come drilling chuck
IanT | 21/06/2020 17:40:50 |
2147 forum posts 222 photos | I've not built a floating reamer holder (as yet) - but there are certainly a few published designs around to choose from. I've watched a number of YouTubes on this subject, mostly from the usual suspects and there does seem to be general consensus that they work. However, on one of the videos (I don't think it was the one referred to here) the holder really did "flop" all over the place, which frankly surprised me, as (somehow) I expected a bit more 'control'. Having too much 'flop' seems a bit counter-intuitive. I think I'd expect the holder to move axially (a wee bit) but still be constrained in other directions. I haven't actually checked but I suspect the various designs I'm thinking of might reflect slightly differing views on this matter on the part of their designers too. Any actual experience here of building one of the published designs and your thoughts as to its effectiveness (e.g. Did it work and was it worth it?) Regards, IanT
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Howard Lewis | 21/06/2020 18:06:51 |
7227 forum posts 21 photos | Ian T You sound as if you would be horrified by my floating reamer holders. Deliberately, I made the ER25 and ER32 holders with 0.010" clearance in the body; and the four capscrews that retain the ER holders, also have a 0.010" clearance. So the collet holders do flop around all over the place. The lead in chamfer on the end of the reamer picks up on the hole, and guides it in without any side force in any plane. The only non axial force present is that due to gravity, which acts on the reamer, the ER collet, and the collet holder, so minimising, as much as possible, the effect. As far as I can tell, the device does what is required of it. If everything were perfectly aligned, Headstock, Tailstock, Reamer, and all tapers, there would be no need, but few of us can claim to have perfect machines and tooling, (Certainly not in the realms of hobby equipment. ) Howard |
Oily Rag | 21/06/2020 18:25:50 |
![]() 550 forum posts 190 photos | Floating Reamer holders are a standard production requirement so industry recognises the need to 'follow the previous operation' to give accurate hole sizes. In many instances the reaming operation may well be done on a 'chucking' lathe whereas the pre-op of drilling was done on a capstan. Therefore the use of a floating reamer allows for the discrepancies between different machines, and also allows us to take advantage of less than industrial machinery! Its similar in bore honing, the hone is 'floating' and it follows the pre-boring process - if the borer is out of kilter the hone will not correct the bore. Honing was always considered to be a 'surface finishing / treatment' rather than a true machining operation. Something I learnt along time ago in the Motor Industry! |
Roger B | 22/06/2020 14:01:21 |
![]() 244 forum posts 105 photos | I have an Angst floating reamer holder like this: It has an adjustable centering spring to control 'droop' when used in a turret/automatic machine.
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GoCreate | 22/06/2020 17:38:30 |
![]() 387 forum posts 119 photos | Thanks everyone for sharing your thoughts and experiences, (especially IanT, Howard Lewis and Oily rag). Roger - that Angnt info, especially the sectional drawings is very interesting, a high end precision tool. I guess for production work a "floppy" reamer would be far from desirable but manageable in a home workshop. Anyway, I've now got some fresh ideas regarding making a floating reamer holder for my larger reamers with MT shanks, but I'm going to leave it for a while, need to re-focus on my Lion build. Cheers |
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