Newtonian Secondary Holders
AstroSystems is the largest supplier of secondary holders and spiders to the astronomical community. There are no tools needed to adjust holders of 2.6" or larger in minor axis size; they come standard with thumbscrews.
Holders from 2.1" and smaller are supplied with a hex key that gives positive seating in the hex screw even in the dark.
All sizes feature our innovative four screw/two-axis adjustment that greatly simplifies collimation. With a four screw adjustment, each screw is centered between the spider vanes, making collimation adjustments a snap.
Two nuts with nylon washers position the holder laterally and also allow easy adjustment of the rotation.
The secondary mirror is held securely yet safely against the front lip of the aluminum bezel with polyester batting. Available in 19 sizes, ranging from 1.3" to 7.0". Use the link below for dimensions, exact weight and sizing.
1.3" to 1.5"
These have a #10 mounting stud and a 3/16" to 3/8" bushing to fit 3/8" spiders. The smaller diameter mounting stud reduces the weight by 30%. They utilize set screws for adjustment and the hex key is supplied.
1.8" to 2.75"
These have a 1/4" mounting stud and a 1/4" to 3/8" bushing to fit both 1/4" and 3/8" spiders. The smaller diameter mounting stud reduces the weight by 30%. The 1.8" to 2.1" utilize set screws for adjustment and the proper size hex key is supplied. The 2.5 to 2.75" have thumbscrews for easy, no tools collimation.
3.0" to 3.5"
These have a 3/8" mounting stud and have thumbscrews for easy, no tools collimation. Shown at center in the above photo.
4.0" to 4.5"
These larger holders have a proportionately thicker shell for proper support of thicker, heavier secondaries and a 3/8" mounting stud. They utilize 1" long thumbscrews for easy, no tools collimation. Shown at right in the above photo.
Our Guarantee Our products are manufactured with the highest quality materials. Years of testing, and high standards of production have produced the best possible products in the industry. If a product has not met with the customer's expectation, with prior approval, they can return the product directly to us for repair or replacement (our discretion). We have no minimums on any of our products, so you can stock just what is comfortable for you and your store. We fully guarantee our products for one year from the purchase date, longer on some products. Our policy is to treat our dealers and their customers as we wish to be treated. If an item does not live up to your expectation, please give us an opportunity to make it right.
We work very hard to ensure that we offer the absolute best prices online. If you find another online store that offers a lower price then us within six months of your purchase date please let us know and we will refund your original payment for the difference. We want you to feel confident that you are getting the absolute best price for the product you are ordering. If you find that our own website has a lower price for the same item you have ordered within six months of your purchase date will refund the difference as well.
To request your partial refund simply e-mail us a link to the same product on our website, or on our competitors website within six months from the date of your order and we will process the credit accordingly.
Our 100% Price Guarantee has some limitations:
- You must purchase the item from our website before requesting your Price Match Guarantee
- Promotions such as rebates and buy one, get one free offers are not eligible
- The item must be in stock on the competitors website
- The competitor must be an online store, they may not have a retail location
- The website can not be a discounter or auction website (ie; eBay, overstock, etc..)
- The competitor must be an Authorized Retailer of the product in question
- The Price Match Guarantee includes the item price and the shipping charges, it excludes sales tax
Order Confirmation As soon as you place your order you will receive an order confirmation e-mail. This means that we have received your order in our system and pre-authorized your credit card for the purchase. As soon as we receive your order we automatically reach out to our suppliers to confirm that it is in stock and available for immediate shipment. If your item is on backorder or unavailable we will void the pre-authorization and reach out to you via e-mail. If your item(s) are available for immediate shipment (within 5 business days) we will process the charges and submit the order for shipment.
Order Shipment If your order is received, the inventory is in stock and your credit card information matches the information, In most cases, we can ship within 5 business days. We will send you tracking information within 24 hours of your order leaving the warehouse to the e-mail address your provide when checking out. If you do not receive tracking information from us within six business days of your order please email us at firstname.lastname@example.org.
Miscellaneous Shipping Information
- We cannot ship to PO boxes.
- Non-standard shipping surcharges will apply to isolated service areas, such as remote areas, areas not readily accessible by a delivery vehicle, islands, etc., as defined by the shipper. These circumstances occur less than 1% of the time.
You can estimate the deliver time to your home or business by viewing the "Ships Within" information listed with every product. This refers to the time from when you place your order, to the time it leaves the warehouse. The total delivery time for your order is calculated from the time your order is placed, until you receive it. The diagram below shows how the total delivery time is broken down into pre-ship processing time and shipping time.
Processing time is the time it takes from when you submit your order to when the product leaves the warehouse. The "Ships Within" time frame listed with each of our products on the website applies to this time frame. For example, if your order a product that reads "Ships Within: 2 Weeks", this means that the product typically leaves the factory within two weeks. If there will be any additional time required to process your order, we will notify you immediately to confirm the delivery period. This time is needed for products that are shipped to you directly from our manufacturers. The manufacturers need this time to fulfill your order. In some cases, the items are custom built. Shipping time is measured when your order leaves the warehouse to when it arrives at your address. Actual shipping time can vary between 2-5 business days. Contact our helpful customer service experts at (888-264-2244) for more information.
Did your shipment arrive damaged or defective?
Please report damaged or defective merchandise to us immediately by email phone. Photos of the items and the packaging would be greatly appreciated. This will speed up our resolution process. We strongly recommend at the time of delivery, if your notice any cartons that look dented, crushed or just not right, open them immediately and inspect the contents. If the contents appear to be damaged, please notate it on the delivery ticket, refuse that item only and contact us as soon as possible for instructions.