Here is a list of all the postings DiogenesII has made in our forums. Click on a thread name to jump to the thread.
|Thread: Hobbymat lathe - couple of questions|
Well reminded, Bazyle -
The 20T gear carrier comprises a simple stepped cylinder 21.7mm long. The central bore is 8mm (ream if possible).
The larger part of the component has a diameter of c.19.98mm (light push fit for a 20mm bore) and is 10.2mm long. It has 4mm wide key slot, 2.6mm deep (which could be formed by hacksaw and file if necessary - aim for perfection, but settle for adequate - it doesn't run at high speed or take a great load, and mates with a moulded component).
The reduced part that carries the 20T gear is c.13.6 to 13.7mm in diameter (mine is firmly fixed and I'm not going to prise it off!), the dimension isn't critical as the gear is permanently affixed by pressing onto the carrier, so make matched components - aim for a fit that requires say, light vise- rather than finger- pressure, but without "stretching" the gear too much - again, a tiny inaccuracy here isn't the end of the world as running clearance is established whilst setting up the gear train in any case. If one could arrange a parallel knurl, this would be exactly the job for which that process is intended, but failing that any knurl would probably do.. An adhesive might do, but I'm not sure that all are effective on plastics - advice welcome!
The gear should be 11mm thick, leaving 0.5mm of the carrier projecting beyond the face to provide axial clearance for the gear once the carrier is secured to the stud with it's screw & washer.
Both outer edges and the ends of the internal bore should be generously chamfered, for ease of fitting, to reduce friction, and to allow the ingress of oil.
In order to cut the blanks for any of these 1Mod gears, simply take the number of teeth required and add 2 to arrive at the finished diameter in mm - thus 30T = 32mm, 60T=62mm, 100T=102mm etc. With the exception of the 20, which is 11mm, all the others are 10mm thick.
I'd get a piece of Leaded ("free-machining" Bright Mild Steel Round Bar (EN1APb) for this job (I note the standard item is "soft", probably to save wear on the studs), and it's an exceptionally pleasing material to work with.
Edited By DiogenesII on 31/12/2019 13:38:05
The gears appear to be 1.0 MOD, are 10mm thick, and have a 20mm bore which is slotted to accommodate a 4mm key.
(50T gear=52mm OD, 60T=62mm, 70T=72mm, = 1mm of PD per tooth plus the addendum (= to mod) on each side).
I can't establish the pressure angle exactly from my worn examples, but 20 degrees seems the most likely to me - it's a "modern" metric machine made in Europe, for those not familiar with it - additional informed comment or confirmation would be very welcome, here.. (..although if you are going to get a set printed, it's rather immaterial in any case, as long as they are all the same.).
You will need; 20, 30, 35, 40, 50, 55, two 60's, 65, 70, 75, and 100, if you want every option listed on the plate. Even for common metric threads you will still need 30, 35, 40, 50, two 60's, 70, 75 & 100. A 20 is "nice-to-have" for a fine finishing feed.
I'm not familiar with the mini-lathe change-wheel sets, but do be aware that the Hobbymat uses a 1mm pitch leadscrew, which I think is finer than that fitted to ?most mini-lathes and therefore the ratio between headstock-spindle-turns versus amount-the-carriage-advances will be different.. might be worth doing the maths/checking the tables before buying any gears, just to make sure that you will be able to achieve the ratios that you need.
|Thread: Strange digital caliper behavior|
Dependent on your calipers, it may be that you may just need to reset the origin.. ..not all have this facility, but some have an "origin" button, and others have a small hole to access the reset switch with a paperclip or similar..
It's just a reset for the original "0" calibration..
|Thread: "Reclaimed Iron Cogs" on Ebay UK|
Jon, ...it's also not uncommon for that sort of thing to get separated at auctions or estate sales, where neither vendor, auctioneer, or sometimes even purchaser actually knows what any of the lots actually are..
|Thread: What Did You Do Today 2019|
Andrew - ..just food for thought, but having slept on the idea, might it be easier to form a shallow cone by starting with a plain cylinder (and removing a long thin fillet) rather than a flat sheet? ..you'd have a bit more control of the metal..
|Thread: MR16 LED Spot lights|
Just for the sake of "completeness" ..the MR16 also has a pair of opposing grooves on the "neck" above the pins which are provided for retention by a clip on some types of holders.. but like others have noted, it'll be easier to contrive a blob of something sticky..
|Thread: "Reclaimed Iron Cogs" on Ebay UK|
..knew I should have bought them.. ..next time you see them they'll be £150..
Not on familiar territory here, but could those splines be ?Colchester-ish?
The smallest is stamped "30B", didn't manage to successfully count the largest..
Apologies if this is a clumsy link, just thought they might be of interest to someone..
|Thread: Myford Super 7b lead screw end float|
..maybe the most careful assembly and close tolerances are to be found in the structure of Hemingway's opening paragraph
|Thread: Screwcutting on the lathe|
"I've moved the cutter forward with the top slide until it just touches the bar. I set the zero on the top slide and advanced it 0.92mm (3 and a bit divisions off a full turn).
Next zero the cross slide and the top slide. Move the topslide back until it just touches the bar again (a bit over one turn)..."
Your tool point looks fine - when you say "move the topslide back", you need to come much further back, and then go forward again to touch, in order to remove any backlash in the feedscrew..
..at present it sounds like you are touching off, turning less than a full turn (to achieve "full depth" zero), then coming back over 1 full turn to touch again.. try coming back, say, 3/4 of a turn, and then go forward again for your final touch..
sincere apologies if I have misinterpreted...
|Thread: Annealing Brass|
+1 for heating to dull red and allowing to cool naturally.
Could part of the problem be the "right angle" requirement - if you are attempting a sharp 90 degree angle, it's asking a lot of the ductility.. It would be much easier if you were able to form the bend over a radius, if there is scope within the design for this to be practical..
|Thread: Inside chuck jaws|
I once owned a 3j scroll chuck with reversible jaws - ancient (it came with a Brittania), maybe a "Crown", 4(-ish) inch size (memory gets rather treacherous here).
IIRC (and I think what Robin means), it isn't that the jaw positions change relative to the slots, it's just that their sequence of engagement with the scroll is reversed, in that "3" requires engagement first, and "1" engages last..
|Thread: A unlucky accident|
Martin, I'm truly sorry to hear of your friend's accident and the consequences, both for him and his family.
I just really wanted to say that you and his family should perhaps discuss whether you really should act immediately on his currently stated wishes to dispose of his collection so soon after such a life-changing event - decisions taken shortly in the aftermath of such a trauma could perhaps not have been (dare I say it - I sincerely mean no offence) effectively reasoned or fully thought through - one never knows what the final outcome for your friend may yet be, and he would certainly not be the first person of my acquaintance to have acted hastily in a ift of depression after such bad news who had cause to regret it later...
Best wishes, and with some uncertainty whether to press the "Add Posting" button at all..
|Thread: Accessing Digital Issues|
Paul, see if this helps..
On the extreme R/H end of the Edge Address Bar (to the right of the "Favourites", "Share", and "Add Notes" icons there are three little dots for Settings - click the "cogwheel" "Settings" icon at the bottom of the drop down list, and then select the "Advanced" choice from the grey, left hand half of the "General" settings list that drops down next - the first item is a blue "switch" device to toggle Adobe Flash on or off - ensure that it is on, otherwise Edge won't let you use it..
Yes. I too got fed-up with drip feed oilers and decided, that as a very bottom line, all I really needed was something that would hold enough oil to last for a "cuts" worth of time - I'm not too concerned about the "inconvenience" of having to check the level and top-up if necessary during the course of a day in the workshop, and neither do I have a problem with memory, so I bought a couple of these;
The reason I didn't buy a larger size was that these fit, and can be easily opened and filled, in the (constrained) space above the back bearing, which is limited by the belt guards. They are probably better than one would expect at that price.. If you have "old," better quality ones, by all means fit them ..the thread size is 1/8BSP .. you could always fit them on a "stand-pipe" to clear the guards if they are larger. Leave time for the oil to reach the bearings before starting if they are "dry".
I never fill them right up - one soon acquires a mental gauge of when to refill, and I found that regular checking and adding a squirt just becomes part of the rhythm of operating the machine, like oiling the ways, the handwheels, and the changewheel studs is, just at a higher frequency. I feel like I waste less oil than I did before, no more lying awake at night thinking of that expensive Nuto running down the front of the headstock and off across the chip-tray under cover of darkness..
It's worked fine for me, it sounds like it might for you, I daresay it isn't right for everyone.
|Thread: Adjusting lathe md65|
There are two socket screws in the rear of the tailstock base - the one at the front (nearest the headstock) is a CLAMP screw. The one to nearest the centre of the base is a FORCING screw which presses against the side of the base, to open the gap and allow the tailstock to slide.
To free the tailstock, loosen the front clamp screw, and gently tighten the forcing screw until the tailstock is free - no more than one quarter of a turn, as there is danger of cracking the casting. As you say, it may be stuck to the bed with old grease.
To adjust the tailstock for use, slacken the back forcing screw, and gently tighten the front clamping screw until the tailstock is only just, but still firmly held. Then gradually tighten the back forcing screw until the tailstock can move. It may take some attempts to balance the forces correctly to achieve smooth movement with a new lathe, as the parts will need to bed in.
The carriage is adjusted in the same way - here, the FORCING screw is in the centre, and the CLAMP screws are at either side.
The plastic parts should already be fitted in your lathe, they are retained there by pins fitted during manufacture. I think Hans had to replace his because someone had removed them, it is not a modification that needs to be done.
These are very accurate lathes if adjusted correctly, as you have a brand new lathe it will be worth trying find a manual so that you can get the best results from it, and look online for further information.
kind regards D
|Thread: Lathe improvements?|
Ha, Niels, this must be an even more temping project now than it looked at the beginning of October - you will need one of these;
|Thread: Boxford metric lead screw fitted to imperial lathe?|
There's a very relevant response (third reply, by Bob Brown 1) in this thread;
|Thread: Limiting pressure to a gauge|
Having chewed this over in my mind for several days, now, I wonder if it is worth trying to take advantage of one of the properties of fluid dynamics, and simply try a long length (coiled against the bulkhead?) of as small-a-bore pipe as you can find - cold oil will find this a singularly difficult passage to negotiate for it's entire length when thick, and with an open-gallery system, find some other route. All you need is a temporary damping of the extreme pressure of start-up.
It needn't cost any more than the price of some pipe to experiment, and I can't see how any damage can result.
I'm half-sure that in the past I have seen this rigged on a low-pressure oil gauge.. - does it ring any bells with anyone else?
|Thread: slidway lapping|
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