Thread: A Dovetail Marker Batch

If you're still looking for a source for the machine bolts you might try these guys.

http://www.shirestainless.com.au/ind...0f5abc7baa9d60

Haven't dealt with them myself, so not a recommendation, just a suggestion.

Works out at about 26 cents per M4x12 screw in 304 or around 10 cents more in 316 S/S.

Are they to be countersunk? Is this accounted for? Can be done in the same setup as the drilling, even the same movement if a suitable bit is used.

Can the brass stock be drilled in way of the screw in the milling process without extra setup? May need one top-plate as template?

Have you thought about this to cut down the assembly work?

I apologise if this has already been worked out.

prozac

Yes the bolt heads will be countersunk. I have not had the time to research bolts. Will ask Rippon if they can tap the brass for us when they mill the slots.

If they're using a CNC mill they should be able to mill the slot, drill the hole and tap it all in one sitting

I spoke to John at Rippon and they can do the tapping no problem for $3 per brass column. This means to get the slots milled and the drill hole tapped it will cost $18 per brass column, this brings the individual marking gauge price to just under $30.

A question:

What diameter, and length bolt/screw should we use? I had planed for a 4 mm wide thread and 15 mm long.

Rippon wants the screw/bolt and the dovetail heads finished before they machine the slots and tap the hole, so they can get a perfect fit.


There are still 13 sets lefts.

Some more questions TS;
1. Can Rippon supply screws at a better rate than we can achieve?
2. At $30 unit cost is this up or down from previous guesstimate, and does it allow for the lower cost/unit of higher volume?
3. Maybe when the price is firmed-up there will be stronger interest and they can be advertised again on the BuySell forum?

prozac

I recalculated the cost of manufacturing the dovetail markers and it breaks down like this:

Manufacturing Cost for 63 dovetail Gauges:

1134.0 - ($18 per unit price) machining and tapping of the brass column
0346.5 - ($5.50 per unit price) laser engraving
0315.0 - ($5 per unit price) Laser Cutting 5 mm thick 304 Stainless Steel (About $5 per marker) inc. Laser Etching Ratios
0015.0 - ($0.25 per unit price) 63 Alan Key Countersunk Machine Bolts 9 mm head, 12 mm long, and 4 wide thread
0251.9 - ($3.99 per unit price) 25 mm x 3600 Brass Rod by George White
-------------------
2,062.4 Manufacturing Cost
-------------------
32.75 Per Dovetail Gauge Cost
-------------------

We are not going to get anymore savings, at this point. The manufacturing cost for an individual Dovetail Gauge is $32.75. This still represents a very good price for a limited run Stainless Steel and Brass Dovetail Gauge.

This means that option 4 with six ratios 1/4, 1/5, 1/6, 1/7, 1/8, and 1/9 (three gauges) comes to $98.25. Option 5 with 4 ratios 1/5, 1/6, 1/7, and 1/8 (two gauges) comes to $65.5 and the saddle square is $32.75.

We can drop the price by $5, if we skip on the laser engraving, but then we only have an etched gauges.

If we do not allocate the remaining 13 dovetail markers, then Prozac, Dj's Timber and Bodgia, will have to miss out.

I will leave this running for two more week to see if we can make up the numbers.

So for example opt. 5 which is 3 markers, we're now looking at $98.25? If that's the case, then I should bow out and let someone else in the line have them as it's now an extravagance for me on something that's nice but I don't especially need and I should really direct the money onto one of two items I need instead. Or both.

That's not to say you've done a great job in getting things this far Helmut.

I have been thinking about Ian who suggested that 1/7 (8.13º), 1/8 (7.15º), and 1/9 (6.35º) are not dissimilar enough with only 1.78º between them so as to not warrant having all of them.

It has been niggling at me, about possible better combinations.

Here is a breakdown of some ratios with corresponding angles.

1/3 (18.43º)
1/4 (14.04º)
1/5 (11.31º)
1/6 (9.46º)
1/7 (8.13º)
1/8 (7.15)
1/9 (6.35)

Some combinations that come to mind are:

• 1/6 and 1/8 Dovetail Gauge
• Saddle Square

OR

• 1/4 and 1/5 Dovetail Gauge
• 1/6 and 1/8 Dovetail Gauge
• Saddle Square

OR we forget the ratios and go for simpler and orderly angles. The advantage with using increments of degrees is that simplifies everything and we can space the progression to optimum effect. Can most people tell a 9.46º dovetail from 10º dovetail.

• 16º and 14º Dovetail Gauge
• 12º and 10º Dovetail Gauge
• 08º and 06º Dovetail Gauge
• Saddle Square

OR

• 14º and 12º Dovetail Gauge
• 10º and 08º Dovetail Gauge
• Saddle Square

I would be happy with the last option consisting of 14º, 12º, 10º, and 8º gauges as it gives a nice spread and a lower price point.

Originally Posted by Waldo

then I should bow out and let someone else in the line have them as it's now an extravagance for me on something that's nice

This one of the reasons I am looking for more effective combinations, each dovetail gauge is still very cheap at 32.5, but I would like to keep costs down even just for my own sake. I have thought of using 25 x 20 mm brass column, but that will only save a maybe $0.50 per gauge.

Its the milling of the slot and the tapping that is costing more then I had hoped for.

I will approach other companies to see if they can quote us a better price on the milling and tapping.

*EDIT* IF Waldo drops out then prozac is next in line to take his place.

Appreciate what you're doing Helmut but I'm out.

The ratios I use (and am likely to use) most are 1:6 and 1:8. The others would be interesting to have but rarely used. I don't think that 1:4 (probably 1:5) or more is useful and 1:9 is as low as I would go. So I think the combos should be either
A. 1:6/1:7 and 1:8/1:9 with the saddle square as a third
B. !;6/1:8 and 1:7/1:9 with the saddle square

[quote=thumbsucker;783361]This one of the reasons I am looking for more effective combinations, each dovetail gauge is still very cheap at 32.5, but I would like to keep costs down even just for my own sake. I have thought of using 25 x 20 mm brass column, but that will only save a maybe $0.50 per gauge.

Its the milling of the slot and the tapping that is costing more then I had hoped for.

I will approach other companies to see if they can quote us a better price on the milling and tapping.

Hi Helmut,
I think that the initial ratios were OK.
I suggested early on that the column could easily be 25 x 10mm without compromising the strength or the designs.
How would that affect the final price?
Thanks again for all your work on this.
Kind regards
SG

jmk89 The problem with 1/7, 1/8, and 1/9 is that there is 1.43º between the lot of them making them almost indistinguishable to the naked eye over the small distance of 5 - 20 mm that most dovetails will cover. I do not think they are worth the cost of a dedicated dovetail gauge, to have all three. That is why a suggested the increments by degree's, 8º, 10º, 12º, and 14º. As a way to maximizes the value of gauge..

Scribbly Gum the 25 x 10 mm brass would save about $1.25 per gauge. Its the milling and tapping were the real savings can be made. I will contact grinding and milling companies tomorrow.