Here is a list of all the postings Brian Wood has made in our forums. Click on a thread name to jump to the thread.
|Thread: Standards of Electrical Wiring|
Frightening isn't it?
|Thread: What type of cutting tool is this?|
I remember those, usually confined to big diameter face mills. They were a job for toolroom grinding when attention was needed to get all the teeth to cut evenly again.
|Thread: oversize ER16 collets|
Why not upgrade to the next size ER 20?
|Thread: Clarke CL250M Metric Screw Cutting Gears|
Maybe Ian could follow the printed chart in the gear cover and dump the misleading piece of paper, it might have saved Howard and myself quite a lot of wasted time.
Thank you for your invaluable checking. You are right of could, a second idler will do the reversing where needed
I didn't know about the bore of the 36 gear although the paper chart lists a 24 in the same position so I assumed, incorrectly it seems, that other gears could be fitted there as required. That adds to the complications
My error completely for 1.25 mm pitch. It should read 50--idler--60; largely academic now but the maths is correct!
Retiring damaged now!!
I didn't bother with the fine feeds, the one that Ian quotes for 0.05mm does calculate correctly
Well done, I hadn't figured on gears being used as spacers, missed it completely
In the meantime I have worked out a greatly simplified chart for all the metric ratios quoted on the machine chart
I can't present a properly drawn out table so Ian will have to construct one for himself from these values
Spindle [W] Driven Driver Leadscrew [Z3] Pitch mm
36 72 40 60 0.5
36 48 40 45 1.0
42 Idler 90 0.7
48 Idler 90 0.8
40 Idler 60 1.25
Sorry about the compression, it didn't like the spacing I presented the values in
Edited By Brian Wood on 10/01/2021 15:09:14
I agree the feed rate you listed fitted up as 36/72 x 24/76 x 19/90 gives 0.05 mm per revolution with a 1.5 mm pitch leadscrew.
However, using exactly the same chart layout ie 36/42 x 24/60 x 40/72 gives a pitch of 0.2857 mm per revolution with a 1.5 mm pitch leadscrew----clearly NOT 0.5 as the chart says. You can see why I am confused.
If I knew the values of all the gears that are available, and the leadscrew pitch I could attempt to work out an alternative table for you.
In the meantime, this will give you 1.00 mm screw pitch--- 36/30 x 40/72 assuming the leadscrew is 1.5 mm pitch and a 30 tooth gear is available
Hello Howard and Ian,
I would love to clarify matters but I am now totally confused. I had no idea there was a second set of gears available nor how they are made up and the chart doesn't help me as I can't get values I trust from it.
It would help a bit if we knew what the leadscrew pitch is. These mini lathes have leadscrew pitches of either 16 TPI or 1.5 mm, not odd values as Howard is struggling with
I have been playing about with other gear sizes. Unfortunately Ian's C1 lathe uses change wheels of 10 mm bore; I had hoped he could extend the range with C2 gears but these are 12 mm bore.
So he is stuck with the gears I listed and the closest he can get to what he wants is 2mm pitch, geared as 24 drives 19. Have assumed a leadscrew pitch of 12 TPI. He could make up a 2:1 reduction with C2 gears, sleeved to run on an intermediate stud and get there that way
Do you know what the leadscrew pitch is? It will be either 1.5 mm or 16 TPI
And what change wheels do you have with the lathe? I have looked at the Clarke download for the lathe. The choice seems to be limited to 72, 19, 76, 24 and 90 teeth but you may have others.
With that sort of information it might be possible to work out a gear train
|Thread: Calculating Gears|
The HPC gearing book suggests another alternative with 0.25 Mod gears of 25 and 50 teeth. They will give a centre to centre gear spacing of 18.75 mm which is 0.738 inches in old money
|Thread: Hello from Yorkshire|
Welcome to the Forum. It is always difficult to chose material to build up a stock from and I would suggest you do so gradually.
You will find M-Machine a useful organisation based in Darlington who supply all manner of materials and cut to size for postal delivery. If you buy a bit more than you need for a job in hand you will quickly build up a shelf full of useful oddments. Metals4U are another supplier, they are based in Wetherby for longer lengths and deliver from on line ordering
I can recommend both
Look at their websites www.m-machine-metals.co.uk
|Thread: Removing soft solder from brass before silver soldering|
It might be easier altogether to make a new brass part and braze to that, this time using other holding methods for the machining.
|Thread: Myford ML7 Cross Slide adjustment|
The gib strips close down on the taper built into underside of the cross slide and when set to give a decent slop free fit for the cross slide that should take out some of the vertical movement.
The bulk of it will come from the saddle lifting on the bed shears. That movement is controlled by two plain flat strips, one for the front shear, the other for the rear and these are clamped up to the underside of the bed shears. Shims are installed in the gap between the bed and strip, with holes through them to clear the bolts. They are in stacks that can have individual shims pealed away so you peal off a shim on both ends of each clamping strip, tighten the bolts and test for lift.
On an old lathe in your age range the lift you have seen could well be bed wear which will have hollowed out the bed over the most frequently used section and you may not be able to adjust it out completely. It may become a compromise on what you can tolerate and a free sliding saddle up to the tailstock
A badly worn bed can be both hollowed out and worn across the bed, it is a grinding job to put right.
I hope that helps
Edited By Brian Wood on 29/12/2020 18:44:08
|Thread: Lathe oil leak prevention|
I have great faith in clear silicone sealant in either metal to metal joints or on paper gasket joints. An even smear all round before bolting up is all that is needed and the joint breaks cleanly if it has to be parted again at a future date.
|Thread: new ML7 headstock bearings|
Your idea is laudable but I rather fear it could founder very badly on the sheer economics of production, purchase of the correct grade of white metal to make up for losses and other such production costs. How would you price them, very difficult in today's value driven and competitive day.
Then you have to tell the world these new bearings are available which means constant and expensive advertising to keep the product visible, postage to distant parts etc etc quite apart from the problems of dealing with those who think they know how to scrape them in but wreck the bearings in so doing and come to you with complaints.
I'm sorry to paint such a gloomy picture but I think the market has moved on so far since those days and in spite of your enthusiasm, maybe there is only a very limited market you could tap into still in existence
Certainly not a money making idea, rather the opposite
|Thread: Colchester MK1 Bantam|
I think this might be common to many tailstocks in that is is related to the engagement of the adjustment thread in the barrel.
Try winding the barrel out until you can feel the thread disengage. Now turn the thread by one rotation and re-engage the barrel to see what effect that has had. If the result is an increase in projection then do it all again but this time turn the thread twice in the opposite direction before re-engaging with the barrel
|Thread: New guy saying Hello|
Welcome to the forum, there are plenty of people here to advise on all manner of things when you are ready to ask them
|Thread: Hacksaw blade orientation - your opinion please|
And a good number of broaches work as pull devices, there have to be equally good reasons for that approach as well
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