Member postings for Andrew Tinsley

Hello,

I now have a good master surface plate and some old Eclipse scrapers. I am stuck for engineers blue! I used to have the paint on variety, but it seems this has been replaced by an aerosol type which dries very quickly.

When I first learned a little scraping some 35 years ago. I used some red material which I think was red lead and castor oil? This was excellent for doing the "rubbing in" and finding the high spots.

If anyone still does scraping what "marking" material do you use? Is the spray on stuff any good? It is fine for marking out, but I doubt it has the same power of moving around under the rubbing action.

I would like to use the red lead and whatever the organic liquid was, which I used to use. has anyone got the make up of that stuff?

Thanks,

Andrew.

Put a really good quality blade on it and then enjoy. Yes the speed is a touch high, but you gets what you pay for. The difference between a good blade and the rubbish they supply with the saw is a revelation.

Andrew.

Edited By Andrew Tinsley on 12/05/2017 20:25:44

Hello Hopper,

You may well be correct, from what was said, it seems to have a hard life. We shall see when I pick it up. Knowing my luck it will be in need of a regrind. When fettled either way, it will be a present to a disabled friend of mine who keeps going through model engineering. His bed was trashed when an RSJ fell on it from a goodly height! Good job he wasn't using it! I have lent him my ML10 while I sort out a bed for him!

Andrew.

Hello Hopper,

I have not set eyes on the bed yet, but the gentleman who is letting me have it for scrap value, seems to think it needs a regrind. Certainly there are hacksaw marks on the bed from a previous owners crude parting off! The chap who is letting me have it sounds a very knowledgeable type so I assume he is correct!

I would be doing the wide guide conversion as a matter of course, it is an excellent mod, which I have done before.

I will report back when I have the bed.

Andrew.

I could not agree more with OuBallie, My garage was attached, but had a simple up and over door which wasn't insulated. Roof was insulated, but bloody hell it was cold in winter and stuff rusted nearly overnight! well maybe a week!

I have built an extension over the garage The new floor / ceiling was stuffed with high grade insulating panels and fitted a roller type insulated door. All doors and windows are double glazed. One needs only a minimal amount of heat in winter. I plumbed in a couple of small radiators from the upstairs central heating. They are thermostatically controlled and are off most of the time even in a cold winter.

More surprisingly during a mini heatwave last summer it was incredibly cool inside! Do yourself a favour and insulate up to the gunnels!

Andrew.

Thanks Martin,

Last time I looked 2 or 3 years ago, they were a lot more expensive. Maybe I will finish up with a granite one in the long term.

I once surveyed the Northern Exploration granite quarry on Spitzbergen. It folded in the early 1920s when they found that the beautiful granite blocks they excavated were actually fissured all over the place. It was only held together because it was frozen solid. When they tried to unload it in the UK it all fell apart!

If only they had gone down another 3 feet. That stuff was fine! It was the site of the most northerly railway in the world (not the coal railway at Ny Alesund). It was built in the mid 1890s and was to seven foot gauge. There are some choice pieces of rolling stock still left there.

Andrew.

Steve,

Thank you for taking such time and trouble in answering my queries. I think it a model reply and only wish there were more like you!

The good plate, I am confident has been stored as you suggest. I will be keeping it in a highly insulated garage that is part of the house. It is heated and has a thermostat that maintains temperature to within 2 degrees centigrade of nominal even in the hottest of weather. I have spent some time at getting this correct, as it is essential for some plating work that I do, I prefer ambient to a heated system. I take on board your warning of temperature stability. Getting a granite surface plate is beyond my financial means, they seem to be in the thousands of pounds range! Just as an aside, would granite that is used for kitchen surfaces be a cheaper way into getting such a surface plate? If so, how would one scrape it? Or more likely what other method would you use?

Initially I would like to get the plate as flat as possible, before scraping. This to reduce the work load because of my medical condition. Thanks for the detailed instructions, I have learnt something new from them. I have scraped before and I have some specially made Sheffield scraping tools (not old files ground to suit!). I have been practicing to hone (!) what skill I previously had. I find it to be quite exhausting, but well worth the effort!

Scraping is rapidly becoming a lost art and I would like to refurbish my old plate and keep the skills alive. So I have an ulterior motive here! I have plenty of time and aim to produce a finish that is the best I am capable of. The initial query about surface grinding was simply to get rid of the imperfections thus allowing me to have to scrape less for a given finish

Thanks once again for such an excellent reply.

Andrew.

Edited By Andrew Tinsley on 09/05/2017 13:07:16

Hello Neil,

Disassembly and cleaning was the first thing I tried on the old Cushman chuck, No problems were encountered with swarf or other debris, just oil that seems to have got there when using an oil can for lubricating metal while turning. No improvement in accuracy was found on reassembly. I do agree that this should be the first port of call if a chuck starts to run out suddenly.

I suppose my reference to grip true chucks was a bit tongue in cheek. I never expected the modification to produce that sort of accuracy! You certainly can reduce the run out to near zero for a particular job. After all, the modified chuck is a crude 4 jaw in effect (having 4 adjusters at 90 degrees to each other) . But no one in their right mind would do this if they had a 4 jaw to hand!

To repeat my findings, the average run out was approx 3 thou, for chucked pieces from 0.5 to 2.0 inches in diameter. So I certainly achieved my hoped for run out on the old chuck. It worked for me and was not a big job, highly recommended for chucks that are getting a bit tired in the run out department!

Andrew.

Edited By Andrew Tinsley on 09/05/2017 12:06:03

Hello Everyone,

I finally got the job finished and checked out. I used 4 adjusting screws as advised. I have set the screws for the best average run out on diameters from approx. 0.5 to 2.0 inches in diameter. I am very pleased that I have beaten my hoped for improvement of average run out. It is now around 3 thou. This from the above range of diameters and repeating the rechecking operation several times.

So the old Cushman chuck can deal with the rough old turning jobs with improved accuracy. In my case it took about 3 hours to do the job and much longer to assess the run outs before and after the mod, I kept getting interrupted by the grandchildren! Certainly worth a try if you have a similar chuck that is in the same sort of condition.

Andrew.

Hello Clive,

I agree you need three rough surface plates to finish up with 3 excellent finished ones. However I have one good and one rough plate. So you just scrape the second plate using the good one as a reference.

The method of doing the three plates is told in the excellent little book from Tee publishing, it is called Elements of Fitting, or some similar title.

Andrew.

Hello Tim,

I never mentioned oil retention at all! This came from another member!

Regards,

Andrew.

Hello David,

Now that sounds an interesting offer! My daughter lives in Nottingham, so maybe I could surprise her too with a visit!I have some transport problems right now but should be mobile in a week or so. Perhaps I could take up your offer then?

I will PM you.

Thanks,

Andrew.

Hello Chris,

What is wrong about that? Each to his own, I say! Why even bother wasting ones time doing model engineering? Yes it is the satisfaction of doing the job, be it scraping or anything else.

Andrew.

P.S. I don't have a mill!

Looks as though I should go the scraping route, it should keep me off the street!

Andrew.

Hello David,

I just saw your post, I am located in Rutland, just about midway between Leicester and Peterborough.

Andrew.

Hello Dave,

Thanks for putting me right about precision surface grinding. It has been many decades since the old timer said scraping was more accurate, so that all ties up!

It was getting on for maybe 35 years ago when I started doing some model engineering. Looking at my notes (amazing that I still have them). I asked the very same question on a forum, about the very same pitted surface plate. I asked about precision grinding to rectify the pitted areas and was torn to pieces by people who said that the only real way to get accuracy was to scrape it! Personal circumstance changed and I have only recently come back to the fold so it looks as though things have changed over the intervening years, which I suppose is hardly surprising! At least this time, the job will get done either by precision grinding, or milling out the corroded area and scraping!

Andrew.

Hello Martin,

I am sorry that I misunderstood your final sentence. You may have a point about milling to get rid of the pits and then scraping to get a good surface. I am still unsure about the accuracy of surface grinding compared to a scraped finish, using a really good surface plate as a reference. My very experienced engineer of the old school (now long since dead), was quite adamant that scraping would produce a much more accurate surface than that obtained by surface grinding, I have no personal experience to say one way or the other! Maybe others can chime in and resolve this?

Hello Duncan! I am sorry that I did not read my post thoroughly enough to prevent such ideas to popping into your head! It just shows that you have to be careful even in the beginners section!

Just had a thought about milling to get rid of the rust depressions. The plate is 18" x 12" and I don't know of anyone who has a mill big enough to do the job at one setting. Not sure I am too keen on repositioning the plate to complete the job, using a smaller mill. But then what do I know about milling!

I am sure that someone will chime in and say that unless you are experienced at scraping, then you are likely to make a complete mess of the job. Well I have done a fair bit of scraping, enough to know the pitfalls anyway. I would not claim to be an expert by any stretch of the imagination. I have scraped much smaller jobs with success, but doing an 18" x 12" plate may well be another matter. Time will tell!

Andrew.

Forgive me, but I was always under the impression that scraping would give a more uniform surface than grinding. I have scraped stuff in the past that had been surface ground and found some highs in the work. An old timer said this was because there were hard spots in the casting and these were revealed when the usual bluing was applied to the master surface plate and the plate to be scraped was then "rubbed" on said master plate.

Now I have no idea if such hard spots are common or if it was a bad casting. The same old timer was quite convinced that a surface ground plate was much inferior to one that had been scraped by a skilled worker.

If I have a good surface plate with no hard spots, then if surface grinding is as good as scraping, then fine! What are other peoples opinion on this? I could well do without the exertion of scraping, if surface grinding is as good!

This is the beauty of the beginners section, you can ask stuff and not look too much of a fool!

Oh! I just noticed that you suggest milling it instead of scraping. Well most mills that I have used do not give a very good surface finish and the surface will only be as good as the accuracy of the slideways. I can assure you that they are nowhere near good enough to give you a true surface for a face plate. Maybe the same comment applies to a surface grinder? I really do not know!

Comments please,

Andrew.

Edited By Andrew Tinsley on 08/05/2017 15:57:58

I have a surface plate, 12 x 18 inches. It has some abuse including rusting and some dings.

I will have an 18 x 18 good surface plate coming in a week. Now I want to scrape the damaged plate in, however to get the rust pitting out will be a very laborious process, especially as I am weak of arm due to a muscle wasting disease. So anyone know where I could get it surface ground, say taking 5 thou off. That would help to reduce the amount of scraping I have to do.

I don't want a precision job, just a good 5 thou removing, anything else I can scrape!

Regards,

Andrew.

Edited By Andrew Tinsley on 08/05/2017 14:52:43

The shaper was made by Realm and is called a Royal shaper, it is 10.5 inch stroke. It has power vertical feed as well as the usual horizontal feed.

I have crawled over and under it to see where lubrication is needed. However I usually miss things, hence my request for help. It is a rather well made unit and was apparently sold into schools and apprentice training centres, That is really all I know about it.

Andrew.