12-03-2012, 10:02 AM
Thanks for reading the thread Gary, and for your kind comments.
Yes, routers can be a bit scary, but when using a router in the jig as shown in 'plunging' mode, I think it's actually safer than when used fixed in a table, or freehand. I don't use the side locking lever - I set the depth gauge by placing a scrap piece of the hardboard against the router sole plate and push the router down till it only just clears the depth of the hardboard. (With the router disconnected of course).
The depth gauge usually consists of three screw 'stops' with locknuts at various heights on a base which can be rotated as desired to set three different heights. A rod which can be moved up and down to set the depth at which it comes into contact with the selected 'stop' has a small handwheel for tightening the rod at the desired depth. The router bit is spring-loaded and the router bit is in the retracted position until you press the router down to plunge it into the material. When you let go, the router bit retracts.
When you cut the slots, all you do is to put the router at the upper position in the MDF guide in the jig, switch on the router, plunge the router bit into the hardboard blank, then draw the router down the jig guide to the lower end of the guide, and the router bit will cut the slot. You take your hand pressure off the router and the bit retracts, then you switch it off till you reposition the back panel blank to cut the next slot.
All of this may sound a real rigmarole, but to cut each slot and reposition the back panel for the next slot takes no more than 20 or 30 seconds.
It's a very safe and accurate way to cut a slot, in that the router bit isn't exposed, the router can only move up and down to the extent that the MDF router guide will allow, and can't move sideways as the guide won't allow it to. The hardboard blank can't move as it's held in place at the upper and lower edges by the two wide strips of hardboard, and can't move sideways as it's held in place by the two panels with the holes over the dowels, on which the two panels are progressively moved to the left as each slot is cut. When you've cut a slot, you switch off the router, move the two end panels onto the next leftwards position on the two dowels, then repeat the process till one row of slots have been cut, then you move the router guide to the next lower position to cut the next row of slots till all rows have been cut.
At no time is the router bit exposed.
As to setting the depth a bit too low, all that would happen is that it would cut through the hardboard into the chipboard baseboard of the jig, but that wouldn't matter. Indeed, it needs to do that slightly to make sure that the bit goes right through the hardboard blank.
Although I used 3mm oil tempered hardboard, MDF could just as well have been used, and as long as the top and bottom strips which allow the blank to slide along the jig as made from the same depth of material, it doesn't matter what thickness of hardboard or MDF is used. For example, if it was desired to use say 5mm MDF for the back panel, the two sideways slides which fit over the dowels, and the top and bottom fixed panels between which the blank back panel slides, must be made from the same thickness of material.
Using a router inverted on a table is fine if for example you wish to cut rebates or slots, as you set the table up then push the wood against the guides along past the router bit until you get to the end of the rebate. I wouldn't attempt to use a router inverted on a router table to cut slots, as really, it must be in plunging mode.
Where people often come unstuck in using routers is by expecting too much of the router. If for example it's desired to cut a groove 3/4" wide x 1/2" deep, it's better to do it in two passes - one at 1/4" depth then a second one at 1/2", rather than to try to cut a groove 1/2" deep in one pass. This is especially so with cheap DIY routers.
I d sometimes use a router inverted on a router table or jog - in earlier posts I've mentioned a router jig that I made for making comb-jointed boxes for various little bits of test gear that I enjoy building. I think such boxes are evocative of how test gear and crystal sets were housed in yesteryear, and are a bit nicer than plastic or metal project boxes, as well as being made to measure.
If you look at post #6 in the thread below, you'll see pictures of that jig, and the safety conscious (or just plain sacred!) will notice that the exposed router bit protrudes through the table at all times to the height at which it is desired to cut slots, and the bit is unguarded. Thus, it's important to keep the fingers well away from the router bit. I could fit a guard over the bit, though as no one but me is going to use the jig, and I'm well aware of the precautions that need to be taken, I haven't fitted one.
Jigs for cutting comb-joints, dovetails etc, can be bought, but I made mine from scrap, and the oak that I've used for making boxes is reclaimed timber from my 'skip ratting' efforts, or offcuts from oak flooring etc. I could afford to buy a jig and the oak, but having been brought up in an era of 'make do and mend', and 'waste not want not' I derive what - in this materialistic age, might seem to some as a perverse sense of satisfaction that I don't get from spending money. Not tightfisted, not impoverished, I'm just programmed that way!
I hope this rather verbose explanation makes things a bit clearer Gary.
For the comb joint jig, see post 6 at this thread:
http://golbornevintageradio.org/forum/showthread.php?tid=1504&highlight=Comb+joint+jig
I've attached a pic of three little projects housed in such boxes - a wobbulator, zener diode tester and ESR meter. ('Not that again' some may say!).
Also attached is a test piece from two contrasting scraps of timber to give an idea of how accurately a jig will cut joints, once set up. I would emphasise that only basic woodworking skills are needed to make these jigs, which in themselves, are actually aids to de-skilling the process of woodworking!
I hope that's of interest and encouragement.
Yes, routers can be a bit scary, but when using a router in the jig as shown in 'plunging' mode, I think it's actually safer than when used fixed in a table, or freehand. I don't use the side locking lever - I set the depth gauge by placing a scrap piece of the hardboard against the router sole plate and push the router down till it only just clears the depth of the hardboard. (With the router disconnected of course).
The depth gauge usually consists of three screw 'stops' with locknuts at various heights on a base which can be rotated as desired to set three different heights. A rod which can be moved up and down to set the depth at which it comes into contact with the selected 'stop' has a small handwheel for tightening the rod at the desired depth. The router bit is spring-loaded and the router bit is in the retracted position until you press the router down to plunge it into the material. When you let go, the router bit retracts.
When you cut the slots, all you do is to put the router at the upper position in the MDF guide in the jig, switch on the router, plunge the router bit into the hardboard blank, then draw the router down the jig guide to the lower end of the guide, and the router bit will cut the slot. You take your hand pressure off the router and the bit retracts, then you switch it off till you reposition the back panel blank to cut the next slot.
All of this may sound a real rigmarole, but to cut each slot and reposition the back panel for the next slot takes no more than 20 or 30 seconds.
It's a very safe and accurate way to cut a slot, in that the router bit isn't exposed, the router can only move up and down to the extent that the MDF router guide will allow, and can't move sideways as the guide won't allow it to. The hardboard blank can't move as it's held in place at the upper and lower edges by the two wide strips of hardboard, and can't move sideways as it's held in place by the two panels with the holes over the dowels, on which the two panels are progressively moved to the left as each slot is cut. When you've cut a slot, you switch off the router, move the two end panels onto the next leftwards position on the two dowels, then repeat the process till one row of slots have been cut, then you move the router guide to the next lower position to cut the next row of slots till all rows have been cut.
At no time is the router bit exposed.
As to setting the depth a bit too low, all that would happen is that it would cut through the hardboard into the chipboard baseboard of the jig, but that wouldn't matter. Indeed, it needs to do that slightly to make sure that the bit goes right through the hardboard blank.
Although I used 3mm oil tempered hardboard, MDF could just as well have been used, and as long as the top and bottom strips which allow the blank to slide along the jig as made from the same depth of material, it doesn't matter what thickness of hardboard or MDF is used. For example, if it was desired to use say 5mm MDF for the back panel, the two sideways slides which fit over the dowels, and the top and bottom fixed panels between which the blank back panel slides, must be made from the same thickness of material.
Using a router inverted on a table is fine if for example you wish to cut rebates or slots, as you set the table up then push the wood against the guides along past the router bit until you get to the end of the rebate. I wouldn't attempt to use a router inverted on a router table to cut slots, as really, it must be in plunging mode.
Where people often come unstuck in using routers is by expecting too much of the router. If for example it's desired to cut a groove 3/4" wide x 1/2" deep, it's better to do it in two passes - one at 1/4" depth then a second one at 1/2", rather than to try to cut a groove 1/2" deep in one pass. This is especially so with cheap DIY routers.
I d sometimes use a router inverted on a router table or jog - in earlier posts I've mentioned a router jig that I made for making comb-jointed boxes for various little bits of test gear that I enjoy building. I think such boxes are evocative of how test gear and crystal sets were housed in yesteryear, and are a bit nicer than plastic or metal project boxes, as well as being made to measure.
If you look at post #6 in the thread below, you'll see pictures of that jig, and the safety conscious (or just plain sacred!) will notice that the exposed router bit protrudes through the table at all times to the height at which it is desired to cut slots, and the bit is unguarded. Thus, it's important to keep the fingers well away from the router bit. I could fit a guard over the bit, though as no one but me is going to use the jig, and I'm well aware of the precautions that need to be taken, I haven't fitted one.
Jigs for cutting comb-joints, dovetails etc, can be bought, but I made mine from scrap, and the oak that I've used for making boxes is reclaimed timber from my 'skip ratting' efforts, or offcuts from oak flooring etc. I could afford to buy a jig and the oak, but having been brought up in an era of 'make do and mend', and 'waste not want not' I derive what - in this materialistic age, might seem to some as a perverse sense of satisfaction that I don't get from spending money. Not tightfisted, not impoverished, I'm just programmed that way!
I hope this rather verbose explanation makes things a bit clearer Gary.
For the comb joint jig, see post 6 at this thread:
http://golbornevintageradio.org/forum/showthread.php?tid=1504&highlight=Comb+joint+jig
I've attached a pic of three little projects housed in such boxes - a wobbulator, zener diode tester and ESR meter. ('Not that again' some may say!).
Also attached is a test piece from two contrasting scraps of timber to give an idea of how accurately a jig will cut joints, once set up. I would emphasise that only basic woodworking skills are needed to make these jigs, which in themselves, are actually aids to de-skilling the process of woodworking!
I hope that's of interest and encouragement.
Regards, David.
BVWS Member.
G-QRP Club Member 1339.
'I'm in my own little world, but I'm happy, and they know me here'
BVWS Member.
G-QRP Club Member 1339.
'I'm in my own little world, but I'm happy, and they know me here'
