What did you do Today 2018

[Neil WyattModerator @neilwyatt]

3D printing in Nylon for a change – I need some flexible (low-)friction pads.

I've discovered a temporary bubble-wrap cover greatly speed up heating the bed to 90 degrees (the 60 degrees used for PLA is not hot enough for Nylon).

Neil

[BazyleParticipant @bazyle]

The replacement plastic gear for the cricket club mower arrived and was easy to fit. Nice to have a machine that you can actually get spares for and is designed for easy maintenance (Atco Balmoral) at least on this part. They aren't half expensive new though. Don't know why the gear decomposed though but might be intended as sacrificial if it hit a stone.
Of course then found someone had broken off the handle for the cast iron tamper so another job for tomorrow.

Edited By Bazyle on 21/09/2018 20:57:51

[Mark RandParticipant @markrand96270]

Posted by Richard brown 1 on 21/09/2018 16:57:36:

Used my old Royal Shaper to put a nice finish on this bracket i'm making.

Question:- On your Royal, is the vertical thread that the table etc. move up and down on an ACME thread or a V shaped thread? Mine's got a V shaped thread and I'm not sure whether this was original.

Regards

Mark

[BufferParticipant @buffer]

Mark

Its an Acme. We need a third owner now to see who has the original !

Rich

[Mark RandParticipant @markrand96270]

I had a feeling that it should have been ACME, since the cross feed screw is.

Of course mine was a 'little used, ex-college machine' when I bought it. This phrase seems to translate to 'put in a factory and flogged to within an inch of it's life, then had a tin of house paint emptied over it'

This was mine in the days before I had a bandsaw

[Ian S CParticipant @iansc]

Spent about 5 flying hours today in an ex RAF Mk 5 Auster along with 41 other aircraft, flying among the foot hills of the Southern Alps to the west of Christchurch (NZ). Perfect weather, a perfect day.

Ian S C

[Anonymous]

Well more this weekend, on and off. I've hogged the smokedoor hinges out of lumps of hot rolled steel:

Note the 1.5mm fillet on the hinge lugs, and between them, but not in the middle of the hinge. That matches fullsize, and will allow me to out count the rivet counters and accuse them of lack of attention to detail.

I've also got five rivet holes as per fullsize rather than the four shown on the drawing.

Generally the machining of the hinges is unremarkable, but just for the hell of it I created the rounded lugs using a form cutter on the horizontal mill:

These type of corner rounding cutters are a bit of a PITA to use. One starts with apparently quite a large cut; and nowt happens due to the concave form. Then, as you sneak up on dimension, it's only too easy to go a couple of thou past. It doesn't sound much, but it leaves a slightly recessed edge which is the devils own job to file away. Much better to stop a few thou short. Or use CNC!

The hinges have also been riveted in place:

The 3/16" rod which will form the hinge pivot fits nicely through the holes by hand. Feeling slightly smug about that, as I drilled the hole about an inch deep separately from each end. No point in drilling all the way through as the middle bit gets machined away.

I've also made, and riveted in place, the small brackets inside the smokebox ring that will hold the bar which the smokebox door locks to via the darts.

Having started machining the hinges with an old cutter I decided to retire it due to a crap finish. I wheeled out my new 10mm YG K-2 endmill from Cutwel. What a difference! I had to go and measure the finishes. The old cutter gave a finish of 5.7µm Ra (badgers), whereas the new cutter gave 1.05µm Ra (babies). The new cutter finish was mirrorlike. Oh, and I sort of fixed the icky LCD display on my surface roughness gauge. A folded piece of paper in a strategic place on the flexi PCB to the LCD got most of the bars back on the LS digit.

Andrew

[David TaylorParticipant @davidtaylor63402]

Nice hinge. A new cutter is always nice, even the cheap ones I get off eBay. One day I'll find a proper supplier and buy a good one and it will no doubt be even better, but it hardly seems worth it with my ramshackle set-ups and out of tram machines.

[David TParticipant @davidt96864]

Made the detent holder for my dividing head. Just need to make a knob for the detent and it'll be usable in its most simple form. I still need to make some gear studs for setting up a gear train, but annoyingly I've run out of stock.

[Ady1Participant @ady1]

Mother in law buried, house tidied up(60 years of junk), house sold, house emptied, blind disabled homeless person on living room floor rehoused after 5 months, own house stripped into garage, ME gear still not connected up until new heating system in this week, plus new windows, plus new bathroom (women are even more expensive than model engineering!) then life should be back to normal-ish

It's been a long 12 months but what doesn't kill you makes you stronger (or drives you nuts)

Normal should be back by Xmas

[Mark RandParticipant @markrand96270]

I've been preparing to make the poly-V step pulleys to replace the current V belt ones on the milling machine. I've roughed out the blanks, cut keyways in them and had made a mandrel to mount the first of them on to turn the diameters and profiles. Said mandrel was turned oversize, had a keyway cut with the shaper (to drive the blank) and was then turned down to size and parallel while mounted in the chuck. At this point I realized that I could do with another bit at the right hand end of the work to allow the tailstock to provide some extra support and keep the blank firm against the mandrel that the chuck was holding. So I took the 8" chuck with its mandrell off and knocked out a bit to fit the end of the pulley blank and a centre hole for the rotating centre to rest in. All fairly routine apart from not doing it in the right order to start with…

 

The Hardinge lathe spindle nose has an 8° taper for chucks, faceplates etc. to mount on. They are drawn into the taper by a dog point screw that engages with an angled slot in the taper. It's a surprisingly accurate and consistend mounting method.

I went to put the 8" chuck back on the spindle nose. Aligned the dog point screw up with the slot, pushed the chuck on to the taper and turned it to lock it in place. There was a slight resistance, then the chuck kept turning round…

Examination showed that the end of the dog point screw had broken off. Further examination showed that when I made it, I hadn't allowed for the depth of the hex socket in the grub screw and that it extended right to the start of the turned down dog point section…

 

So there was almost no strength there at all.

 

I decided that I could make a new dog point screw by turning down the hex head end of a grub screw so the socket was the bare minimum that was needed and there would be more than enough metal to do the job. At this point I went back into the house and had some lunch and a cuppa.

As I was laying some salad on a plate in the kitchen, I realised that the 8" chuck and the pulley blank (total weight 50lbs/23kg) had been whizzing around at 2000rpm yesterday, with no tailstock support to restrain it. If it had cut loose then, it could have killed me and would almost certainly have made a hole in the shed wall. At this point, I nearly wet myself!

 

 

Edited By Mark Rand on 30/09/2018 21:57:52

[Ian PParticipant @ianp]

How did you do that!

I clicked on the image and the view changed.

Normally I avoid clicking on images in this forum, as it closes the main window so I have to use the back button to see the thread. Sometimes I do open images in a new tab but tonight I didn't withe the result that I see a different picture.

Ian P

[Neil WyattModerator @neilwyatt]

Posted by Andrew Johnston on 23/09/2018 18:15:06:

A folded piece of paper in a strategic place on the flexi PCB to the LCD got most of the bars back on the LS digit.

Andrew

I guess you know to try meths on the zebra strip?

[Neil WyattModerator @neilwyatt]

Edited By Neil Wyatt on 30/09/2018 21:59:03

Edited By Neil Wyatt on 30/09/2018 22:01:10

[Mark RandParticipant @markrand96270]

Posted by Ian P on 30/09/2018 21:49:12:

How did you do that!

I clicked on the image and the view changed.

 

I realised that I'd got the links from pictures 1,2&3 all pointing to the full sized number 1. So I must have been in the process of editing the post to get it right.

It seems to be a good idea to have a smaller picture to avoid overwhelming the flow of the text, but with a link to the full, gory details available for those that want to see them using the link feature of the 'add a picture' button.

Like what neil said…

Edited By Mark Rand on 30/09/2018 22:05:32

[Neil WyattModerator @neilwyatt]

Excuse my experiment above (that's what I did today…) but it seems you have to embed a picture using a link THEN add the link to it as well.

Neil

[RobinParticipant @robin]

Posted by Neil Wyatt on 30/09/2018 21:54:48:

I guess you know to try meths on the zebra strip?

A zebra strip is layers of metal conductor and rubber insulator. I remember once a factory used a photosensitive resist mask containing sulphur. It took time for the rubber in the zebra strips to vulcanise, expand and break the contact. Plenty of time to test, package and sell the product all over the world

[Anonymous]

Posted by Neil Wyatt on 30/09/2018 21:54:48

I guess you know to try meths on the zebra strip?

Zebra strip? What Zebra strip? The original patent application for elastomeric connectors was in 1974 and I suspect my surface roughness gauge was designed a bit earlier, judging by the internal electronics. The LCD holder is soldered to the PCB, so I can't easily remove it. But it would have been daft to use Zebra strip and run a flexi PCB to the display.

We used Zebra strip in the early 90s on race car electronics and they were a right PITA. If an assembled unit didn't display properly the instructions were to disassemble, reassemble and test again – repeat until the display worked properly. Not my design I hasten to add.

Andrew

[Nigel (egi)Participant @nigelegi]

I've just finished making a planishing hammer

Mild steel head with case hardened surfaces.

Edited By JasonB on 01/10/2018 17:10:10

[BazyleParticipant @bazyle]

Gosh, no posts for almost a week.
This ebay ad is interesting for the background. The passing of British manufacturing.

[Alan Waddington 2Participant @alanwaddington2]

Posted by Bazyle on 08/10/2018 22:53:05:

Gosh, no posts for almost a week.
This ebay ad is interesting for the background. The passing of British manufacturing.

Haha, love the time and effort expended by the seller on the description ………What a beast, hope someone saves it !

[mechman48Participant @mechman48]

Did a modification to my Aldi scroll saw; the plastic table insert really is not strong enough to do what it's s'posed to do so set about making an alternative insert… as supplied 'out of the box' …

Alternative insert…

Next is to modify the reaction bar / stripper bar, as it is it's only thin MS plate so am looking at making something out of round bar stock.

George.

[Sam Longley 1Participant @samlongley1]

Mechman 48

I followed some plans I found online to make a fretsaw & it is not particularly good. However, I do see ways of improving the design. I intend to have another go just for the hell of it. I did make one years ago that worked very well but I lost it when I moved. Could you tell me please, what you estimate the stroke of the blade on your Aldi saw to be.I think my version has too long a stroke.

I also wonder how many strokes per minute . Although you may find that difficult to estimate.

Any indication would help

Thanks

[mechman48Participant @mechman48]

Hi Sam

I'm curious too, will get back to you later…

George.

[Sam Longley 1Participant @samlongley1]

Posted by mechman48 on 10/10/2018 10:28:49:

Hi Sam

I'm curious too, will get back to you later…

George.

Thanks

It is just that the existing design has an eccentric driven off a pulley that drives a block up and down 2 posts. I want to drive the eccentric straight off the motor shaft & then have a small shaft running through the block similar to the shaft that drives a steam engine slide valve. Then I will not have the weight of the block etc reciprocating. Hopefully this will reduce vibration. But first i think that the actual stroke can be a lot less than I have, as I only want to cut thin material- up to 3mm. I have a bandsaw for thicker material.

I need to know if the motor is fast enough so that i can eliminate the pulley & belt etc . I can easily slow the motor with a resistor but not speed it up.

It cannot be rocket science & more fun than forking out £ 60-00

 

 

Edited By Sam Longley 1 on 10/10/2018 11:29:18

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