Schappy Posted June 16, 2009 Report Posted June 16, 2009 Im going to cut a body with a jigsaw then use a router and template to smooth it out before sanding. Which router bit do I use? Quote
madhattr88 Posted June 17, 2009 Report Posted June 17, 2009 Im going to cut a body with a jigsaw then use a router and template to smooth it out before sanding. Which router bit do I use? I use a 1/2" flush cutting bit. Quote
Schappy Posted June 17, 2009 Author Report Posted June 17, 2009 Is this what Im looking for. http://www.rockler.com/product.cfm?page=54...mp;cookietest=1 This bit is only an inch in height. Do I make multiple passes(high and low) or look for a longer bit? Quote
Dadovfor Posted June 17, 2009 Report Posted June 17, 2009 You probably won't have much success finding a longer bit ... but see what's around. You could: Use the pattern bit with the bearing at the top and let it ride on your template ... which will probably make it half or three quarters of the way through the thickness of your body. Then remove the template and let the pattern bit ride along the freshly routed body. Depending on the length of the shank on the bit, you might be able to adjust the bit so it reaches the final half or quater. Alternatively you could use a top bearing pattern bit to route half way through the body as above ... and then if you have a pattern bit with the bearing on the bottom, flip the body over and route it from the other side. The bearing will ride neatly on the bit you just routed using the template. I've used the latter option with perfect results. Quote
j. pierce Posted June 17, 2009 Report Posted June 17, 2009 You can get a bit longer bits if you have a router that can take 1/2" shank bits. I use a Whiteside bit with a 2" cutting length, and a 3/4" diameter. Quote
Prostheta Posted June 17, 2009 Report Posted June 17, 2009 I use shorter bits such as the 1/2" mentioned. Anything more and you're ideally looking at a router table on the basis of safety. Quote
ihocky2 Posted June 17, 2009 Report Posted June 17, 2009 If you have a router table and a collet for 1/2" bits, Frued and Whiteside both make a 1/2" dia x 2" cut flush trim bit with the bearing at the bottom (top in a router table). Quote
exiler Posted June 17, 2009 Report Posted June 17, 2009 I use a 2" * 3/4 diameter CMT flush cut bit with a top bearing in a router table. Bought it on amazon. In my experience CMT bits give the best cuts. If you don't have a table, I wouldn't use such a big bit... just seems dangerous... maybe buy two 1" length bits, one with the bearing on top and one on the bottom, then rout half the body thickness using a template with the top bearing bit, flip the body over and route the other side with the bottom bearing bit using the finished part of the body as the template. I wouldn't use too short a bit... you don't want to have to pull it out of the collet to get the depth you need. And definitely use the 1/2" shank if you can. Quote
Schappy Posted June 17, 2009 Author Report Posted June 17, 2009 So a 2" bit is a no-no with a handheld router? Quote
Prostheta Posted June 17, 2009 Report Posted June 17, 2009 (edited) The worst that can happen is that it kills you. Between that and the least likely thing happening (it does the job) you just have degrees of injury. A big router bit is capable of biting into the workpiece even when you don't think you're doing a climb cut or routing end grain. One of two things (at worst, both) happen. The workpiece gets thrown across the room by the router, or if you clamped it well enough (like you should) the router will get thrown across the room instead, with the user attached. Routers excel at removing hard ligneous material from the workpiece when under control. Remove that control whilst combining flesh, tendons and other squishy easily-removed stuff with a crazy high speed cutting tool moving with force in a random direction, you have problems. You won't be able to react in time, believe me. Sorry to be so dramatic, but it's better drama than a hospital visit or stay. Router table with a solid fence is the way to go in the ideal world. Below that, go for shorter bits and take less wood out with each pass for the sake of safety. Serious stuff over - i'm off to drink cider and watch bad eighties horror. The best horror there is. Edited June 17, 2009 by Prostheta Quote
Schappy Posted June 18, 2009 Author Report Posted June 18, 2009 I think I need some more advice on how to clean up the rough cut with a router and template. I tried to search for some info but have found little. If you guys could give me some advice or point me to some good threads I would greatly appreciate it. Quote
anderekel Posted June 18, 2009 Report Posted June 18, 2009 Well, it's pretty simple really. Rough cut with the jigsaw. If you have a drill press (REALLY handy tool to have) or are very careful with a drill you can drill holes around the body to make it easier to cut out. Since it's a jigsaw you might want to leave as much as 1/4 or more, since jigsaw blades tend to bend. After that if you have a rasp take it down to about an 1/8 inch or so around the outline, otherwise just be careful with the router and don't try and take it to the template in one pass. When you're ready to route take small passes, not the full depth of the bit (if it's a 1" bit), around a half inch at a time. Quote
Schappy Posted June 18, 2009 Author Report Posted June 18, 2009 So if the body is 1.75" thick and I use a 1" bit(with bearing on the top) I use the router in 1/2" increments then flip the body over and finish the remaining portion with another bit that has a bearing on the bottom. Does the bearing ride on top of the template? Will I have to make a template for the back of the guitar as well as the top? Quote
DrkIncGuitars Posted June 18, 2009 Report Posted June 18, 2009 I also recommend a tip From Chris Monck at eguitarplans.com, taking a washer and putting the tip of the pencil inside and tracing the outline of the body then using a jigsaw to cut the body. I would also recommend a 1/2 inch ball bearing bit with 1" length to make a few passes at a time. If you lined up the pickup routes correctly you can take your time. It's a lot of work your first time, but measure twice, cute once...he also has a few helpful documents for the novice guitar builder for free! Quote
Prostheta Posted June 18, 2009 Report Posted June 18, 2009 David Myka on YouTube: 0:24 - cutting the body with a bandsaw (note that it's *very close* which means less for the router to clean up) 1:24 - cleaning up a body using a router table (although I presume he wasn't using a fence for the purposes of the video) As has been said - remove as much material as possible before moving to the router. The more material the router has to remove at once, the more likely it is that any mishaps can happen. I've had chunks blown out of my bodies before, and had the router bite on end-grain and "fanning it out". It's probably worthwhile reviewing Perry's multiscale build on YouTube also, plus there are countless other vids on there that can help. A great resource. http://www.youtube.com/user/rhoads56 Quote
Dadovfor Posted June 18, 2009 Report Posted June 18, 2009 So if the body is 1.75" thick and I use a 1" bit(with bearing on the top) I use the router in 1/2" increments then flip the body over and finish the remaining portion with another bit that has a bearing on the bottom. Does the bearing ride on top of the template? Will I have to make a template for the back of the guitar as well as the top? Schappy ... trace your template onto the blank in whatever you think is the best spot (for grain, flame, etc) and cut out your shape just outside, but very close to the outline. Then attach your template to the body (double sided tape works) and use your 1" bit with the top bearing. The bearing rides along the edge of the template and the bit is shaving an inch all the way around the side of your blank. Depending on how close you managed to cut out your blank in the first step, shave back with your router in passes so as not to overload your router bit. Keep going until your bearing is riding smoothly along the template. Take your template off and you now have a perfectly shaped body ... but only 1" through your 1.75" blank So flip the body over and use a 1" pattern bit with the bearing at the bottom. That bearing will now ride along your perfectly cut body and it will clean up the final .75" Make sense? Quote
Schappy Posted June 18, 2009 Author Report Posted June 18, 2009 Yeah makes sense. So no template on the flip side. Quote
Dadovfor Posted June 18, 2009 Report Posted June 18, 2009 No ... you don't need it and it would be next to impossible to line it up with your routing from the top. In effect, your 1" deep routing from the top creates an accurate template that your routing from the flip side will ride along. As long as you are using pattern bits (where the bearing and router are precisely the same size) you can't go wrong. Take your time and think about each stage as you do it ... you'll be surprised how straight forward it is. Just to clarify some things from an earlier post ... when you route from the top, make sure that the shank of the bit is fully and securely locked in the collet of the router. And then make sure that the guide bearing through the base of your router by the same distance as your template so that it will ride along the edge of your template. Don't plunge the router as you go, lock it down in the correct position and eyeball it before you start routing. Then when you're sure you've got it all lined up, start routing. But something that may have confused you ... you're routing will be consistently 1" deep through the thickness / side of the body if you've locked your bit in properly ... okay. But depending on how closely you cut out your guitar shape, there will be a quarter inch or so that will be visible past your template when you view if from above. That's the bit that people are telling you to take gradually. If you use a half inch bit, don't shave more than about a quarter of an inch at a time. I'm sure your router will let you do it, but you'll blunt your bits ... that's all. Go for it ... and post some pics if you want to double check anything. Quote
postal Posted June 19, 2009 Report Posted June 19, 2009 Good info in this thread- I only have one thing to add. Spiral cutter bits cost a little more, but make a far cleaner cut than straight bits. Someone "amana"? makes angled cutting flutes pretty cheap as well- but spiral is great. Only thing better is a "compression" bit. It's a double spiral- Look carefully when searching for spiral bits as there are downcut and upcut bits.... Routing using a pattern from the top, you want a downcut spiral. When you cut through the bottom of the body, an upcut spiral is best. The spiral cutter cuts much cleaner with less tearout, but must be used properly for the task. The upcut spiral used on the top of the body, will want to pull wood upward which is bad- You always want to push wood downward INTO the workpiece.... so a downward spiral cutting through the bottom of the body, would push wood out the bottom- hence you WANT the ucut spiral for this. This is where the "compression" bit comes in. 1/2 is downward spiral, then the flutes change direction, and the lower part is an upcut spiral. These can be found in 2" long pattern bits which are perfect to rout full body thickness on a router table. These bits do cost more, but spirals are worth it- Quote
Prostheta Posted June 19, 2009 Report Posted June 19, 2009 I forgot to mention in my post re: David Myka/router tables, that David was probably using a downward cutting spiral bit. I think he mentioned such a while back in router bit conversation somewhere. It would make sense, as buying an expensive router bit - or spending more on one - is far more preferable to a cheap bit damaging, ruining or leaving an undesirable finish on a comparably more expensive workpiece. Quote
Schappy Posted June 19, 2009 Author Report Posted June 19, 2009 Should I use a plunge or fixed base? When starting at the top with my template and 1" bit do I route the whole 1" or do I set the depth at about 1/2" and then reset the depth at 1" before I flip the body over and finish up? Do Spiral bits have bearings as well? Quote
Woodenspoke Posted June 19, 2009 Report Posted June 19, 2009 Should I use a plunge or fixed base? When starting at the top with my template and 1" bit do I route the whole 1" or do I set the depth at about 1/2" and then reset the depth at 1" before I flip the body over and finish up? Do Spiral bits have bearings as well? You can decide for yourself how many passes to make around the body. The deeper you go the more difficult the operation is, even when removing only 1/8". So take your time. The down side to this is it creates small lines in the wood which will have to be sanded out. The more passes the more lines that are created. Even a guide bearing can and will create their own lines (indents) as well. All of which is normal unless the bearing is not clean and lubricated in which case it will most likely burn the wood from friction. To go back to earlier comments about using two bits. First yes you can do it that way. Secondly you dont really need two bits. Once you have the deepest cut you can make using the template and the 1" template bit (I really suggest 1 1/4" long 1/2" shaft template bit to start) just remove the template and keep going using the routed body as your guide. When you get to the bottom just hang the body off the edge of the table so you can finish up without eating up your work surface. You will need to clamp the body and move it around several times as you finish up. I use a 2" bit and make one pass its not for the faint of heart as my first student can attest to, he didn't like routers after that. From now on I will use a smaller bit when I take on a new student, LOL I have seen some spiral bits on OLF that are bolted to the shaft but can not find a price list, if anyone has such a source please let me know. Quote
exiler Posted June 19, 2009 Report Posted June 19, 2009 plunge or fixed base router? Shouldnt matter... both are adjustable height and you won't need to do any actual plunging, so if you use a plunge base you'll be using it the same way you'd use a fixed base. Personally I'd use fixed for this just cause it's marginally easier to set the depth without fighting the springs Quote
Woodenspoke Posted June 19, 2009 Report Posted June 19, 2009 plunge or fixed base router? Shouldnt matter... both are adjustable height and you won't need to do any actual plunging, so if you use a plunge base you'll be using it the same way you'd use a fixed base. Personally I'd use fixed for this just cause it's marginally easier to set the depth without fighting the springs +1. there is no advantage in this operation using a plunge. If you can afford it get a plunge but it is not necessary to build a guitar. Quote
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