Frequently Asked Questions

I try to use the Online Estimator but nothing happens when I click on the part type When do I get my custom adapter if I order it today? How do I specify the part I need? Do I need to use the Online Estimator to specify the part? How does the Online Estimator calculate the cost of making a part? The part I need is difficult to specify using the Online Estimator I cannot find the material I need my part made of in the Online Estimator. When would I need to select a "Tube Wall Thickness" in the Online Estimator? The Online Estimator says my piece is too big When I press Estimate Cost, I get a message window instead of an estimate How do I choose the proper material for a part? Why is the estimated cost higher than the price of a similar commercial part? Can you make parts in volume? Can I return the part if it doesn't fit? How is a steel part hardened? What is Type II anodizing? Do you have an extra charge for quick delivery? Q. I try to use the Online Estimator but nothing happens when I select the part type. A. Please verify that your browser has JavaScript enabled. JavaScript is needed to use the Online Estimator. Check the Preferences or Options menu for your particular browser. Q. When do I get my custom adapter if I order it today? A. We strive to provide a fast lead time, with a part ready to ship within a few days of a confirmed order for simple specifications and standard stock. Generally our turnaround time depends on the complexity of the requirements and the type of material desired, and of course the size of our current backlog. Please always consult us. Q. How do I specify the part I need? A. You can of course give us the complete measurements and specifications for the piece you need, but more simply you can just tell us where the part is to be used: we maintain an extensive knowledge base of specifications on telescopes, cameras and accessories, and we can usually quickly figure out the length, threads, diameters and finish for an adapter to match specific instruments and accessories. Q. Do I need to use the Online Estimator to specify the part? A. No. The Online Estimator purpose is to provide a rough idea of how much a part might cost to make. The Estimator only needs the part basic dimensions and main features to estimate the fabrication cost. Q. How does the Online Estimator calculate the cost of making a part? A. The cost of a part is determined based on the following criteria, most important first: Overall size. Machining complexity: for example a thread is more complex to make than a simple surface, and an internal thread more so than an external thread thus an internal thread will be more costly. Type of material: for a small, one-of-a-kind part, the cost of the material is normally less influential on the cost of the finished part than the difficulty of machining the material. For example, aluminum as a material is more expensive than many steels, however a part made of steel may be substantially more expensive than a part made of aluminum due to the higher level of difficulty in machining steel. Precision required: a dimension tolerance of one thousandth of an inch (half the thickness of a human hair) is more difficult to machine than a standard 1/100 inch (0.25 mm) tolerance, thus if you do not require any dimension closer than 0.01 inch (about the thickness of a business card), it is not necessary to specify any tolerances. However, specific tolerances may sometimes be required, such as the bore to fit a 1.25" or 2" telescope eyepiece which is normally specified at a 0.005", or 0.1 mm, tolerance. A machined thread is another feature that normally requires tight tolerances, 0.002"/0.05 mm or better. Surface finish desired: the standard finish for precision machined parts is a very fine and smooth surface with machining lines barely visible, if at all. A special finish can also be specified, for example for a replacement part for an antique telescope which would require polishing to a high gloss, or for a part that needs knurling to provide a gripping surface, or for black anodizing to match certain existing telescope components. A minimum charge of US$30.00 applies per order. Q. The part I need is difficult to specify using the Online Estimator. A. Please first make sure you are using the appropriate Estimator form: there is a form for cylindrical parts, such as adapters and tubes normally mounted in an instrument optical train, and a form for rectangular pieces, plates, dovetails, or forks parts. The Estimator forms can be found here. Q. I cannot find the material I need my part made of in the Online Estimator. A. There are nine different materials available to machine cylindrical parts such as adapters and tubes, although there may be size restrictions based on the type of material selected. Material availability is more limited for rectangular parts due to the difficulty in finding stocks in certain combinations of material and size. Please consult us for unusual size and/or material. Q. When would I need to select a "Tube Wall Thickness" in the Online Estimator? A. Many parts can be more economically machined from tubular stock. However, since the Estimator only knows the basic dimensions of the part, it assumes by default that the part will be machined from solid stock unless a tube wall thickness is selected. The wall thickness should be selected so it can accommodate the minimum and maximum diameters of the part. An appropriately sized aluminum tubular stock must also be available. Tubes are supplied only in a finite variety of external/internal diameters combinations. The Estimator verifies that an appropriate tube stock exists or displays an error message if the requirements cannot be fulfilled with an existing tube stock. The Estimator selects tube sizes from a table of standard stocks. The table can be displayed by clicking on the "Tube Wall" field name on the Estimator page. The Tube Wall option is available only on the Cylindrical Part Estimator page. Remember, the Estimator performs only an approximate cost calculation based on the data supplied. The full specifications and dimensions of the part are usually required to calculate the best price. Q. The Online Estimator says my piece is too big. A. There are limits in the size of parts we can machine. Generally, a cylindrical part should be no wider than 6 inches or longer than 18 inches. There are also specific limits that apply to specific materials and types of machining. In addition, certain surface treatments have their own size limits. Clicking on the name of the feature in the Estimator page will show the specifics for that feature. We will be glad to assist you with any special size requirements even if we cannot do your project ourselves. Q. When I press Estimate Cost, I get a message window instead of an estimate. A. The Estimator performs basic consistency checks on the data entered, and alerts the user if some data are contradictory, a selected feature is not available for the material desired, or if size specifications are inconsistent. Click OK in the message window and then correct the information entered. Clicking on a feature name provides a detailed description of that feature. Q. How do I choose the proper material for a part? A. The appropriate selection depends mainly on the mechanical properties required (ie. resistance to bending, shearing, abrasion, torsion, etc) taking into account any weight limitation, and on the finished appearance desired (for example to match an existing instrument). Most telescope accessories are made of aluminum or stainless steel, although sometimes it can be advantageous to use less conventional materials, such as Titanium or Acetal. Please contact us if you need assistance in selecting an appropriate material. Q. Why is the estimated cost I got higher than the price of a similar commercial part? A. The cost of a one-of-a-kind, custom made part will always be substantially higher than a part manufactured in volume since the later is generally fabricated through an automated, less labor-intensive process. Thus if the part can be purchased on the commercial market, this will almost certainly be the least expensive alternative. PreciseParts excels in hand-machining precision components that are either too specialized to be economically mass-manufactured or that are no longer available from their original suppliers. Q. Can you make parts in volume? A. PreciseParts specializes in making one-of-a-kind components essentially one at a time. This is where we believe we can best serve the amateur astronomy community. Although we can generally make two or three units for a reasonable price, we would suggest contracting with an automated machine shop to make parts in higher volume at an optimum cost. We also perform part prototyping to test design iterations. The availability of a prototype can substantially facilitate later dealing with a production machine shop. Q. Can I return the part if it doesn't fit? A. If some specified dimensional tolerances have been exceeded or the part doesn't meet a stated specification, we will accept the part back and rework it (or at our option replace it) at no cost. If the part meets the mutually agreed specifications, the part can be sent back to us and we will make alterations at a previously agreed price if the part doesn't need to be re-made. If the part would need to be re-made, a new part should be ordered. Or, to use legal terminology: our responsibility is limited to altering or exchanging a part. We cannot be held responsible for any consequential damages resulting from using a part we made. Q. How is a steel part hardened? A. Hardening involves heating the part past a so-called "transition" temperature that varies slightly with the type of steel but usually lies around 1450ºF (the metal becomes red hot at this temperature) and then dropping it into a bath of water or oil to quickly cool it, an operation called quenching. Quenching leaves the steel very hard but also quite brittle, somewhat like glass. Thus another heating operation is required to stabilize the steel and make the part more resistant to breakage. This last operation, called tempering, is performed at a lower temperature; the exact value depends on the final hardness required. Q. What is Type II anodizing? A. The purpose of anodizing aluminum is to deposit a hard coating on the surface of the piece to protect the metal against scratches and to produce a non-fading, non-flaking color (black is used for most telescope accessories.) Aluminum can be anodized through various processes. One process commonly employed in large scale fabrication is called Type III or Hard Anodizing. It is performed at low temperature and high voltage in electrolytic bathes with special additives. Type II anodizing is performed at ambient temperature and requires a moderate electric voltage. Type II anodizing is a practical method for low volume or single part anodizing and sporadic usage. The process produces a high quality, scratch resistant anodic layer that is visually undistinguishable from Type III anodizing and that can be dyed in various colors. Check available anodizing colors Q. Do you have an extra charge for quick delivery? A. No. We will do our best to prioritize your part to accomodate an emergency and we can also ship the part overnight if required. Contact us with your special requirements.