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Post by Roger on Mar 11, 2014 10:19:01 GMT
I can see the sense in that, it's a means to an end. I'll make a note of that. So they're almost loose, a good clearance over the rivet diameter, almost like a pivot, just there to stop it from falling apart.
We used to refurbish radial Air Bearings which had a series of 0.2mm jets that were flush with the inside diameter of the 1" bore and quite a long way in. There was no access to the outside of them and they had a tendency to get blocked. We tried various ways, mostly by hand, of twiddling a 0.2mm drill in the hole but usually ended up breaking them off. In the end, I devised a really simple tool to do the job which could possibly be used as the basis for a tool along the lines of the one you'd like.
I made a square section bar with a slot in each end for a pully, and stretched an 'O' ring over them. A vee in one end used the shank of the tiny drill for the bearing, it being held in place by the 'O' ring and the other was the same but with a small rod which you could turn with your fingers. It still had to be used with care, but it worked a treat and the 'O' rings allowed enough 'give' to save the drill if you were a bit clumsy.
Now I'm not sure if an 'O' ring would give enough grip, but a small watch chain would. OK, it's a fantasy product that's probably not worth the effort of making, but it's an interesting thought nonetheless.
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Post by Deleted on Mar 11, 2014 18:39:25 GMT
one thing that would be quite useful is a method of counterinking the holes for the firebox stays in the inside of same. there must be an easy way of doing this but i havent discovered it yet! anyone any ideas please? usually i rotate a sharp rose bit by hand. cheers, julian Hi Julian What about something like this... www.ebay.co.uk/itm/Angled-Drill-Chuck-RIGHT-ANGLE-DRILL-ATTACHMENT-ADAPTER-TOOL-Angled-Drill-Driver-/271420433770you'd need to check the size as they come in all shapes and sizes but I'd have thought something like this may do, especially when using a countersunk tool which are usually a lot shorter than drill bits. If you can't find a small enough electric adapter I'm sure you'd be able to find a 90 degree airtool which can go pretty small, would also be easier to use, although more costly. Regards Pete |
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jma1009
Elder Statesman
Posts: 5,922
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Post by jma1009 on Mar 11, 2014 22:16:31 GMT
hi pete, the distance between the inner firebox wrapper i only 2 15/16" so i suspect the tool you referred to is too long.  i came across these bits in the workshop. i know the tool on the right is for deburring, but no idea what you call the other bits as a bit rasp like to me but precision made. the round nosed tool looks ideal for countersinking the firebox side stay holes on the inside. what are they actually for? cheers, julian |
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Post by Deleted on Mar 11, 2014 22:19:20 GMT
They look a lot like burr tools for dremel type drills and the like, good for casting fettling, etc.
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Post by Deleted on Mar 11, 2014 22:35:13 GMT
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jma1009
Elder Statesman
Posts: 5,922
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Post by jma1009 on Mar 11, 2014 22:53:46 GMT
hi pete,
erm, £300 for such a tool is more than i will have spent on the copper and silver solder for the boiler!
and more than i paid for my lathe and mill!
looks like twiddling a sharp rose bit by hand again! thankfully not so many stays on STEPNEY's boiler than previous boilers ive made as much smaller.
cheers,
julian
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Post by Deleted on Mar 11, 2014 23:05:33 GMT
I agree.. far too expensive... I did just find this which may fit... gives length as 160mm and looking at the picture the depth may be small enough and the price is very reasonable.. may be worth considering for future jobs.
regards
Pete
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Post by Deleted on Mar 11, 2014 23:15:22 GMT
Julian, those are Dental Burrs......  |
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jma1009
Elder Statesman
Posts: 5,922
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Post by jma1009 on Mar 12, 2014 0:04:00 GMT
for horses?
they arent anything like my dental burrs! all mine are quite fine and 3/32" dia shanks
cheers,
julian
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Post by Roger on Mar 12, 2014 0:17:44 GMT
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Post by Roger on Mar 12, 2014 0:21:03 GMT
Check out 'Low speed dental handpiece' on ebay, that's probably the nearest commercial angle drive that would do the job. you won't like the price of those either!
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Post by Deleted on Mar 12, 2014 2:34:14 GMT
for horses? they arent anything like my dental burrs! all mine are quite fine and 3/32" dia shanks cheers, julian -------------------------no, these are from an on-line catalogue of similar sizes items...If you hover your pointer over the image and "right-clik" you'll get a drop-down menu...select "Search Google for this image for image" and then "left-clik" on it.......This will show you the source( and similar) of that image and the details of those dental burrs............. |
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Post by ejparrott on Mar 12, 2014 7:21:29 GMT
We use them all the time for deburring and fettling
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Post by digger on Mar 15, 2014 23:33:15 GMT
Julian, those are Dental Burrs...... Dental burrs for an elephant! Digger |
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jma1009
Elder Statesman
Posts: 5,922
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Post by jma1009 on Mar 17, 2014 22:29:24 GMT
  i silver soldered the crownstays to the inner firebox this eve. i decided to add an additional middle crown stay which together with my 2.5mm inner firebox wrapper compared to the 1/16" original should give a very sturdy construction. there are a few areas that need attention - one cant expect everything to go ok first time. the rear most rivets flowed through with silver solder but not the outer front two though the front middle rivet was ok as per the first pic. there are a few areas on the webbing of the crownstay girder stays that also require some further attention. the middle crownstay was perfect! 10mins start to finish after lighting the propane, but fitting the parts and fluxing up took far longer. cheers, julian |
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Post by Roger on Mar 17, 2014 23:24:46 GMT
That looks mighty sturdy Julian, I really like the fanned edges of the stay. Is that done to allow water to flow or to give extra strength? You can certainly see that it's really taken hold when it's done that way.
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jma1009
Elder Statesman
Posts: 5,922
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Post by jma1009 on Mar 17, 2014 23:44:28 GMT
hi roger,
both really. ive sort of done a variation of the original martin evans design that i dont particularly approve of. this is the first boiler ive done with 'webbed feet' crown girder stays as per martin evans. they are bit of a pain as the inner firebox is slightly curved whereas all the ones ive done till now have had flat topped inner fireboxes. i should have been a bit more generous with the silver solder this eve.
the original advantage of the 'webbed feet' design claimed by martin evans was to give better water circulation. i added some additional circulation holes further up as you can see which isnt on the design but doesnt compromise the strength of the stays.
i added heat underneath from inside the firebox and this is quite sufficient. when the tops of the stays get silver soldered to the outer firebox wrapper the heat will be whacked up and directed from the outside.
you wont have any problems with SPEEDY's boiler as it has a flat topped inner wrapper and flat topped outer wrapper so a piece of cake! unless you decide to fit rod stays.
cheers,
julian
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Post by Roger on Mar 18, 2014 7:51:59 GMT
It's worked out really well though and worth the effort in my opinion. There's absolutely no doubt that stay is on there for good and the circulation can only be helped by it.
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shooter
Part of the e-furniture
If it 'aint broke....don't fix it!
Posts: 252
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Post by shooter on Mar 18, 2014 7:58:12 GMT
Superb work Julian, as always. Impressed with your silver solder skills. Do you take commissions  ???thinking Doris boiler> Cheers for now Steve. |
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Post by Roger on Mar 18, 2014 8:11:32 GMT
Superb work Julian, as always. Impressed with your silver solder skills. Do you take commissions ???thinking Doris boiler> Cheers for now Steve. We may have to form a queue... |
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... there may be cheaper types out there. 
???thinking Doris boiler>