Customer Reviews

Jasper 400J Model 400 Router Circle Cutting Jig

5 star:		(7)
4 star:		(4)
3 star:		(3)
2 star:		(1)
1 star:		(0)

 

 

The circle jig comes with a 1.5" pin to be inserted into the work piece and into the jig. The jig being attached to the router then rotates around the pin giving you a perfect circle. The only problem I ran into is if you have stock less than 1.5" thick and you wish route part way into the wood and the jig pivoting point you need to use is under the router base, a hole must be drilled completely through the stock. Would be nice if they supplied an additional 1" or .5" pin. (I made one out of the shank of a 'new' eighth in. drill bit - holes in the jig are very tight tolerances, no slop.)

Installed easily and worked well. I used an 8D finish nail with the head cut off for the pivot instead of drilling and using the provided dowel. I wanted the cut-out for a project but didn't compensate for cutter diameter and was undersize at first attempt. Ooops.
An aluminum version would be better.

This thing works great, is precise, and repeatable (which is it's primary value over some other jigs including homemade ones) Unfortunately, the material is just not up to being mounted and dismounted a lot, so use care and watch the torque when mounting it.

It's one of those odd tools. Given the fragility of the material, and the fact the cheap materials means there has to be a HUGE markup, it is overpriced. However, it works very well if you don't break it. It's the kind of tool after using I'd consider paying 3 times the price to get one in laser etched anodized aluminum rather than plastic.

I give it only 3 starts becuase made out of acrylic, it's essentially a consumable and WAY too pricey for that.

I have used this product previously for acrylic manufacturing and found the pivot point holes to be very accurate. It is very helpful to use a drill press instead of a hand drill for the holes. Extra pins are almost essential as tool is useless without it. Item is semi-consumable because of softness and thickness of the plastic it is made from, but very good accuracy for my needs.

I did receive wrong item from Amazon vendor so I am commenting on an item I bought locally.

In the Technical Details section, it says, "7- to 18-3/16-inch cutout range and 1 to 7 1/2 inch holes" I needed to a hole/cutout for a 9" speaker, so I thought this would work. However the maximum hole/cutout that the 400J can do is 7 1/2", so it is not useful to me. I give it two stars so you'll read this and not make the same mistake that I did. Look like the 200J may be the correct product for larger holes. NOTE: I'm not an expert and it seems the terms "hole" and "cutout" are used somewhat interchangeably; additional reading seems to imply that "hole" is used when you want to remove material from the inside of the circle and "cutout" is used when you want to remove material from the outside of the circle. Either way, the 400J doesn't go beyond 7 1/2 inches.

I use this jig for speaker building and it has worked fairly well, although it has a few minor faults:

1. The 1/4" hole in the calibration disc is too large, leading to about 1mm of slop when mounting the jig. Also, most of the 1/8" holes in my jig were slightly oval, allowing a small amount of pivot pin movement. If you want accurate cuts, the disc should be mounted while checking your measurement across the bit and pivot pin with calipers (be sure to subtract half of the pin width - 0.0625").

2. In order to flush mount a standard diameter (104mm) tweeter, a 9/32" router bit (not easy to find) can be used with the jig pin set in the 4-1/16" hole. If the disc has been mounted accurately, this will give you a very close cut to within a few thousandths of an inch.
Considering this jig was originally designed for speaker hobbyists, and most speaker builders will be using the model 400 jig to flush-mount standard dia. (104mm) tweeters, I was surprised and disappointed that it doesn't have a pin setting that's close to 104mm. With a standard 1/4" bit, the best you can do is an ugly 1mm gap around a 104mm tweeter. I think I speak for a lot of speaker hobbyists when I say: I hope Jasper will consider revising their jigs to include a 104mm pin setting so we don't have to fiddle with more measurements and hunt for odd sized router bits.

This is an absolutely jig and its amazing that it doesn't exist at the local stores. Following the instructions leaves no questions unanswered and it performs perfectly. In recessing holes it produces absolutely repeatable results. I used this to recess and cut holes for a set of speakers I find the only thing to keep in mind is that when completely cutting a hole out it would be beneficial to make one pass that nearly cuts through and then plunge the router further to make the final cut through. The reason is that otherwise the wood will come off center as you are about to complete the circle and you'll get a lump in the side. It also comes with a small tube to hold all the screws which is something that ever tool should come with. Absolutely worth the price if you plan on cutting more than one diameter circle.

This Jig Is A Must If You Are A DIY Speaker Builder! This Jig Will Route Very Accurate Recessed Areas and The Cut Out Area Also, For A Very Professional Look!
The Unit Was Very Easy To Install And Align On My Skill 1823 Plunge Router. Just Follow The Directions If All Else Fails And You Will Be Up and Running Shortly. The Pivot Pin Is A Tight Fit, No Play With this Little Feller. Do Recommend Having A Spare Pin Or 1/8" Drill Bit Laying Around For BackUp! As An After Thought The 1/8" Drill Bits Extra Length Is Easier To Work With Then The Pin! For Routing, A Standard 1/4" Bit Will Work Fine, But A 1/4" Upper Cut Spiral Bit Is A Better Choice!
For First Timers, It Takes Abit Getting Used To And Highly Recommend Doing Some Practice Work On Scrap Stock To Get Comfortable With It! Nothing Worse Then A Botched Up Front Baffle For Your New Speaker System!
This Unit Is For Plunge Routers With A 1/4" Collet And The Use Of A 1/4" Router Bit! Unit Is Made From Acrylic Plastic So A Little TLC Is Required For Years Of Trouble Free Use!!!! A Good Buy!!!!

I bought the Jasper model 400 circle jig for a DIY loudspeaker project to cut holes and to provide countersink lands for the drivers. I use it with a Bosch 1617EVSPK plunge router. I appreciate the supplied calibration disk and 1/4" pin that allows the jig to be centered easily on the router base.

The jig is designed to be used with a 1/4" diameter cutting bit but I wanted to use a 3/4" diameter bit for a large woofer countersink land. I quickly discovered that the 1/4" bit specification is for real because the 3/4" diameter bit wouldn't pass through the opening on the jig.

No problem - just plug in the router, dial in a slow speed, and plunge the 3/4" bit through the jig itself! By enlarging the center opening, I lost the 1", 1-1/16", and 1-1/8" pin holes, but for holes this small I'd probably just use a hole saw anyway. Don't try this with anything larger or you'll lose the ability to center the jig on the router base using the supplied calibration disk.

The jig does a nice job, works easily, and does what it's advertised to do. I'd buy another in a heartbeat when this one breaks or wears out, especially for Amazon's current price of just under $20 bucks.

I'm a DIY loudspeaker builder.
I usually use Porter Cable 690 LRVS router for flush mounting of speaker drivers.
With model 400 Jasper circle Jig flush mounting is easy and accurate. But I can't say it's perfect. There are a few points to be made better.
First; It was designed to use 1/4" shank router bit. I know well it from the manufacturer's spec and advertisement of this item. At first I chose 1/4" shank 1/2" diamenter mortising bit to make my work easy. But it was'nt possible for a minor protruding of the inner surface of this jig's hole kept blades of my router bit from any rotating. It was 0.8mm or so bigger sized obstacle to 1/4" shank 1/2" diamenter mortising bit from working.

Second; Collets of my P/C 690 LRVS can never pass the hole of model 400 Jaster circle Jig. And this made cutout of my 3/4" MDF
loudspeaker enclosure not possible. It is possible solely with 1/4" diameter mortising bit. If this problem were to be solved, I think the cutout range from 1" - to 1 1/4" be sacrificed.

Otherwise the jig is well designed and built.