ………….

[Oompa LumpaParticipant @oompalumpa34302]

Very droll John, very droll!

[Luke GrahamParticipant @lukegraham30014]

Posted by jason udall on 29/12/2013 09:47:44:
Luke..you might find copper is not good choice for a coil former..eddy current loses…btw good luck with the rail gun

I did wonder about the copper, but in practice it works well enough for me.

I wouldn't bother building a rail gun, it wouldn't work as well as my air rifle anyway 😀

It's for a solenoid valve to water my plants actually!

[Michael GilliganParticipant @michaelgilligan61133]

Spent some time trying to tidy the workshop this afternoon, and came across a Model Engineer "cover gift" from 1992.

"Andy Angle" … came with Vol.169, No. 3930, 2-15 October 1992

Very clever little gadget … I wonder if they still have the mould ?

MichaelG.

 

Edited By Michael Gilligan on 31/12/2013 20:18:10

[MuzzerParticipant @muzzer]

Posted by Luke Graham on 28/12/2013 23:40:44:

I've been doing electronics-oriented things over Christmas. I made a pen holder for the mill, which will hold a pen that can draw acid-resistant traces on copper circuit board. This means I don't need to use a UV light box or developer.

Never done it myself but apparently a common technique is to use a Dremel-type device to route out the copper from the PCB surface. This avoids the need for the nasty chemicals altogether and I suspect you may have problems getting a consistent flow of ink if you are using Dalo pens (from memory – do you still use them?).

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