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> concentricity tool
concentricity tool
@ 11:06 pm (GMT) |
Mike NeesonHello all. I've been investigating buying a concentricity gauge and came across a dude who asked the question: Why don't you make one? I laughed to myself, but a few clicks later, I was telling myself: why don't you make one! There is the usual plethora of Chinese made dial test indicators on eBay and barring the more expensive Mitutoyo found somewhat appear to be British made(?) Moore and Wright or another by Draper. If anyone has any experience in buying good and bad DTIs I'd love to hear from you.I will also need to get a stand of some sort, there appears to be heaps to choose from on eBay too. Will a V block suffice for supporting the case? Excuse and errors... Using my phone for this one. |
Replies
@ 11:42 pm (GMT) |
Nathan FosterRe: concentricity toolYep, your on the right track. If you have the tools and skill, why not.A V block will be fine. Just needs to be true and squarely mounted. |
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@ 11:44 pm (GMT) |
Nathan FosterRe: concentricity toolSorry- the DTI that came with my Sinclair is Chinese. I was initially a little worried about using it but its fine. |
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@ 11:05 pm (GMT) |
Mike NeesonRe: concentricity toolTools and skill eh? Hmmm... oh well nothing ventured nothing gained. |
@ 12:01 am (GMT) |
Shawn BevinsRe: concentricity toolI did a post a while back about working with various concentricity gauges. Some of them did not give me repeatable results as the gauges were of poor quality. The design on some kits left me wondering what the heck were these fools thinking.I ended up making my own with 4 machinist tooling balls, a block of aluminum and a dial indicator. Since I had the dial indicator and a post, the 4 tooling balls ran me $24(US) on ebay. It took me less that 45 minute to true the block up, lay it out and drill everything. I have since drilled more holes to accommodate different cartridges. If I did it again, I would use a steel block. Other than that, it does the job. I did find out I had a bad die in my 264 that has since been replaced. [b] |
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@ 07:21 am (GMT) |
Mike NeesonRe: concentricity toolThanks Shawn, sounds excellent. Any chance of a photo or two? What DTI are you using? |
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@ 11:28 pm (GMT) |
Shawn BevinsRe: concentricity toolI am currently using a Browne and Sharpe. It is very consistent,. I have a Federal that i check it against. It isn't about reading right one time, it is about reading accurately all the time. I think this is where the Chinese gauges let you down. How many times do you plan on using this?If I figure how to post pictures I while. |
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@ 06:57 am (GMT) |
Mike NeesonRe: concentricity toolHi Shawn, I plan to use it to constantly track how my reloads are going. I am currently going through a "phase". I have been using a Dillon RL550 to reload on and the phase i am going through goes something like "My ES is 35fps why? is it my reloading press, my dies etc" So I would like to gather some data on concentricity using the press in different ways and have some actual data on what works or whether or not I need to get a proper single stage press. The Dillon is a relic of my "running and gunning" days - before kids etc. My budget is limited and I don't want to say good bye to the Dillon if I don't need to. If the data shows that it needs to go, then so be it. But I don't want to be running around blindly changing stuff here and there and never actually achieving anything other than a concerned wife and a bank balance under strain.I have noticed differences in sized cases depending on where they were sized in the process and have figured that there is a fair amount of stretch in the tool head. If I neck size (lee collet) and also use the Redding body die on the opposite station. The shoulder gets set back more if there isn't a case getting neck sized - ANYWAY sorry to splurge like this. I'm probably really just waiting on Nathan's next book to get published. I have also just received my Rem700 back from the gunsmith with a new TF 22" barrel (308W) on so that's a clean slate for me and this rifle. Have to redo bedding etc - going to be busy. But I don't want to rush - as I have done in the past. |
@ 06:07 pm (GMT) |
Martin TaylorRe: concentricity toolMike cannot help you with your press woes as l use a Fairly new Hornady, but are you enealing your cases?I find the seating pressure (feel) changes or varies from case to case very quickly, after sometimes as little as 3 sizes on many brands of brass! In my 308 l run new Lapua and S/H Whin, Fed & Hornady and all benifit from enealing which will effect your neck tension & in turn your ES. |
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@ 07:34 pm (GMT) |
Mike NeesonRe: concentricity toolHi Martin, no annealing. I'd like to start somewhere it doesn't require a large investment. I'm not sure there is a good cost/benefit ratio with annealing 308 cases. From my new start point I will make sure all the brass I use has been fired the same amount of times. That should hopefully sort out neck tension in regards to brass hardness. I may also look at lubing the necks with graphite or Hexagonal Boron. I guess I want to know if my press is making my life difficult or not. And then move on from there. |
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@ 08:12 pm (GMT) |
Martin TaylorRe: concentricity toolYeah fair call Mike, your press is the heart of your loading for shore and needs to be sound, especially when you start looking for the most out of your kit!Think my gas torch & canister was under or around $100 from Bunnings, so may be an option to look at in the future to build your kit. Don’t write off constant brass temper/neck tension if ES is grieving you, is what l'm trying to get at, reguardless of cal. |
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@ 01:00 pm (GMT) |
Mike NeesonRe: concentricity toolJust picked up a Mercedes Benz DTI made by Hahn and Kolb of Germany for $65 off eBay. Hopefully it will be reasonably consistent. |
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@ 05:01 pm (GMT) |
Shawn BevinsRe: concentricity toolGet yourself a few pieces of metal that are smooth and flat. Some shim stock & washers of various thicknesses to use like gauge blocks. Measure them with a decent micrometer capable of 0.0001" Record the measurements of each. You should be able to duplicate the thicknesses determined by the micrometer with you DTI. You may see some variations around "zero". No worries here.. What is critical is that your DTI returns to the same spot once you remove the "gauge blocks". You can use these gauge blocks to verify your DTI in the future. |
@ 06:06 pm (GMT) |
Rob Hughes-GamesRe: concentricity toolget a piece of guage plate.(ground plate). 4 ball bearings around 1cm and a bolt (5cm) and 2 nuts. drill 4 holes in the plate so the ball bearings are almost touching. solder or epoxy them in to the holes. drill a hole between them at the end for the bolt. either drill and tap it or but a nut on each side of the plate. that bolt will be the backstop for the case. ideally the bolt is non threaded where the case rubs and is square. then either make a stand for the DTI or use a magnetic stand.I dont think it matters if the DTI is accurate or what it measures in. it just has to be fine/sensitive enough. you are juat looking for movement when you rotate the case. no movement, no run out! |
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@ 10:24 pm (GMT) |
Mike NeesonRe: concentricity toolThanks Rob, I've read your description about 5 times and I get the picture. I'll give it a crack. Thanks. |
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@ 07:56 pm (GMT) |
Rob Hughes-GamesRe: concentricity tooli just re read it and it does not make 100% sense. hope you can invision what i mean.heres a link to something similar. if you google concentricity guage and search for images you will get lots of pics. there are some ones that do necks and neck wall thicknesses ect http://forum.accurateshooter.com/index.php?topic=3803356.0 cheers |
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@ 12:17 am (GMT) |
Mike NeesonRe: concentricity toolHi Rob,Thanks for the Pic, and yes that is pretty much what I had in my minds eye from your description. Thanks again. |
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@ 01:51 am (GMT) |
Shawn BevinsRe: concentricity tool[img][url=http://smg.photobucket.com/user/shamus1/media/hunt/IMAG1006-1_zps98989c04.jpg.html][img]http://img.photobucket.com/albums/v693/shamus1/hunt/IMAG1006-1_zps98989c04.jpg[/img][/url] |
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@ 02:33 am (GMT) |
Mike NeesonRe: concentricity toolLooks great Shawn, what have you got supporting the bearings -a nylon washer or something? |
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@ 03:16 am (GMT) |
Shawn BevinsRe: concentricity toolThese are tooling balls. The balls come in different configurations. The ones in the picture are considered .500" x.500". These particular components have a .250" stud protruding from the bottom. This allows me to change for the length of the cartridge I am checking. I have since started using trimming pilots to check for case neck thickness. With this set up. I will try to post more pics soon.I like the ball bearing idea because of the economics. As I said,, I would use a steel plate next time. |
@ 11:36 am (GMT) |
Ronald Le MayRe: concentricityOkay going in on a limb there after a few if's using the concentricity gauge I use a Hornady and am soon to switch to the a Sinclair set up.They are mepltatted as well and do I feel it increases the X ring count maybe it does but there are a few little warries to behold; [a] In getting the runnout perfect say within say like 1/2 a thou does this affect neck tension like I do this maybe a factor. (B) Is full neck the go or just enough to hold the projie. (C) Meplatting will this help have consistent string of the projies in flight (D) Case trimming to the absolute munimum. ( E) Primer pockets reamed for depth and clearance of the hole. (F) ANNEALING the rounds to help soften the brass for equal neck tension after the neck die. Anyway the is just a small thing I do with all my shells not to mention 3-4 inspections each case every time it is reloaded |
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@ 07:45 pm (GMT) |
Mike NeesonRe: concentricity toolH Ronald,I shoot AMAX or SST's exclusively so no meplat trimming/pointing - pointing any hollow point reduces it effectiveness on game which is what I am aiming for. I shoot the 308W. The 308 was designed with a long jump, so I, under Nathan's direction, load for full projectile support. Also allows the cartridges to fit the magazine! See Nathan's article http://www.ballisticstudies.com/Knowledgebase/Determining+COAL.html at the end of the article he explains full neck support. Annealing may be an option for me, but before I try this I'll use my brass in batches, keeping brass with the same amount of firings together. My DTI has arrived and I'm looking around for some stand options. Will probably get some of those tooling balls that Shawn suggested. My bedding is currently curing, wish me luck for the break-out! |
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@ 09:24 pm (GMT) |
Martin TaylorRe: concentricity toolDon't forget to take some pics Mike, be great to see how you get on with the bedding! |
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@ 09:49 pm (GMT) |
Mike NeesonRe: concentricity toolHere it is sunbathing...
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@ 06:00 pm (GMT) |
Rob Hughes-GamesRe: concentricity toolfor a stand get a rod with a thread on the bottom. then a piece or steel or aluminium and drill two holes in it. one the size of the rod and the other the size of the dti stem area. drill a little hole at 90 degrees to each of these screws and use them for set screws to hold everything together.http://www.sinclairintl.com/reloading-equipment/measuring-tools/concentricity-gauges/sinclair-concentricity-gauge-prod37479.aspx |
@ 09:16 pm (GMT) |
chris murphyRe: concentricity tooljust wizzed up a concentricity gauge thought i would share. cost $85 for dial gauge and stand rest i had lying around. all so what is considered too much run out before it really affects accuracy? my loads came out at .1mm so .05mm outand i tested some factory ammo at .15mm out. also tested come ex military 30-06 rounds at .4mm out  [/url]
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