前天下午，一家做植保无人机的客户发来一张照片。
地上散着几片碎件，是起落架的支腿，断口齐整，像被掰断的塑料尺。他说：
"我这片起落架材料用的是普通玻纤尼龙，摔了一下就裂了。你们有没有更抗摔的？"
我问了他三句：落差是硬着陆还是侧翻？电机多少瓦？主要在什么温度下飞？
他答不上来第三句。这正是问题——起落架和电机座，根本是两条不同的载荷线，不能用同一种"更抗摔"去套。
这篇把这两件拆开讲清楚：它们分别被什么约束，以及什么条件下改性尼龙该收手。
一、起落架和电机座，是两条不同的载荷线
很多人以为都是"机身下面的件"，用一种料就行。其实差得很远。
起落架吃的是"一下"。 落地那一瞬间，几百毫秒内把整机的动能吃进支腿里。它要的是单次大冲击下的韧性——撞了不能断，断了不能飞溅。
电机座吃的是"一直"。 电机就在它上面转，长年振动是常态，还叠加上电机散出来的热。它要的是抗振动疲劳 + 耐温老化——不是撞一下，是熬几年。
这两件事对材料的要求甚至相反：起落架要超韧，电机座要刚性加耐热。把它们混在一起选料，等于拿一个指标去压另一个指标，哪头都顾不上。
还有一种更常见的错法：把两件按同一个牌号采购。
起落架和电机座装在同一台机器上，图省事就合并成一个料号。
等落到零件上，总有一头是凑合的。
一句话：先分清件吃的是"一下"还是"一直"，再谈料。
二、两件被什么夹击：六个维度
温度。 电机座紧挨电机，连续作业时表面能到八十到一百度；起落架在户外，冬天能到零下二三十度。两个件的温度区间完全不一样。
载荷。 起落架是冲击载荷，峰值高、次数少；电机座是振动载荷，峰值不高、次数极多。
介质。 植保机接触药液、高湿；行业机接触雨水盐雾。尼龙吸湿后冲击韧性会变化，要一起算。
寿命。 起落架以起降次数算，电机座以飞行小时算，两个量纲不同。
外观。 外露件，色差和浮纤先看得到。
合规。 载人机型涉及适航，但这两件以结构和耐候为主。
把六维摆在一起：起落架的账在"低温冲击"，电机座的账在"长期热老化"，它们甚至不共享同一条失效曲线。
三、两条路线怎么分工
| 路线 | 组成 | 给什么 | 代价 |
|---|
| 超韧 PA66-GF30 | 核壳增韧 + 中玻纤 | 冲击韧性好、成本低 | 刚性略低、易蠕变 |
| 超韧 PA12 | 长碳链 + 增韧 | 低温韧性好、吸水小 | 成本高、耐温低 |
| PA66-GF40 + 耐热稳定 | 高玻纤 + 热氧体系 | 刚性 + 耐温 + 抗疲劳 | 冲击不如超韧 |
第一行是起落架的主流。 普通玻纤尼龙摔一下就裂，是因为没做超韧。加核壳增韧剂后，缺口冲击能从几 kJ/m² 提到十几，落地那一下的存活率高一个量级。但增韧剂的玻璃化转变温度要低于使用温度——这是低温脆断的关键，下面专门讲。
第三行是电机座的主流。 它不靠韧性吃饭，靠刚性和耐温。电机座的失效不是撞，是长年热加振动下的老化与蠕变。
选择上还有一个现实条件：增韧剂的玻璃化转变温度要低于最低使用温度。
这一条说起来简单，做起来先要客户把"最低温度"说清楚。
很多项目给的是"我们一般在零上飞"，没把冬天极端的那几天算进去。
温度给的是平均值，断掉的却总是极端那几天。
还有一条容易被忽略：这两件的验证设备不是一套。
起落架要落冲击台架，电机座要振动台加热箱。
两个验证都要排期，报价时就得把这部分时间算进去。
省掉验证不是省成本，是把钱挪到售后去花。
一句话：起落架选"韧"，电机座选"稳"，两套逻辑，别混。
四、选型判据表（这一页最该收）
下表的门限是方向性建议，不是验收标准——实际数值必须由具体项目、具体工况和实测确定。
| 指标 | 方向性门限 | 验证方法 / 标准 | 常见失效 | 通行解法 | 对应助剂体系 |
|---|
| 落冲击韧缺口冲击 | 超低温度参考 10–15 kJ/m² 量级 | ISO 180（-30℃） | 低温摔裂 | 超韧 + 低 Tg 增韧剂 | 增韧剂（核壳结构） |
| 振动疲劳（10⁷ 次） | 不低于静态 28% 量级 | 振动台 + 应变监测 | 根部裂纹 | 加筋 + 圆角过渡 | — |
| 电机座长期热保留率 | 100℃×1000h 后 ≥75% | ISO 527 | 发白脆化 | 耐热稳定化 | 抗氧剂（受阻酚 + 亚磷酸酯） |
| 干湿态尺寸差 | 尺寸变化 ≤0.2% | 调湿前后实测 | 装配间隙漂移 | 低吸水基材 | 材料本征，不靠助剂 |
| 长期蠕变（持荷） | 千小时蠕变量 <0.5% | ISO 899 | 支腿缓慢变形 | 高玻纤体系 | 偶联剂（抑制界面滑移） |
| 玻纤取向一致性 | 收缩差 ≤0.4% | 模流 + 实测 | 翘曲、孔位偏 | 调浇口与流动平衡 | 偶联剂（降界面应力） |
怎么用这张表：不要逐行打分。先看第一行和第四行——起落架盯冲击，电机座盯热老化，把件认准了再填表。
五、六类常见失效，和它们的真根因
失效一：摔了一下就裂。
根因通常是没做超韧，或增韧剂选错了类型。普通玻纤尼龙缺口冲击低，落地应力一集中就断。换超韧体系能解决大半。
失效二：低温下特别容易碎。
根因是增韧剂的玻璃化转变温度高于使用温度。常温下韧的料，到了零下二十度以下，增韧剂自己先变脆，件就跟着脆。常温断和低温断是两件事，方案完全不同——低温件必须用低 Tg 的核壳结构增韧剂。
失效三：电机座飞了一年发白、裂。
根因是长期热氧老化。电机座局部温度高，普通抗氧剂顶不住几年。但看到局部黄变、发白，先查抗氧剂在混料阶段分散均不均匀——很多时候是分散不均，不是体系选错。
失效四：同一批支腿，有的韧有的脆。
根因在助剂侧——增韧剂或色母分散不均，导致一批件里韧性波动。看到这个现象，先查母粒化和混料工艺，别急着换基材。
失效五：支腿裂的位置不在落地点。
先看裂口和浇口的关系。
裂口沿着熔接线走，说明熔接线落在了受力路径上，这是模具的事。
断在哪儿，比断不断更能说明问题。
失效六：飞了半年，电机座的孔位偏了。
根因常是长期蠕变叠加振动，孔位一点点挪出去。
先做长时持荷测试，再谈换料。
孔位偏不是一下子发生的，是几百小时慢慢挪出来的。
一条时间线。 我们见过一个起落架件的完整过程：夏天装机一切正常，入冬后第一批霜冻天，连续三起落地断裂；拆回来测，断口全部齐整。回头查，是增韧剂 Tg 偏高，低温下失效。起点是夏季合格，潜伏是温度悄悄越过 Tg，爆发是霜冻天集中断裂，结算是整批召回换超韧料。
六、上机要盯的几件事
干燥。 尼龙必烘。含水率超标，熔融时分子链被切断，件发脆——对本来就吃冲击的起落架，这是雪上加霜。
增韧剂分散。 超韧料的关键是增韧剂分散均匀，母粒化和混料顺序要定死，否则一批件韧性飘。
浇口与取向。 支腿是细长件，翘曲由取向决定，浇口要先做模流分析。
模温与浮纤。 外露件模温提到 110–120℃ 上下控浮纤。
验证顺序。 建议这样排：
1. 材料级：缺口冲击（常温与低温）
2. 件级：尺寸与翘曲，调湿后测
3. 起落架：落冲击台架
4. 电机座：振动台 + 热老化联合
5. 环境叠加：高低温循环 + 湿热老化
顺序不能换。 前一项不通过就往下走，后面数据没有解释意义。
七、什么时候这件事不该谈
以下四种情况，起落架和电机座走改性尼龙这条路不建议推进：
其一，重载荷载人机的主起落架。 这类要金属或复材，尼龙进去是越界。
其二，长期工作温度持续越过所选体系窗口。 电机座尤其，热老化顶不住就是定时炸弹。
其三，极寒地区又要求高可靠。 低温冲击的门槛起伏很大，验证要专门做，没这个条件别开这个头。
其四，用量小到摊不平专用模具与验证。 超韧料和耐热料都要专门配，年用量小不划算。
其五，要求整机通过适航级阻燃与烟毒考核。 那属于整机级适航的账，
这两件本身以结构和耐候为主，别拿通用阻燃结论去套。
其六，结构上留不出圆角与加强筋。 起落架的抗冲击很大程度靠圆角过渡，
空间上留不出圆角和筋位，材料再好也发挥不出来。
把这六条写在前头，不是劝退，是省时间。
八、两件分开算：一张对照表
把两条载荷线摆在一起，差异一眼就看得出。
| 件 | 主要载荷 | 时间尺度 | 关键指标 | 典型失效 |
|---|
| 起落架支腿 | 落地冲击 | 几百毫秒一次 | 低温缺口冲击、圆角 | 摔一下就裂 |
| 电机座 | 振动 + 热 | 连续几年 | 热氧保留率、抗蠕变 | 发白、孔位偏 |
两件最容易被混淆的地方，是它们都用"尼龙 + 玻纤"这个说法。
但一个要的是韧，一个要的是稳，玻纤含量能差一档以上。
一句话问出来，答案只能是折中的，而折中的件两头都不牢。
换料风险清单（从金属 / 原方案换到改性尼龙，要动什么）
| 环节 | 要动什么 | 容易漏的点 |
|---|
| 模具 | 支腿按件做收缩补偿 | 玻纤取向导致方向性收缩差 |
| 干燥 | 按实测含水率定窗口 | 回用料掺入带入水分 |
| 料温 / 模温 | 模温提到 110–120℃ 控浮纤 | 只按牌号推荐值给，不看件 |
| 增韧体系 | 确认增韧剂 Tg 低于使用温度 | 低温工况用错增韧剂 |
| 调湿 | 强制调湿 + 复测尺寸 | 按平均壁厚估时间，厚壁没吸透 |
| 色差 | 外露件色板提前确认 | 玻纤件批次有色差 |
| 验证顺序 | 冲击 / 热老化 → 台架 → 环境 | 前一项未过就往下走 |
一页纸汇报表（给要向上汇报的人）
`
项目：无人机起落架 / 电机座 · 材料路线评估
结论方向：改性尼龙可作候选，能否落地取决于四项前置条件
一、必须守住的三条
1. 起落架与电机座分两套料，不混
2. 增韧剂 Tg 低于最低使用温度
3. 无低温冲击 / 热老化数据不进入验证
二、前置条件（任一不满足则建议暂缓）
· 长期工作温度 ≤ 所选体系持续使用区间
· 有落冲击台架与振动台验证条件
· 年用量足以摊薄专用料与模具
· 机型适航要求已确认不涉及主承力
三、下一步动作
1. 取真实落差与电机功率，定载荷
2. 做常温与低温缺口冲击
3. 电机座做热老化 + 振动联合验证
风险提示：本路线主要不确定性在低温冲击与长期热老化。
`
读者常问的三句
问：POM 能不能顶起落架？
POM 刚性好、自润滑好、尺寸稳，但抗冲击偏弱，不适合大冲击位置。落地冲击大的地方，超韧尼龙更抗打。两个都不足的位置，就该重新想结构。
问：电机座能不能也用超韧料？
看工况。电机座要刚性和耐温，超韧会牺牲这两样。除非电机座同时吃大冲击，否则优先高玻纤加耐热稳定体系。
问：起落架和电机座能不能共用一个料号？
技术上不推荐，但可以有折中：配方分开，采购上合并报价。
前提是先把最低飞行温度和电机座表面温度都测出来。
没有温度数据就合并料号，等于赌一个"不影响"。
结语
无人机起落架材料和电机座的选材，说到底是一道载荷识别题，不是材料题。
判断链只有三条：
件吃"一下"还是"一直" → 温度定体系 → 验证定成败。
三条都定完，"这料抗不抗摔"才有答案。
如果你手上正有一个起落架或电机座要定料，把三样东西发过来就能给方向：落差方式、电机功率、最低飞行温度。
有些生意我们不做。
不问用途、不问工况就报"更抗摔的料"，这种单子我们不做。选错了方向，再便宜也是贵。
我们做的事很具体：把 PA6、PA66、PA46、PA11、PA12、PA6T、PA9T 和尼龙合金这些树脂，改成某个件真正能用的样子；顺带做改性 PPO、PPS 和热塑性弹性体。
同时经营各大化工巨头的尼龙树脂、副牌料与大包料，另长期收尼龙原料、水口回料与各类尼龙废料，有正规处置渠道。
配方里的助剂体系按件的工况配——常规助剂常备现货，特殊型号按需配套；你报工况和牌号，料和助剂一次配齐。
The afternoon before yesterday, a client who makes plant protection drones sent a photo.
A few fragments were scattered on the ground; they were the struts of the landing gear, with clean breaks, like a plastic ruler that had been snapped. He said:
I used ordinary fiberglass nylon for the landing gear material, and it cracked after a fall. Do you have something more impact-resistant?
I asked him three questions: Was the drop a hard landing or a rollover? How many watts is the motor? At what temperature does it mainly fly?
He couldn't answer the third sentence. This is exactly the problem—the landing gear and the motor mount are fundamentally two different load paths and cannot be forced into the same 'more crash-resistant' standard.
This article explains these two things separately: what constraints each of them is under, and under what conditions modified nylon should be stopped.
1. The landing gear and motor mount are two different load paths.
Many people think that all are 'parts under the body' and that one material is enough. In fact, the difference is very big.
The landing gear 'absorbs' the impact. At the moment of touchdown, within a few hundred milliseconds, it takes in the kinetic energy of the entire aircraft into the struts. What it needs is toughness under a single large impact — it cannot break when hit, and if it breaks, it cannot scatter.
What the motor mount 'feeds on' is constant stress. The motor spins right on top of it, so long-term vibration is normal, and on top of that, there's the heat dissipated by the motor. What it needs is resistance to vibration fatigue and heat aging—not surviving a single impact, but enduring for years.
The material requirements for these two things are even opposite: the landing gear needs to be extremely tough, while the motor mount needs to be rigid and heat-resistant. Mixing them together to choose materials is like using one criterion to suppress the other, and neither is properly addressed.
There is another more common mistake: purchasing two items under the same brand.
The landing gear and motor mount are installed on the same machine, and to save trouble, they were merged into a single part number.
When it comes down to the parts, there’s always one end that is just passable.
In one sentence: First distinguish whether the item is eaten 'once' or 'continuously,' then talk about the seasoning.
2. What the two things are being pinched by: six dimensions
Temperature. The motor mount is right next to the motor, and during continuous operation its surface can reach 80 to 100 degrees; the landing gear is outdoors, and in winter it can reach minus 20 to 30 degrees. The temperature ranges of the two parts are completely different.
Load. The landing gear experiences impact loads, with high peaks and few occurrences; the motor mount experiences vibration loads, with low peaks and very frequent occurrences.
Medium. Plant protection machines come into contact with pesticide solutions and high humidity; industry machines come into contact with rainwater and salt spray. The impact toughness of nylon changes after absorbing moisture, so it must be taken into account together.
Service life. The landing gear is measured by the number of takeoffs and landings, while the motor mount is measured by flight hours; the two have different dimensions.
Appearance. External parts, color differences, and floating fibers can be seen first.
Compliant. Manned models involve airworthiness, but these two focus mainly on structure and weather resistance.
Putting the six dimensions together: the accounts of the landing gear are in 'low-temperature shock,' and the accounts of the motor mount are in 'long-term thermal aging'; they don't even share the same failure curve.
3. How to divide the work between the two routes
| Route | compose; consist of | Give what | Cost |
|---|
| Super tough PA66-GF30 | Core-shell toughening Medium glass fiber | Good impact toughness, low cost | Slightly low rigidity, prone to creep |
| Super Tough PA12 | Long carbon chain Toughening | Good low-temperature toughness, low water absorption | High cost, low temperature resistance |
| PA66-GF40 Heat Resistance and Stability | High Glass Fiber Thermo-oxidative System | Rigidity Temperature Resistance Fatigue Resistance | Impact is not as good as super toughness |
The first line is the main stream of landing gear. Ordinary fiberglass nylon will crack with just a drop because it hasn’t been made extra tough. After adding core-shell toughening agents, the notch impact energy can increase from a few kJ/m² to over ten, making the survival rate on landing an order of magnitude higher. But the glass transition temperature of the toughening agent must be lower than the operating temperature—this is the key to low-temperature brittle failure, which will be discussed in detail below.
The third line is the mainstream of motor mounts. It doesn't rely on toughness, but on rigidity and heat resistance. The failure of a motor mount is not due to impact, but due to aging and creep under long-term heat and vibration.
There is also a practical condition in the selection: the glass transition temperature of the toughening agent must be lower than the minimum operating temperature.
This is easy to say, but to do it, customers must first clearly state the "minimum temperature."
Many projects give 'we generally fly above zero' and do not take into account the few extreme winter days.
The temperature given is the average, but the days that break down are always those extreme few.
There is also one easily overlooked point: the verification devices for these two items are not the same set.
The landing gear needs to go to the impact test rig, and the motor mount needs the vibration table heating box.
Both verifications require scheduling, so this time must be accounted for in the quotation.
Skipping verification doesn't save costs; it just shifts the money to be spent on after-sales.
In a nutshell: choose 'tough' for the landing gear, 'stable' for the motor mount, two sets of logic, don't mix them.
4. Selection Criteria Table (This page should be collected the most)
The thresholds in the table are directional recommendations, not acceptance criteria — the actual values must be determined by the specific project, specific working conditions, and actual measurements.
| Indicator | Directional Threshold | Verification Method / Standard | Common Failures | Common solution | Corresponding auxiliary agent system |
|---|
| Falling impact toughness notch impact | Ultra-low temperature reference on the order of 10–15 kJ/m² | ISO 180 (-30°C) | Cracking due to low temperature | Super tough Low Tg toughening agent | Toughening agent (core-shell structure) |
| Vibration fatigue (10⁷ cycles) | Not less than a static level of 28% | Vibration table Strain monitoring | Root crack | Reinforced Rounded corner transition | — |
| Long-term heat retention rate of the motor housing | After 1000 hours at 100℃ ≥75% | ISO 527 | Pale and brittle | Heat resistance stabilization | Antioxidant (hindered phenol, phosphite) |
| Dry and wet dimensional difference | Dimensional change ≤0.2% | Measured before and after humidity adjustment | Assembly clearance drift | Low water absorption substrate | Intrinsic properties of the material, without relying on additives |
| Long-term creep (load-holding) | Thousand-hour creep strain <0.5% | ISO 899 | The support leg is deforming slowly | High glass fiber system | Coupling agent (inhibits interfacial slippage) |
| Glass fiber orientation consistency | Shrinkage difference ≤0.4% | Mold Flow Actual Measurement | Warping, misaligned holes | Gate Adjustment and Flow Balance | Coupling agent (reduces interfacial stress) |
How to use this table: Do not score line by line. First, look at the first and fourth lines — focus on shocks for the landing gear, focus on heat aging for the motor mount, identify the parts correctly before filling out the form.
Common failures of categories five and six, and their true root causes
Failure 1: It cracked after just one drop.
The root cause is usually either not using super-toughening, or selecting the wrong type of toughening agent. Ordinary glass fiber nylon has low notch impact strength and breaks when the stress is concentrated during dropping. Switching to a super-tough system can solve most of the problem.
Failure 2: Particularly prone to breaking at low temperatures.
The root cause is that the glass transition temperature of the toughening agent is higher than the usage temperature. At room temperature, the material is tough, but below minus twenty degrees, the toughening agent itself becomes brittle first, and the part becomes brittle as well. Fracture at room temperature and fracture at low temperature are two different matters, requiring completely different solutions — low-temperature parts must use core-shell toughening agents with a low Tg.
Failure three: The motor base has been flying for a year, turning white and cracking.
The root cause is long-term thermal-oxidative aging. The local temperature of the motor housing is high, and ordinary antioxidants cannot withstand several years. But when you see local yellowing and whitening, first check whether the antioxidants are evenly dispersed during the mixing stage—many times it is uneven dispersion, not that the system was chosen incorrectly.
Failure 4: Legs from the same batch, some are tough and some are brittle.
The root cause is on the additive side—uneven dispersion of toughening agents or color masterbatch, leading to toughness fluctuations within a batch. Upon seeing this phenomenon, first check the masterbatch production and mixing processes, and don’t rush to change the base material.
Failure 5: The position of the outrigger crack is not at the landing point.
First, look at the relationship between the split and the gate.
The crack follows the weld line, indicating that the weld line is on the stress path, which is a matter of the mold.
Where it breaks tells more than whether it breaks or not.
Failure six: After flying for half a year, the motor mount holes became misaligned.
The root cause is often long-term creep combined with vibration, causing the hole position to shift little by little.
First conduct a long-duration load test, then discuss material replacement.
The misalignment of the hole didn't happen all at once; it slowly shifted over several hundred hours.
A timeline. We observed the complete process of a landing gear component: everything was normal when installed in summer, but after the first frost in winter, three units broke on landing in succession; upon disassembly and testing, all fracture surfaces were clean and even. Looking back, the issue was that the toughening agent’s Tg was too high, causing it to fail at low temperatures. The starting point was that it passed inspection in summer, the latent stage was when the temperature quietly exceeded Tg, the outbreak was the concentrated fractures during frost days, and the outcome was a full batch recall and replacement with ultra-tough material.
6. A Few Things to Focus on When Using the Computer
Drying. Nylon must be baked. If the moisture content exceeds the standard, the molecular chains break during melting, making the part brittle — which is adding insult to injury for a landing gear that is already subjected to impact.
Toughening agent dispersion. The key to super-tough materials is the uniform dispersion of the toughening agent. The masterbatching and mixing sequence must be fixed, otherwise the toughness of a batch will vary.
Gate and orientation. The strut is a slender part, and warpage is determined by orientation. Gate analysis should be performed first.
Mold temperature and floating fibers. Raise the mold temperature of exposed parts to 110–120°C to control floating fibers.
Verification order. It is recommended to arrange it like this:
1. Material level: Notch impact (room temperature and low temperature)
2. Piece level: Size and warpage, measured after moisture adjustment
3. Landing Gear: Drop Impact Test Bench
4. Motor Base: Vibration Table Heat Aging Combination
5. Environmental Superposition: High and Low Temperature Cycling Humid Heat Aging
The order cannot be changed. If the previous item fails, move on to the next one; the subsequent data has no explanatory significance.
7. When This Matter Should Not Be Discussed
In the following four situations, it is not recommended to pursue the route of using modified nylon for the landing gear and motor mount:
First, the main landing gear that carries heavy loads of the aircraft. These need to be metal or composite materials; using nylon would be out of bounds.
Secondly, the long-term operating temperature continuously exceeds the selected system window. Especially for the motor housing, thermal aging that cannot withstand it is a ticking time bomb.
Third, extremely cold regions also require high reliability. The threshold for low-temperature shock fluctuates greatly, and verification needs to be done specifically; without this condition, don't start this.
Fourth, the quantity is too small to justify dedicated molds and validation. Both super-tough materials and heat-resistant materials require special preparation, and it is not cost-effective for small annual quantities.
Fifth, it requires the entire aircraft to pass airworthiness-level flame retardant and smoke toxicity tests. That falls under the airworthiness category at the whole aircraft level.
These two items themselves focus on structure and weather resistance, don't apply general flame-retardant conclusions to them.
Sixth, the structure cannot accommodate fillets and reinforcements. The landing gear's impact resistance largely depends on fillet transitions.
If there is no space for fillets and rib positions, no matter how good the material is, it cannot perform to its potential.
Writing these six points at the beginning is not to discourage, but to save time.
8. Count the two items separately: a comparison table
Place the two load lines together, and the difference can be seen at a glance.
| item | Primary payload | Time scale | Key indicators | Typical failure |
|---|
| Landing gear strut | Impact upon landing | Once every few hundred milliseconds | Low-temperature notch impact, fillet | It cracks with just a fall |
| Motor base | Vibration Heat | Several consecutive years | Hot oxygen retention rate, creep resistance | Pale, misaligned holes |
The two most easily confused points are that they both use the term 'nylon fiberglass'.
But one requires toughness, the other requires stability, and the fiberglass content can differ by more than one grade.
If you ask in one sentence, the answer can only be a compromise, and a compromise is weak at both ends.
Material Change Risk List (From metal / original plan to modified nylon, what needs to be changed)
| link; segment; part | What do you want to move? | Points that are easy to overlook |
|---|
| Mold | Legs make shrinkage compensation per piece | Fiber orientation leads to directional shrinkage differences |
| Dry | Determine the window based on the measured moisture content | Incorporate recycled materials with the carried water content |
| Material Temperature / Mold Temperature | The mold temperature is mentioned to be 110–120℃ to control the floating fibers | Only give according to the recommended value by grade, without looking at the pieces |
| Toughening system | Confirm that the toughening agent's Tg is below the usage temperature | Using the wrong toughening agent in low-temperature conditions |
| Humidity control | Forced humidity adjustment Re-measure dimensions | Estimate the time based on average wall thickness; the thick walls haven't absorbed fully. |
| Color difference | Advance confirmation of exposed parts color board | There is color variation in batches of fiberglass parts |
| Verification order | Impact / Thermal Aging → Bench → Environment | Skip the previous item and proceed |
One-page report form (for those reporting upward)
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Project: Drone landing gear / motor base · Material route evaluation
Conclusion: Modified nylon can be a candidate, but its implementation depends on four prerequisites
1. Three Essential Materials
1. Separate two sets of materials for the landing gear and motor base, not mixed
2. Toughening agent Tg below minimum operating temperature
3. No low-temperature shock / thermal aging data not included in verification
2. Prerequisites (if any one is not met, postponement is recommended)
· Long-term operating temperature ≤ Continuous usage range of the selected system
· Verification conditions for drop impact benches and vibration tables
· Annual usage sufficient to thin special materials and molds
· Model airworthiness requirements confirmed and do not involve main load-bearing
3. Next steps
1. Take the actual head difference and motor power, fixed load
2. Perform ambient and low-temperature gap impact
3. Thermal aging + vibration combined verification of motor base
Risk warning: The main uncertainties in this route lie in low-temperature shock and long-term thermal aging.
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Three Questions Readers Often Ask
Question: Can POM support the landing frame?
POM Good rigidity, good self-lubrication, and stable dimensions, but weak impact resistance and not suitable for heavy impact positions. In areas with heavy impact on the ground, ultra-tough nylon is more impact-resistant. For areas where neither is sufficient, the structure needs to be reconsidered.
Question: Can ultra-tough materials also be used for motor bases?
It depends on working conditions. Motor bases need rigidity and temperature resistance; ultra-toughness sacrifices both. Unless the motor base is subjected to both strong impacts, prioritize high-fiberglass combined with heat-resistant stabilization systems.
Question: Can the landing gear and motor base share the same part number?
Technically, it's not recommended, but there can be a compromise: separate formulas, and combine the pricing for procurement.
The premise is to measure both the minimum flight temperature and the motor base surface temperature first.
If there's no temperature data, merging part numbers is basically betting on "no impact."
Conclusion
The selection of drone landing gear materials and motor base is, ultimately, a load identification problem, not a material problem.
There are only three judgment chains:
Whether the piece takes a "hit" or "always"→ temperature determines the system → verification determines success or failure.
Once all three are set, the answer to "Is this material drop-resistant?"
If you have a landing gear or motor base to prescribe, send over three things and you can give directions: drop method, motor power, and minimum flight temperature.
There are some businesses we don't do.
If you just report "more drop-resistant material" without asking about purpose or working conditions, we won't do such orders. If you choose the wrong direction, even the cheapest will be expensive.
What we do is very specific: modify resins like PA6, PA66, PA46, PA11, PA12, PA6T, PA9T, and nylon alloys to make them truly usable; Additionally, we produce modified PPO, PPS, and thermoplastic elastomers.
simultaneously handles nylon resin, sub-brand materials, and bulk materials from major chemical giants, and also regularly receives nylon raw materials, sprue return materials, and various nylon scraps, with formal disposal channels.
The additive system in the formula is tailored according to the working conditions of each piece—regular additives are always in stock, special models are matched as needed; You report the working conditions and grade, and all materials and additives are prepared in one go
