Member postings for Dave Smith 14

Planet rock for me, for a commercial station /i reckon as good as the Beeb.

Dave

The other thing is they lighter, you remove mass from the point where you do not not want it. Buckling comes down to stiffness again for a given load which is controlled by the cross section as you say. In my racing days we did as much as we could to take the mass out of the pistons and the little end of conrods.

Dave

My two pennies. It is not about stress but stiffness. This what a lot of engineers miss, it may be adequately strong but deflections is sometime the overriding consideration. The rod is strong enough we know that from the smaller little end, but the crank end needs to be a larger to ensure the crank or whatever it is attached to does not flex unduly. Particularly where the attachment points are cantilevered.

Dave

Great result, but please keep your fingers away from the moving parts even a small machine will take a finger off.

Oxy/Propane is great alternative to Oxy/Acetylene providing you do not want to weld with it. It will happily silicone bronze braze, but you will not be doing that. I do 95% of my silver solder joints using it. From the data I have the gap should be closer to 2 thou, which as Duncan says is easily controlled using bronze screws, a mallet and feeler gauges. You do not flux the joint until you are ready solder so visibility should not be an issue.

Dave

I originally had magnetic scales, but had heaps of problems with resetting randomly and eventually ditched the optical ones. I bought the Warco optical scales for both my WM16 Mill and WM250V Lathe, they are clones of all the other optical units you see advertised. You can get them cheaper on the web, but I an very happy with these and buying from Warco you get some comeback if you problems. One thing on your mill fit the, x axis scale on the front of the table, fitting it on the rear reduces the y axis travel by about 25mm. You loose the stops on the front but I never used them anyway.

Dave

Rik

I got fed up with the same issue, bit the bullet and replaced them with optical scales, never had a problem since. I also fitted them to the lathe about 6 months later. If you do replace think about a 3 axis read out for the mill. You can either then put a scale on the z axis or do what I did, removed the warco quill DRO and replaced it with a 100 mm optical. This means I can now see the read out and it has greater resolution.

Dave

Areas are all the same.

This weekend

Highlights from qualifying for the Austrian Grand Prix , Channel 4 on Saturday 4th July at 6:45pm with the race highlights at 6:30pm on Sunday 5th July.

British GP will be live on Channel 4, all the rest including the second British race will be highlights as per last year. Not sure what races the I hate F1 mob were watching last year but there were some superb races with lots of action, Austria and Italy immediately spring to mind. Sure there will always be some boring races, it happens in all motorsport including Moto GP. Even football can be exceedingly boring.

Dave

Pete

Put the same post on Model Engineering Clearing House. Bob who used to own and run Pheonix is always around the site and he will give you chapter and verse.

Dave

Gavin

As your lathe is under warrenty your first port of call is with Warco, it is their problem. Give them a ring, I have found them very helpful in the past with issues I have had both in and out of warrenty.

Dave

Garry

Only one way to find out, just try it on a test piece. It should work, your biggest problem may getting all the residue out of the pipe.

Dave

All modern cleaners have some form of filter between the dust collection and the motor. It is not just swarf that would kill the motor, the dust would as well. I use a Henry that was a cast off from my son. I do not use bags just let it accumulate in the drum and empty it when it starts to get ful, it saves a fortune!. You alsoget better suction not using the bag because the motor does not have to overcome the additional pressure loss.

Dave

Providing you protect the steel properly then there is no issue with using steel for any plate work including tanks, after all the prototype uses it and some of those have been around an awful long time. My Aspinall with the exception of the tender flares all of it is in mild steel. It is all laser cut with slot and tab construction, to my own design and was done at work just before I retired ,being chief designer had its perks!. Assembly is with silver solder using an oxy-propane kit. The tender tank has access plates in the bottom with the whole top plate also removable, which enables it to be properly protected from corrosion. As it cost me nothing rather than £200 plus in brass it was a no brainer.

1st phot shows typical construction. 2nd shows completed tender awaiting painting. 3rd shows some of the loco plate temporarily put together. The splashers are just held by the fit of the tabs in the slot.

Dave

Been busy. I ended up with a big block of ally on my face plate. Turned it all square and made up a removable arbour (so It becomes universal) which was final machined in place. Wheel bolted to block and roughed down to +0.5mm on final size which will be done on the assembled axles. Took a bit of time to set up, but it will also be used for machining the crank pin holes.

Thanks

Dave

Lovely, what is the blackening system you are using?

Dave

Gents

Food for thought to consider tomorrow. The chuck mod is very interesting and I may do that anyway.

Dave

Hi. Need some guidance please. I am machining the driving wheels for a 5” gauge DonYoung Aspinal and encountered an issue for which I am not sure of the cause. I mounted each wheel in the independent 4 jaw with the back face outwards gripped on the tread. The 4 jaw was adjusted to give the best concentricity on the inner edge of the wheel tyre. I then turned the outer diameter to + 0.5 mm and then machined the back face to give the best axial position of the spokes. Then the centre axle hole was drilled, bored within 0.3 mm of size, then reamed. I was very careful only taking 0.25 mm cuts with a 6mm diameter insert tool. Having read lots of threads on machining wheels I decided to mount the first wheel back in the 4 jaw (my 3 jaw is not quite big enough) gripping on the turned outer diameter and with the back face against the chuck. The wheel was tapped into place against the chuck and clocked into the centre axle hole for good measure. Again taking small cuts I took off enough to clean up the front face of the tyre, I still have 2 mm to take off the front face. This is where I found a problem. I check the tyre width all round and found it is running out by .155 mm or 6 thou. So what is causing this I would have expected it to be a lot closer. I stopped at this point although the wheel is still in the chuck.

Questions:

1. Is it just bad set up by myself. If so what can I do to reduce the error?

2. Is it the chuck?

3. Is it something else?

I am seriously considering the following route. Put the face plate up. Take a skim cut across it just to ensure it is square, then mount the wheel on that and face the front features. Is that a reasonable approach?

For the tread I will use an arbour to rough nearly to size and then finish turn after the wheels have been assembled to the axles.

I machined the joy valve gear slide shaft last week. It seemed easy compared to this!

Dave

SOD

Reference saving locally. I agree Fusion has to phone home occasionally, but I am talking about saving a file locally and then opening it again, different thing. CATIA has to phone home when its working remotely unless you have a stand alone licence, but it has no effect on whether you can save locally or not.. I just export the file and use the option to save the files locally. Then when opening just use the option to open from a local directory. not had an issues so far.

Dave

I use CATIA, which is virtually the aerospace and motor industry standard. Unless you have a truck load of cash or like me have access to it, you will not be going anywhere near it. However Solid Edge comes very close to it in terms of functionality for mechanical design and if my CATIA licence ever goes the proverbial I will replace with SE. I already have it running on my laptop along with Fusion 360. High end systems tend to be logically set out and easy to use after a small amount of training. After all we wanted our engineers designing product not wasting time working out how to use the system. With CATIA we have taught people who have no engineering knowledge or experience to be modelling parts and assemblies within a couple of a days. I have a couple of friends using SE now and they are getting on just fine, one has never used CAD, the other only Autocad. Investing a little time now will pay dividends for that big project later on. By the you do not have to save to the cloud with Fusion 360. If you use the export command you can save to a folder on your hard drive.

Dave