On Tuesday, July 22, 2014 1:13:45 PM UTC-4, Paul K. Dickman wrote:
"rangerssuck" wrote in message

...

On Tuesday, July 22, 2014 12:10:02 PM UTC-4, Paul K. Dickman wrote:

"rangerssuck" wrote in message



...



On Monday, July 21, 2014 4:13:23 PM UTC-4, rangerssuck wrote:



I need to make (or have made) a custom router bit. The groove I need to



make is a truncated V 15/16" wide at the top, 3/8" wide at the bottom

and



1/4" deep. The dimensions aren't super critical, but closer is better..







I do NOT have a real tool grinder, and HF seems to have discontinued



theirs. I also don't (as will become apparent) have more than a very



little bit of experience grinding tool bits. I DO have 1x30 and 4x36

belt



sanders, a set of 5C collets and a square collet block.







I'm thinking that I could lay out the shape on a blank, hold it in the



collet block, set the fence on the sander to 41 1/2? (to form the V



angle), tilt its table to 20? or so (to form the cutting edge and then



grind to the line. Then grind the flat end and its cutting edges.







Question 1:







Does the above sound reasonable?







I have found a source for HS blanks http://goo.gl/13G1cD but a) they're



not at all cheap and b) they have a half-inch shank and I have a 1/4"



router. I'm not opposed to a new router, but only if I really need it..







Question 2:







Is there any reason I couldn't start out with a 15/16" spade bit as my



blank? Even the most expensive spade bit is going to be less expensive



than that router bit blank. Is there something about a spade bit that



would make it totally unsuitable for this?







Question 3:







should I just job this out? If so, is there anyone here who would want



to do it? How much should I expect to pay?







Thanks for the input.







Thanks for the input so far, and here are some answers to the questions

that



were raised:



1) The project is modifying the double-hung windows in my house to work

with



replacement jamb-liners. These are spring-loaded and are the mechanism

from



jeld-wen windows, purchased from an outfit in Milwaukee. They used to sell

a



router bit for the purpose, but they say they can't get the blanks

anymore -



what they were actually doing is modifying an HSS v-groove cutter that has



been discontinued by Sears. I had purchased a bit from them and it's done



OK, but then I hit a nail and even though I've resharpened, it's not going



to put up with that too many times and I have 25 more windows (50 more



grooves) to do. The material I'm cutting is chestnut oak.







I have to do these windows one or two at a time, as the whole job is kind

of



big and I don't want to disassemble all 25 windows at once.







I have a router table (shop made) set up to do this with the appropriate



fences and feather boards, and I'd much rather not have to switch bits for



each cut. I imagine that two passes (3/8 straight) and a 45 v-groove with



the bearing removed would probably do a great job, but it's either a bit



change or a second machine. Also, having standard-size cutters (and

carbide,



too) would be a major plus.







As for the spade bit being only a 1/4" shank, the router (and bit) that I



have now is 1/4" shank, and that's not a problem.







What I would REALLY like is a shaper table to do this, but that's not in

the



cards now, and would still involve either two passes or a custom cutter..







If I could come up with a way to do a quick-change of the bits (straight &



V) that would get them to the same height (perhaps a small collar under

one



or the other if they're close to begin with the bit-switching wouldn't be

so



bad. If I have to adjust the height each time, it would be a bitch - my



router table doesn't have a lift mechanism.







But back to the original question - is there anything inherently bad about



using a modified spade bit in a router? Would it be likely to fly apart at



speed if it was slightly off balance? [I've done some design work on



controls for 90K RPM motors and seen some spectacular failures]







A paddle bit will twist up as soon as it hits the wood and screw up the

job



and probably put your eye out.







I assume you are plowing the sashes to fit the patent balance.







From the dimensions and the descriptions of the modified tool this angle

is



close enough to 45deg to be designed that way.







Don't reinvent the wheel.







Buy a 5/8" 45deg. v-grooving bit. Blunt the end to around 3/16 and cut in

two passes.



http://www.mlcswoodworking.com/shops...-Groove_Anchor



The blunted end will leave the bottom fuzzy but it probably won't make any

difference because the sashes probably locate on the bevel before they

bottom out on the flat.



Paul K. Dickman



This raises an interesting question (setting aside that the 5/8 is too small

and I'd have to go to the 3/4" size) : are the dimensions that I have,

supplied by the distributor, correct? They are probably "close enough for

government work" but if you're a carpenter with a ruler that only goes to

16ths, they many not be correct, and the angle may well be 45� rather than

41.6�.



I will check the dimensions today.



Buy a 5/8" 45deg. v-grooving bit. Blunt the end to around 3/16 and cut in

two passes.



Why two passes?



Because the 5/8 is too small.

more easily dealt with by going up to the 3/4" bit and lowering it in the router table, I think.

BTW, #5419 on http://www.mlcswoodworking.com/shops...-Groove_Anchor is, except for the totally wrong dimensions, exactly what I need. It cuts a v-groove with a flat bottom.