Price: 1070 rubles
Drills are made by special technology. If the vast majority of panelists diamonds supported on the drill body in one layer and fastened in some way (electroplating or vacuum brazing), that is attached to the drill body segment consisting of diamond and ligaments.
Drill completely cylindrical, hollow, single diameter throughout its length. The slits for removing the core is not provided, the two holes in the lower part are designed to release water when it is fed into the drill bit (when drilling is doing on the machine). Although, if necessary, they can also be use to remove the core. Or knock him from the top, through the axial hole.
Informative packaging is insufficient. Provides detailed information on the operating mode (how to supply water to the drilling zone, how often to apply the drill in the pulse mode is to recover the drill after overheating). However, no data on the operating speed is not granted, and in bold inscription «Do not push» would do well to clean. Judging by the results of the tests, to push just right. The very same categorization as a free wording is confusing: under the weight of drill drill drill does not, especially in the front. To the process has begun, just need to push and push strongly the bit begins to operate at a much higher load than our standard 13.5 kg. Table B shows the results obtained in the «general» conditions. It is seen that they are small, except for one sample. The loss of efficiency has always been associated with brining the diamond segment, margin adjustment was still very decent. I must say that recover these drills is not too difficult — just posverlit vulcanite grinding wheel. It effectively abrade bunch, opening new diamonds. We checked — the method of truly effective. So, be reserved volcanics.
Further guidance on the application of drills contained in the instructions, which the manufacturer, according to the company, gives each customer. We got it up already then, at the stage of discussion of the preliminary results. Instruction is more informative — at least there is a recommendation in terms of turnover (in this case 2300 rev / min, if the characteristics allow drill). But there is a contradiction — simultaneous recommendations drill bit attached to the front, and at the same time with a slight pressure. This method does not work.
On the recommendation of representatives of the manufacturer, we started to put pressure on the drill is stronger (with a load of about 20 kg), the result is significantly better — one sample nasverlili 35 holes, the second — 47. In this case, the loss of efficiency was also associated with brining segment. Removing the core difficult — it is very tightly stuck to dislodge it, often have to remove the drill bit from the chuck.
Drilling in manual mode with the buildup was not provided by the manufacturer. Nevertheless, we decided to test one sample — had reason to believe that the result is supposed to be good. So, in general, it happened — the tested samples did 95 holes, with a very high speed (drilled 2300 rev / min). The rate was about the same throughout the test, which is quite logical — at least wear segment opened new diamonds. The test was stopped when the segment has been almost completely worn out, the body is already partially opened drill. The effectiveness of the work has fallen sharply.
Summarizing, we can say that the drills «monale» characterized by increased insistence. That there is only the need to have on hand vulcanite grinding wheel (not the most common thing, they are often used in the production, but not in construction). And, with manual clearly need to do something, the best modes here are not those specified in the manual.