|nick morrison||09/07/2010 18:58:10|
|23 forum posts|
I have recently, in retirement returned (so I thought) to model engineering. I have found two major problems 1) I don't know as much as I thought I did, & 2) As mentioned in this forum time and time again it takes a lot of money! I don't consider myself a newbie (whatever that is!), but a near rank beginner.
I have some small imperial adjustable reamers - how do I use them? Do I measure and then ream or ream to fit - this is how I replaced king pins years ago. I wondered if there are any publications that would be useful.
Any advice,tips or pointing in a right direction would be appreciated,
16269 forum posts
I would ream to fit or ream out a worn bore until smooth and then make a new shaft to fit.
From when I used to have an Austin 7 I seem to recall that the king pins could be bought oversize by varing amounts like 0.005", 0.010" . I'm not that old but did restore one.
|466 forum posts|
Adjustable reamers are a repair tool, I would not advocate their use for sizing a hole to a specific size. It is better that a hole is bored to size. In use the reamer is adjusted (by means of the collars at either end of the reamer) to just and I do mean just scrapes metal from the hole. The reamer can then be adjusted by slacking of the collar at the end nearest the square by say 1/16th of a turn and the tightening the collar at the other end. repeat until the hole has been cleaned up or has reached size. Do not be tempted to take a larger cut as adjustable reamers have a tendency to dig in, this if it happens leaves a hole nicely out of round. Do not attempt to ream a hole that is out of round to start with. It is far better to run a drill through the hole to make it round before you start.
Hope this helps. Dusty
|nick morrison||09/07/2010 23:00:56|
|23 forum posts|
Jason - sorry I didn't really ask the appropriate question. I wrote (twice) a nice long description of what I am doing - or hoping to! I keep getting timed out and loose all my hard well thought prose.
I will work my way out of that via word as there are a number of queries at the back of my mind.
Dusty, I think you must be phsycic a number of my question answered, I have a set of metric reamers so now will use those.
I'm going to make a number of plain bearings is phosphor bronze. The reason I am going a reamer route is the bore of the bearing is only in the order of 1/4'' or so. The application is high speed approx 14000 revs scale woodworking planer/surfacer.
I will get this off and again thanks - lets hope it only posts once. I'm a good typist . . .but!
|John Shepherd||10/07/2010 09:01:16|
|216 forum posts|
This time out problem is a real pain on this forum but there seems to be no solution?
If you copy your text you can re paste it when you log on again. I find this better than using Word and then pasting as I find this has its own problems with the format even if you use the paste from Word function.
|417 forum posts|
|Yes, that automatic logout is a nuisance, but there is an easy solution, or even more than one:|
1. Tick the 'Remember me' box BEFORE log-in.
2. Use the Editor (not Word!) to write your text. What you need is a plain text file, not fancy formatting and rendering. As I did here...
This brings up an idea - sorry if i'm going very much off-topic here. It seems that the people at the head of this forum are not willing to do something towards the much asked-for 'Help'-system. So why could not we users create a thread under the title 'FAQ' where we would give the answers for the newbies?
It seems that there are always the same questions floating up:
1. the logout - see above.
2. Pictures: how to insert a picture directly in the posting? there? How to insert a picture without creating/using an album first? How to create an album and insert pictures there?
3. Links: How to handle long links? How to insert a link so it becomes clickable? Why are my links often not clickable? ( I see both cases every day)
Now you can add your specific problems here....
And then maybe we will move that into a new thread (with the friendly help of Mr. Barber?
|Martin W||10/07/2010 10:46:43|
|792 forum posts|
Re losing your post this has happened to me more than once when I have taken too long to submit it.
I posted this workaround earlier in another thread and it is something that I use now if my entry is likely to be long or will take time to compile. Typing skills not too slow but brain takes time to marshall my ideas in a logical format . Must be my advancing years .
What I do now is wait until I've finished the entry and before submitting it to the forum and with the cursor still in the posting:-
'Right Click' on the mouse and when the menu comes up
'Left Click' on the menu 'Select All' at this stage all of your text should be highlighted, (mine screen comes up with white writing on a blue background).
Then 'Right Click' mouse again and on the menu 'Left Click' on the menu 'Copy', I then 'Left Click' anywhere in the 'Post' to return the text to normal and submit the post.
Then if you do lose your first post all you need do is to open another 'Post a Reply' box and 'Right Click' to get menu and then 'Left Click' on 'Paste' and your post should appear. Quickly, well fairly, submit to forum.
Hope this helps and a quick question to the moderator "IS ANYBODY LOOKING AT CURING THIS FAULT"
|Richard Parsons||10/07/2010 18:07:49|
645 forum posts
Adjustable reamers are really scraping devices. They scrape out small quantities of metal from holes. They are not as rigid as solid reamers and should only be used to take small cuts.
There are usually two types. The 5 bladed reamer and the 6 bladed reamer. The 6 bladed can be measured to determine the hole size, 5s cannot.
To set the reamer up for he first cut, put the reamer into the hole and adjust it until it just begins to grip the hole. Then increase its size by ¼ of a turn of the collars. Always make sure that the top collar is tightened down. Make your first cut. Repeat this by increasing the size of the reamer by no more than ¼ of a turn of thee collars. Measure the hole frequently. Measuring the 6 bladed reamer gives you an idea and only an idea of the hole size.
As I have very few metric reamers I use expanding reamers quite frequently.
There zummat wrong yer. posted this once an it aint yer but tiz on me 'postings.'
Edited By Richard Parsons on 10/07/2010 18:09:53
167 forum posts
You posted to the other thread. There are 2 identical threads and your original posting is on the other one.
Edited By Andy Belcher on 10/07/2010 18:36:07
|466 forum posts|
I fear I am or about to be a prophet of doom. Be very careful of the grade of phos you use for these bearings if you intend to ream them. Drawn Phosphor Bronze is an absolute B****** to machine it has a tendency to grab drills and reamers. Try to get something like colphos or perhaps a leaded bronze. These will, I feel sure suit your application. They are much friendlier to machine.
|Richard Parsons||11/07/2010 09:58:33|
645 forum posts
Dusty – I agree with you PB can be the very devil, but it can be machined if you use sharp tools with negative rake, take it slow and gentle. With most brasses and bronzes most of the problems (including reaming) stem from being too ‘wholesale’ and trying to emulate ‘industrial production speeds’. Does it matter if it takes you another ½ hour to do the job? Listen to the tools a nice hissing noise as you cut and all is well and use plenty of cutting oil to lubricate the cut.
Andy -yes I know but this was the thread I was aiming at.
Getting back to reamers ‘ream to fit’ Rule 8. You can always take out more but it is the devil own job to put metal back in to the hole. As the my friend the Chinese inspector Mr Wun Thou Wong says ‘Softly softly catchee monkey’
Edited By Richard Parsons on 11/07/2010 09:59:50
|nick morrison||13/07/2010 23:45:25|
|23 forum posts|
I am very grateful for your replies regarding reamers,it certainly has given me a lot of food for thought. As advised I will practice with very sharp tools and take it very slowly.
Thanks also for info about the time out.
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