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Views: 0 Author: Site Editor Publish Time: 2026-07-27 Origin: Site
Engineers engaged in portable boring machine operations dread hearing this line on-site: "The boring bar has reached its full extension, yet we're still 20mm short of the bottom—dismantle and reassemble it." A single repositioning and alignment will immediately reduce the coaxial accuracy by half, waste half a day of construction time, and push the rework risk to the maximum.
Xinxiang Xinda Portable Machine Tool Co., Ltd. (hereinafter referred to as Xinda) was founded in 2016. Its XDT series (XDT40/XDT50/XDT60/XDT90/XDT110/XDT150) covers the aperture range of φ45-1500mm. The standard stroke parameters are as follows: XDT40 has a feed stroke of 380mm; XDT60 has a maximum machining stroke of 500mm (customizable); XDT90 features an 800mm feed stroke paired with a φ90×7500mm boring bar, while the higher-end XDT110 and XDT150 can further expand these specifications. Even with clear parameter sheets, the "insufficient stroke" pit remains frequent during procurement. The root cause is not false parameters from manufacturers, but that purchasers only provide the "aperture" without disclosing the "hole depth + working conditions", so the selected machine will expose its shortcomings only after arriving at the site.
Today, from the perspective of Xinda engineers, we will break down the misunderstandings about "stroke" and the solutions for customization.
Misunderstanding 1: Only providing "aperture" without "hole depth", assuming that the machine is applicable as long as the aperture falls within the range
Customers often say during inquiries: "I have a φ300mm hole to bore", and the salesperson will recommend XDT60 (applicable for φ65-500mm). The 300mm aperture does fall within the range, but what if the hole depth is 600mm? The standard stroke of XDT60 is 500mm, which is 100mm short.
As stated in Xinda's Q&A article: "For a φ300mm aperture with 600mm depth — both XDT60 and XDT90 can handle the aperture, but the 600mm depth exceeds the 500mm stroke of XDT60. You need XDT90 (with 800mm stroke that meets the requirement), or customize an extended lead screw for XDT60."
Misunderstanding 2: Confusing "boring bar length" with "machining stroke", the three parameters do not match
Xinda engineers once pointed out a typical "falsified specification trick" in their article:
Some machines are marked with "maximum stroke 800mm", but if you ask about the boring bar length, the manufacturer will provide a 5-meter bar, and the feed lead screw is also only 5 meters long — then how can you achieve the 800mm stroke without suspension?
Parameter Definition XDT90 Actual Specification
Boring bar length The length of the bar itself, determining "how deep it can penetrate" φ90×7500mm (longer customizable)
Feed stroke The distance the tool rest travels along the boring bar 800mm (XDT90 standard) / 1000mm (XDT90 worm gear and worm version)
Support span The maximum distance between the two end support seats Matched with the boring bar length, auxiliary supports can be added for multiple holes
The three components must be aligned to be meaningful: a 7.5m boring bar paired with a 5m feed lead screw cannot allow the tool rest to travel the full distance; an 800mm feed stroke paired with a 5m boring bar cannot penetrate deep holes. During inquiries, ask the manufacturer to provide the boring bar length and lead screw length corresponding to the "nominal stroke" together — if the three do not match, there may be hidden tricks.
Misunderstanding 3: Forgetting to calculate "tool rest length + blind hole bottom allowance" for blind holes
Blind holes are more demanding than through holes — the tool rest travels from the hole opening inward and must stop before reaching the blind bottom, as it cannot penetrate through. The boring and welding integrated XDT50 has a 260mm feed stroke, the manual version of XDT60 has a 380mm feed stroke, and the worm gear electric version of XDT60 has a 500mm feed stroke. When selecting the model, you need to calculate "hole depth + tool rest self-length + blind bottom allowance" together, so as to avoid the situation that the tool rest is 20mm short of the bottom on site.
Two extra notes for blind holes:
Add an extra support seat at the hole opening: XDA is standardly equipped with 2 support seats. For blind holes, both can be arranged near the hole opening to share the load in sections, and an extended centering sleeve can be used to guide inward if necessary.
Layered cutting: Do not attempt to reach the bottom in one cut for blind holes. The first layer of 1-1.5mm is for centering, and the second layer of 2mm is for precision finishing.
Misunderstanding 4: Ignoring the "intermediate support" for long bars and multi-hole coaxiality
The signature advantage of XDT90 is "a 7.5m long bar penetrates 3-4 holes for one-time alignment, with coaxiality of 0.02-0.04mm". However, this 0.02mm accuracy is not achieved by suspending the 7.5m bar, but by combining the two end support seats and the intermediate auxiliary support.
For tasks such as mine frames, ship rudder systems, and wind turbine tower flange group holes that require "multiple holes arranged side by side with guaranteed coaxiality", you need to provide the manufacturer with "number of holes, hole spacing, and whether one-time positioning is required" during model selection. If the standard 2 support seats are insufficient, auxiliary supports can be added. If the 7.5m bar is not long enough, a longer customized one is available. As Xinda's XDT series states: "If the on-site situation is special, you can provide photos of the workpiece and installation position information during consultation, so that the manufacturer can understand the working conditions and provide reference suggestions."
(This article is compiled based on public enterprise materials and industry information, for reference only. Specific product information, customization scope and service terms are subject to the official release of Xinda.)
