Here is a list of all the postings david lockwood has made in our forums. Click on a thread name to jump to the thread.
|Thread: Jacobs Gear Hobber|
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
|Thread: Alfred Herbert Surface Grinder|
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.
|Thread: measuring thread depth|
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?
|Thread: The Greatest Mechanical invention|
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
|Thread: rotary table size|
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
|Thread: Clarification please|
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
|Thread: Forth road Bridge nuts|
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
thats a good tipabout putting the vice over a leg I will do that thanks
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
as it happens I have some railway sleepers but I promesed them to a friend befor I needed to make the bench
I had conciderd a ply top, one nice thing about roled steel top though is that, the one I have used at least, is so flat that I have hardly used my suface plate since I put it up
Ian yes the floor is solid, concrete
hello all, I am about to start making my workshop benches as I had to take the others down, so I am wondering which material would be best for my mill bench and an assembly bench.
I am convinced that wood is better for a manual work bench as the steel one I made vibrates horribly when I saw something in the vice.
I would very much like to be able to get the mill bench and assembly bench very level or at least get the mill level on jacking screws, so I can try using my precision level to set jobs up. this may seem a redundant point but on past experience the bench has to be very rigid or the machine moves in and out of level when moving other things around the bench or leaning on it et cetera, also I wonder if a wooden bench will warp and twist as the moisture levels change
as an extra point i will need to have shelves under the benches but these could be on a separate frame so as to keep weight changes off the bench when loading and unloading the shelves
if any one has any thoughts on the mater or any bench making tips these would be very much appreciated
thanks in advance David
|Thread: Harrison L5|
Thanks Jon i will give it a go. I should probably get my bench set up first as I had to take every thing down just to get the lathe in so I am now without a bench or shelves it s such a mess sob sob
Thanks for the replies. I have tried poking it with the scriber but it is suprising how long these oil ways go and there only needs to be a little of the stuff to stop the oil. I have stripped the top slide and cross slide and cleaned them, the rest are mostly in the carriage which looks like a very complex assembly with the power cross feed gears and such. also the lead screw bearings and gearbox have probably been greased this will be awkward if / when i have to strip them down to clean the grease out i was hoping that there would be some sort of dissolver or something
Hello every one I have recently bought a Harrison lathe and have a query regarding the oil nipples on my lathe they have all been filled with grease and the lubrication chart on the lathe states only oil. I have tried to oil the lathe through the nipples but the grease blocks the oil from getting through . I would be worried about striping down the lathe as I have doubts about my ability to fit it together again properly. would blowing It through with a compressor be sensible?
|Thread: Dore Westbury adjustments|
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.
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
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.
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 .
How would other people check which part was out of square?
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,
|Thread: milling vices|
looks like it's going to be an expensive one then, would any one have a guide price for a decent vice?
hi thanks for the replies every one, may be i have confused matters by mentioning jaw lift and the flexing of the suposedley non moving jaw i do not realy need any advice on how to remedy this as as Andrew suggests it will be recylcled. i actualy think it will be ok for a hand held vice on the drill press where it will not need to be tightend up as much, also it was home made by the gentleman i bought the mill from. I am a little concerned about bringing down the makers work i do not want to insult any one so in his defence the 20 thou of movement comes with a very forceful tightening of the handle, more then when using it. i really just wanted peoples advice on other vices i have been looking at the tool maker vice type but i was concerned when looking at the base of that design it looks more like hollow box section than a solid casting. so if any one has used one do they flex? i have looked at some of the vices sugested by others above and they look nice the emco one i saw on ebay seemed a little expensive at £180 i only paid £350 for the mill so it seemes a little disproportional possibly i am wrong
thanks again for all the replies
Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!
You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.
Click THIS LINK for full contact details.
For subscription issues please see THIS LINK.