>Has anyone made D bit reamers as explained in this article
>
[quoted text clipped - 4 lines]
>It might be one solution to my need to ream various sizes of valve guides
>without buying dozens of custom ground reamers.
Sure Dave,
They work just fine and to a decent tolerance.
If you want to do valve guides it pays to do a stepped version where the
first part at full diameter is to the original size then steps up to the
size you need.
Turn a small groove at the transition point between the two
Mill or grind the 'D' shape so it's on the larger diameter and part of the
pilot diameter and then hand sharpen the leading edge of the groove to act
as the cutting edge.
With a pilot they tend to cut tight as regards tolerance. If you have
access to surface grind the D after hardening then choose the rotation of
the wheel so it throws the burr out over the cutting edge as opposed to the
trailing edge.
--
Regards,
John Stevenson
Nottingham, England.
Chris - 14 Apr 2004 01:43 GMT
: >Has anyone made D bit reamers as explained in this article
: >
[quoted text clipped - 24 lines]
: John Stevenson
: Nottingham, England.
Agree with John they are unbelievably simple to make just mill 1/2 thickness
of silver steel angle end and polish, superbly effective they were better
than the cheaper reamers on sale to use. Have a go it takes little time or
material
Chris R
Dave Baker - 19 Apr 2004 17:48 GMT
>Subject: Re: D bit reamers
>From: John Stevenson john@stevenson-engineers.co.uk
[quoted text clipped - 29 lines]
>John Stevenson
>Nottingham, England.
Thanks John. When I get a roundtuit I'll make one and give it a try.
Dave Baker - Puma Race Engines (www.pumaracing.co.uk)
I'm not at all sure why women like men. We're argumentative, childish,
unsociable and extremely unappealing naked. I'm quite grateful they do though.
speedy - 30 Apr 2004 02:27 GMT
[near-total snip]> Thanks John. When I get a roundtuit I'll make one and
give it a try.
I did have a pile of roundtuits while I was at work - one of our staff made
a batch and stocked up everyone with them. Sadly, with the passage of
ime - non-power-transmitting, of course - my stock has dwindled, like the
wind in a clock, to zero, so there is no power left to transmit rouindtuits
to deserving recipients, nor are there any roudtuits to transmit :(
They were SO useful, while we still had them, and quite pretty with it, but
now I just can't roundtuit to find any more roundtuits..........
Dave.
p.s. I expect that the twerps of the EU will have outlawed them, along with
curly bananas, and other magical things, so the only permitted roundtuits
will probably now be square ones, and will no longer fit wholely snugly in
the round hole in your anvil...............
(Change feet to foot to reply)
> Has anyone made D bit reamers as explained in this article
>
[quoted text clipped - 4 lines]
> It might be one solution to my need to ream various sizes of valve guides
> without buying dozens of custom ground reamers.
I second the comments others have made - they work surprisingly well with
close tolerance. Since you want to ream through holes (ie. not blind holes)
then there is a varient that is even easier to make. Simply mill, or file,
the flat at a shallow angle to the axis of the rod. IE. Something like
this...
_
| \
| \
| \
| |
| |
That way there is no need to carefully measure anything. Just try it, you
will be surprised. You still need lubricant though.
--
Regards, Gary Wooding