I am contemplating the best way to go about boring a large number of identical holes into wooden blocks (into the end grain, specifically). The difficulty is that the holes that I need are not cylindrical. Currently I am completing the task by drilling a cylindrical 1" hole into the wood blocks using a drill press, then mounting the blocks onto a lathe to hollow out the approximate shape that I am after. However, this is somewhat difficult and very tedious - not to mention highly variable - and I am trying to come up with a more efficient and precise solution. The shape that I am shooting for (as well as approximate dimensions) is below:
(https://forestryforum.com/gallery/albums/userpics/15533/boring.jpg)
What would your solution to this problem be? I am not necessarily looking for a low cost solution or a high cost solution. I am simply trying to identify the best solution, and will consider just about any ideas. The critical aspects are quality of the results (I am looking for a smooth cut that will require minimal cleanup), efficiency, and repeatability.
Currently, I am leaving towards a custom bit that I can use on my drill press and that will cut the desired shape. If this is indeed the best solution, then do you have any recommendations for companies that could make the cutters? Any pitfalls that you can think of? Thanks in advance for your help. If you need more information to formulate an answer, then ask away.
Now you have peaked my curiosity as to what it is you are making. ??? Apparently you are needing to make a fairly large number of these holes. My first thought is the same as yours - a custom drill bit. Don't have any suggestions on sources though. Maybe someone on here will know someone who can make a bit.
That's a pretty interesting set of dimensions to work with. I'd have to suggest either a custom ground tapered spoon bit or a custom made router bit that you could put in a plunge router. You'd certainly want to use a variable speed router with a bit that size and I think I'd make a sort of upside down router table. Have the router mounted to a plate that will hold it and the block you're routing securely so you can just plunge the router without worrying about holding on for dear life.
You might take a standard spade bit and grind it to the required dimensions. That would be a cheap solution. You could get it very sharp, and maybe it would do OK in the end grain. That way, you would have the control of the drill press to ease the bit into the wood.
Thinking maybe a bit with inserted teeth like the teeth in the spiral planer heads, but with the tooling that you can set the teeth at the desired depths. ?? ::)
Chip removal may be tricky if this idea even is possible. But air blown down the center of the bit shank might blow the chips up and out. ::)
Quote from: WDH on October 04, 2012, 10:34:34 PM
You might take a standard spade bit and grind it to the required dimensions. That would be a cheap solution. You could get it very sharp, and maybe it would do OK in the end grain. That way, you would have the control of the drill press to ease the bit into the wood.
I have actually ground spade bits to custom shapes before with success. But I am thinking that chip clearance may be a big problem with a hole this big. Plus, I think HSS or carbide will be a necessity. The number of holes I am thinking of is in the thousands. Maybe more.
if you have that many, I'd contact a drill manufacturer, or a router bit company for a custom bit.
I don't think a router is the tool I will be wanting to use for this application. The hole is simply too big. I have thought some about milling machines. I don't want to buy a milling machine (not planning to drill quite that many holes just yet), but I was wondering if the bits could be used in a drill press? From the looks of them, it would appear that the bits would cut wood very cleanly. This is a primary concern. Anybody out there with milling machine experience? I know they can be used on wood, but not sure if this wood be a good application or not.
you could put the router bit in a drill press or milling machine.
have you contacted a tool maker?
If you spec out your requirements, they can probably give you a hand.
Does the shape have to be repetetive, with little tolerance from one to another?
Or can the shape gradually change as the bit wears and can then be resharpened?
Thinking of a mini size rotary well drilling head that has three cutter wheels. But would be very expensive to make (I'd think).
I would look to get a custom made router bit to that profile. Drill the hole first to hog out most of the material, 1" drill bit?
Once the bulk of the material is removed from the centre a big plunge router with a custom bit should clean up the hole to that profile.
You don't want to spin a 1.75" bit at full router speed, but a big variable speed router like my Makita 3126c spins a 2" dia flat bit on my slab surfacer with the speed set to 2 out of 5 on the speed control. The electronic controller keeps the torque up even with the slower RPM, and the cutter's speed stays correct for the bigger router bit.
Ian
A custom made router bit would be the way to go. I'd prefer a mill for the boring myself, although a heavy drill press would do the job. Lots of companies will make custom bits. Whiteside Machine is one, although I've never dealt with them. (A quick search just found 'em online.)
Older used milling machines can be had relatively cheaply, but moving them is a bear They ain't light.
Do a search for "reamers" Dodgy and see what you come up with. I don't know if you can get one blunt enough.
i would find a shop that has a cnc machine. have them qoute the job, that way you know a fixed price and a cnc will hold tight tolorences and give you consistinacy every part.
I'm also thinking of a custom router bit.
In the past I have worked with WDR sales to make custom moulding knives. Bill, the owner has been around for a long time. He has made a lot of custom and one off tooling. Give him a call. He may have an idea that we haven't thought of here.
This is one of their products. I've never seen one and have no idea how it works but it's certainly worth exploring.
http://www.wdr-sales.com/routerbit.htm
Just another thought. A overarm router rather than a plunge router might be the right tool. If a slower speed is required a custom machine similar to a drill press might work. I picked up a custom machine that uses an air cylinder to run the drill bit up and down. It was used to drill one end grain hole in novelty wood train whistles by the thousands.
I would look into making it with a reamer as SD sayes, you can cut and sharpen a reamer for the bottom of your hole. They are on the $$ side, first try it with a small one ;) We often used reamers on structural steel to help out bolting the peices together. I would probably used compressed air to help with the chips, as the reamers do not carry chips well.... ;)
You could also make the hole a two step , one cut to make the bottom with a wood bit, then a reamer to get your tapper .
Quote from: Dan_Shade
you could put the router bit in a drill press or milling machine.
have you contacted a tool maker?
I hadn't considered putting a router bit in a drill press. That's something to consider.
I haven't contacted a toolmaker, because I've had very bad luck just picking out an ad on the internet and crossing my fingers. I sent $300 worth of blades to an tool sharpener a few months ago and got back the most useless, mangled tablesaw blades I've ever laid my hands on. I was hoping for recommendations this time.
Quote from: beenthere
Does the shape have to be repetetive, with little tolerance from one to another?
Or can the shape gradually change as the bit wears and can then be resharpened?
The shape could change over time with sharpening with little effect on the final product.
Quote from: LarryIn the past I have worked with WDR sales to make custom moulding knives. Bill, the owner has been around for a long time. He has made a lot of custom and one off tooling. Give him a call. He may have an idea that we haven't thought of here.
This is one of their products. I've never seen one and have no idea how it works but it's certainly worth exploring.
http://www.wdr-sales.com/routerbit.htm
Thanks for the link, Larry. That looks like it would be an good, affordable option.
Quote from: red oaks lumber
i would find a shop that has a cnc machine. have them quote the job, that way you know a fixed price and a cnc will hold tight tolorences and give you consistinacy every part.
Thanks, but I'm not looking to outsource the production.
Quote from: SwampDonkey
Do a search for "reamers" Dodgy and see what you come up with. I don't know if you can get one blunt enough.
A reamer-type bit is actually exactly what I had in mind to begin with. I would need to get one custom made, though, I'm sure.
Quote from: isawlogs
I would probably used compressed air to help with the chips, as the reamers do not carry chips well.... ;)
That's a good idea, and it would be easy enough to set up. Compressed air would probably help if I went the way of a router bit, too. Lots of good ideas, thank you all. This is exactly the kind of brainstorming that I needed! :) Feel free to add more ideas, and I will report back as I make progress.
Quote from: Larry on October 05, 2012, 08:06:40 AM
Just another thought. A overarm router rather than a plunge router might be the right tool.
That was what popped into my head too. AKA a pin router, they were replaced by CNC and can therefore be found very cheaply these days. I picked up a Delta RU50 for $400 but I haven't gotten around to using it yet. Bought it for a project that I have been planning to do for 25 years now. Someday......
may be easier to have someone remold the candles to fit your drill bit holes....
Quote from: Brad_S. on October 05, 2012, 04:00:25 PM
Quote from: Larry on October 05, 2012, 08:06:40 AM
Just another thought. A overarm router rather than a plunge router might be the right tool.
That was what popped into my head too.
Interesting, I had never heard of an overarm router, but that looks like it would be perfect for what I have in mind. Maybe if things go as planned, that would be the next step.
Quote from: ely on October 05, 2012, 04:33:21 PM
may be easier to have someone remold the candles to fit your drill bit holes....
DanG, now why didn't I think of that? ??? Oh yeah, I'm not making candle holders :D
Sorry for being so vague, but I can't go around throwing my brilliant, million-dollar ideas on the interwebs before they are ready for production, now can I? ;) Just kidding. Maybe I will earn a few bucks on the side, and y'all will be the first to know if I decide to take my idea into production. :)
Me thinks you are running into the same trouble as me looking for fine yarn or fine SS strip wire. Everything is industrial quantities or off shore. This continent is going to $%^$^%$ :D
swamp.. i found you a company that had wire close to your spec, too bad they didnt want to ship to you.
tapered reamer almost seems like the ticket for this job. Id go with a 2 flute, but it has to be a grind that cuts on the sides and the bottom. I think its called a mortising bit
You could do something like the lumberjack countersink bit
My first thought was to have a special bit made, whether it is carbide or hss resharpening will come into play. 'the other thought is changing the geometry of the hole. What would be the most cost effective solution. If the existing geometry has to be met, I see a two stage operation, one roughing hole, followed by the finishing pass.. Just by your sketch it appears you only have a few degrees of taper per side, not knowing the bottom dia. and the radius call out. Is a clean top edge important? is the bottom radius important? This size of this bit is costly no matter what it is made from, this is definetly an interesting problem. Good luck,, david
First post, might as well jump right in...
If you have already determined that your product is viable, and you want to produce it in house, (in large numbers) I would be inclined toward the use of a lathe with a turret tail-stock. Probably one with lever actuation.
Not all that familiar with cutting end grain, but were it aluminum or similar, I would go with a pilot drill, then your 1.75, maybe a large end mill for the floor of the hole, and the final cut with a 'form tool', which you could probably make yourself.
A dedicated set of jaws for the lathe chuck would be in order for fast changeover. This would require a bit more care on consistency of stock sizing.
The advantage to the lathe is the chips will tend to self clear, the surface finish will probably be better than the drill press/mill, and the form tool for the final cut can be fabricated in house by welding/brazing, and finish grinding.
Once set up, it should also be rather fast.
Using a custom reamer might work, so long as the chip load per 'plunge' doesn't exceed the flute volume. The upper flutes might not self clear, however, and a dull reamer is harder to sharpen than a form tool.
Of course, more specific and set criteria might dictate another approach.
welcome to the forum, North River Energy.
Do you run a machine shop?
Another welcome to the Forestry Forum, NRE
Very interesting suggestion using the lathe.
There is a new listing on eBay about some spoon auger used to cut holes in logs, in the end grain for making log pipes.
The forum rules don't allow me to post an active link so you'll either have to do a search on ebay for "spoon augers" and look for the set selling for $450 in Carver, MA or PM me and I'll send you the link.
There is one spoon auger in the set that may be the right size to make your holes.
And it maybe possible to put this into a motorized machine to make the cut, if you fabricate something to hold the spoon auger.
There was a video somewhere I saw recently showing a machine that was used to hold the spoon auger bit to bore holes in the end of logs to make a wooden pump, but that could have been on another forum.
Jim Rogers
Quote from: drobertson on October 05, 2012, 08:31:59 PM
Is a clean top edge important? is the bottom radius important?
The whole cut needs to be clean, and it is important that the bottom be radiused. The specific dimensions of the radius doesn't really matter, but there can't be a sharp corner at the bottom.
Quote from: North River Energy on October 05, 2012, 10:54:07 PM
If you have already determined that your product is viable, and you want to produce it in house, (in large numbers) I would be inclined toward the use of a lathe with a turret tail-stock. Probably one with lever actuation...
...The advantage to the lathe is the chips will tend to self clear, the surface finish will probably be better than the drill press/mill.
That's actually a very good idea. My lathe has a much more powerful motor than my drill press, and you have a good point about the ease of chip clearance when drilling horizontally. I only have a screw tail-stock, but a lever action would be nice if I actually make some money to put into this idea. I have not yet determined that it is viable (it's an entirely novel product - I will have to create my own markets) so I'm looking to start small and work my way up if I have a little success.
Quote from: North River Energy on October 05, 2012, 10:54:07 PM
A dedicated set of jaws for the lathe chuck would be in order for fast changeover. This would require a bit more care on consistency of stock sizing.
I do have a chuck that will hold the parts that I am drilling nicely.
Quote from: North River Energy on October 05, 2012, 10:54:07 PM
Using a custom reamer might work, so long as the chip load per 'plunge' doesn't exceed the flute volume. The upper flutes might not self clear, however, and a dull reamer is harder to sharpen than a form tool.
More good thoughts. Welcome to the Forestry Forum, and thank you for your contributions! :)
Thanks for the greeting(s).
QuoteDo you run a machine shop?
Yes, and not really.
I use machine tools primarily for my own nefarious purposes, (and not every day); for outside work when necessary and/or interesting.
Most of the iron is obsolete by today's production standards, but that provides perspective.
Dodgy,
I'll think on it some more. If you can provide any more information on either the work piece itself, (without compromising your idea) or your present tooling array, that would help.
I recently finished two small parts runs on the lathe, with multiple tool changes, so this stuff is still fresh in the mind.
And you're welcome.
Quote from: red oaks lumber on October 05, 2012, 08:03:26 AM
i would find a shop that has a cnc machine. have them qoute the job, that way you know a fixed price and a cnc will hold tight tolorences and give you consistinacy every part.
I'd second this option. You could supply the wood, in consistant sizes, and they could handle the machining. I have years of experience with programming, set-up, and operation of CNC routers, and they can do some really precise work.
Hi Dodgy... this may seem stupid, but in a pinch I have used coarse grinding stones to make a final shape. Bore your initial hole 1' wide by 2.5" deep. Take a large profile or cylinder bit and redress the stone to the desired shape. You'll need to take it slow and use compressed air periodically and clean the stone after each bore, but with some trial and error, it should give good results, as long as you're not wanting to do 1000's of them. cost might be under $20.
Drill a small 1/4" or so hole. Insert fire cracker, light. Examine results and adjust powder charge accordingly... Just kidding but everybody else took all the good ideas. I am a very curious person and the suspense is killing me.
Does one need a spiraled cracker to drill ???
Quote from: 5quarter on October 10, 2012, 12:59:30 AM
Hi Dodgy... this may seem stupid, but in a pinch I have used coarse grinding stones to make a final shape. Bore your initial hole 1' wide by 2.5" deep. Take a large profile or cylinder bit and redress the stone to the desired shape. You'll need to take it slow and use compressed air periodically and clean the stone after each bore, but with some trial and error, it should give good results, as long as you're not wanting to do 1000's of them. cost might be under $20.
I am currently able to do it faster by hand on a lathe than I would be able to do with a grinding stone. Looking to scale up to where I could do thousands in a matter of weeks.
Quote from: hackberry jake on October 15, 2012, 01:12:48 PM
Drill a small 1/4" or so hole. Insert fire cracker, light. Examine results and adjust powder charge accordingly... Just kidding but everybody else took all the good ideas. I am a very curious person and the suspense is killing me.
Haha, I like your style but I am currently exploring other options :D
Don't hold your breath, it's likely to take a couple of months before I'm ready to bring my product public, but believe me, y'all will be the first to know :)
Put me down for one, whatever it is :).
Whatever it is, I wish you every success in the venture. :)
Will do, Danny! And thanks, SwampDonkey :)
I just caught up on this thread and agree with North River Energy. Welcome aboard, BTW!
A machine bench lathe could do the job for you consistantly. The change out of the pieces would take a few more seconds per part over the turret lathe. Smaller, used bench lathes are fairly common and inexpensive, too. Not to mention they are handy to have around. :) A simple shaped HS scraper tool held in the tool rest and fed into a prebored hole will make your part in about 2 seconds. Most of your time will be changing out parts in the chuck.
Custom tooling, of course, is very expensive. Your biggest problem with prototyping is making changes to your ideas over time. If a tool and die shop is involved the charges rack up big time. Not to mention the frustration for you as well as the tool maker. My best friend is a tool and die maker and he is constantly venting to me about change orders from customers. Contracts are involved, of course, so nobody is surprised by pricing, but it's still frustrating.
I am a manufacturing engineer who has progressed up through the ranks. I started as a machinist, then a toolmaker, then a tool designer, CNC programmer. Now I do it all, from start to finish.
There are problems with the manual turret lathe option. First, have you tried to find one in good shape lately? I have. The aren't too plentiful. Second, they are quite costly.
There are problems with the CNC router option. First, without a form tool to complete the operation, contouring with a ball end mill would be time-consuming if you want a decent surface finish. Second, custom tooling for a form tool to be used on a router would be expensive, but probably under $1K.
I know it has been mentioned to modify a HSS paddle bit. This could be done very easily and when the proper relief angles are added, will cut quite well. You could grind off most of the point on the end, leaving just enough to help stabilize the bit in the cut. You could put it in the tailstock of a wood lathe and accurately guage the depth of cut. If the small hole on the bottom left by the point on the bit is a problem, make another bit with no point on the end, put it in another drill chuck, and swap out the rough bit for the finish bit and take a tiny cut to remove the small hole.
I don't recall the number of parts needed, but I would think you could easily produce 30-60 parts per hour after you get your rhythm down. The HSS bits might be able to produce that many parts without resharpening. You could make the bit and resharpen it by hand. If you haven't done much tool grinding, it will take some practice, but once you gain experience, it will not be too difficult.
I got the impression that Dodgy Loner didn't want to spend thousands of dollars to get this project going and would prefer to do it himself if possible. This would be the solution.
Thank you for your thoughts, metalspinner and grweldon.
Ok, I've been exploring custom tooling, and as metalspinner noted, it will be quite expensive no matter which route I take. More expensive than I was initially expecting. I'm looking to start this project with minimal expense, and perhaps if I find success, I will scale up with better equipment and tooling.
A HSS paddle/spade bit would be an inexpensive way to get started, and no doubt the best way to use it would be in the tailstock of my lathe. I have used spade bits in my tailstock before, and have alway found that the shaft flexes to an intolerable degree. The obvious solution is to use a bit with a very short shaft, since a long shaft is unnecessary for this application, but these seem to be rarer than hen's teeth, because I can't find any. Of course I can order a custom spade bit with a shorter shaft, but then the cost goes back up. Maybe I'll just order a standard HSS spade bit and if I find that I'm able to grind it to the tolerances I need, I can try a custom bit. This is turning out to be more work than I thought! :)
You can stiffen up the shaft of a spade bit with a thicker piece of round stock with an accurately placed drilled and reamed hole with a setscrew hole tapped into the side. A bit more work, but will work well.
You can also just cut off the shaft of a spade bit with an abrasive cutoff tool. You can get small ones for dremel tools that will work.
If you sincerely give several attempts to grind the proper bit without success, I could try to offer assistance. I know how to grind tools and have ground several hundred by hand, but I am also out of practice. If you need assistance with how to grind one properly, I can probably describe it to you without writing a book...
I know the feeling. At times it seems things are all against ya. Can't find this or that and live in an area don't work with the little guy. ;)
You have really piqued my curiosity ???. When you have it all sorted, will you need an agent in New Zealand?
Well, you are in luck. I just so happen to have the cure to your problems at hand. I can easily alleviate your concerns of equipment choices and multiple tooling requirements, and by doing so, greatly reduce your capital expenditures and overhead for your quest.
Simply put, I make Holes.
I happen to have in stock the hole in the identical dimensions you have posted, although a few minor changes may be required along with additional information needed to obtain the proper holes of which you desire.
Think about it, no expensive tools, no additional space required for all that expensive machinery, no additional electrical requirements nor higher electrical bills, no tooling to shape, sharpen or break. Sound too simple, well it is.
I will box up as many holes as you need in the exact dimension you desire and ship them directly to you. A partial payment deposit of 75% of total order may be required prior to shipping the holes to you.
Now, if the UPS /Fedex gorillas happen to mishandle the package during shipment, thus resulting in loss of some or all of the holes, I will gladly resupply the lost holes to you at a greatly reduced rate.
The only reason I am selling some of my holes is to pay off my Ocean front property in Arizona. So please hurry yer order right along............ :D
-----Sounds like you have gotten some goodfeed back on how to obtain your 'holes'.......... I jus' couldn't help myself... ;D
But wait, there's more! If you call in he next five minutes, we'll throw in an extra set of holes, a $50 value for only $19.99 plus s+h. If you act now!
This afternoon I thought I would grind out something and give it a shot. I scrounged around to find some knife steel wide nuff, and what I found is really too thick but its what I had. I wanted to do a proof of concept more than anything.
(https://forestryforum.com/gallery/albums/userpics/10125/DSCF7020.JPG)
(https://forestryforum.com/gallery/albums/userpics/10125/DSCF7021.JPG)
I first drilled into face grain. It was really taking the power and I didn't finish the hole. Second try was into end grain and that drilled fairly easy as the drill was pulled out fine powder. I had to clamp the work because without some kind of pilot the drill wants to wander. It might work better with a pilot, similar to a spade bit. I suppose it would take 15 seconds to drill a hole if you had a good clamping system. I was using just a standard drill press on the slowest speed. Probably has a ½ horse motor.
There wasn't a diameter on your drawing for the bottom of the hole so I sorta scaled it. The width and depth are per the drawing. The cutter is high carbon steel and needs to be hardened so I can put a really sharp edge on it. That might improve the finish also. It would be better if it was HSS but I didn't have any. If you want me to harden and finish the cutter send me a pm with your address. I'll drop it in the mail after I harden it. No charge as I was just furthering my education.
That's the ticket Larry! Above and beyond the call of duty! Good Job!
i love this place!
Quote from: Dodgy Loner on October 18, 2012, 12:02:04 PM
This is turning out to be more work than I thought! :)
Dodgy, genius can be a lot of work ;D.
Larry, you are amazing 8).
Gotta love ff hospitality!
Wow, Larry - I can't believe you did that (but I'm grateful that you did!). PM sent :).
Ernie - I'm afraid I'm getting everyone's hopes up for a product that is more groundbreaking than what it really is :D. You will probably all roll your eyes when I let the cat out of the bag, but I guess you can say that I had a "vision" while lying in bed one night, and it involves as much marketing as substance. The product might not blow you away, but my hope is that the marketing will ;D
Dan, Danny, and Jake - this is the best place on the internet, isn't it? :)
May be a little late on topic, although several (many) years ago my father and I were boring out birch blanks for bird houses. Used both a vertical mill and lathe. The vertical mill worked great had plenty of power and great variable speed for both feed and bit RPM. The trick was holding blanks, Dad was great at figuring this stuff out. Lathe also worked albeit slower with more fiddling around.
I heat treated the bit this afternoon. Left it really hard...hope that's not a mistake. Cleaned it up and sharpened. The finish improved along with the ease of drilling.
I'll drop it off at the post office Monday.
The hole on the left is the last one I drilled. The one on the right is before heat treatment. A picture of the dust. I didn't have to stop to clear it while drilling.
(https://forestryforum.com/gallery/albums/userpics/10125/DSCF7034.JPG)
(https://forestryforum.com/gallery/albums/userpics/10125/DSCF7036.JPG)
(https://forestryforum.com/gallery/albums/userpics/10125/DSCF7035.JPG)
If the bit shows promise once you try it out, we might talk about production drilling/clamping.
Way to go Larry !
Another member comes thru for another.
stump
Hey Larry, while you are in the process of making things for members, I could use a time machine, or a winning lottery thicket printer, or a robotic replica of myself so I can get twice as much work done. 8) oh but if you make the replica, leave out the mouth, I get tired of hearing that jerk ;D
My 7 year old grandson says you can't build time machines. If you went back in time, you could "really mess things up". :D
Dig out the Star Trek TOS DVD's, episodes "City on the Edge of Forever" and "Tomorrow is Yesterday". :D
Couldn't mess it up any worse than the first time through. ;D
Quote from: hackberry jake on October 22, 2012, 03:48:02 PM
Hey Larry, while you are in the process of making things for members, I could use a time machine, or a winning lottery thicket printer, or a robotic replica of myself so I can get twice as much work done. 8) oh but if you make the replica, leave out the mouth, I get tired of hearing that jerk ;D
If you had the time machine you wouldn't need the winning lottery ticket printer, would you? ???
It would save paper.
Larry's bit came in today 8)
It will be tomorrow evening at the earliest before I get a chance to try it out, but it looks great. I'll report back with the results. I intend to give it a go in my drill press and my lathe to see which works best. I'm excited.
Thanks Larry! :) :) :)
It is a boring customs custom boring bit.
Well, it sure is a custom bit at least. Happy boring. :)
Well I gave the bit a spin on Friday evening, and it worked very nicely and left a clean cut, but unfortunately, the dimensions I gave in my original drawing were a bit too "approximate" and the bit is going to be too big. I'm going to try to grind it down some to get the size that I will need. I would have measured more carefully if I had known that my drawings would be used to create an actual bit! :D
Thanks again to Larry. I think eventually I will order a HSS or carbide bit, but I'm hoping that I can get this one working well enough to get me started. My grinding skills are not as good as Larry's, so I'm gonna take it slow :)
I'm just glad to hear the bit worked. At least you know which direction to go.
The bit is carbon steel and will lose temper if you get it hot. I sharpened it with a 120 grit belt on a belt grinder. You might be able to do the same with a belt sander in a vise. Don't burn your fingers ;D
Some fashion of tool steel will be needed. M2 High Speed steel would be a good choice. A2 is an air hardening tool steel that would be good for a cutting tool, but it isn't cheap.
Here's a link.... This is a cut to length bar of A2 1/4 thick and 2 1/2 wide. I think it's a bit over $42 per foot.
http://www1.mscdirect.com/cgi/NNSRIT2?PMAKA=05945845&PMPXNO=1748373&cm_re=ItemDetail-_-ResultListing-_-SearchResults
When you actually machine your tool blank, don't overheat it. Keep it cool enough that it doesn't change colors from silver to bronze or (worse yet) blue. Grind it about a 1/16" oversize because it will change slightly when you heat treat it. For heat treating, heat cutter blank up to bright orange-red, which will be about 1500-1600 degrees, then put a fan on it until it's room temp. Then, polish up one side enough to tell when it will start changing colors from bronze to a medium blue when you temper it. This will bring the hardness down to around Rockwell (C-scale) 50 or so, which will be hard enough to last a while but soft enough not to chip. If you need it harder, only heat it to a medium bronze color before you put the fan on it. This will be harder (Rc-55-60) but it will be more brittle. It's a tradeoff any way you go.
I can't stop wondering what is going in the holes... And why it is going into end grain... Dodgy, you are much better at keeping secrets than myself. Guess I'll just keep wondering. Here are my thoughts so far.
1. Wooden shot glasses
2. Candle holder(but you already ruled that out.)
3. Some form of stackable wooden toys
4. This whole thing is a torture test for curious people (me) ???
Thanks for the grinding advice, Larry and grweldon. I've got lots of experience grinding plane blades and chisels without ruining the temper, but I don't have to worry about symmetry with those. It's keeping the bit symmetrical that gives me nightmares! I'm just going to take it slow, dip it in water often, and check my progress regularly, and hopefully it will all come out alright.
Jake, you're right - I am good at keeping secrets ;D
Don't waste your time with carbon steel. You will be very quickly disappointed and you will spend more time sharpening than cutting...
Quote from: Dodgy Loner on October 29, 2012, 05:10:27 PM
Thanks for the grinding advice, Larry and grweldon. I've got lots of experience grinding plane blades and chisels without ruining the temper, but I don't have to worry about symmetry with those. It's keeping the bit symmetrical that gives me nightmares! I'm just going to take it slow, dip it in water often, and check my progress regularly, and hopefully it will all come out alright.
Jake, you're right - I am good at keeping secrets ;D
If you haven't skinned this cat yet or didn't like what you found after skinning it, you might check with http://www.magnate.net/index.cfm?event=showCustom They do lots in the size range you are looking at. Their standards aren't too costly. Looks like the only dimensions missing from your drawing for what they'd need is the taper angle and the bottom shoulder or heel radius you are wanting.
Just wanted to add to kelly's great idea. We made similar blades a few years back, using the shank for the holder while grinding the profile. I thought I had some of the bits saved back, sorry been a few years back. Here is a few images of the basic idea. I hope they help, We used A-2 as Gr mentioned, a very stable and grindable tool steel. david
(https://forestryforum.com/gallery/albums/userpics/30023/IMG_0073.JPG)
(https://forestryforum.com/gallery/albums/userpics/30023/IMG_0072.JPG)
My apologies to Larry, just had a phone call from Kelly, sorry, Larry great idea you have there man. We just made our interchangeable so that we could have different diameters for the coin tubes. Have a good day, Merry Christmas. david
For some reason this post popped into my head today and I checked it to see if dodgy had spilled the beans yet... nope. Any updates? Can ya tell us what its for yet? Did you get something to work?
And I was working with him last week. I coulda twisted his arm. ;D
Quote from: Cypressstump on October 18, 2012, 03:20:01 PM
Well, you are in luck. I just so happen to have the cure to your problems at hand. I can easily alleviate your concerns of equipment choices and multiple tooling requirements, and by doing so, greatly reduce your capital expenditures and overhead for your quest.
Simply put, I make Holes.
I happen to have in stock the hole in the identical dimensions you have posted, although a few minor changes may be required along with additional information needed to obtain the proper holes of which you desire.
Think about it, no expensive tools, no additional space required for all that expensive machinery, no additional electrical requirements nor higher electrical bills, no tooling to shape, sharpen or break. Sound too simple, well it is.
I will box up as many holes as you need in the exact dimension you desire and ship them directly to you. A partial payment deposit of 75% of total order may be required prior to shipping the holes to you.
Now, if the UPS /Fedex gorillas happen to mishandle the package during shipment, thus resulting in loss of some or all of the holes, I will gladly resupply the lost holes to you at a greatly reduced rate.
The only reason I am selling some of my holes is to pay off my Ocean front property in Arizona. So please hurry yer order right along............ :D
-----Sounds like you have gotten some goodfeed back on how to obtain your 'holes'.......... I jus' couldn't help myself... ;D
There was a fellow in a small New Zealand settlement called Waimuckaroun who come up with a similar solution,This was about 40 years or so ago,anyway he was thinking more agriculturally and his idea that he put into production was fence post holes.Some how his first big order,and it was a big order,was a shipload and they were going to Japan as I remember.Anyway he got the order finished and sent them to port for loading.This was in the days before containerization and all the loading was done by wharfies or watersiders.They finished loading on a Friday night and the boys were in a hurry to get to the pub after work and were a bit sloppy about loading them but the leading hand signed it off so 'no probs' Not to be the case,half way across the Pacific they rain into rough weather and the load shifted.....badly. All those post moved around and when they hit the side of the boat well you can imagine what happened.In short order the hull resembled a fishing net and went down. My mate lost the contract but worse they sued him for failure to supply,he lost every thing, well almost ,he's still got all the plans but the banks wont touch him ,reckon his budgets full of holes. [couldnt help myself either] cheers john . PS come on Dodgy spill.