Here is a list of all the postings Adam Harris has made in our forums. Click on a thread name to jump to the thread.
|Thread: Large 12" chuck - can anyone identify brand insignia TLS?|
Someone has pointed out to me that the jaws are very likely not original to the chuck because the chuck jaw slot designations are in Roman Numerals whereas the jaws themselves are designated in English numerals. I have come round to guessing the unbranded chuck must be an old cheapo from China/Taiwan
Edited By Adam Harris on 10/07/2019 20:17:38
This old 12" 4 jaw chuck appears very nicely made and from a decent material that has not rusted badly, but the only maker's stamp is on the jaws. Can anyone help identify the maker's insignia please??
Edited By Adam Harris on 10/07/2019 13:16:43
|Thread: Variable Speed Drive belts - acceptable dimension tolerance|
Thanks Hopper - fair assumption of the existing condition of the pulley system.
EDIT: "of the outer top edge of the belt"not "pulley"
Edited By Adam Harris on 20/05/2019 23:52:30
Edited By Adam Harris on 20/05/2019 23:52:47
Ian it is difficult to know where the noise is coming from but it is from the area of the variable speed pulleys, and there should be no doubt that a belt that is hard and cracked (presumably from age and overheating) on the outer edge is at least a contributing factor. I think your feeling that only 1 degree should be accommodated by the flexibility of the rubber, and Colin's feeling that the belt will wear to fit the 26 degree sheave, is encouraging me to give it a go at least. My concern is that the wear process will cause overheating that results in the same hardening and cracking of the outer top edge of the pulley. The Hardinge HLV-H owner community is somewhat of a cult in my opinion and I don't think any of them could contemplate using a belt that is anything other than specified and branded by Hardinge.
Edited By Adam Harris on 20/05/2019 22:07:13
Colin would the deformation process result in the outer top edge becoming hard and cracked/crusty or do you think it would deform remaining pliable ? The belt I am replacing has its outer top edge worn into a state where it is hard and cracked and I believe this is making the big noise from the variable pulley system. I'm not sure in the world of variable speed pulleys how significant a 1 degree difference is in profile of the sheave vs belt
Edited By Adam Harris on 20/05/2019 19:35:14
Although this is a general question, my specific situation regards a Hardinge HLV-H lathe. When the cost or difficulty in finding a replacement variable speed belt of an old machine is too great (in this case a US machine where the belt is still available in the US but expensive even before adding shipping cost) , similar belts can be found here in the UK and I am wondering what differences would be acceptable ie unnoticeable in use. The Hardinge belt is a 1" wide , 38" long , 26 degree sheave profile, variable speed belt . Available in the UK is a different variable speed belt 0.6 mm wider (2.3% wider), 3mm shorter (0.3%), but with a 27 degree sheave profile as opposed to 26 degree sheave profile of original. I was thinking the small extra width and shorter length would probably have limited combined impact on performance, but I was wondering if the angle profile difference of 1 degree would have a noticeable impact on smoothness of operation and of belt wear (and so subsequently smoothness of operation). Any thoughts on these dimension differences please?
Edited By Adam Harris on 20/05/2019 17:20:26
|Thread: Bore micrometer|
Thanks I'll check that link out in more detail when the Tesa toy arrives.
Using the lathe to hold two of the axis steady is good
Edited By Adam Harris on 10/05/2019 14:19:43
I have indeed up until now used the spring bow internal calipers wiggle feel method, but not good for aiming at press fit accuracy.
Edited By Adam Harris on 10/05/2019 13:12:29
Edited By Adam Harris on 10/05/2019 13:13:11
My investment - a large sensitive dial that will no doubt go whizzing round and around erratically as i tear my hair out finding the "best" reading!
Edited By Adam Harris on 10/05/2019 13:09:50
Ah yes quite right - register a Maximum reading in the finger twiddle rotation plane, but a MINIMUM reading in the wrist dipping plane - not so easy to get both right simultaneously I suspect! Well I have now got my dial comparator and have plenty of time allocated to practice.
Edited By Adam Harris on 10/05/2019 12:56:36
Edited By Adam Harris on 10/05/2019 13:03:32
Thanks Simon. Oh dear , what to do? What to do?....And I was thinking that with a dial comparator all i need to do is take the peak dial reading as I twiddle it carefully about in the bore , and adding/subtracting difference to the preset reading, I am done for the actual bore...
Edited By Adam Harris on 10/05/2019 12:33:05
Ok great - I will look for a dial comparator. Many thanks
Would it be less fiddly (better) or more fiddly to use a high quality telescopic bore gauge (eg Mitutoyo) with the aim of measuring down to 0.001"?
Edited By Adam Harris on 10/05/2019 10:05:28
Oh I see thank you both. So without a gauge ring, I could take its reading against my known other (digital) micrometer set reading, then insert in the bore and measure the difference in readings and add/substract from set reading of my (digital) micrometer to get an absolute bore measurement?
Edited By Adam Harris on 10/05/2019 10:02:20
When looking at used bore micrometers, analogue dial with a variety of tips each having a specific range, should the small revolution counter dial (not the main outer dial) be at zero when at rest with nothing touching the tip? If not at zero at rest, how would one get an absolute reading for a bore? It seems on ebay the used ones are often far from zero at rest...
|Thread: Laser Tachometer|
Absolutely delighted with this £9 purchase on ebay (many sellers offering it). Tested on the trusty Super 7. Gizmo comes in nice little blue pouch. It comes with sticky reflective tape. Snip off a bit, stick it on the chuck, and aim the laser device at it. So on theoretical slowest belt setting of 210rpm, gizmo shows 237 rpm, and on fastest theoretical belt setting of 2105 rpm, gizmo shows 2093 rpm. Could not be more pleased! Pictures to follow...
Edited By Adam Harris on 09/05/2019 17:35:57
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