Recent Posts

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21
Project Logs / Re: Studio camera stand
« Last post by DaveS on January 25, 2021, 01:49:56 PM »
Having repaired these type of machines for 30 odd years or more Iv'e seen a lot of carnage from just broken tooling and fixtures to repairs going into thousands.
Probably 25% caused by not proving the program on a first off. All it needs is a misplaced dec point.  Yes the first one will take a bit longer but in the long run it can save time and money and a lot of aggro. Some engineering places might take a chance,  but for the small business or hobbyist it can devastating.

 My lathe and mill are both manual and I've dropped a clanger a few times, it's worse if you do it after spending a few hours and cock it up on the last operation! :bang: :doh: 
22
New from Old / Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Last post by awemawson on January 25, 2021, 11:43:37 AM »
Amazing what a new ribbon does for a till roll printer !

This is the analysis of the 'Piston Alloy'
23
New from Old / Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Last post by vtsteam on January 25, 2021, 10:21:19 AM »
What I find odd about the rubbery one that I removed is that the illustration definitely shows it as flat, whereas mine is exactly curved to sit fully against the cover with no air (or fuel) behind it, and it it fixed at the periphery by the cover and the centre by the retaining screw thus greatly reducing any potential movement.

HI Andrew. My experience recently rebuilding a couple of outboard motor fuel pumps is that plain rubber diaphragms do often retain stretch over time even though they may start out flat. I also think that some of the modern fuel additives (not just ethanol in petrol but also additives in diesel) can soften the rubber and accelerate that kind of aging.

In normal usage, even though the pulsator is pinned down in center, the thinness of the rubber does allow elastic flexing into the space surrounding.

I think you're right that the height of the fuel tank relative to the engine intake probably provides fuel pressure by itself. I think the function of the pulsator diaphragm is not to provide fuel pressure (that's the function of the pump diaphragm) but to smooth the fuel pulses, and reduce the peak loads on the pump diaphragm and fuel line components. I don't think problems if any will show up in the short term.
24
CNC / Re: DIY Laser cutter/engraver design advice
« Last post by picclock on January 25, 2021, 10:12:32 AM »
@MetalMagus
I've looked at several diy designs on the internet including the lasersaur one, but I have never been impressed. In my mind I keep seeing all the wrong engineering decisions. Look at the lasersaur. The way in which he uses aluminium section is like he has shares in the company, quite absurd. The y axis is driven by a belt reduction shaft which connects to two toothed belt pulleys which drive each end of the X axis rail. On mine I will drive the X rail with two stepper motors connected in parallel to a stepper driver, so much simpler and more elegant. I would mention the X axis motion but I grow weary. Check out the video

I used to lecture at a technology college and half of the students would try to copy this stuff off the internet and present it as there own work. All rather sad.

@BillTodd
I forgot to add I bought the laser (Reci W1) and mirrors from aliexpress. Brexit has altered things for them as they now collect the VAT for the UK (or it appears that way). So when you order stuff and pay for it 20% VAT is added. Lasers have 0% import duty (Customs and Excise), so having paid my costs (209.78) it should just turn up  :coffee:, one day.

Best Regards

picclock 
25
New from Old / Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Last post by awemawson on January 25, 2021, 08:38:49 AM »
OK Matthew, I've machined both the 'Diecasting Alloy Ingot' and the 'Piston Alloy Ingot'

No signs of porosity / gas bubbles in either and they machined beautifully, despite being a rough and ready hand feeding bit of machining using an end mill out of my 'waiting to be sharpened' box !

Quite pleasing really  :thumbup:

(no saying if there are defects further in, but this is a good indication )
26
New from Old / Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Last post by awemawson on January 25, 2021, 07:24:36 AM »
Not sure about gas bubbles yet Matthew as I've not machined any of it, but it's on the to do list - in fact I'll try and do it this afternoon.

Yes alloy wheels generally machine nicely when cast, but with tight lock down at the moment I cannot drive around  to make suitable contacts. It's tempting just to buy an expensive pallet load of LM4 or LM5 - no point in small quantities as the transport gets too pricey.

(Awaiting my invite for the vaccination as I'm in the second tier age-wise - hopefully this week)
27
CNC / Re: DIY Laser cutter/engraver design advice
« Last post by MetalMagus on January 25, 2021, 07:14:09 AM »
Hello,
I am thinking of doing the same thing some time in the future. I "lurk" in several laser groups on FB and most use the Ruida controllers in combination with lightburn.

I came across the site below for a DIY laser build. It has downloadable plans and could be modified for a true home built affair without buying any hardware from them.

http://www.lasersaur.com/

regards

Sean
28
CNC / Re: DIY Laser cutter/engraver design advice
« Last post by picclock on January 25, 2021, 06:30:17 AM »
Hi Bill
Depending on what you want to cut or engrave a diode laser may work for you. No mirrors, water cooling or high voltage power supply. Co2 lasers are big, typically 1M plus long. Also they can make lots of smoke, which means a dedicated enclosure with fume extraction. 

Only reason I am doing mine is that I couldn't find a readymade with the correct footprint. Mine will sit on a dedicated bit of kitchentop  :med:, and I'll weld up a trolley with a shelf for the air pump/water cooler and reservoir. 

I also opted for a Ruida controller as it seemed the best fit.

Good luck with the router.

Best Regards

picclock
29
Metal Stuff / Re: Electro Engraving Problems
« Last post by mattinker on January 25, 2021, 05:45:48 AM »
Adev,

If your making MkI Edgewick plates, could you make two of the one on the top of the saddle, the thread indicator one? I will of course pay!!

Cheers, Matthew
30
New from Old / Re: Resurrection of a CFEI 100 KVA Induction Furnace
« Last post by mattinker on January 25, 2021, 05:36:30 AM »
Hi Andrew,

I imagine that here are no gas bubble problems with your induction furnace! I was thinking, is it worth ingotting? By the way , you probably know, Al car wheels are a really useful alloy, tyre shops are sometimes a good source!

Cheers, Matthew
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