Member postings for david lockwood

Thank you Pete

Does anyone know what rpm I should be running the Jacobs hobber at ?

I am just about to machine up the belt drive and I have to work the ratios out

many thanks to anyone who can help

David

Hello everyone. I have also acquired a Herbert grinder and I am wondering if anyone can tell me how to change the grinding wheels ?

Also could anyone suggest a good place to buy new grinding wheels.

thank you every one for your help i will get on with the job

hello every one,I have just roughed out two lead screws for a jacobs gear hobber 3/8 BSF. I should probably have bought a die when I bought the tap but I forgot, any way I have a set of wire pins for mesuring thread depth, can any one tel me how to use them?

I have measured accross the tap with some pins and got a measurment of .4 inch, I could just cut untill I get the same measurment on the work but how much clearance I will need?

It might be worth mentioning that the tap is oversize by 8 thou accross both sides when measured directley without the pins, I was expecting it to be less then 3/8 inch because of the rounding of the thread crest but it isn't

any thoughts on any of this any one?

I was going to say that i vote for the water wheel while i was thinking of Sheffield’s steel industry which i am told once produced a quarter of the worlds stainless steel this industry grew in Sheffield because the city has several streams running through it which were used to drive grind stones sharpening cutlery this of course grew into a very large industry over time. but then i thought the knife, how could we ever have got this far without it , can anyone think of a civilisation that didn't use the knife?

In a bare bones survival courses you may well be instructed on how to survive with only a knife but not many will give alternatives you just have to have one

Used for making shelter cutting and gathering food and of course defence from wild beasties I know I still use them every day

The other really good one is the water container if that can be called mechanical. If we had had to spend all our time hanging around watering holes ( where the beasties wait for you) we might never have got out of Africa in the first place

Thanks for the super speedy reply

hi every one i am wanting to buy a rotary table is the size quoted the diameter or radius ? or some other measurement thanks in advance David

i have tryd this method of cutting a thread but i simply could not get the tap to cut at all so i gave it up for a bad job

would any one have any tips for using this method

regards David

my old man recons that in the local pit they had nuts of about 6 inch across flats and these where turned with a special spanner about three feet long with a large blob of metal on the end of the handle designed to be hit with a big hammer or mundy hammer as some seem to call it

well that sound about solid enough for me and if there’s ever an air raid I suppose I can get under it I am still wondering if warping might be a problem though

Thanks for the advice both of you I hadn't thought that the head could be repositioned. I was under the impression that it was made as close as possible and then adjusted by shimming the base.>>

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so if it is possible to check the squareness of the head, T piece and column base separately then how would I go about checking which part is out of square as tramming the head only tells me that something is out but not which component >>

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I could put a brass pinch screw through the nut which is used to set the height on the main column which because of the particular design of the nut and thread , would not affect the operation of the mechanism but I could tighten the screw to lock the nut and swing the assembly without loosing the height adjustment.>>

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Possibly I could swing the whole head and column with a dial test indicator in a chuck but I could only do this over a small arc and may not get an indication of squareness .>>

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How would other people check which part was out of square?>>

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I could put an indicator on the milling table in a stand and run the table up and down with the indicator against the cross bar similar, to checking against a test bar in the lathe,>>