Member postings for Ajohnw

This one has a 6mm shank and can bore an 8mm dia hole - Unusual for RDG to give info

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There bars with the triangular tips going on the one I have wont face inside a hole as the tip isn't at the correct angle. The far edge is more or less square on.

John

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Edited By John W1 on 16/11/2015 16:18:41

No. The only problem with hand reamers is that the tapered section on the end has to pass completely through the hole to get it parallel. Often that isn't a problem. I use either type in the lathe depending on what I have.

The usual instructions for using a reamer are, drill, bore and then ream. It assumes that the drilled hole might not be too good but with decent drills not just rammed in any old how and a reasonably set up lathe in respect to the headstock to tail stock alignment the difference is likely to be very marginal.

Really on you lathe one question that needs answering is how big a drill can you use on it. That might mean using several gradually opening up the hole. That and the tool post sets how big a boring bar you can use. The smallest size is set by what you might want to make. Sounds stupid but it wouldn't be difficult to make an HSS tool that would bore a 1/8 dia hole. Reamers may help you avoid having to make boring tools like that and larger ones. Sets might be a problem. For say 0.5mm steps from 3mm the only ones I have seen run up to 13mm. it may be better to buy as needed.

Parts can be made to fit in drilled holes as well. It's surprising how accurate they can be at times but a reamer gives a much better finish and that aspect is usually important.

1/8" holes and no reamer and didn't want to buy one? Many would make a d bit. The tolerance they give isn't all that much worse than a reamer. A reamer on well aligned gear should give a tolerance of it's actual size -0 +0.0005" usually relaxed a bit to 0.0007". A d bit should up that to around +0.0015". Good job too as accurate holes had to start some where to get where we are now. Once reamers get large the tolerances are usually increased.

John

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Edited By John W1 on 16/11/2015 15:50:42

This is the typical min hole size for the smallest insert boring bar I can find. 3mm over shank size isn't that unusual. There may be smaller bars elsewhere on the site.

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Remember though that when tips and bars are sold together it generally works out cheaper.

From Hopper's checks on your lathe drills and reamers are another option but do run the reamers as slow as you can and some sort of lubricants helps. Sets of reamers can be found fairly cheaply over a range of sizes. The super high precision ones tend to be rather expensive but often holes are made to accept things so the part that is to fit be it running, tight clearance or force fit it can be adjusted to suit.

Hand reamers have a taper on the end, Chucking and machine reamers don't.

John

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Edited By John W1 on 16/11/2015 13:51:39

Yes. There is usually a threaded hole in the end of the arbour so that it can be pulled back fairly firmly into the morse taper. Also handy for getting it out. There doesn't seem to be any MT1 ones about. There are MT1 arbours around that could be used to make one and I think Shereline also do one that is MT1.

The arbours are soft ended - morse taper end hardened and the part on the end left soft. They might be a bit much for your lathe and the dia of the ends may be too small for slitting saw support anyway.

You should be ok with a chuck held one. It's just that the morse taper types hold the saw more accurately.

John

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It comes up with post to long if the suggestion is followed.

Good idea really as I feel x m l aught to be banned. For some reason software people especially OS types love it.

John

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The "stop" in the V could match the keyway width so that is probably the best answer yet.

John

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Presto are probably correct if the morse fitting is useless. It's more a case of the tang limiting slip while the tapers lock due to cutting pressure - we can't hammer the things in.

John

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Doh - I assumed he had a 2 morse spindle. Not that chuck mounting matters that much, just that a morse fitting will cut more precisely.

I also meant to add that some people knock up a table to fit on the lathe so that it can be used as a sort of table saw.

John

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Edited By John W1 on 16/11/2015 11:01:09

If you are interested in this area you will have to make use of the web to find out what terminology means. Often wiki what ever it is will produce some information. Unfortunately due to the way some one wrote the software that runs this site I can't put the letter x m l together as one word as it will assume I am not posting plain text.

John

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The tang is for driving the drill if the taper happens to slip but lathe tailstocks don't usually come with the facility needed to use it. Drilling machines usually do.

I do have a few morse taper drills and reamers but in the case of the drills apart from very long ones I happened on cheaply I can't say as I went to any trouble to get them. I use 1/2" shank blacksmith drills. Those can go to larger sizes than a 2 morse shank drill. In cases where they don't well they are being driven via 2 morse anyway at the back of the drill chuck - in my case as the tailstock is 2 morse. If some one has a 3 morse or larger tailstock things can be a little different.but morse 3 only goes up to around 1 1/4 dia so not much bigger than a 1" blacksmith drill. Morse 4 goes up to 2in and 5 3in. Big difference their.

Reamers are pain. The size to shank relationship is similar to the drills so big reamers have a big morse taper shank. I have used them via a 2 to 3 morse step up sleeve at times.

The other argument for using both morse taper reamers and drills is the accuracy of their presentation to the work. A chuck will add some error. Apart from rather large sizes, say 3 morse plus that is the main reason for using them - accurate holes.

John

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ASCOM as it is now comes from the days of dev kits. Every software man and his dog just had to have a dev kit 'cause microsoft did them and they too masked what is actually going on. It's worse these days as C++ and various compiler outputs are supposed to document the code. There has also been a period when documentation was done by what in real terms are not software people who may not even really know what is actually going on. It leads to extremely wordy documentation that would even have page after page of the so called philosophy used to generate the code and hardly and use orientated docs at all.

John

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Arceuro do slitting saws and morse taper arbours that will take them Brian. You may need to make a draw bar for the arbour. I usually use a length allthread to save the bother.

John

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There is a stop in the V block formed by the base so it could be used to check a dimension off a round or square bar with some shape on the end.

It will also sit flat on a surface plate so could be used for checking thickness and it just happens to have the V block type facility. I'd guess that is most likely.

John

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PA is ok if you can see it Neil. Dead north of me is B'ham city centre. i generally can't see it at all. If clear south is "ok".

In some ways there isn't much difference how each set up is aligned. iOptron, point at pole star and then their 2 star alignment. Done that way I assume so that the axis can be set more accurately. Vixen if I remember correctly telescope level and pointing east west. Celestron pointing at the meridian and Meade level and north south. Vixen were the first as far as I am aware to offer solar system alignment including the moon pointing out that it wouldn't be terribly accurate. They also offered a button press that could be used later once something had been centred. I think both Meads and Celestron offer much the same now. Celestron offer some gizmo that can be plugged into the scope and it will align itself. It recognises star formations. It seems they are still updating it and it wont work on equatorial mounts. They have probably nicked some open source plate solving software. The main manufacturers offers the same methods in alt az or equi. Not iOptron though - equ and alt az come with different controllers.

Really they are all just setting basic angles as a starting point. For instance if some one didn't know how to set for the merdian they could use a digital level and set the scope with that. The same could be done with iOptron for the pole star if it can't be seen. A lot of it goes back to the initial methods. The scope chooses which stars to finally align on and centres them roughly for the user to adjust. Now they usually offer a choice and 1 star, 2 stars and solar system and a later correction as per Vixen have for a long time - apart from iOptron but I would need to check that. I don't think it offers a choice of which 2 stars it will keep swing to,

The problem with iOptron is that they are the new kids on the block. All sorts of thing offer the facility to work with Meade., both old and new stuff and the protocol is simple, Not sure about Celestron protocol.

I thought the 2 links I posted might be of interest. They control goto scopes and add things like auto focus and complete remote operation including camera control. They drive the scope by sending stellar co ordinates. The 2nd link is the more interesting one. The work horse is a rasberry pi and graphics and star charts plus guidance via a tablet. It works remotely over wi fi. It uses dslr control software from the open source community and other bits and pieces from the same source. The Indi one is professional observatory stuff and uses x m l to set what a driver actually does. The driver is sort of generic and can drive anything. Great but x m l is complicate and many complain that there isn't even a decent editor available for it.

I'd guess you are aiming to say that the scope is aligned on the pole star using a polar scope and then working from that but I suspect you will still need to add corrections and the sums to go with it even then. I'm not sure if that facility is built into stellarium software. I get the impression it's built into the mount / controller.

John

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I seem to be having a bad day so trying again.

I'm inclined to agree with you about ASCOM Neil. What it's actually doing is buried too deep. I'd wonder about iOptron in terms of their method of aligning especially in unfavourable conditions, if you go that far - it swing back and forth between 2 stars. Celestron like the scope pointing at the meridian. Meads horizontal and pointing north.

I use a spirit level and a compass. It's surprising how accurate that can be. What's wrong with Meade's protocol. It's compatible with just about everything and is in all of their scope manuals.

A couple you may not be aware of and both pretty powerful.

These nuts use x m l and are talking about thin clients but there is some use of a 'pi around. The other problem is that the insist people run bleeding edge Linux distro releases.

http://indilib.org/

This one is a mix and graphics are handled by a tablet. Lot's of reading on this link. The code is on sourceforge.

http://www.cloudynights.com/topic/385710-piastrohub-raspberrypi-for-autoguidingdslrgoto/

John

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Edited By John W1 on 15/11/2015 20:13:57

Solved I made the mistake of using the letters x m l close together ???????

John

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I'm inclined to agree with you about ASCOM Neil. What it's actually doing is buried too deep. I'd wonder about iOptron in terms of their method of aligning especially in unfavourable conditions, if you go that far - it swing back and forth between 2 stars. Celestron like the scope pointing at the meridian. Meads horizontal and pointing north.

I use a spirit level and a compass. It's surprising how accurate that can be. What's wrong with Meade's protocol. It's compatible with just about everything and is in all of the scope manuals.

A couple you may not be aware of and both pretty powerful.

These nuts use x m l and are talking about thin clients but there is some use of a 'pi around. The other problem is that the insist people run bleeding edge Linux distro releases.

http://indilib.org/

This one is a mix and graphics are handled by a tablet. Lot's of reading on this link. The code is on sourceforge.

http://www.cloudynights.com/topic/385710-piastrohub-raspberrypi-for-autoguidingdslrgoto/

John

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Just tried copy pasting the problem post in this thread and the same thing happened. It's plain text and contains 2 links created with the correct button.

Any clues anyone?

John

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For some reason my posts wont go through. An odd box pops ups telling me I need to use paste from word !

John

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